Return to the Transitive Inference Task page

Script Author: Katja Borchert, Ph.D. ( for Millisecond Software, LLC
Date: 04-18-2014
last updated: 02-03-2016 by K.Borchert ( for Millisecond Software LLC

Copyright © 02-03-2016 Millisecond Software


This script implements a nonverbal Transitive Inference Task similarly to the one described in:

Frank, M.J., Seeberger, L.C. & O’Reilly. R.C. (2004). By Carrot or by Stick: Cognitive
Reinforcement Learning in Parkinsonism. Science, 306, 1940-1943

Participants work through a learning and a test phase. 
During the learning phase participants get presented 4 overlapping pairs of symbols (AB, BC, CD, DE)
and have to learn to pick the winning symbol of each pair (A > B > C > D > E).
Throughout the learning phase participant are given positive and negative feedback.
During the test phase, two novel pairs (AE and BD) are presented amongst the training pairs.
No feedback is given during the testing phase.

The default data stored in the data files are:

(1) Raw data file: 'TransitiveInterferenceTask_raw*.iqdat' (a separate file for each participant)

build:							Inquisit build
computer.platform:				the platform the script was run on
date, time, subject, group:		date and time script was run with the current subject/groupnumber 
/phase:							1 = learning; 2 = test
blockcode, blocknum:			the name and number of the current block
trialcode, trialnum: 			the name and number of the currently recorded trial
									(Note: not all trials that are run might record data; by default data is collected unless /recorddata = false is set for a particular trial/block) 
/pair:							current pair of symbols (e.g. "AB")
stimulusitem:					the presented stimuli in order of trial presentation
								Note: does not need to correspond to spatial presentation of stimuli
/winletter:						contains the winning letter during learning
response:						the participant's response (scancode of response button)
correct:						the correctness of the response (1 = correct; 0 = error)
latency: 						the response latency in ms

(2) Summary data file: 'TransitiveInterferenceTask_summary*.iqdat' (a separate file for each participant)

script.startdate:				date script was run
script.starttime:				time script was started
script.subjectid:				subject id number
script.groupid:					group id number
script.elapsedtime:				time it took to run script (in ms)
computer.platform:				the platform the script was run on
/completed:						0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run)
block.learningphase.totalcount:	how many learning phases participants went through
/percD_DE_training:				percent correct for the different pairings during the last training session
/percD_DE_test:					percent correct for the known pairings during test
/percB_BD:						percent correct for the novel pairings during test

Letter-Symbol-Assignment: each of the provided 5 symbols gets randomly assigned to 'play the role' of letters A, B, C, D, E

Learning Phase: 
* each learning block runs for 80 trials (20 per symbol pair -> can be edited via parameters.trialnumber_learning)
* it can be controlled via editable parameters whether certain learning criteria have to be met before
moving on to the test phase.
=> if learning criteria are set in place, the learning block will be repeated if not all criteria are met
within the current learning block and the learning cycle starts afresh.

Test Phase:
* the test block runs for 120 trials (20 per symbol pair -> can be edited via parameters.trialnumber_test)

Trial Set-up:
The left-right position of the symbol pairs is counterbalanced across each block
-> symbol A appears on the left side in 50% of the trials 

The stimuli are 5 Hiragana characters presented in Frank et al (2004).
Their size and location can be easily controlled via section Editable Parameters.

To use a different set of images, simply replace the stimuli under
section Editable Stimuli -> item.symbols

The instructions are not the originals. They can easily be edited under section Editable Instructions.

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:

/responsekey_left:						scancode of the response key for symbol on the left (default: 30)
/responsekeyleft_label:					label of the response key for symbol on the left (default: "A")
/responsekey_right:						scancode of the response key for symbol on the right (default: 38)
/responsekeyright_label:				label of the response key for symbol on the right (default: "L")

/x_right:								horizontal coordinate of the right symbol in screen percentages (default: 35%)
/x_left:								horizontal coordinate of the left symbol in screen percentages (default: 65%)
/symbolheight:							the height of the symbol image in screen height percentages (default: 40%)

/trialnumber_learning:					the number of trials in a learning session (default: 80 -> 20 per symbol pair)
/minD_DE:								minimum proportion of winning symbol-selections in all 4 learning pairs that have to be met in the current learning block (default: 0.6 for all)
											Note: to remove a criterion, set the corresponding value to 0. In that case, any selection or none
											of the corresponding letter (A, B, C, D) fulfills the criterion. If all values are set to 0, the learning phase
											will be as long as specified under parameters.trialnumber_learning.
/trialnumber_test:						the number of trials in the test session (default: 120 -> 60 per symbol pair)

/feedbackduration:						the duration of the feedback stimuli in ms (default: 1000ms)

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