LGCS 121: Psycholinguistics
Fall 2012
Linger: powerful and flexible software for presenting stimuli and recording
responses and reaction times
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Easy to use
Runs on a variety of platforms
Quickly becoming the standard in psycholinguistics for simple tasks
Free!
You can find Linger here:
http://tedlab.mit.edu/~dr/Linger/
Note that it requires the Tcl/Tk platform which is also freely available from
Active State:
http://www.tcl.tk/software/tcltk/download.html
You can run a variety of presentation types on Linger:
 Self-paced reading (today’s demo)
Read sentences phrase by phrase at your own pace
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Lexical decision (today’s demo)
Decide whether a string is a word or not
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Primed lexical decision (today’s demo)
Decide whether a string preceded by a prime string is a word or
not
Cross modal lexical decision
Listen to a prime or a sentence and make a lexical decision
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Simple questionnaires
Grammaticality, acceptability, naturalness judgments
- On scale
- Forced choice
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RSVP (Rapid serial presentation)
Presentation of words is displayed in a fixed position, presented
serially and very rapidly (e.g., 300ms per word) with some
interval in between. Decision about sentence made after
presentation.
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Stops-making sense
The subject reads a sentence phrase by phrase and makes a
decision about whether the sentence continues to make sense at
each phrase.
Run Linger by clicking on Linger icon (PC) or running “wish linger.tcl” from
terminal (Mac). Experiments are stored in the “Experiment directory” with the
following files:
items
contains the experimental and filler sentences and questions
preferences contains commands that override the default preferences
introduction contains commands that run the intro and practice trials
break
contains commands that run if a rest break occurs
conclusion contains commands that run at the end of the experiment
The items file is a text file with all the items listed. Above each item is a tag
telling the program what experiment, number, and condition the item belongs
to, with the form: # experiment_name item_name condition_name
A dummy experiment:
# filler 1 a
This is a filler sentence
# filler 2 a
This is another filler sentence
# lex 1 a
This is a sentence from experiment “lex”, item 1, condition a
# lex 1 b
This is a sentence from experiment “lex”, item 1, condition b
# lex 2 a
This is a sentence from experiment “lex”, item 2, condition a
# lex 2 b
This is a sentence from experiment “lex”, item 2, condition b
Questions:
In addition, you may ask questions after a sentence or presentation. An
example of a Yes/No question would be:
# lex 1 a
This is a sentence from experiment “lex”, item 1, condition a
? Is this a boring item? Y
In the above, the “Y” signals that the correct answer is Yes. You can also ask
questions with multiple-choices: This is a sentence from experiment “lex”,
item 1, condition a
! How boring is this item? {Not_boring Semi_boring Very_boring}{Very_boring}
Here, you’ve listed the possible answers in the first parentheses and the
“correct answer” in the second.
The preferences file sets the preferences for how the items will be displayed
and what the defaults are. Examples for a variety of experiment types may be
found in the documentation on the Linger website.
You experiments should start off with a short and clear set of instructions,
preferably with a guided practice so that your subjects can get a feel for the
task. It is typically best if you are with them for this practice portion, so that
they can ask you any questions that arise.
These instructions are contained in the instructions file that has it’s own
special syntax.
instruct {This are some instructions.}
Prints text and waits for the subject to press a key to continue.
command {Commands are like instructions but are displayed in big font and
centered.}
You can create and display practice items like so:
createItem {# practice 1 –
This is a practice item.
? Is this a practice item? Y
}
presentItem practice:1:-
For your experiments, you can probably ignore the break file, since you should
not be presenting lots and lots of items to your subjects.
Data from each subject is recorded as a .dat file in the Results folder. Data
from subject 1 is recorded as 1.dat. Exactly what data is recorded will depend
on your experiment, but typically you will record reaction time and the
response, in addition to the experiment, condition and item:
From a sample lexical decision experiment:
Subj
1
1
1
1
1
1
1
1
1
1
Experiment
practice
practice
practice
practice
filler
prime
filler
filler
filler
prime
Item
1
2
3
4
6
4
4
2
12
4
Cond
a
unrel
a
a
a
rel
Typ
?
?
?
?
?
?
?
?
?
?
Ans
N
Y
N
N
N
N
N
N
Y
N
Correct
0
0
1
0
0
0
0
0
0
0
RT
682177
452260
574044
601802
1295462
1143701
801746
605113
971657
892299
NB: the reaction times are recorded in milliseconds. These are long reaction
times because this experiment records the time before presentation as well.
When starting up an experiment, you’ll see a window like so:
You should choose the experiment you want to run from the Experiment tab.
Note that the experiments are just the items, preferences, instructions, and
conclusion file contained in a folder, e.g., 12SE1_2 above, within the
Experiments folder of the Linger directory. You can select which number you
want to run the subject as, but Linger will keep track of this automatically.
Click on Run when you wish to run a subject and record the data; results will
be stored as N.dat and N.itm files in the Results folder (where N = subject
number).