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*PROCESS DISSOCIATION TASK*
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 04-14-2015
last updated: 02-25-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 02-25-2022 Millisecond Software
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BACKGROUND INFO
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This script runs the Process Dissociation Procedure by Yonelinas et al (1995).
The Process Dissociation Procedure is a procedure to help separate the contributions of automatic
(here: familiarity) and intentional (here: recollection) processes on cognitive tasks (here: recognition memory).
Reference:
Yonelinas, A.P. & Jacoby, L.L. (1995). The relation between remembering and knowing as bases for recognition:
Effects of size congruency. Journal of Memory and Language, 34, 622-643.
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TASK DESCRIPTION
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Participants study 2 lists of geometrical shapes. The shapes are presented in 2 different sizes.
The geometrical shapes of both lists as well as an equal number of new shapes are used for a later recognition test
(Half of the shapes of list 1 and list 2 are presented in their original sizes; half of them change size.
Participants are instructed that the size doesn't matter only the shape itself is of importance).
2 types of instructions are used for the recognition tests:
1) Was presented shape part of list 1? Say 'Yes' if it was or if it looks familiar but you don't recall whether
it's from list 1 or list 2. Say 'No' if you know the item is new or you know it is a shape from list 2.
2) Was presented shape part of list 2? Say 'Yes' if it was or if it looks familiar but you don't recall whether
it's from list 1 or list 2. Say 'No' if you know the item is new or you know it is a shape from list 1.
Participants work through 4 study-test blocks: 2 blocks with instruction 1 ('list1 instructions')
and 2 blocks with instruction 2 ('list2 instructions').
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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: 'processdissociation_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.
round: counts the blocks/rounds
instructiontype: 1 = list1 instructions;
2 = list2 instructions
currentlist: 1 = list1 item;
2 = list2 item;
3 = list3 (new) item
size: 1 = small size;
2 = big size
congruence: 1 = study and test size are the same;
2 = study and test size are not the same
nextitem: contains the currently selected stimulus itemnumber
stimulusitem: the presented stimuli in order of trial presentation
response: the scancode of the response button
30 - A (left)
38 - L (right)
responseCategory: "Yes" vs. "No"
correct: correctness of response (1 = correct; 0 = incorrect)
latency: the response latency (in ms); measured from onset of stim
congruent items (c):
count_11_c: counts test trials in which a list 1 items is presented under list1 instructions
count_12_c: counts test trials in which a list 1 items is presented under list2 instructions
count_21_c: counts test trials in which a list 2 items is presented under list1 instructions
count_22_c: counts test trials in which a list 2 items is presented under list2 instructions
countyes_11_c: counts how often participant says 'yes' to list1 items under list1 instructions => item1 familiar and recollected
countyes_12_c: counts how often participant says 'yes' to list1 items under list2 instructions => item1 familiar but not recollected
countyes_21_c: counts how often participant says 'yes' to list2 items under list1 instructions => item2 familiar but not recollected
countyes_22_c: counts how often participant says 'yes' to list2 items under list2 instructions => item2 familiar and recollected
countno_11_c: counts how often participant says 'no' to list1 items under list1 instructions => failed recollection; failed familiarity
countno_12_c: counts how often participant says 'no' to list1 items under list2 instructions => correct recollection
countno_21_c: counts how often participant says 'no' to list2 items under list1 instructions => correct recollection
countno_22_c: counts how often participant says 'no' to list2 items under list2 instructions => failed recollection; failed familiarity
(same for incongruent items)
count_new: count test trials in which a list 3 item (new) is presented
countyes_new: counts test trials in which a list 3 item (new) is presented and participant replies 'yes' (instead of no) -> False Alarms for new items
(2) Summary data file: 'processdissociation_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)
In this task: p(R ecollection) and p(F amiliarity) are estimated using
Inclusion Measure = p(accepting a target list item = 'yes') = p(Recollection) + p(Familiarity) - p(R&F)
Exclusion Measure= p(accepting a non-target list item = 'yes') = p(Familiarity) - p(R&F)
=> Recollection Estimate = p(R) = Inclusion Measure - Exclusion Measure
=> Familiarity Estimate = Exclusion Measure/p(no recollection) = Exclusion Measure/(1-p(R))
inclusion: probability of saying 'yes' to items from the targetlist
('yes' to list1 items under list1 instructions as well as 'yes' to list2 items under list2 instructions)
(+ separate measures for congruent and incongruent items: inclusion_c, inclusion_ic)
exclusion: probability of saying 'yes' to items not from the targetlist
('yes' to list2 items under list1 instructions as well as 'yes' to list1 items under list2 instructions)
(+ separate measures for congruent and incongruent items: exclusion_c, exclusion_ic)
recollection: probability of recollecting an item:
estimated by subtracting the Exclusion measure from the Inclusion measure
(+ separate measures for congruent and incongruent items: recollection_c, recollection_ic)
familiarity: probability of familiarity of an item: estimated by dividing the Exclusion measure by the probability that item was NOT recollected (= 1-recollection)
(+ separate measures for congruent and incongruent items: familiarity_c, familiarity_ic)
FA_new: Commission Errorrate for new items (across instructions)
(Commission = classifying a new item as an old one)
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EXPERIMENTAL SET-UP
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2 congruence (congruent, incongruent study-test shape sizes) x 2 types of instructions (list 1 instructions; list 2 instructions)
tested within subjects.
Blocks:
4 Study (list1 -> list2) - Recognition Test Blocks:
-> 2 with instructions 1 (see above)
-> 2 with instructions 2 (see above)
=> order of blocks randomly determined for each participant
Study Trials:
* 1 between-list trial: 5s (automatically starts list 2)
* 20 trials each:
-> list shapes are randomly presented for 5s (default; editable parameter) each
-> half the shapes are presented big (by default: image is sized to be 80% of the screen height);
the other half small (by default: image is sized to be 20% of the screen height)
Test Trials:
* 1 instruction trial: 5s (automatically starts the list)
* 60 trials each: 20 list1 shapes; 20 list2 shapes; 20 new shapes ('list3')
-> half the shapes of each list are presented big (by default: image is sized to be 80% of the screen height);
the other half small (by default: image is sized to be 20% of the screen height)
-> for list1/list2 shapes: half of the shapes are presented in the same size as during the study phase (congruent); the
other half is presented in the opposite size (incongruent)
NOTE:
a) before each study-test phase, 20 shapes are randomly assigned to each of the 3 lists.
The shapes are randomly drawn from the pool of 240 shapes (initially) without replacement
=> all 240 shapes will be used over the course of this experiment
=> the assignments will be different for each participant
b) Response key (yes/no) assignment to left and right response keys is counterbalanced by groupnumber
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STIMULI
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provided/generated by Millisecond Software.
240 (20 shapes per list x 3 number of lists/block x 4 blocks) geometric shapes were computer generated by
randomly selecting 5 points out of 100 possible ones and connecting them.
The size of the 'big' and 'small' shapes can be set under section 'Editable Values'
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INSTRUCTIONS
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Instructions are not original to the task. They are provided by Millisecond Software
as htm/html pages and can be edited by changing the provided htm/html files.
To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac)
or Notepad (Windows).
Note: once the study phase starts, the process (including instructions) are started automatically.
Timing can be controlled via editable parameters (see section "Editable Values")S
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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:
Responsekey Assignments:
/responsekey_left: the left response key (default: "A")
/responsekey_right: the right response key (default: "L")
/getReadyDuration: the duration (in ms) of the get-ready-trial
/liststimduration: duration in ms of the stim presentation during study (default: 5000ms)
/studybreak: duration in ms of the break between list1 and list2 (default: 5000ms)
/testinstructionduration: duration in ms of the instructions for the recognition test (default: 20s)
/bigstimsize: size of image size of big stims in % of canvas height (default: 80%)
/smallstimsize: size of image size of small stims in % of canvas height (default: 20%)
=> B/S = 4
