Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 29, 2020
Last Modified: January 11, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements a Think/Not Think Task procedure to study the effect of thought suppression on memory. The procedure is based on Anderson & Green (2001).
Anderson, M.C. & Green, C. (2001). Suppressing unwanted memories by executive control. NATURE, 410, 366-369.
Phase 1: ~5-10min per round Phase 2: ~20 minutes Phase 3: ~5 minutes
Participants work through 3 phases:
1. Phase I: Learning of 40 random word pairs where the left word is going to be the recall cue of the right word. Recall is tested via textbox input in this script. 2. Phase II: Active Thought suppression instructions for some of these word pairs 3. Phase III: Re-testing all word pair learning
1. Phase I: Learning of 40 random word pairs where the left word is going to be the recall cue of the right word. (study-phase)
2. Phase II: Active Thought suppression instructions for some of these word pairs (suppression-phase)
3. Phase III: Re-testing all word pair learning (test-phase)
The 40 word pair associations are divided into 4 major 'repeat' groups:
- Repeat16: 10 word pairs are repeated during phaseII 16 times (5 are 'recall' pairs, 5 are 'suppression' pairs)
- Repeat8: 10 word pairs are repeated during phaseII 8 times (5 are 'recall' pairs, 5 are 'suppression' pairs)
- Repeat1: 10 word pairs are presented only once during phaseII (5 are 'recall' pairs, 5 are 'suppression' pairs)
- Repeat 0: 10 word pairs are never presented during phaseII (=baseline pairs, 5 are 'recall' pairs, 5 are 'suppression' pairs)
'Recall' pairs: participants should recall the associated word given a particular cue word during phase II
'Suppression' pairs: participants should supress the associated word given a particular cue word during phase II
1) Word Pair Assignment:
By default, this script runs preassigned fixed word pairs (the assignments were randomly generated).
The word pairs can easily be edited by changing the assignment lists under section Editable Stimuli.
The advantage of pre-fixed word pairs is that phaseI can be distributed across several sessions.
2) Phase I:
PhaseI is divided into a study and a recall phase:
a) Study: each word pair is presented for 5000ms (default; editable parameter)
b) Recall: each word pair is tested via textbox input
Phase I Termination:
By default phaseI is terminated after 100% correct recall (editable parameter) on all 40
word pairs (= successful completion) OR after 10 unsuccessful (editable parameter)
rounds.
If (and only if) successful phaseI completion => phase2 is started
3) Phase II: 250 trials
Participants are given the list of suppression cues during instructions.
Each suppression and recall word pair is presented for 5000ms (editable parameter) together with a response textbox.
Participants are instructed to view the (suppression) cues for the entire duration and to try NOT to
think about the associated word pair. If participants respond to a 'suppression' cue word
(responding that can be detected by computer: typing some input into the textbox even if it is erased),
feedback is provided.
The number of times as particular cue is presented differs according to 'repeat' group assignment.
repeat1_recall pairs: 1 time (5 pairs presented once => 5 trials)
repeat1_suppression pairs: 1 time (5 pairs presented once => 5 trials)
repeat8_recall pairs: 8 times (5 pairs presented 8 times each => 40 trials)
repeat8_suppression pairs: 8 times (5 pairs presented 8 times each => 40 trials)
repeat16_recall pairs: 16 times (5 pairs presented 16 times each => 80 trials)
repeat16_suppression pairs: 16 times (5 pairs presented 16 times each => 80 trials)
=> Total of 250 trials
4) Phase III:
All 40 word pairs are re-tested once (via textbox input)
80 demo words provided by Millisecond - can easily be edited under section Editable Stimuli
the 80 demo words were randomly assigned to the 8 main experimental conditions:
4 (number of repeats during phase 2: 0, 1, 2, 3) x 2 suppression condition (recall vs. suppress)
(also words were randomly assigned to be the cue or the recall word).
Assignments can easily be edited under section Editable Stimuli
provided by Millisecond - can be edited under section Editable Instructions
File Name: thinknotthinktask_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
Phase1 |
|
| countPhaseI | The number of phase1 rounds run in this script |
| propCorrectPhase1 | The overall proportion correct recall performance during phase 1 if performance < parameters.minPropRecall_phase1 => phase2/phase3 are not run in this script |
Phase3 |
|
| propCorrectPhase3 | The overall proportion correct recall performance during phase 3 |
| propCorrectPhase30Recall | The proportion correct recall performance of baseline items randomly assigned to be the 'recall' condition comparison |
| propCorrectPhase30Suppression | The proportion correct recall performance of baseline items randomly assigned the 'suppression' condition comparison |
| propCorrectPhase31Recall | The proportion correct recall performance of items in the 'recall' condition that were presented only once during phaseII |
| propCorrectPhase31Suppression | The proportion correct recall performance of items in the 'suppression' condition that were presented only once during phaseII |
| propCorrectPhase38Recall | The proportion correct recall performance of items in the 'recall' condition that were presented 8 times during phaseII |
| propCorrectPhase38Suppression | The proportion correct recall performance of items in the 'suppression' condition that were presented 8 times during phaseII |
| propCorrectPhase316Recall | The proportion correct recall performance of items in the 'recall' condition that were presented 16 times during phaseII |
| propCorrectPhase316Suppression | The proportion correct recall performance of items in the 'suppression' condition that were presented 16 times during phaseII |
File Name: thinknotthinktask_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockcode | The name the current block (built-in Inquisit variable) |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialcode | The name of the currently recorded trial (built-in Inquisit variable) |
| trialnum | The number of the currently recorded trial (built-in Inquisit variable) trialnum is a built-in Inquisit variable; it counts all trials run even those that do not store data to the data file. |
| countPhaseI | Counts the number of phase I rounds run by this script |
| pairNumber | The pairNumber of the currently presented word pair |
| indexCueWord | The itemnumber (item.words) of the cueword |
| cueWord | The cue word |
| indexRecallWord | The itemnumber (item.words) of the recall word |
| recallWord | The recall word |
| stimulusItem | The presented stimuli in order of trial presentation phase I: the word pair with the cue word on the left phase II: the cue word phase III: the cue word |
| response | The participant's response |
| correct | Accuracy of response: 1 = correct response; 0 = otherwise |
| latency | The response latency (in ms); measured from: onset of cue |
| phaseIIFirstcharLatency | The latency (in ms) of the first input into the textbox during phase 2 (even if response was later erased) => if latency > 0 => participant attempted to respond to item |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Design |
||
| runPhase1 | True = phase1 is run by this script false = phase1 is skipped and script automatically starts with phase2 if false -> script assumes that phase1 criterium has been reached | true |
| runPhase2 | True = phase2 is run by this script (if criterium for phase 1 has been reached) false = phase2 is skipped by this script | true |
| runPhase3 | True = phase3 is run by this script (if criterium for phase 1 has been reached) false = phase3 is skipped by this script | true |
Sizing Parameters |
||
| wordHeight | The proportional sizing of the word pairs | 5% |
Timing Parameters |
||
| acquisitionDuration | The duration (in ms) that study word pairs are presented | 5000 |
| minPropRecallPhase1 | The minimum proportion correct recall performance after phase1 that is required to move on to phase 2 (default: 1.0 => 100% correct recall performance) | 1.0 |
| maxStudyRepeatsPhase1 | The max. number of study-recall repeats run in this session the script terminates after 10 unsuccessful phase1 rounds | 10 |
| phase2Timeout | The timeout (in ms) for responding during phase2 | 5000 |