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CONSONANT TRIGRAMS
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 10-07-2015
last updated: 02-21-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 02-21-2022 Millisecond Software
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BACKGROUND INFO
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This script implements a variant of the Brown-Peterson Trigram Task inspired by:
Brown, J. (1958). Some tests of the decay theory of immediate memory.
Quarterly Journal of Experimental Psychology, 10, 12-21.
Peterson, L. R. & Peterson, M. J. (1959). Short-term retention of individual verbal items.
Journal of Experimental Psychology, 58, 193–198.
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TASK DESCRIPTION
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Participants are presented a consonant trigram (e.g. TRD) for 1500ms (default - can be edited)
They are instructed to study the trigram for a potential recall test later on. To prevent
rehearsal, participants are then presented a random 3 digit number and are asked to count backwards from it
by 3s as long as prompted (number of prompts depends on delay between offset of trigram and onset of recall box;
by default each prompt is presented for 1000ms and default delays are 3000-18000ms).
Half the trials ask participants to enter the last number they were prompted to count backwards to,
the other half the trials ask participants to enter the trigram.
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DURATION
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the default set-up of the script takes appr. 25 minutes to complete
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DATA FILE INFORMATION
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The default data stored in the data files are:
(1) Raw data file: 'consonanttrigramtask_raw*.iqdat' (a separate file for each participant)
build: The specific Inquisit version used (the 'build') that was run
computer.platform: the platform the script was run on (win/mac/ios/android)
date, time: date and time script was run
subject, group: with the current subject/groupnumber
session: with the current session id
blockcode, blocknum: the name and number of the current block (built-in Inquisit variable)
trialcode, trialnum: the name and number of the currently recorded trial (built-in Inquisit variable)
Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those
that do not store data to the data file such as feedback trials. Thus, trialnum
may not reflect the number of main trials run per block.
recalltype: 1 = trigram recall; 2 = last number
delay: stores the current delay between offset of trigram and onset of textbox
stimulusitem: the presented stimuli in order of trial presentation
response: the participant's response
correct: the correctness of the response (1 = correct; 0 = incorrect)
latency: the response latency (in ms)
Note:
* for trial.trigram/trial.lastnumber the latency reflects the duration of the trial
from onset of trigram to offset of the last prompt (parameters.trigramduration + values)
* for openended trials the latency is measured from onset of textbox to selecting the next button
startnumber: stores the first (start) number
lastnumber: stores the number last prompted to count down to
correct_lastnumber: sums up all the correctly counted last numbers per trial
totalcorrectlastnumber: counts all correctly entered last numbers across task
trigram: stores the current trigram
correct_consonants: sums up all correctly recalled consonants (position important) per trial
totalcorrectconsonants: counts all correctly recalled consonants (consonant position important) across task
(2) Summary data file: 'consonanttrigramtask_summary*.iqdat' (a separate file for each participant)
inquisit.version: Inquisit version run
computer.platform: the platform the script was run on (win/mac/ios/android)
startDate: date script was run
startTime: time script was started
subjectid: assigned subject id number
groupid: assigned group id number
sessionid: assigned session id number
elapsedTime: time it took to run script (in ms); measured from onset to offset of script
completed: 0 = script was not completed (prematurely aborted);
1 = script was completed (all conditions run)
totalcorrectlastnumber: counts all correctly entered last numbers across task
meancorrectlastnumber: calculates the proportion of correctly entered last numbers
totalcorrectconsonants: counts all correctly recalled consonants (consonant position important) across task
meancorrectconsonants: calculates the mean number of correctly recalled consonants per trial
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EXPERIMENTAL SET-UP
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=> 2 (recall type) x 6 delays (measured from offset of trigram to onset of textbox = foil task duration)
1.Instruction/Demo Block: runs one trial sequence with additional instructions (timing is different from actual trials)
-> can be repeated
2. Practice Block: runs 6 trials by default (same trial timings as in actual test; change number of trials under section BLOCK block.practice)
3. Test Block
* 1 Block of 48 trials (default; the number of trials can be edited under block.trigrams under section BLOCKS)
=> half the trials result in a trigram recall (Target Trials), half the trials result in a last number recall (Foil Trials)
=> default delays (measured from offset of trigram to onset of recall box): 3000, 6000, 9000, 12000, 15000, 18000ms
Trial Sequence:
Trigram (default: 1500ms) -> start 3-digit number (default: 1000ms)->{prompts; each for 1000ms}*-> recall textbox (either last number or trigram recall) -> Feedback
* no voice records are recorded during the count trial; the first prompt is to REPEAT the start 3-digit number
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STIMULI
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Trigrams: randomly assembled of 3 consonants (except y) - no repeats of consonants within the same trigram
-> no repeats of Trigrams (possible for trialcount < 500 only)
Number: randomly selected 3 digit number
-> no repeats of starting number (possible for trialcount < 500 only)
presented in black on white
Size can be edited under Editable Parameters
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INSTRUCTIONS
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Instructions are not original. They are provided by Millisecond Software and can be edited under Editable Instructions.
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EDITABLE CODE
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check below for (relatively) easily editable parameters, stimuli, instructions etc.
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code
to further customize your experiment.
The parameters you can change are:
/stimulusheight: the size of the trigrams/digits in canvas percentages (default: 5% of canvas height)
/trigramduration: the presentation duration (in ms) of the trigrams (default: 1500ms)
/promptduration the presentation duration (in ms) of the counting prompts (default: 1000ms)
Note: the promptduration needs to be in synch with the delays (see list.trigram_delays);
promptdurations < 1000 require additional changes on the trial level
/feedbackduration: the duration of the accuracy feedback (in ms) (default: 2000ms)
/ITI: the intertrial interval (in ms) (default: 3000ms)
/countby: counts backwards by 3'
