Perception as Practiced
Gadi Geiger
Center for Biological and Computational Learning
Brain and Cognitive Sciences
Massachusetts Institute of Technology
Cambridge MA 02139
[email protected]
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V
The form-resolving field (FRF) of English-native adults
correct recognition [%]
ordinary readers (OR)
100
80
60
40
20
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of English-native adults
ordinary readers (OR)
correct recognition [%]
dyslexics
100
80
60
40
dyslexics
20
0
-15
OR
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of English-native adults
ordinary readers (OR)
dyslexics
correct recognition [%]
the differences in recognition
100
80
60
40
20
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of English-native adults
ordinary readers (OR)
dyslexics
correct recognition [%]
the extent of recognition
100
80
difference
60
40
20
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
When ordinary readers look at text
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
When dyslexics look at text
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
Demonstrating lateral masking
N
x
TENET
Keep your gaze on the x without moving your eyes
The form-resolving field (FRF) of English-native adults
ordinary readers (OR)
correct recognition [%]
dyslexics
100
80
60
40
dyslexics
20
0
-15
OR
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of Hebrew-native adults
correct recognition [%]
ordinary readers (OR)
100
80
60
40
20
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of Hebrew-native adults
ordinary readers (OR)
correct recognition [%]
dyslexics
100
80
60
dyslexics
40
20
OR
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The regimen of practice for learning a new
perceptual strategy
The practice comprises two parts:
1.
Novel, small-scale, hand-eye coordination tasks like
painting, drawing, modeling, embroidery etc..
2.
Reading with a window-mask.
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
Reading with a window-mask
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
Reading with a window-mask
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
Reading with a window-mask
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but
how we have learned to practice seeing. There are several
strategies that we pick between depending on what we have
learned to see, and we switch between them as the task changes.
So for example, a hunter uses a wide field of vision to locate prey,
a scribe uses a narrow field to write and a painter or architect
uses a variable field to arrange an ensemble into a whole. Each
discipline of seeing take practice. But suppose, like a dyslexic,
you have a strategy inappropriate to reading.
The form-resolving field (FRF) of English-native
Dyslexics
correct recognition [%]
before practice
100
80
60
40
before
20
OR
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of English-native
Dyslexics
correct recognition [%]
before and after practice
100
80
60
before
40
20
0
-15
after
OR
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of a
“conditional dyslexic”
correct recognition [%]
In the “alert” phase
100
80
60
40
20
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field (FRF) of a
“conditional dyslexic”
In the “alert” phase
correct recognition [%]
in the “tired” phase
100
80
60
40
tired
20
0
-15
alert
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
Smooth and jagged letters
The FRF of adult ordinary readers when presented with
correct recognition [%]
smooth letters
100
80
60
40
20
0
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
Smooth and jagged letters
The FRF of adult ordinary readers when presented with
correct recognition [%]
smooth letters
jagged letters
100
80
60
40
jagged
20
0
-15
smooth
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
The form-resolving field adults
correct recognition [%]
Ordinary readers
“speed readers”
100
80
60
speed readers
40
20
0
-15
OR
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
Line drawings of objects used as stimuli
The form-resolving field (FRF)of adult ordinary readers
correct recognition [%]
large letters
“objects”
100
80
letters
60
40
objects
20
-15
-10
-5
0
5
10
angular distance from center of gaze [degrees]
15
Main points
-Dyslexics and ordinary readers differ in their perceptual strategy.
A wide strategy for dyslexics and a narrow one for ordinary readers.
-Dyslexics are able to learn the narrow strategy for reading by practice.
-Similarly, ordinary readers are able to learn “speed reading”.
-A perceptual strategy is task-determined and is learned by practice
to optimize task performance.
Collaborators:
-Jerry Lettvin, MIT.
-Olga Zegarra-Moran, SISSA, Italy
-Manfred Fahle, Tuebingen University, Germany