PROC E S S I N G OF INFORM A T I O N A C Q UIRED AT A
PR E C O N S C I O U S LEVEL OF AWARENESS:
I N S T R UCTION
AND SEX EFFECTS
ON H E M I S P H E R I C LATE R A L I T Y AND A C C URACY
Kinga M.Perlaki
Patricia R. Barchas
Program
T echnical
Report
in S o c i ophysio 1 o g y
#85
-
Autumn,
1982
This work was supported, in part,
by The Of f i c e of Naval
Research.
We wish
to a c k n o w l e d g e the a s s i s t a n c e
of Clete
Kushida, Rik Hecker and Dave Levy during the p r e p a r a t i o n and
execution of this study.
PROCE S S I N G
LEVEL
OF
INFORMATION
OF AWARENESS:
ON H E M I S P H E R I C
ACQUIRED
AT A P R E C O N S C I O U S
INSTRUCTION
LATERALITY
AND SEX
EFFECTS
AND A C C URACY
Int r o d u c t i o n
It
is
a well
hemispheres
and
learn
a p prehend
language
1981).
and
organization
and
t o p o graphical
right
and
step-wise
hemisphere
fr a g m e n t a r y
tasks.
The
programmed
left
brain
and
examples,
not
benefit
to a s s o c i a t i v e
m ore
It
responsible
Our chief
we could
the
by
for
conc e r n
i n f luence
or
emotional
in this
hand,
right
w hich
than
study was
which
1
through
the
right
rules
and
error correction,
hemisphere
it tends
i n tuitive
the h e m i s p h e r e
for v i s u o-spatia
to s p e cific
content
in
oth e r w i s e
rule and
from specific
patterns
h o l istic
by
other
The
W hile
proceeds
sythesizes
exposure
from experience.
makes
and
learns
and
l i n g u i s t i c a l l y mute
is adva n t a g e d
On
learn
wholes.
wholes
left
faces.
for
for
spatial
logical
not
expos u r e
data,
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1981;
specialized
and
fashion,
strategies»
i‫־‬s s p e c i a l i z e d
is
of spatial
cerebral
Nettleton,
of
h e m i s p h e r e does
learn
dif f e r e n t
hemisphere
hemisphere
but does
two
re c o g n i t i o n
instruction.
does
the
and
perceives
information,
with
hemisphere
re c o g n i t i o n
analytic
that
Bradshaw £
left
right
orientation
linguistic,
sequential
(e.g.,
The
the
fact
the world
differently
Dennenberg,
the
documented
to grasp
judgments
the
needs
left
and
as
is
brain.
to d e t e r m i n e whet h e r
is most
active when
PAGE
using
in f o r m a t i o n
awareness,
and
thus
the a p p r o p r i a t e
never
be
of
the
inform a t i o n
could
yet
inf l u e n c e
of
the brain
s earched
has
processed.
uj on
a w areness
be processed
out
engaged.
entered
To
brain
F u nctional
resources
found
of
as
in
con s c i o u s
the
left
one
way
awareness
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right
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expl o r e
idea,
we
in
this
which
to
an
i nformation
a w areness
paradigm
activity
in which
which may
conscious
the
of
in f o r m a t i o n
However,
paradigm
into
wanted
be
level
situa t i o n s
are
cortex.
behavior would
We
m e asuring
social
processed.
an es t a b l i s h e d
not
preconscious
cerebral
wer e
for
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con s c i o u s
human
and
that
behavior
with
at
approximate
consciously
a ssociated
half
acquired
2
lend
must
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itself
to
index
of
cognitive
kind
of
measurable
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functioning,
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stimuli
and
attached
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reach
McConnell,
do not
detection,
has
been
Cutler
"mere e x p o s u r e
experimentally
Moreland
£ Zajonc,
stimuli
latter
i.e.,
has
1968).
that
concept,
The
known
and
1980;
results
of
exposure
to
a w areness
they wer e
(see
proposed
Zajonc,
repeated
of concious
of subliminal
been
£
by
necessary
inves t i g a t o r s
A related
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threshold
by several
Zajonc,
showed
be
phenomenon
(K u n s t - W i 1son
below the threshold
their a t t r a c t iveness:
the
1958).
effect"
1977;
studies
can
the minimal
explored
tested
these
some
b e h avior
£ McNeil,
)
have
to it.
that
perception,
the
to
possibility
for c o nscious
as
also
increased
preferred
over
PAGE
others
that
conscious
simi l a r
differentiation
possible.
as,
w ere
Kunst-Wilson
K-W £ Z)
c o ncluded
but
unfamiliar,
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that
even
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types
(from now
on
3
though
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to
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\
performed
in the a b s e n c e
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p a r a d i g m appears
empirically
the
p r e c o nscious
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information.
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kinds
and
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measures
stimulus
slides
(Edwards,
Hecker,
to
recognition.
lend
proce s s i n g
itself
that
that may u n & e r l i e
In a series
adapted
behavioral
of con s c i o u s
of
this
occur
the
use
at
the
of social
pretests
the K-W £ Z paradigm
purpose,
a l t hough
taken.
In each
graciously
provided
Perlaki
to probing
£ Barchas,
of
with
these
by
only
studies
K-W w ere
the
utilized
1982).
Ex p l o r a t o r y Study
In an
at 3
e x p l o r a t o r y study,
ms,
clos e l y
recognition
approximated
However»
possi b l y
di f f e r e n c e s
Hecker
£
w ere
Barchas,
indications
the
that
exposure
above ch a n c e on
The stimulus
of
irregular
spatial
preference
the
results
the
category.
the
1982).
who
shapes,
accuracy
smaller
for
by
likely
(Perlaki,
there
score
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were
during
below
than
task.
in this
and
Accordingly,
K-W £ Z.
some details
to
held
females
sa m p l e size,
significant
perceived
recognition
used
time was
Never t h e l e s s ,
were m ore
slides
octagon
of
exposure
reported
statistically
subjects
phase
the
and
because
not
when
e x periment
thus
fall
were composed
into
the a p p r o p r i a t e
the visuo(i.e.,
most
PAGE
efficient)
should
p r ocessing
require
hemisphere.
the
strategy
relative
Apparently,
interview,
those subjects
the shapes
seen
visual
on
processing.
and
This
visual
the r e f o r e
for
the
of
seems
reported
some
believed
that
task
the
they
left
the e x p osure
intuition
target
inferior
of
and
appropriately
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left
by
to
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relying
left
right
brain
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hemisphere
immediately
available
increasing
could
deal
and
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given
the spatial
no
to mak e
a
p r ocessing
s t r a tegy
who
the
task
of
saw nothing
but
to
objects.
1 task,
stimuli
r ationally
a tactic
discrimination
stimulus
consciously
target
na t u r e
alternative
who
initial
the
used
those
their
subjects
with
they
by
during
image of
to the v i s u o - s p a t i a
hemisphere.
recall
of
the p r e c o n s c i o u s l y
in the
brain
Thus,
of mental
novel
to
performance
those who c o n s c i o u s l y
when
if
the shapes
to the
phase had
pos t - s e s s i o n
responses.
brain),
inappropriate,
In contrast,
right
kind
‫ ־‬right
rec o l l e c t i o n
processing,
by these subjects.
possessed
(using
due
task
these s u b jects
d i r e c t l y and
the
parts
pr e s e n t a t i o n was
employed
were stored
incorrect
seeing
of
explained
hemispheric
that
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corresponds
scores
be
wer e not
left
probability
It
images
the
the
an attempt
which
can
to
of
them s y s t e m a t i c a l l y ,
The a c c u r a c y
below chance.
perceived
mad e
process
particular
activation
who had
and match
a conscious
this
a c c ording
earlier,
fragments
for
4
which was
the stimuli.
at
all during
follow
their
between
the
Therefore,
they a c tivated
the
PAGE
Neurophvsiological
The
Index
In
differences
in
r e latively
order
to test
brain
when
scalp,
via
EEG
the
dealing
brain
of the
restful
appearance
of a
wav e
i.e.,
brain
falls wi t h i n
task
is
the
presented,
respo n s i v e
ongoing
state
to
events
results
decrease
in alpha
involved
"alpha
(EEG)
task
of
in
the
the
supression.
production
is observed
the task.
This
block"
(Bunnell,
1981).
of such h e m i s p h e r i c
asymmetry
is the
is expressed
power,
as a right/left
a ratio
of
information,
we
concurrently
relat i v e a c t i v i t y
was
measured
directly
from
right
(or
as
i n d icate
that
with
"alpha
Higher
on
a
more
becomes
activation
Conseq u e n t l y ,
a
the side which
phenomenon
is
referred
A conventional
laterality
alpha
the
When
thus
a
rhythm"
is often
and
left/right)
hemispheric
the
system.
brain
other.
index
of
associated
question
that
in alpha
with
to
the a c t i v a t i o n
brain waves
known
of
included
measures
activities
is u s u a l l y
side
r elatively mor e a c t ivated
reliably
study
the
The
behavioral
8 to 13.5 Hz fre q u e n c y range.
one
the
on
l a t eralization,
regular waveform,
that
to as
with
an e l e c t r o e n c e p h a l o g r a p h
relaxed,
is more
obse r v e
Activity
ex p l a n a t i o n
present
To
electrical
recording
above
data collection.
the two hemispheres,
by recording
the
the
events.
the h e m i s p h e r i c
the behavioral
entirely
neuro-physiological
the two h e m i s p h e r e s
recorded
relied
accuracy,
obj e c t i v e
the under l y i n g
of
Relative Hemispheric
p r e l i m i n a r y studies
measures.
with
of
5
measure
index,
ratio
to total
which
of alpha
alpha,
or
PAGE
a difference
r elative
in power
to the
between
total
as
hemispheric
the
using
indivi d u a l s
scores
which
are c o m p a r a b l e
ratio m e a sures
cannot
for
raw
modification
the
relative
this
permits
one to
the
d ecreased
misleading
that
is
by
hemispheric
elicited
adjusted
prior
to adjust
to
the
treatment
data
weakness
on
r e l ative
the
b a s eline
of using
either
about
does
the
treatment
the h e m i s p h e r i c
prior
a
not
index
of
observed
one side,
or both.
experimntally
the
as,
relat i v e changes
activity
by the
for
in
the p o s s i b i l i t y
treatment.
alpha values
such
that
a ratio
whether
the
for
the
subtracting
An operational
that
is
ratio
while
the
about
on the other side,
changes
unless
about
produces
A sta t e m e n t
Thus
increased
is
left h e m i s p h e r i c
level,
by changes
in the
it
manner
be caused
or both.
as
However
prob l e m
directly
problem
yet
One such
it excludes
to
for mea s u r i n g
in the same
or d e c r e a s e
are due
prevailed
problem
subjects.
make c o n c l u s i o n s
activity
hemispheric
between
information.
questions
Another
own control
the denominator,
s p e cific
ratio changes
he m i s p h e r e s
accepted,
their
data.
two h e m i s p h e r e s
addressing
left
index
is w i d e l y
be evaluated
i n c rease
p rovide
among
as
in a ratio could
the numerator,
and
laterality
activity
allows
example,
right
power.
The use of a ratio
r elative
the
6
right/left
could
as ymmet ry
A solution
induced
to this
right
pre - e x i s t i n g
values
to com p u t i n g
difference
be
and
alpha
from
both
the
ratios.
scores
in the
PAGE 7
ratio
formula
is that
very
speci f i c
problems.
either
p o s itive
cancel
out
variability,
are
Thus
the mean
deviations,
!values will
having
eff e c t i v e
except when
there
produced
is
v a r iances
within
group
Despite
Cu rrent
An
as
the
deviations
and
will
not
be smal l e r
that
difference
this
large
prob l e m
variability
and
v a riances
suffer
for
than
in
individuals.
be
will
of
that
similar
example,
the
in
standard
the analysis
fact
some
positives
m e a sures
will
are q u i t e
is the
can
the means
scores
the effects
treatment
groups
are used
on
by various
s i g n i ficant
while
the c o n s e q u e n c e
compounding
of
a s i t u a t i o n may arise,
performed
with,
other,
with
scores
as neg a t i v e s
values,
variances
Further
the m a g n i t u d e
standard
positive
consequences.
which
each
are aff l i c t e d
Since d i f f e r e n c e
by the signs,
i.e.,
always
ratios
or negative,
be grea t l y affected
can
such
of
the
not
be
substantial.
that,
to begin
the amount
of alpha
Therefore,
effects
considerably
are n e c e s s a r y
to c o m p e n s a t e
to
larger
for
elicit
between
the sizable
variances.
the problems
the
index
involved
best
with
suited
ratio measures,
they
for our questions.
Study
experiment
was
modifications
of
"consistency"
hypothesis,
he m i s p h e r i c
i nformation
the
designed
paradigm
activation
acquired
that
for
outside
to
in
(a)
incorporate
order
task
p r ocessing
of
the
to
range
test
some
the
appropriate
v isu o-spatia 1
of
conscious
PAGE
awareness
could
Cb ) a c t i v a t i o n
the
right
Thus
be
of
instructions
right
brain
served
the same
for all
set
on half
of
process
holistically
should
the
as
type
the
right
trials,
sided
of
that
this
case,
the
task
elicit
alpha
was worded
the
judgments,
based
peculiarity
to
of
who were
and
greater
supression)
frame
m ode
design was
could
response
not
time was
for all
the
The stimuli
were
asked
was
of
type,
mental
to make
feeling.
For
an
the
experimentally
of making
r ecognition
thinking.
to avoid
model
requirement,
randomized.
used
on
used
the w i t h i n - s u b j e c t s
to
a " h olistic"
of mind
on an analytic
given
instruction
later
based
task
the
the
impose
subs e q u e n t
in
of
variable.
judgment,
A between-subjects
inherent
instruction
regardless
an " a nalytic"
with
of
treatment
the subjects,
induced,
exposure
(i.e.,
(in
and
a c c u a r c y scores.
na t u r e
affective
other half,
co nditions
in higher
the spatial
i n s t r uction
intuitive,
bias
hemisphere
between
s tudy
subjects
the
result
instruction,
accuracy.
this
but
would
p r ocessing
and grea t e r
In
to
by
the a p p r o p r i a t e
brain)
consistency
conditioned
8
the
when,
response
due to a
the order
In addition,
of
the
the same
subjects.
E x p e r i m e n t a 1 H y potheses
Hypothesis J.:
hypothesized
that
c o ndition would
processing
I nstruction
than
subjects
effect
in
the
be r e l a t i v e l y mor e
subjects
in
on
laterality.
holistic
likely
the
to use
analytic
It was
i nstruction
right
brain
instruction
PAGE
condition.
We
supr e s s i o n
in the
during
left
an analytic
relative
a
therefore
to the
greater
condition
Hvoothes i s 2.:
predicted
that
ac c uracy
scores
holistic
in
that
appropriate
co g n i t i v e sets
those
relying
previously
during
3.:
right
in the
right
in
to observe
the
It was
stimuli
greater
subjects
in
the
to the analytic.
instructions,
upon
target
stimuli
those
task
and
would
mor e
who
We
(analytic)
the subjects,
approach
than
analytic
condition.
inappropriate
holistic
testing
Lateral i t v - a c c u r a c v
that
in higher
response
the
imposed
spatial
for
compared
task
to the
on a c c u r a c y .
be observed
and
alpha
that
select
frequ e n t l y
adopted
the
strategy.
hypothesized
st r a t e g y
be
the
presented
Hypothesis
would
right
to
laterality
r e latively higher
brain,
relationship.
holistic
a c c u r a c y scores,
while
be
to
d e t r i mental
accuracy
r e l a t ionship
lower
on
subse q u e n t
analytic
result
would
ratio
to v i s u o - s p a t i a l
manipulating
of
processing,
effect
condition
(holistic),
and
in the holis t i c
response
would
relative
h o l istic
laterality
than
beca u s e
thinking,
I n s t r uction
instruction
expected
of
during
right/left
instruction
hemisphere
m ode
left
expected»
9
was
the
expected
laterality
ratio
was
index,
predicted
a c c u r a c y score.
p rocessing
left
brain,
accuracy.
to
It was
show
i.e.,
to
would
analytic
Therefore
an
inverse
a relati vely
correspond
to
PAGE
No
specific
differences.
hypo t h e s e s
N e v e rtheless,
a s sessment
of
there are
measurable
in their
the q u e s t i o n
of
a c c u r a c y are
formulated
the design
of w h e t h e r
di f f e r e n c e s
lateralization
if any,
were
permitted
under
on
the same
the sexes
lateralization
in the
empirical
and
and w h e t h e r
instruction
sex
these condi t i o n s
between males
response,
for
regarding
10
the
and
females
effects,
performance
population
used.
Method
Su b iec t s
The sample
males
and
years,
hand
and
c o n sisted
24 females,
based
learning
a completely
female
(a)
or
tested
under
subjects
their
subjects
familial
and
were
(b)
(i.e.,
each
were all
of
Thus
of
of
19.5 and
clear
speech
design,
to
type
24
19.0
right
l e ft-handedness,
impediments,
disorders.
assigned
holistic.
age of
history
free
r a n domly
undergraduates,
expressed
neurological
condi t i o n s
analytic
wer e
no
average
between-subjects
subject was
experimental
an
All
on s e l f - r e p o r t
disability,
48 S t a nford
with
respectively.
p r e f e r e n c e with
was
of
Since
this
each male
and
one
of
12 males
of
the
two
instruction):
and
the
two
in s t r u c t i o n
volunteers
who
received
12 females
types.
a payment
The
for
participation.
Materials
Stimuli.
generated
octagon
Stimuli
test
shape
wer e
slides,
against
provided
by
each c o n t a i n i n g
a
light
background.
35-mm
a dark
The
computer
irregular
projected
PAGE
shapes
measu r e d
an aver a g e
from a d i s t a n c e
was
7.1
x 6.9
of 75 cm,
cm.
randomly divided
E xperimental
into
the mean
phase
two
10-slide sets,
of
outline
below
m e a sures
ac t i v i t y were
take.
slides
from each
set were
other set,
thus
In the
Set
A and
Set
and
in the
both
c o nsisted
A and
Set
were
B.
to all
as
(i.e.,
B.
slides
During
appeared
position.
a set
phase,
awareness.
the test
10
and
equally
The same
Preceding
of
the
and
the
phase,
each
slides
from
a novel
stimulus
a
stimulus.
in the
Set
the
c o n tained
often
both
brain
both
A,
a slide
pairs
phase,
and
half
the test
an
of slides,
from Set
to
and
e xperienced
to do
familiar)
subjects.
the
K-W £ Z study,
performance
exposure
resulting
B slides
second
as well
slides
of co n s c i o u s
r a n domly assigned
the
exposed
a light
of
from Set
previously
sets
Set
subjects
for how
female sample wer e shown
other half
the
the threshold
at
presented
viewed
angle s ubtending
20 stimulus
they w ere shown
i n s t r uctions
time
of
their slides,
They wer e given
male and
and when
visual
total
in which
each at a level
which
of
cm,
The
the general
dupli c a t e s
exposure
9.2 x 8.9
Paradigm
Following
using
of
11
pairs
A and
first
were
B slide
10 test-pairs, was a focusing slide that
of a c e n t r a l l y
positioned
black
"X"
sign,
against
background.
Equipment
St imulus
sided
and
pres entat i o n .
covered
Subjects
experimental
wer e
cubicle
tested
with
in a t h r e e ­
solid
black
PAGE
walls
that m e a sured
183.0
cm
152.5 X
(see Figure
kept
similarly
completely
of the
table stood
a
side
keyboard.
back
24
c o mprised
the
At the
Model
of
other
rear c o n d e n s o r
chest
the purpose
shutter
(Vincent
of
were
end
end
of
of
located,
was
to the
a
wincow,
tunnel
was
a
attached
in front
(Model
3607-606
from a
of an A m e r i c a n
image size.
via
a
screen
tunnel.
E ktagraphic
4.4 cm
shutter
in front
101.6
cm,
Exposure
Unibjitz
panel
for
time and
Shutter
D i r ectly
below
consisting
a
#3622
Delineascope),
310-B).
indicator
the
the shutter was
19.0 x
Optical
to the
by
elect r o n i c
of
On
response
The
Kodak
fastened
and
felt.
aliened
viewing
A Uniblitz
was
the table,
screen.
the
23XOBOX)
of
occupied
long
the
26 cm high
two-button
the table was
of
A
black
of
projector.
a response
end
a small,
projection
Model
in front
with
159 cm
controlled
In the center
height.
of a
regulating
it was
table,
covered
table was
end
Associates,
p r ojector was
long
it was
below
Associates,
the projector,
con d e n s o r
the
front
a height
here
experiment.
adjustable
Plexiglass
AF-2 slide
(Vincent
and
cm
19.0 cm
the
was moun t e d
The o p p o s i t e
wall
29.2 X
of
1 about
room w h e r e
80 cm
chair with
the chair,
the right
to the
an
s t y r o f o a m chi n - r e s t
facing
Figure
dark during
chamber was
with
1).
Insert
The cubicle,
152.5 cm,
12
the
Timer
the
of a red
V
FIGURE 1
PAGE
and
a green
signal
by a neutral
affixed
density
to the
EEG
light.
flat
recorded
and
right,
area
(10-20)
by Grass
central
locations,
electrodes
resistence
1 and
5k o h m s .
The EEG
of
EEG
equipped
used
obtain
artifacts,
or
a m p l i t u d e cutoff
was
1 cm
cali b r a t e d
pin
calibration
was
set
to 7.5
in
During
( V/mm).
(P 3,
P4)
of
the
7 P 51 1
.3 Hz
at
the m i d l i n e
above
the
paste.
measured
between
f o u r - channel
a
the
and
contact,
electrode
and
Grass
Grass
Model
Reverters
ongoing
(e.g.,
operating
and
100 Hz
setting
to
of
a
collection
5
was
brain
visually monitor
was
(lo)
monopolar
earlobes,
R5DC Tape
r e s ponse
data
International
Each
c o n cerns
a Sensitivity
deflection
parietal
by a
Model
recording
of
as
EC2
and
using
pulse.
Grass
the c a l i b ration,
points
left
electrical
of
Grass
from
forehead,
record
The
elect r o d e s
linked
System,
Grass
that was
data
e lectrodes
written
other
electrodes).
the
wer e amplified
a
to check
to
with
all
with
2.0)
reduced
(EEG)
System.
good
Amplifier
Polygraph
activity,
ensure
signals
7P511
scalp
as well
on the
were applied
The
to
C4)
referenced
To
N.D.
was
E 1 e c t r o e n c e p h a 1ographic
Placement
located
nasion.
96,
the g u i d e l i n e s
Electrode
was
illumination
rear condensor.
gold-cup
following
the ground
(Kodak
on the
(C3,
ele c t r o d e site was
Model
filter
Data c o l l e c t i o n .
was
the
Stimulus
14
for
dislodged
with
1/2
(hi),
and
5 to produce
50 V
a
internal
the S e n s i t i v i t y
PAGE
The a m p lified
Analysis
o n-line spectral
study has
enables
already
designed
four
to allow
f r e quency
averages,
of
and
this
the
bands,
(a)
8-13.5
rejection
option was
and
eye
frequency was
sampling
of
Hz,
set
to
obtained.
0-3.5
(d)
used
during
The time
bands
w ere
14-20
data
col l e c t e d
10
required
on
Hz.
such
number
of
purpose
defined
4-7.5
as
Hz,
The artifact
with
the Grass
acquire
is
up
to ensure
data.
Upper
the m i n i m u m
7P511),
was
artifact-free
the
as,
the
collection
per sa m p l e
to
a sweep
package
Theta
(consistently
The
analyzes
For
(b)
in this
of
range,,
contamination-free
100 Hz
until
acquisition
Hz,
the
memory.
level.
Beta
f r equency setting
con t i n u e d
12K
parameters,
fre q u e n c y
and
averages
sy s t e m used
fre q u e n c y
rejection
used
to perform
The s o f t w a r e
to def i n e
Delta
m o v ement
1/2 a m p l i t u d e hi
the number
four
that
simultaneously
maximum
transmitted
program
with
in memory.
the user
(c) Alpha
mu s c l e
The MED-80
the pro c e s s o r
the
following:
software
i ndependent
a rtificial
study
(FAP)
capability
the
residing
simultaneously
purpose c o m p u t e r
analysis.
time data w h i l e
data
to
Package
multi-channel
buffer m e m o r y
of
were
M E D - 8 0 special
to a Nicolet
Frequency
EEG signals
15
10,
and
i.e.,
sweeps
were
a si n g l e sweep was
1.28 sec.
P r ocedure
S ubjects
area
sign
were
received
by a female host who
a
pre-experimenta
1
and
directed
also
requested
consent
form,
to
the pr e p a r a t i o n
that
they
while
read
a
and
second
PAGE
exp e r i m e n t e r
were
then
(male)
escorted
cubi c l e w h e r e
on the
termination
by the
they wer e
ch i n - r e s t
operate
applied
of
the
and
instructed
to sit
this
and
sufficiently
(Baseline
1)
10 c o n t a m i n a t i o n - f r e e
eyes
open
relaxed,
but with o u t
their chin
until
were
shown
given
a
settled
a baseline
samples
focusing
Subjects
experime ntal
resting
were c o m f o r t a b l y
seemed
with
the
position
w ere
chair and
of
to
Subjects
board
they
electrodes.
experimenter
the session.
Once
EEG
to m a i n t a i n
respo n s e
practices.
the
on
16
was
any
the
how
to
few
trial
in
their
recording
collected
parti c u l a r
ob j ec t .
Exposure
Phase.
the subjects
faint
wer e
flashes
whether
the
verbally
cha nce
The
repeated
for
the
last
correction
the
warning,
in
w ere
after
board
visible
slide
the screen
presented
response
S u b jects
the the
to w atch
light
flash was
selection.
between
told
of
experimenter.
Preceding
or
was
not.
r e s ponse
a
presentation,
closely
for the
warning
by
used
to
The
experimenter
to give
event
of
also
asked
to avoid
and
the
indicate
the subjects
the
"flash",
the
incorrect
a
key
blinking
proj e c t i o n
of
the
I
slide.
F o llowing
two
presented
on
subjects'
eyes
located
practice
the
were
"X" mark.
(contingent
screen
trials
the
where
it
properly
Slides
on the previous
focusing
remained
focused
from either
on
Set
random assign m e n t )
the
A
s lide
was
until
the
centrally
or Set
were
B
flashed
PAGE
on the screen
five times,
for
thus
pre - r a n d o m i z e d
push
the
the
response
5
with
Test
another
task.
EEG
the
recording
first
baseline.
for a longer
female s u b jects
period
of slides
then
them during
the e x p os ure
two members
of
each
they thought
pr e v i o u s l y shown.
and
the
or
appropriate
exp e r i m e n t e r
before,
pair
they
kept
than
time
the second
2)
was
on how
on
the
a record
of
both
to
phase,
obtained,
wer e
then
as
given
to a p p r o a c h
the
to the conditions,
half
were
decision
button
10
until
of
Their
50 *A sure)
phase
required
informed
that
task was
and
as
(i.e.,
were
of
to view
first
indicated
types
flashed
one
(i.e.,
response
and
to
the
to de c i d e w hich
the
judgment
they
individually
one of w hich was
that
record
5 minutes.
recognized
of
to
inter s l i d e
co n t i n u e d
analytically.
Selection
in a
began s i m u l t a n e o u s l y
presented
phase.
the c e r t a i n t y
less
types
to
the e x p o s u r e
S u b jects
on their a s s i g n m e n t
to see pairs
the
The
(Baseline
instruction
m ale and
of
and
about
shown
by the subject
to c o m p l e t e
the b e ginnning
the two
50% sure,
time
was
presented
experimenter
the d u r a t i o n
Phase.
were going
slide)
by the
phase was
for
were
wer e collected.
At
10 slides
required
presentation
samples
Depending
shape
50 slides
time
and
the
data c o l l e c t i o n
slide
b a s eline
both
button
of
the e x p o s u r e
specified
one of
The
The a v e r a g e
first
co m p l e t e
of
dete r m i n e d
artifact-free
of
order.
minutes.
the
Each
a total
response
intervals.
was
1 msec.
17
that
was
or second
m ore
than
by pressing
board.
responses.
The
The
PAGE
other half
slides
of
keyboard,
and
which
they
i nstruction
as
and
until
reasons
c o m pleted
c leanup
should
liked
better,
from moving
right
hand
view
the
and
to
refrain
see
via
Subje c t s
of
the
in
on the
10
each
image
how
both
as much
response
responses
were
3)
first
also
the
also
was
the
those
a p p r oach
other,
reasons
for
recorded.
baselines.
and
When
asked
the
obtained,
slide
began
"ana l y t i c "
over
for
and
their
A final
as descr ibed
The
test
phase
5 minutes.
where
the
the subjects
they
(see A p p endix
p r o c e d u r e was
the
obtained.
the
were
remained
experimenter
use
the previous
form w h i l e
were
appro a c h
the session
area
the
test-pairs
signal
one slide
(Baseline
of
EEG
to
the "hol i s t i c "
of
the
with
samples
s e l ecting
in about
end
slide
instructed
for
under d i s c u s s i o n
consent
they
would
choice.
wer e com p l e t e d
recording
questionnaire
they
w here
10 "clean"
T hese
pr e p a r a t i o n
they
experimenter,
Concurrently
who wer e
the
the
their
screen,
recording
preference.
At
their
that
which
two
focusing
sec.
those who used
was
the
to keep
the
10 test trials
baseline
of
told
the trials.
presentation
their
inform
were asked
1
subjects
then
slide
on the
continued
pairs,
groups
Following
exactly
in
of
during
projcted
were
wer e
possible,
board
subjects
presented
holisticallv
sure
the
18
A)
were
and
e l ectrodes
completed.
asked
returned
to the
to
out
to sign
wer e
The host
fill
a
a post - s e s s i o n
removed
and
also a n s wered
the
any
PAGE
q u estions
were
they had
paid
required
and
concerning
thanked
for the
for
entire
their
test
the central
ac c u r a c y
The
phase
(C3,
scores
i ndependent
(analytic
vs.
female).
The
be e q uivalent
any set
cerebral
no
confounds
sets was
var i a b l e s
were:
information
and
in the
findings,
randomized
type.
di f f e r e n c e s
due
was
B)
was
also
included
in
in
In
to
the
their
indepe n d e n t
addition,
analysis
to
of
any
a
on
set
third
of
possible
the two slide
detect
indepe n d e n t
as
effect
variables,
assigment,
as anot h e r
since
sensitivity
avoid
to
found
However,
presentation
slide set
treated
to
(male vs.
have not
presumed
order
the
by the
the
instruction
w ere assumed
that
about
the
measures.
of subject
studies
of
of
as stimuli
available
activation,
type
sex
from
area s - - a n d
dep e n d e n t
differences.
because
time
20 minutes.
about
P4)
(a)
used
behavioral
(P3,
(b)
on previous
The
TP--Ca 1c u 1 ated
prim a r y
and
two s lide sets
i n s t r uction
Set
parietal
the
based
required
TC and
provided
activity
hemispheric
and
the subjects
Results
indices,
holistic),
related
there was
C4)
and
Then
p a r ticipation.
procedure
Analysis
The two
the study.
19
sex
and
possible
(Set
A
variable
vs.
and
independent
variable.
Laterali tv Ind ex
The
on-line analysis
p e r c e n t a g e values
sub-bands,
along
of
the
with
of
the
total
the
EEG
signals
spectral
energy
corresponding
provided
for
fre q u e n c y
the
of
the
four
the
PAGE
peak
energy
in
di s t r i b u t e d
due to
loss
across
.5 Hz gaps
at
the
Therefore,
that
the
bands
the
between
high
and
its
computed,
one
p h a s e — for
for
both
did
of
not
the p ercentages
add up
bands,
and
fre q u e n c y
percentage
for
of
four
total
f r equency
100 %,
frequency
points.
w ere adjusted
the
to the
alpha
to
to
cutoff
values
each
proportion
in the s u b s e q u e n t
subject
bands
low
The cor r e c t e d
each
The sum
successive
p e r c e n t a g e value
r epresented
For
four
the obtained
collected.
used
each sub-band.
20
so
f r e quency
frequencies
percentages
were
analyses.
two sets
the
of
exposure
central
and
laterali'ty
phase
and
parietal
indices
one
for
were
the test
recordings--by
the
fo r m u 1 a :
(R - B*. ) - (L - B¿ )
= 10 0 ------------------------I( R - By ) + ( L - B¿ ) I
Laterality
where
R
= p e r c e n t a g e of right h e m i s p h e r i c alpha
during treatment
Br = p e r c e n t a g e of right h e m i s p h e r i c alpha
during b a s eline
L
= p e r c e n t a g e of left h e m i s p h e r i c alpha
during treatment
B^ = p e r c e n t a g e of left h e m i s p h e r i c alpha
during baseline
Accordingly,
and
left
the d i f f e r e n c e s
hemispheric
phase w ere adjusted
values
in order
calcul a t i n g
by the
to obtain
the test
from the h o m o l o g o u s
corresponding
alpha
phase
between
produced
right
the
and
e l e c t r o d e sites
Baseline
2 alpha
during
left
exposure
index,
the amount
the
the alpha
right
exposure
B a s eline
phase
1 alpha
index.
For
data colle cted
wer e adjusted
percentages.
of
using
the
PAGE
A
brief
late r a l i t y
use,
index
are given
The
in
description
formula»
the amount
and
index
is
of
alpha
to
con v e y
produced
during
task
presentation
as
a
less
result
po s itive
the
elicited
mor e
Pre-T r e a t m e n t
To ensure
the
were
EEG
The
prior
e q uivalen t
task
associated
unila t e r a l
alpha
p roduction
with mor e
(alpha
represents
supression)
involvement,
reduced
that
index
the
alpha
task
brain
while
a
production
on
performance
has
manipulation
the
P h a s e ) Analysis
to the expe r i m e n t a l
in their
c o llected
2
(sex)
pattern
during
the
x 2 (instruction)
(ANOVA),
using
£ Council,
1979),
indices
calculated
from
their
of
alpha
right
involvement.
(Helwig
for
the a s y m m e t r y
of
alpha
production,
exposure
phase
were
to analysis.
variance
and
its
and
A negative
of
suggesting
that
above
left
r i g h t -sided
(E x p o s u r e
data
subjected
side.
left-si ded
the
the
is a s s o c i a t e d
is the sign
side,
to m e a s u r e
by
right-hemispheric
of mor e
index
left
groups
Lower
on the affected
of
rat i o n a l e s u p p o r t i n g
the d i r e c t i o n
baseline.
relat i v e l y
the
intended
over
activity
development
3.
asymmetry
a
the
and
in A p p e n d i x
later a l i t y
he m i s p h e r e s
of
21
the parietal
i n t e r actions
indicating
that
during
the
was
locations.
the
SAS
phase
on
data
None
of
statistically
first
s lide
analysis
st a t i s t i c a l
performed
e x p osure
were
x 2 (set)
the
for
the
of
package
late r a l i t y
the central
effects
nor
significant,
present a t i o n s ,
prior
PAGE
to
receiving
(experimental
existed
the
manipulation),
between
analytic
or
group-appropriate
males
and
no
assigned
int u i t i v e conditions,
phase c o n d i t i o n
was
not
instruct ions
significant
females
and
differentiated
22
d i f f e rences
to either
that
by
the
the
the
exposure
independent
variables.
Treatment
(Test
P h a s e ) Effects
H y pothesis J.: Lateral i tv D a t a .
effect
and
of
instru c t i o n
parietal
for the
indices
eight
using
the
means
produced
to
any
of
no
this
and
that
with
Table
be
to the
and
the TP
1, w h i l e Table
for Set A and
Set
B.
test
that
(SAS,
to
As can
set)
subgroups
phase.
The TC
be related
subsequently
General
Linear Model,
any
all
restricted
statistically
at the
future
to
the
area,
central
discu s s i o n
l a terality
which
has
been
tasks
(Kandel
E Schwatz,
(Fried
et al.,
1982).
for males
ins t r u c t i o n s
2 displays
wer e computed
The
detect
parietal
the
the central
could
lateralization
indices
analytic
by
factors.
visuo-spatia 1 perception
holistic
the
s p a t io - m a n ipu 1 a tive
of
type
Conse q u e n t l y ,
will
relate
in
laterality,
pattern
failed
location.
The means
the
also
section
a s sociated
during
of v a r i a n c e
to e v a l u a t e
respectively)
instruction
differences
he m i s p h e r i c
1981)
by
TP,
systematic
analysis
procedure)
findings
(TC and
the expe r i m e n t a l
significant
in
on h e m i s p h e r i c
data co l l e c t e d
performed
GLM
(sex
In order
and
females
are presented
the same TP means
be observed
under
in
separately
from T able
2,
the
PAGE
laterality
indices
considerable
(b)
sex,
and
asso c i a t e d
differentiation
(c)
mean
Focusing
TP
v alue
compared
for
wer e
finding was
ANOVA
for
type
Z
was
(1,40)
that
the
w ere
lower under
instruction,
43.91
for males,
pattern
of
h y pothesis
exhibit
site show
in s t r u c t i o n
2 about
type,
the
right
to the
left.
performed
the ANOVA
effect
at
the
for
the
results
instru c t i o n
.05
level,
the
four cells
in
Table
ratios
for
both males
and
females
holistic
the
later a l i t y
that
subj ects
r e l a t i v e l y greater
that when
c o m pared
c o n tains
-5.06)
of
30.71
Insert
3
the smaller
=
intuitively,
significant
demonstrated
and
task
1,
(X
suggests
the main
Comparison
the
in T able
by the s u b s e q u e n t l y
Table
revealing
here
condition
involved
subtantiated
laterality
as
the
actively
statistically
shows
1 and
(X = 81.73)
to treat
ratios,
= 4.17.
parietal
(a)
the h o l istic
(GLM procedure).
the TP
by:
on the column means
h e m i s p h e r e was mor e
This
Tables
to the analytic
instructions
the
slide set.
Insert
(a)
with
23
vs.
c o m pared
by
the means
119.56
means
in the
right
Table
to
for
the
is c o n s i s t e n t
holistic
brain
3 abovt
vs.
Thus
with
condition
activity.
here
analytic
of -40.84
females.
1
the
the
would
PAGE 24
TABLE 1
Test Phase Laterality Index
for Parietal EEG Location (TP)
by Instruction Type and Sex
Instruction Type
Sex
Holistic
Analytic
Raw Mean
30.71
119.56
75.13
Male
-40.84
43.91
1.53
Col.
Mean
-5.06
81.73
Female
Note:
Negative or smaller indices represent relatively less righthemispheric alpha (i.e., more right-sided activity) while
larger positive values indicate relatively less left-sided
alpha - consistent with more left-sided activity.
PAGE 25
TABLE 2
Test Phase Laterality Index
for Parietal EEG Location (TP)
Set A
Set B
Instruction Type
Instruction Type
Holistic
Analytic
Sex
Row
Mean
Holistic
Analytic
Sets A&B
Combined
Row
Mean
33.60
0.30
16.95
27.82
238.82
133.32
75.13
Male
-121.68
39.99
-40.89
40.00
47.82
43.91
1.53
Col.
Mean
-44.04
20.14
-11.95
33.91
143.32
88.62
Female
Holistic Mean (across sex and set) = -5.06
Analytic Mean (across sex and set) = 81.73
Note:
Negative or smaller indices represent relatively less right-hemispheric
alpha (i.e., more right-sided activity) while larger positive values
indicate relatively less left-hemispheric alpha - consistent with more
left-sided activity.
PAGE 26
TABLE 3
Summary of the Analysis of Variance Results
for the Parietal Laterality Index (TP)
SS
MS
F
Source
df
Instruction (I)
1
90402.88
90402.88
4.17*
Sex (Sx)
1
65000.59
65000.59
3.00
Set (St)
1
121355.15
121355.15
I x Sx
1
50.51
50.51
0.00
St x Sx
1
2997.13
2997.13
0.14
I x St
1
6136.49
6136.49
0.28
I x Sx x St
1
118896.00
118896.00
Error
40
866982.00
21674.56
Total
47
1271821.31
*£ <.05
**£ <.03
5.60**
5.49**
PAGE
(b)
The
the males
row means
had
a
in T able
tendency
i.e.,
in t u i t i v e
tended
to be mor e
results
failed
did
reach statis t i c a l
not
(c)
with
to
support
U n e x pectedly,
respect
Table
2,
to the
in m ore
the test
phase,
respectively.
significant,
subgroups
females
(in s t r u c t i o n
to Set
(i.e,
produced
a c t ivity
think about
w hen
was
asked
the task
to
use
statistically
males
failed
to
a shift
of slides
index.
to
reach
effect
by set)
mor e
and
affected
and
not
males
the
by the
B,
during
vs.
88.62,
statistically
for
alpha)
.02
to
right
This
comparison
level.
However,
at
under
the
a p r onounced
instructed
that
asked
to the
this
the holistic
eight
he m i s p h e r i c
when
treatment
significance
the
revealed
shifted
suprisingly,
left when
from
to Set
left
approach.
showed
during
also
further
analyically,
at
neutral
suppression
computed
demonstrated
less
level.
.03.
the means
statistical
the
was
effect
be seen
of -11.95
sided
processing
towards
alpha
the ANOVA
not
A c o m pared
the set
B
wer e
As can
Set
means
significant
exposure,
brain
sets
the h o l istic
With Set A exposure,
right
.05
at
left
were m i n i m a l l y
p re-task
the
by sex
exposed
females
the sex
on the
of
the
as
significance
that
hemispheric,
while
finding,
( 1 , 40 ) = 5 .6 0 , £. <
P a i rwise c o m p a r i s o n
right
this
hemispheric
Indeed,
£
mor e
show
However,
expos u r e
based
two sexes
(X = 75.13).
the
right
the
(X = 1.53),
laterality
pretask
resulted
towards
p r ocessing
analytic
1 for
27
Set
comparison
.05
shift
level.
towards
instruction,
to
B
a p p roach
and
the
PAGE
task
analytically.
statistically
pattern
during
significant.
opposite
but
and
the
this
Females
to the males,
the analy t i c
condition,
However,
in Set
i.e.,
toward
the
comparison
shift
left
d i f f e r e n c e was
statistical
significance.
The d i f f e r e n t i a l
males
females
the
and
substantiated
interaction,
by a
was
lower
However,
type
Set
late r a l i t y
by the
B,
the
exposure.
but
for
under
small
to
effect
of set
reach
types
on
was
x
set
in s t r u c t i o n will
the
two
separately
for
for
i nstruction
total
the
females
groups
sample.
instru c t i o n
Set
A
under
for males
difference
male-holistic
was
Accuracy
Z '■
obtained
stimuli
out
under
failed
and
Set
between
for
in Table
4, w h i l e T able
Set
B.
counting
during
the
computed
A and
The a c c u r a c y
the
of a p o s s i b l e
during
each sex
Data .
by
c o r r e c t l y c hose
that wer e shown
for Set
the holistic
the analytic
prevaled
the
right
Set
Set
to
B
A
A,
reach
significance.
Hypo t h e s i s
subject
and
females
pattern
exposure,
holistic
than
only
a
.03.
that
compared
the
x instruction
obtained
held
The same
statis t i c a l
selected
wer e
effect
male-analytic
subject
and
toward
in s t r u c t i o n
sex
£. <
ratios
data
when males
conditions
pre-task
= 5.49,
our h y p o t h e s i s
sup p o r t e d
two
significant
F (1,40)
In summary,
elicit
under
not
A demonstrated
during
too
was
28
the
exposure
by i n s t r u c t i o n
5 contains
number
10,
that
test
phase
phase.
type,
score
of
is,
for
correctly
when
the
those slides
The means
and
each
were
are displayed
the same means
separately
PAGE
Insert
The
Tables
4 and
were
then
a c c u r a c y scores
nonparametric
continuity
Previously
were
exposed
often
slides
25.33),
mean
slides
in Set
nor
of
sex,
between
26.15
When
the
and
(with
set,
the
two
one-way
3CX= 14.57,
<
and
appeared
Set
results
.05.
to be
B accuracy
showed
that
ho 1 i s t i c a 1 1 y ,
and
=
slides
25.92)
than
analytically,
of
of
between
23.67
(with
and
rank
6 ),
the
(n.
=
variance
between
set,
the
Set
separately.
Set
instructed
to
view
liked
asked
the one
groups,
between
to
they
detected
the
differences
were
No
type,
s u bgroups
the one
B
instruction
exposed
select
Set
.02.
types
by
analyzed
those who
and
<
to the variable,
were
to select
£.
were
for analytic).
differences
subjects
better when
than
rank means
the
sets.
= 29.27)
were detected
22.85,
(with
stimulus
= 2.35»
eight
related
significantly
mean
z
test
by
signif i c a n t
correctly
divided
Since
data
two
A (rank mean
analysis
significant
groups
and
analyzed
2 - s ample
instruction
sample was
statistically
£.
the
respective
obtaining
K r u s k a l - W a l 1 is
and
in a c c u r a c y
for holistic
total
ranked»
selected
19.73),
differences
here
statistically
between
=
females
.5),
or
about
Milcoxon's
found
(rank mean
and
of
recognized
significant
males
Using
correction
differences
more
methods.
5
29
to
they
B
A
The
performed
the
more,
look
slides
(rank
at
recognized
the
as
PAGE 30
TABLE 4
Mean Accuracy Scores
by Instruction Type and Sex
Instruction Type
Holistic
Analytic
Row Mean
Female
5.17
5.08
5.13
Male
5.41
4.75
5.08
Col.
Mean
5.29
4.92
Sex
Note:
Maximum score = 10
PAGE 31
TABLE 5
Mean Accuracy Scores
by Sex, Instruction Type and Set
Set B
Set A
Sets A&B
Combined
Holistic
Analytic
Row
Mean
Holistic
Analytic
Row
Mean
Female
4.83
5.83
5.33
5.50
4.33
4.91
5.13
Male
6.00
5.50
5.75
4.83
4.00
4.41
5.08
Col.
Mean
5.41
5.66
5.54
5.17
4.17
4.67
Sex
Holistic Mean (across sex and set) = 5.29
Analytic Mean (across sex and set) = 4 . 9 2
Note:
Maximum score = 10
PAGE
the
previously
exposed
differ e n c e s
between
significance
using
£ <
.03.
found
None
Therefore,
two
the other
the p r e d i c t i o n
was
groups
only.
B attained
trials
than during
failed
to yield
that
indices
higher
accuracy
the analytic,
(from
TP
Insert
differences
the score
that
scores
a worse
T able
Accu racy
stated
for
for
the Set
A and
during
these
B
females
holistic
co m p a r i s o n s
differences.
Data .
the eight
to
to the
Displayed
subgroups,
lowest),
2a presents
with
in
in
the
the same
TP
6 and Fi g u r e 2 about here
a c c u r a c y means,
5--which
could
than
of
respond more
form.
posit i v e number marks
means
scores
significance
Fig u r e
2b are the
from
or group)
c o m pared
in Set
both
highest
means.
in graphic
In Fig u r e
3. = 2.17,
sex
will
substantiated
6 are the a c c u r a c y means
corresponding
subjects
A l t hough males
statistically
order
(by
The
statistical
test,
in s t r u c t i o n
Hvpothes is 3.: L a t e r a l i t y vs.
ranking
reached
comparisons
the holistic
in Set
Table
= 13.54).
two-sample
statistically
exposure groups
mean
differences.
a c c u r a t e l y under
analytic,
these
(rank
Wilcoxon's
of
significant
slide
32
represents
be attained
a better
cha n c e
in this
the ch a n c e
by guessing
than,
offer
as
their
level,
i.e.,
a l o n e — thus,
while a negative
recognition.
form
expressed
a
value
The aver a g e a c c u r a c y
the a d v a n t a g e
of
easier
PAGE 33
TABLE
6
Ranking Order of Mean Accuracy Scores
and Corresponding Laterality Ratio (TP) Means
by Sex, Instruction Type and Set
Sex
Instruction
Set
Accuracy Mean
TP Mean
Male
Holistic
A
6.00
-121.68
Female
Analytic
A
5.83
O. 3O
Female
Male
Holistic
Analytic
a
tie
5.50
27.82
39.99
Female
Male
Holistic
Holistic
tie
4.83
b
33.60
40.00
Female
Analytic
B
4.33
238.82
Male
Analytic
B
4.00
47.82
Notes:
}
)
Accuracy means are based on raw scores, i.e. the number of
correctly identified stimuli out of a possible 1 0 .
Laterality mean for the four groups with >5 Accuracy Mean = - 13.39
Laterality mean for the four groups with. <5 Accuracy Mean = 90.06
PAGE 3^
FIGURE 2
Average Laterality Ratio (TP) and Response Accuracy
for Sets A and B by Sex and Instruction Type
Laterality Ratio (TP)
a.)
Set B
Mean
Laterality
Ratio
(TP)
Set A
Instruction Type
Instruction Type
)
Recognition Accuracy
Set B
Mean
Accurracy
(Score
- 5)
. Set A
Instruction Type
Holistic
Analytic
Instruction Type
PAGE
visual
comparability
include
both
Comparison
exhibit
than
l a t e r a l i t y show
as
low a v e r a g e
left
sided
index under
left)
Set
assoc i a t e d
these
with
two measures,
in
to the somewhat
observed
of mor e
and
cha n c e
accuracy
scores
higher
towards
relationship
is,
during
in the
between
holistic
the analytic
scores
during
the
a s l i ghtly
the
for
A
i nstruction
Females
That
the
right
a much
shift
lower mean
than ch a n c e
above
a
to
in general,
the h o l istic
reverse.
relative
and
to Set
identical
trials
h olistic
exposed
a c c u r a c y mean.
laterality
lower
from
a c c u r a c y mean,
aver a g e
to
opposite
under
higher,
corre s p o n d
pattern
(signalling
except
projection
that,
(indicative
show an almost
therefore
b reveal
laterality
a lower
They
fields.
Males
higher
and
their
expected.
the analy t i c
A subset
a
involvement)
with a c o r r e s p o n d i n g
requires
2a and
means.
values,
negative coordinate
of Figures
a c c u r a c y measure,
laterality
negative
representation
the p o s i t i v e and
hemispheric
the
posit i v e and
their graphic
both
with
35
during
the
the
analytic
i ns t ruet i ons .
When
exposed
similar
inverse
l aterality and
for
females
holistic
B
females
relationship
response accuracy.
has
a
compared
same d i f f e r e n c e
contrast,
to Set
is
substantially
to the analytic
present,
both sexes
but
exhibited
as well
as males
between
the
The
lower
'minimal
a higher
a
of
late r a l i t y
v alue
condition.
to a
degree
aver a g e
mean
display
for the
For males
degree.
a c c u r a c y mean
the
In
under
PAGE
the h o l istic
and
a lower
a c c u r a c y mean
under
36
the analytic
instruction.
The
finding
that
higher
associated
with
right
processing)
brain
means
lower
obtained
late r a l i t y
when
to w h e t h e r
accuracy)
or the bottom
6
reveals
combined
high
is also
the
according
Table
they
that
that
four
the
a c c u r a c y mean
had
a rela t i v e l y mor e
(less
subgroups
accurate)
in a higher
correlational
sex,
the
a
top
of
that
across
coefficient
Thus,
means
produced
indicating
found
that
for
lower
with
compared
fell
to
below
5
resulted
for
type,
the total
sex,
a small
but
and
set,
negative
n.s.).
significant
.0 0 1 ,) was
the combined
r e l a t i v e l y mor e
suprisingly,
instruction
low
it appears
l a t e r a l i t y mean
1atera 1 i t y - a c c u r a c y r e l a t i o n s h i p
statistically
the
a n ‫ ׳‬average
that
with
of
for the
while
processing,
(r. = -0.16,
(high
value c o n s i s t e n t
associated
Not
ranks
I n spection
attained
negative
more
divided
computed
90.06.
accuracy
activity.
four
be
l a terality
were
-13.39,
hemispheric
who had
by the
(more accurate),
a c c u r a c y scores
(_r = -0.64, jj. <
the males,
5
a smaller
averaged
later a l i t y and
When
a mean
p o s itive value,
when
was
and w h o s e combined
left h e m i s p h e r i c
sample,
to the
to
(relatively
s u bgroups
l a t e r a l i t y mean
than
right
reflected
tend
(low accuracy).
s u bgroups
greater
l aterality mean
four
four
a c c u r a c y groups
attained
the
belong
scores
ratios
eight
the
a c c uracy groups
for
accuracy
was
inverse
the
by
correlation
females
laterality
analyzed
but
scores
not
for
(i.e.,
PAGE
r elat i v e l y
more
a s sociated
indices
tended
the
right
with
higher
(i.e.,
shift
to be coupled
correlational
subgroups
the one
to Set
indicating
received
there
ratio
with
found
that
a
females
instruction
p r onounced
to be assoc i a t e d
tendency
with
summarize,
calcu l a t e d
for
s i g n i ficant
w ere
the total
findings:
consistently
of a shift
processing)
compared
the analytic
orientation).
accuracy
statistically
dif f e r e n t i a l
slide
sets
significant
significant
impact
was
set
in t e r action was
on
the
also
with
who
l aterality
score.
in
index
the
right
by
ratios
c o ndition
hemispheric
obtained
left
sided
derived
from
the
effect.
(2)
The
shift
The sex
following
higher means
is
means
laterality
relatively
hemispheric
statistically
,0.82‫) ־‬,
females
h o l istic
instruction
(3)
exposed
in particular,
laterality
also s u b s t a n t i a t e d
effect.
only
Results
relatively
finding
> .£
for
eight
set)
a higher
relatively
(consistent
This
B,
The a v e r a g e
towards
to the
and
resulted
under
the
and
(x. = 0 5 .
for
the
sa m p l e
lower
(indicative
for
of
(1)
Among
who wer e
in Set
a lower
analysis
accuracy.
for
group
in general,
l a terality
mode)
instruction,
in the a n a lytic
likely
p r ocessing
c o m puted
Summa rv o f S t a t i s t i c a l l y S i g n i f i c a n t
To
left
to be s i g n i ficant,
for
mor e
higher
recognition
by sex,
the "ana l y t i c "
was
a m ore
lower
uere
scores;
coefficients
females
B was
accuracy
towards
(partitioned
for
orientation)
37
the
exerted
by
the
statistically
by i n s t r u c t i o n
significant,
by set
s uggesting
PAGS
that
males
predicted,
females
but
but
of
For
sets
higher
reached
accuracy
of
responded
holistic
condition
significant
This
differences
between
eight
addition,
accuracy
with
was
laterality
condition
data w e r e analyzed
activity
that
as
sex
the
and
two
employed
r e l ativ e
compared
between
for Set
slide
the
two
a
to
to the
followed
between
due
A
sets
to
was
effect
in
by sex,
the
female
for
that
subjects
under
the
the
analytic
a statistically
for
B.
Statistically
that
Set
only
were
also
resulted
showed
and
B.
by
Howe v e r
by sex,
in
Set
suported
accuracy
si g n i f i c a n t
the two
to the much
than
found
those
instruction
scores
ratios.
statistically
B
strategy
signi f i c a n c e ,
two
s u b groups
divided
for
Set
the d i f f e r e n c e s
compared
instruction
while
significant.
finding
sample was
(4) Wi t h i n
s i g n i f i c a n t l y m ore a c c u r a t e l y
significant
the
target,
as
manipulation,
in
proc e s s i n g
obtained
the
the
types,
obtained
females
st a t i s t i c a l
B
condition.
that
data,
score
as
B exposure.
The d i f f e r e n c e
statistically
S e p a r a t e analysis
in Set
Set
left-hemispheric
the a c c u r a c y
used
the h o l istic
instruction.
also
A was
in s t r u c t i o n
instructional
right-sided
rela t i v e l y mor e
groups was
Set
two
group means
found
basel i n e under
analytic
the
the
the
types
r e latively mor e
their
to
only under
comparison
i nstruction
to
only when
responded
expected,
set
responded
33
an
when
type,
detected
the
and
inverse
total
set.
In
rel a t i o n s h i p
this
negative correlation
for
the
for
females
females
in
Set
when
the
B,
who
PAGE
were
instructed
separate
to
analyses
instru c t i o n
type
treat
the
task
w er e
performed
by set)
subgroups.
a n a l ytically,
on
the
eight
39
when
(sex
by
D i scussion
Out
of
ratios
our
two
for the
statistically
physiological
central
task
compared
to
following
discussion
parietal
cerebral
significant
specific
evoked
the
first
a
ref e r e n c e
holistic
small
from
laterality
no
that
the
this
Therefore,
to
on
area
in
the
relates
to
about
the
alpha
relative
left sided
making
as
predicted,
right
in more
(with
a selection
subjects
analytic
obtained
ratio
strategy
under
activity
the
the
the demand
request
precipitated
for
on the
corresponding
In contrast,
left
to rely
more
right
involvement.
2.: I nstruction
Somewhat
mean
our
laterality
for an
resulted
to
supression).
on "feeling" when
Hypot h e s i s
task
as
positive
called
Thus,
Laterality.
su p p o r t e d
negative
instruction.
left, h e m i s p h e r e
rather
was
i n s t r uction
to the
"thinking"
and
Effect
hypot h e s i s
the
compared
males
produced
suggesting
region.
s i g n i f i c a n t l y grea t e r
mean when
than
(TC)
l aterality
activity.
attained
sided
the
involv e m e n t
parietal
any
area
findings,
less
H y pothesis J_: I nstruction
The
measures,
higher
females
accuracy
when
than a n a lytic
Effect
the
on
scores
R e s ponse
were
instruction
judgment,
Accuracy
attained
called
although
this
for
by
both
intuitive
effect
became
PAGE
statistically
target.
significant
As
strongly
described
influenced
respon s i b l e
for
Specifically,
only
whan
previously,
by
the
the
p ronounced
accuracy--similarly
by the same variable,
Hypo t h e s i s
3.: Lateral i t v - A c c u r a c y
predicted,
indexed
result
by
a lower
in
higher
he m i s p h e r i c
ratio)
relatively
laterality,
were
reached
females
and
one
support
to our original
which
influenced
seems
of
on the
the pheno m e n o n
how the
ideas
another
piece
that
different
affective
activity
that
later a l i t y
only
The chain
careful
of
further
attention
It may
also
the s p e c u l a t i o n
cognitive
for
the
basic
are c o nditions
in f o r m a t i o n
Howe v e r
and
the n e g a t i v e
study gives
these
to
left
accuracy
although
This
(as
likely
higher
significance
track.
and
hea v i l y
relatively
measures,
attained
for
laterality.
mor e
a
with
situation.
e v i dence
were
be
can
be
reasoning
study
of
paid
to
provide
yet
of K-W
£ Z
judgments
may
have
bases.
It appears
most
than
are o p e r a t i o n a l i z e d .
of
in
was
related,
that
,that
hemispheric
ratio)
hypo t h e s i s
requires
was
laterality--was
the subgroups.
right
accuracy
Relationship
two
preconsciously
the
set.
st a t i s t i c a l
by the social
to be
(1980)
the
in v e r s e l y
correlation
under
to
(associated
S p e c ifically,
as
factors
r e s ponse a c c u r a c y
i nvolveme nt
served
shifts
right
laterality
B
response
same
influenced
As
Set
40
that
effectively
our
particular
(as
evidenced
spatial
by
task was
higher
executed
i n cidence
of
PAGE
correct
responses)
activated
the
task
Consequently,
associated
with
the
and
task,
condi t o n
For
Set
l aterality mean
actually
instru c t i o n
with
when
involved
task
c o n s i s t e n c y with
females
to the
consistent
instructions
became
in the analytic
appropriate
low
inst r u c t i o n s
but
the v is u o - s p a t i a 1
was
right
corresponding
the
of
a c c u r a c y score mean,
type,
values
reflected
a stimulus
contrary
for
a
scores
the
right
while
laterality
expe n s e
showed
appropriate
high
the
example,
A
the task a p p r o p r i a t e
Sex
at
of
scores,
hemisphere
accuracy
that was
The c o r r e s p o n d i n g
left)
likely
(reflective
higher
the "wrong"
more
accuracy
Interestingly,
late r a l i t y
under
the
the
the instruction.
for the
to
hemisphere.
were
ratios
higher
evoked
in accuracy.
appropriate
was
and
sucessfully
right
judgments
later a l i t y
a shift
did not succeed
ins t r u c t i o n s
appropriate,
judgments
(signalling
decrease
lower
shift)
cognitive
the
affective
with
hemispheric
when
41
task
at hand.
w h i l e unexp e c t e d
with
activation
of
hemisphere.
E f f ec t
As was
w ere
stated
formulated
versus
The overall
sex
the
differences
that may
findings
related
exist
do
not
differences.
no s p e cific
expected
N e v e rtheless,
to detect
l a terality shift
introduction,
regarding
females.
examined
strong
in the
the
h y potheses
b e h avior
effect
of
of
sex
in e x p e r i m e n t a l l y
between males
indicate
As
is
and
males
induced
females.
the e x i s t e n c e
frequently
was
of
the case,
PAGE
the higher
or
lower
are over s h a d o w e d
observed
this
within
averages
by
the d i f f e r e n c e s
each group.
study compared
mor e
than
finding
shift
right
may
to males
it reflects
females
actual
male-more-right
finding
that
respond
differently.
reasons
for this
e x p l a nations
under
related
with
the s t a t i s t i c a l l y
between
late r a l i t y
females
but
subjects
not
and
predictor
of
more
visuo-spatial
task.
with
rely on
this
p r onounced
left
the
males
Insofar
females
observed,
all
inverse
indicates
laterality
values)
respo n s e
may
the
possi b l e
In
rel a t i o n s h i p
detected
that
the
i n t e r action
and
and
was
as
literature.
for the
for our
right-hemispheric
accurate
and
hi g h l y s p e c ulative.
that
left
However,
by set
significant
more
by lower
to
previously
are
for the males,
(o p e r a t i o n a l i z e d
in
f e m a 1 e - m o re - 1 eft
accuracy
relat i v e l y
female subjects
the
unclear,
females
be
B exposure.
As was
point
that
Set
by i n s t r u c t i o n
outc o m e are
and
could
to the
some c o n d i t i o n s
at this
range
a tendency
is c o n s i s t e n t
sex
suggests
in
processing.
occurance,
significant
addition,
had
hemispheric
for
for males
In general,
be an a r t ifact
observed
The
obtained
42
female
a c t ivity
is a reliable
judgments
on
this
Slide C o n s i d e r a t i o n s
For
the
similar
effects
later a l i t y
holistic
combined
ratios
compared
on
for
Set
A and
males
B data
and
both sexes
to the analytic
the
females,
had
i n s t r uctions
as
smaller
condition.
the
values
had
ave rage
in the
However,
when
PAGE
the data were s e parated
r e l a tionship
appeared
to
emerged
be the
by
stimulus
between
function
sets,
sex
of
and
the
a very
different
in s t r u c t i o n
target
43
set.
that
It seems
\
that males
behaved
when
A
Set
served
f a m i l i a r i t y with
Set
The s i g n i f i c a n t
response
to the
an outcome
c o m puter
w ere
of set
as
w ere assumed
on
the
behavioral
and
suggests
that
for some
of
set
on the
and
sets,
as
under
the
to have
a
observed
slides
the s lide
equivalent.
as well
females
females
S ince all
two
were
then
sets
thus
effect
measures
in s t r u c t i o n
reason
types
the sets
diametrically
was
and
The strong
physiological
unidentified
dif f e r e n t
for
only
response.
both males
two
females
but
same s p e c i f i c a t i o n s ,
to be
males
sufficiently
for
the
into
of both
effect
unexpected.
using
while
a simi l a r
moderating
divided
predictions,
target,
B evoked
i n s t ructions
g e nerated
to the
the
that was most
randomly
obtained
a c cording
were
opposite
impact.
A l t hough mor e
i n v e s t i g a t e all
indepth
significant
the two slide sets,
examination
investigation
of
A
and
r e l a t ionship
between
dimensions.
It appears
average vertical
visual
vertical
a ngle
B
their
visual
the h orizontal
visual
characteristics
a preliminary
Set
would
d e t ected
vertical
that
angle
( and
Set
that
angle,
is smal l e r
be required
assoc i a t e d
rather
a
reverse
and
than
Set
order
horizontal
A slides
for
with
rudimentary)
subtend
is somewhat
while
to
greater
B
than
slides
the horizontal.
an
the
There
PAGE
is v i r t u a l l y no
of vertical
inform a t i o n
versus
perception.
1973).
a
h o rizontal
However,
susceptibility
to
horizontal
vertical
line,
s omewhat
when
at
but
mor e
than
intera c t i o n
similar
other
yet
point,
a l t hough
required
a ngle
have
effect,
unidentified
this
been
an
angle
males.
Whether
function
or
factors
in
about
same
size
of
the
tendency
to
the
of set
sex
by
is
due
to a
in c o n j u n c t i o n
with
some
at
this
cannot
possibility,
estimate
a
on
(Murch,
the size
heve
alone
reported
to a
overestimate
the
the effects
differences
females
as
on
illusion
to mak e
right
both sexes
segment,
i n s t r uction
visual
sex d i f f e r e n c e s
line drawn
overestimate
literature
vertical-horizontal
Apparently,
vertical
in the
44
be
howe v e r
stated
remote,
should
not
be e x c l u d e d .
Methodological
Considerations
Due to a system
time-locked
The
as
to the
EEG samples
little as
depending
12.8
on the
due to artifacts
hand,
the
throughout
was
beyond
exactly
imposed
behavioral
used
sec
and
as
in the ongoing
capability
mad e
as
to
that
the
an
judgments).
wer e col l e c t e d
3
min
that
time
had
On
d e cisions
long
collect
judgment
,,overall"
trial.
EEG
within
intervals,
to be
EEG signals.
3.5 min
to
EEG data were not
(accuracy
or c o g n i t i v e
the a p p r o x i m a t e l y
was
long
of samples
10 a f f e c t i v e
our
data
the
in the analysis
number
corresponded
assumption
constraint,
rejected
the
other
wer e
made
Since
it
samples
that
responses,
the
p r ocessing
state
PAGE
(predominantly
would
prevail
left,
t h roughout
to the p r o p o r t i o n
attempt
will
in each
of
and
c o g n i t i v e set.
they
At
feel
the
been
reveals
the nature
of
i n t uitive
that was
available
also
that
of
of
were
this
responses,
to them
be
w e r e ' mad e
to
to
control
Subjects
focusing
on any
and
m ade
However,
how
their
preliminary
comprehended
although
w hile
test
provide
the Q u e s t i o n n a i r e
clea r l y
some
subjects
restorted
scant
to
a
inf o r m a t a i o n
recognition.
laterality
into c o n s i d e r a t i o n
the
to
when
to the
that
Post-Session
understood
for c o n scious
noted
the desired
d e s igned
inst r u c t i o n s
s t r a t e g y due
than
Presumably,
the
report
s u b jects
altering
rather
induce
ins t r u c t i o n s
analytic
prior
without
18
the s u b jects
all
that
recording.
and
A)
time of
by taking
open,
future an
on
think.
r e l iably
17
the
were calcu l a t e d
prevailed
solely
f o r mally analysed.
the
somewhat
baseline
related
source
holisticallv
than
m ore
well
the expected
received
attempts
be
In the
this
relied
rather
could
how
inspection
It should
h e m i s pheric)
it would
rectify
phrases:
followed
data have not
who
two
(see A p p e n d i x
about
judgments.
to
Q u estions
Questionnaire
closely
and
responses.
manipulation
instru c t i o n
i nformation
trial,
right
error.
analytically,
s t r onger
the
mad e
instruction
tho words
predominantly
of a c c u r a t e
be
methodological
The
or
45
phase,
"mental
indices
the alpha
no
deliberate
content"
wer e asked
to
particular
object,
level
during
relax with
w hile
eyes
the
PAGE
baseline data were collected.
It
some students,
tested
adv a n t a g e
of
especially
these m ome n t s
state c h a r a c t e r i z e d
ac t i v e l y
involved
problem solving
may well
induced
by
or
slip
plain
state
into
and
the
have
activity,
thinking.
Further
been
e.g.,
analysis
relationship
subsequent
took
a semi-awake
others may
of mental
on examining
that while
in the morning,
back
mind,
some kind
just
laterality
to
"blank"
with
concentrate
initial
those
is c o n c e i v a b l e
46
between
experimentally
l a t e r a l i t y shift.
Summary
In conclusion,
the
im m e d i a t e aim
to examine
the
r e c o g nition
of m i n i m a l l y
c o ncurrent
Both
response
may
be
cerebral
our
behavioral
effects
to
by
results
c o n firmed
left
right
or
for some
as
p rocessing
modified
instruction
exposed
laterality
well
as
sex
study was
on a c c u rate
stimuli,
in f o r m a t i o n
altering
that
and
on
emphasis
this was
conditions.
S p e c ifically,
males
likely
responded
the
attained
i n s t ructional
to behave
the
other
Notwithstanding
the
fact
measured
later a l i t y
slide
that
ratio
was
the
emphasis.
to one of
in
similar
could
The
although
certain
the slide
while
instruction
(TP),
in
to trigger
only under
predicted,
set
events
successful,
true
that
preconsciously
manipulation
exposed
as
suggest
brain
instr u c t i o n a l
the s u bgroups
sets w ere mor e
data
the ongoing
of
by the
present
and
spatial
and
hemispheric
to
the
processes.
accuracy
response
of
of
females
manner.
effect,
be m o d ified
as
by
PAGE
the "inc i d e n t a l "
sample,
as
well
instru c t i o n
analytic,
detected
factor,
as
for
type were
as
set,
p h y s iological
our
both
An
behavioral
(laterality
(i.e.,
l a t e r a l i t y value)
accurate
w hile
a relat i v e l y
l a terality
less
index)
total
left
did
not
studies
using
improved
methodology.
the
awareness
will
social
alter
a
larger
study
that
are
social
may
be
be a d a p t a b l e
processes
elements
such social
of
the
processed.
are m e d i a t e d
of
that
(i.e.,
higher
asso c i a t e d
the
with
in
that
to
interest;
with
approach
accompany
out
the
future
s u bgroups
begin
is
for
r e l a t ionship
cla r i f i e d
fewer
our
types
especially
of
conscious
a p a r adigm which
about
the brain,
a n alogous
in
stimuli,
significance
questions
by
result
laterality-accuracy
to
that
to
target
to be
or
functioning.
is
likely
We now have
to asking
in f o r m a t i o n
activation
be
us
and
hemispheric
proces s i n g s
focus
judgments)
predicted.
however,
inform a t i o n
brain
also
The
allows
obscure cerebral
r e l a t i o n s h i p was
involv e m e n t
sample
holistic
the
spatial
should
the
as
st a t i s t i c a l
relationship
present
ways
the
the total
under
m ore
a tendency
It appears,
The
of behavior
was
sided
reach
exists.
oth e r w i s e
right
for
than
measures,
responses.
sample.
The
of
showed
accurate
correlation
m ore
recognition
lower
( a ccuracy
ratios)
a rela t i v e l y
more
under
inverse
In general,
lower
sets
consistently
predicted.
between
the group means
47
how
and
We now
to spatial
certain
how
they
believe
that
i nformation
PAGE
in that
both
If this
contention
re l i a b i l i t y
significant
comparison
evoke
then
r elat i v e l y
can
right
be s u b s t a n t i a t e d
a new av e n u e will
social
processes,
hemispheric
p h enomena
and
as
normative
48
processing.
e x p e r i m e n t a l l y with
be open
for studying
stereo t y p i n g ,
behavior.
such
social
PAGE
49
Ref erenc es
Bradshaw, J.L., £ Nettleton, N.C.
The na t u r e of he m i s p h e r i c
s p e c i a l i z a t i o n in
man.
The
Behavioral and
Brain S c i ­
ences , j4, (1), March, 198 1 , 5 1-92.
Bunnell, D. E.
Comp o n e n t s
of
visual a t t e n t i v e n e s s in s u p ­
pression of the occipital alpha r h v t h m .
Paper presented
at the S o c i e t y of P s y c h o p h y s i o 1o g i c a 1 Research,
Washing­
ton, D. C., 1981.
Dennenberg, V. H.
H e m i s p h e r i c l a t e r a l i t y in animals and the
effects of
early experience.
The Behavioral
and Brain
S ciences , 4., (1), M arch 198 1 , 1-50.
Doyle, J . C.,
Ornstein, R.,
£
Galin, D.
Lateral s p e c i a l ­
ization of c o g n i t i v e mode:
II.
EEG fre q u e n c y analysis.
P s v c h o p h v s d o l o g v , 1974, J_1 ( 5), 567-578.
Edwards, C.A., Hecker, R.R., Perlaki, K.M., £
Barchas, P.R.
M i n i m a l l y exposed v i s u a l - s p a t i a l s t i m u l i : The mere e x p o ­
sure ef f ect and s ex
d i f f e r e n c e s in r e c o g n i t i o n a c c u r a c y .
(Tech.
Rep.
#79) Stanford: Stanford University, Program
in S o c i o p h y s i o l o g y , January, 1982.
Fried, I.,
Mateer, C.,
Ojemann, G.,
Wohn, R., £ Feido, P.
O r g a n i z a t i o n of v i s u o - s p a t i a l functions
in human cortex.
B r a i n , 1982, 1 0 5 . 349-371.
Grabow, J. D., Aronson, A. E., Greene, K. L, £ Offord, K. P.
A c o m p a r i s o n of EEG a c t i v i t y in
the left and right c e r e ­
bral h e m i s p h e r e s
by p o w e r - s p e c t r u m analy s i s
during l a n ­
guage and n o n - l a n g u a g e tasks.
E l e c t r o e n c e p h a l o g r a p h y and
Clinical N e u r o p h y s i o l o g y , 1979 , 4_Z> 460-472.
Helwig, J. T.,
£
Council,
Gary, North Carolina:
SAS
K. A.
SAS
u s e r ’s
In s t i t u t e Inc., 1979.
guide.
Kandel, E. R.,
£
Schwartz, J. H.
P r inciples
of
neural
sc i enc e s . New York: Elvier North Holland Inc., 1981.
K u n s t - W i I s o n , W. R., £ Zajonc, R.
tion
of stimuli
that cannot
1980, 2 0 7 , 557-558.
B.
be
Affective discrimina­
recognized.
Science,
McConnell, J. V., Cutler, R. L., £ McNeil, E. B.
Subliminal
stimulation:
An overview.
Ameri c a n P s y c h o l o g i s t , 1958,
1 3 , 229-242.
Moore, W. H.
A
study of alpha h e m i s p h e r i c
verbal and nonverbal stimuli in males and
and L a n g u a g e , 1980 , 9., 338-349.
a s y m m e t r i e s for
females.
Brain
PAGE
50
Moreland» R. L . , £
Zajonc, R. B.
Is stimulus recogn i t i o n a
necessary
condition
for
the
occurance
of
exposure
effects?
Persona I i t v and Social
Psychology,
1977»
3j5
(4), 19 1-199.
Morgan, A. H., Macdonald, H., £
Hilgard, E. R.
EEG alpha:
Lateral a s y m m e t r y related to
task,
and h y p n o t i z a b i 1 i t y .
P s y c h o p h y s i o l o g y , 1974 ,
( 3), 275-282.
Morgan, A. H., McDonald, P. J., £ M a cdonald, H.
D ifferences
in bilateral alpha a c t i v i t y as a function of e x p e r imental
task, with a note on lateral eye m o v e m e n t s and h y p n o t i z a bility.
N e u r o p s v c h o l o g i a , 1971, 2., 459-469.
Murch, M. G.
Visual and
The B o b b s - M e r r i 11 Co.
auditory p er c ep t io n .
Inc., 1973.
Indianapolis:
Perlaki, K. M., Hecker, R. R., £ Barchas, P. R.
Sex differences in pe c o g n i t i o n and
p r e f e r e n c e a c c u r a c y under three
exposure time c o n d i t i o n s .
(Tech.
Rep.
#80)
Stanford:
Stanford University, Program in S o c i o p h y s i o l o g y , January,
1982.
Zajonc, R. B.
The
attitu d i n a l
effects
of
mere exposure.
Journal o f
P e r s o n a l i t y and
Social P s y c h o l o g y
Monograph
S u p p I ement , 1968, 9. ( 2,Pt.2)>
1-27.
PAGE 51
APPENDIX A
Laboratory for Social Research
Stanford University
POST-SESSION QUESTIONNAIRE
This form contains questions that are relevant for analysis
of the brain wave measures that were collected during the pattern
discrimination task.
It is important for the data analysis that each
question be answered as completely and as honestly as possible.
Responses will be held in strict confidence. They are stored by subject
number, not name, and are seen only ty the social scientists in charge
of the study.
Thank you for your cooperation.
INSTRUCTIONS
For most of the questions you are to check the answers which best
fit your situation or best describe your experience. There are a few
questions which ask you to write in the answer.
Please answer as fully
as you can.
PAGE 52
Date
Subject
Age
1.
Sex
Do you consider yourself;
a.
b.
c.
2.
Right-handed
Left-handed
Anbidextrous
Don't know
Is your father (biological):
a.
b.
c.
d.
4.
Right-handed
Left-handed
Anbidextrous
Is your mother (biological):
a.
b.
c.
d.
3.
Right-handed
Left-handed
Ambidextrous
Don't know
Please indicate by a number how many (if any) of your biological siblings or
half siblings (not step-siblings) fall into these categories.
a.
b.
c.
d.
Of
Of
Of
Of
a
a
a
a
total
total
total
total
of
of
of
of
year in school are you?
a.
b.
c.
d.
e.
Freshman
Sophomore
Junior
Senior
Graduate
is your college major?
minor T
7.
!■That is (are) your favorite subject(s)?
8 . What is your least favorite subject?
9.
if _________
What is your strongest academic area?
are Right-handed
are Left-handed
are Ambidextrous
I don't know about
PAGE 53
10.
What is your weahest acadenic area? ____________________________
11.
Have you ever studied or plays‫ *׳‬a musical instrument?
12.
!That is your native language?___________________________________
13.
If you speak another language (or languages) please list.
14.
Do you have any visual impediments?
a.
b.
c.
d.
15.
No
Yes, I wear eyeglasses
Yes, I wear contact lenses
Other
Please indicate if you are or have ever been afflicted by any of the follow­
ing:
a.
b.
c.
d.
16.
Yes___ V.o_
Learning disability (e.g., dyslexia)
____
Speech impediment (e.g., stuttering)
____
Neurological disorders (e.g., epilepsy)____
Visual disorders (e.g., amblyopia,
stabismus, astigmatism)
____
Were you aware of any shapes during the first set of slide presentation?
a.
If so, please describe your impressions of them.
b.
If not, please describe what you experienced.
17.
Please write down, as closely as you can recall, the instruction given to
you prior to the second set of slide presentation.
18.
Please describe as best you can, how you made your decision regarding one
slide over the other, within each pair. What criteria, if any, did you use?
PAGE
A P P ENDIX
54
B
Laterali tv Ratio
One
requirement
research
is
to
the
asymmetries.
that
left,
or left
' For
simple
used
R/L
a
right
example,
ratio
1980;
sided
formula,
than
right
score
right
of
right),
their
a
r ef le c t i v e
formula
by
of
a
to the
relat i v e l y mor e
a
negative
equal
left
.50
left
sided
i.e.,
R/R+L
1971),
w here
Using
more
left
alpha),
the
production
more
on the
equality.
(1974)
adopted
In
a
mor e c o m p r e h e n s i b l e
difference
proce s s i n g
w hile
a
researchers
a relatively
hemispheric
EEG
used
alpha.
sided
alpha
relatively
right
expressing
indicates
to
percent
value,
and
total
produced
left
a right
(1974)
Other
her c o l l e a g u e s
that
and
in
with
relative
score,
Galin
ratio,
corresponds
and
for
£ Mcdonald,
(decrease
Morgan
Using
p o s itive
a c t ivity
.50
and
thar
of
raw or t r a n s f o r m e d
power.
less
is assoc i a t e d
this
10 0 ( R - L / R + L ),
the
induced
lite r a t u r e
forms
the unit
this
adjusted
(i.e.,
than
later work,
figures.
of
a value grea t e r
.50
of
in
task
relevant
various
as
McDonald,
was
the
O r n stein
version
p r ocessin g
and
variant
Doyle,
activity
sided
ratio
observed
Morgan,
less
of
adopted
right
specialization
for m e a s u r i n g
of a v e r a g e alpha
alpha
this
by
to
m o d ified
(Moore,
hemispheric
Review
investigators
later a l i t y shift
data.
the
to e s t ab lish means
he m i s p h e r i c
reveals
of
mor e
a
is
alpha
indicated
right
zero
ratio,
sided
value
production.
is
PAGE
Somewhat
Green,
index
and
the
tasks.
the
d i fferent
Offord
resting
from
s tate
who
and
tasks.
of d i f f e r e n c e s
left
as
and
The
sides
during
Aronson,
techniques
function
sides
first
)>
three
the
the
separately
for
performance
called
activity
for
between
for
to
of various
wer e c o l lected
approach
in alpha
(ARL¿
by G r a b o w ,
compared
the h o m o l o g u e
(baseline)
di f f e r e n t
calculation
right
(1979),
wer e used
laterality differences
EEG data
several
meth o d s
55
each
of
the
the
task,
simply as:
ARL¿
where
R
and
•
current
task
= R¿- L¿ , for
Lc
are
(marked
task
the alpha
i=1,....n
values
by sub s c r i p t
" i")
associated
at
the
right
with
the
and
left
formula,
but
s i d es .
The second
appro a c h
used
the data
for both sides
baseline
as:
A RLu
in
which
collected
s u b script
from the
refers
to the
The
third
by
the
= (R¿-
"i"
right
a p p roach
task
a d justing
preceding
were
the same
adjusted
R< )
‫־‬
left
the c o r r e s p o n d i n g
L 1)
(L¿ ‫־‬
denotes
and
for
the
expe r i m e n t a l
iides,
and
data
su b s c r i p t
" 1"
b a s e l i n e values.
l ater a l i t y changes
on which
basically
state
that
induced
the
right
(denoted
a t tempted
to
compensate
for
occur with
the
passage
time and
l a t e r a l i t y shift
and
left
by su b s c r i p t
of
the
is superimposed,
differences
" i - 1 "),
for
prior
the
to the
PAGE
presentation
of
by using
formula:
the
the current
‫־‬
For
of
( R¿
1'
purp o s e
of
the
to deve l o p
our
the
necessary
the above
i.e.,
formulas
to be able
relative
to
di f f e r e n c e s
overall
task
the
alpha
differences
own
‫• ־‬i.
total
activity,
by s u bscript
‫־‬
present
all
study
three
right
of
we
found
a c t ivity
to
the
alpha
level,
i.e.,
(c)
adjust
for
right
and
exist
between
the
just
reviewed
objectives,
hemispheric
relate
that
it
since none
our
(b)
and
" i"),
K -i>
l a t e r a l i t y measure,
(a) m e a s u r e
left,
to the
‫־‬
s a t isfied
to:
(marked
56
right
s cale
left
by the
the p r e - t r e a t m e n t
left
he m i s p h e r i c
activity.
All
of
criterion.
i.e.,
as
The
formula
1 0 0 / ( R - L / R + L ),
well,
howe v e r
pre-treatment
by
p a rticular
feature;
the
of
requirements
both
does
not
on the
expressed
1974)
(Rc
(as
which
the
cited
al.,
(1974),
cri t e r i o n
for
inc o r p o r a t e d
their
scores
To c o m p l y
the desired
in Gr a b o w
resulted
first
the
laterality measure
hand,
difference
to c o m b i n e
our
control
(1979)
differences.
formulas
et.
allow
other
as
meet
by the second
Only
et al.
we decided
et al.,
Laterality
it
the R-L
of these
Mor gan
is a c c e p t a b l e
Gr a b o w
are si m p l y
ratio
by Morgan
later a l i t y state.
presented
units
used
meth o d s
in:
‫¿* ־‬-i ) ‫ ־‬CL¿
‫ ־‬L( H )
(R¿ - R¿.^ ) + (L¿
- L¿., )
= 100
this
later a l i t y
rather
with
than
all
features
et a¿.,
1979
our
of
and
PAGE
w here
R¿ and
levels
L¿ denote
during
L.•^ represent
resting,
right
feature
dev i a t i o n
from
we believe
the
third
c o llected
and
during
the one
col l e c t e d
of
the
L¿-,!
only
and
first
wer e
and
Br
(left
in Formula
that used
only
= 100 -------------------------(R - Br ) + (L - B^ )
and
the second
preceding
N
used
baseline
task
Therefore,
before
the
phase.
alpha
we
first
between
(test)
nor
the
Thus,
c o llected
col l e c t e d
during
1:
( R - B r ) - ( L - B t
data,
the
alpha
Laterality
b a s e l i n e was
the session,
(right
resulting
first
of
baseline
baseline),
The
a
a p p roach
the second
by
represents
but
for
second
replaced
baseline)
during
collegues,
immediately
a
and
recorded
acceptable.
baseline
phase
R^and
and
the b e g inning
entirely
alpha
while
ratio
by Gr a b o w
the second
at
hemispheric
values
laterality
are
a first
alpha
tested
neither
left
treatment.
our
c o rrected
(exposure)
completion
before
and
manipulation,
left
that
performance
R
and
of
that
the baselines
right
e x p e r imental
immediately
This
the
57
)
to adjust
the
for c o r r e c t i n g
exposure
phase
the
phase
test
data .
While
closer
at
first
Formula
examination
revealed
features.
(Morgan
As men t i o n e d
et al.,
1974)
1
appeared
several
previously,
a positive
or
to
be
functional,
potentially
using
the
relatively
p r o b l ematic
ratio m e a s u r e
larger
value
PAGE
represents
r e l a t i v e l y mor e
relative d e c r e a s e
smaller
number
hemispheric
activation
side).
R - BK and
L - B^,
numerator
and
those
Since
degree)
as
during
task
during
(one
situation
is
as
are
task
for the
R = 20
Br = 4 0
in this
right
side
block
indic a t i v e
left)
negative,
the
exceeds
of
then
similarily
numerator, R - L .
left
a m ore
the
that
higher
appear
of
acts
become
the
ratio may
(to a larger
the alpha
always
and
on
in both
this
or
values
grea t e r
performance.
right,
right
supression
L values
or
than
Thus
the
two
for
the
left
one
likely negative.
by Exam p l e
(a):
L = 15
B^ = 3 0
(R - B^) - (L - B ¿ )
(20 - 40) - (15 - 30)
(-20) - (-15)
-5
example,
the
R and
almost
be most
and
and
=
=
=
=
alpha
blocker,
i llustrated
then ,
Numerator
If,
by
(i.e.,
a negative
relatively
the outc o m e
an alpha
b a s eline
processing
while
proc e s s i n g
in the n u m e r a t o r will
let
the
when
the d e n o m inator,
d i f f e r e n c e scores
This
with
d i f f e r e n c e scores
col l e c t e d
side)
right
alpha)
(manifested
However,
be inaccurate.
obtained
than
sided
is c o n s i s t e n t
the right
smaller
in left
left
58
the d i f f e r e n c e
(i.e.,
right
resulting
to
the one
exhibits
sided
s core
a greater
activity
numerator
obtained
for
for
alpha
relative
value
will
the
the
to
be
ratio
PAGE
The
i.e.,
m ore
reversal
oi
rela t i v e l y
pronounced
illustrated
the
left
m ore
left
alpha
by Exam p l e
and
right
hemispheric
hemispheric
suppression
on
activity
the
values,
marked
left
59
side,
by
is
(b):
let R = 15
B^ = 30
and
and
L = 20
40
then,
Numerator
Again,
this
is c o n s i s t e n t
larger d i f f e r e n c e
left)
the
results
locus
= (R - Br ) - (L - B¿ )
‫ ) ־‬15 ‫ ־‬3 0 ( - ) 20 - 4 0 (
= ) - 1 5 (‫׳‬- ) - 2 0 (
= 5
for
the
the problem
denominator.
To ve r i f y
Laterality
left
side
in a p o s i t i v e value.
of
wer e computed
with
by Formula
is not
this
It
providing
=
1 0 0 -------------------------
) 20 ‫ ־‬4 0 ( - ) 15 - 3 0 (
) 20 - 4 0 ( + ) 15 - 3 0 (
)-2 0 ( ‫ ) ־‬- 15(
)-2 0 ( + ) - 15(
-5
=
1 0 0 --- 35
= 100
=
14.3
)0 . 1 4 3 (
is
then
the values
(R ‫ ־‬B r ) - (L ‫ ־‬Bt )
100 ------------------------(R - B ^ ) + ( L - B c )
1 0 0 ----------------
formula,
(l a t e r a l i t y shift
=
=
ratio
as a
to the
apparent
in the n u m e r a t o r
fact
1, thus
the
of
but
in the
Example
Exam p l e
that
(c):
(a)
PAGE
W hile
on the
in this
right
exam p l e alpha
side compared
to the
a p o s itive value s i g n i f y i n g
it indicates
reason
for
a mor e
this
resultant
m eaning
of
is
than
completing
obtaining
the 5/-35
results,
resolve
that
this
dir e c t i o n
value
of
that
the
denotes
greater
a
(as
in
will
shift
dictate
negative
value,
positive
by the
negative
positive,
established
left
sided
the
that
the
to
of
the
i.e.,
right,
denominator
then
of
by p o s i t i v e
to ensure
It
has
the
or smaller
left.
If
permanently
the
been
a positive
to the
is
the
value.
represents
and
the
is
negative
the sign
the d i r e c t i o n
with
in a n e g a t i v e
the n u m e r a t o r
the
(b),
supression,
then
the
outcome.
Example
positive.
to a shift
ratio)
divided
alpha
is,
denominator
dest r o y i n g
for
is
The
When
di r e c t i o n a l
solution
w h i l e a p o s itive divided
outcome.
outcom e
processing!
obvious.
l a t e r a l i t y shift,
of
final
is q u i t e
always
the sign
the R-L/R+L
always
since
be
value c o r r e s p o n d s
positive status
sided
unacc e p t a b l y ,
conflict,
the d e n o m i n a t o r
e s t a b lished
pronou nced
a p o s i t i v e v alue c o n s i s t e n t
p r onounced
To
the
the c a l c u l a t i o n s
r elat i v e l y more
ratio
is more
the opposite,
right
always
the p r e v i o u s l y
Conversely,
rather
than
is divided
value
left,
exac t l y
inconsistency
negative numerator
the
left
supression
60
of
by a p o s i t i v e
the
secured
the num e r a t o r
resultant
produces
or
a
also
ratio,
negative
yields
a
PAGE
A
si m p l e
eli minating
and
the n e g a t i v e
the a b s o l u t e value
A modification
resulted
mathematically
of
used
2 provide
Laterality
the
is to use
two d i f f e r e n c e
inc o r p o r a t e d
this
scores.
feature,
and
‫־‬
Br )
‫־‬
(L
‫־‬
B¿)
100 ------------------------I( R ‫ •־‬Br ) + ( L - Bc ) I
The values
F ormula
of
for
2:
(R
=
1
solution
from the d e n o m i n a t o r
the sum
of Formula
in Formula
Laterality
sign
sound
61
in
Example
Example
(c)
(d) with
when
substituted
the following
into
result:
) 20 ‫ ־‬40 - ) 15 - 3 0 (
= 100 --------------------------I(20 - 4 0) + (15 - 30) I
-
(-20) - (-15)
1 0 0 -------------------------------------------------I(-20) + (-15)1
=
1 0 0 -----
-5
I-35 I
-5
=
100 —
35
= 100
(-0.143)
= ‫ ־‬14.3
Thus
with
Formula
our
dir e c t i o n
later a l i t y
2 will
conception
of
a
result
in
of
negative
a
r e l a t i v e l y more
balance.
a ratio
right
that
shift
sided
is c o m p a t i b l e
(towards
processing)
the
in
PAGE
Similarily,
the
values
given
illustrated
Laterality
calculation
in
by Example
=
of
the
Exam p l e
laterality
(b)
and
shift,
Form u l a
62
using
2,
is
formula
will
(e):
(15 - 30 - (20 - 40)
100 --------------------------1(15 - 30) + ( 20 - 4 0 ) I
(-15) - (-20)
= 1 0 0 ----------------I(-15) + (-20) I
5
=
1 0 0 ---I35 I
5
=
100 —
35
= 100
‫־‬
Again,
14.3
appropriately
produce a ratio
shift,
( 0. 143 )
which
p roc ess i ng .
that
is
for
the
reflective
is assoc i a t e d
with
model,
of
the
a positive
a r e l a t i v e l y m ore
late r a l i t y
left
sided