Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 04, 2017
Last Modified: January 31, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the Weapon ID Task as described in:
Payne, B.K. (2001). Prejudice and Perception: The Role of Automatic and Controlled Processes in Misperceiving a Weapon. Journal of Personality and Social Psychology, Vol. 81, 181-192.
Https://bkpayne.web.unc.edu/research-materials/
Notes: (1) This script runs the Weapon ID Task without a response deadline. (2) This script is written in such a way, that primes and targets can easily be substituted (see section Editable Stimuli). (3) This script template makes the following prime-target compatibility-assumptions* (relevant if primes and targets are changed): compatible pairings: prime1-target1; prime2-target2 incompatible pairings: prime1-target2; prime2-target1
•Payne (2001): the original Weapons ID Task explicitly states that the 'Black faces - weapons' condition is compatible whereas the 'Black faces - tool' condition is incompatible but does not make any explicit pairing assumptions about the 'White faces' conditions.
7 minutes
Categorization task of images as gun (target1) or tool (target2) after seeing either a black face (prime1) or a white face (prime2). The targets (gun or tool) are masked after 200ms (default) and participants have to press one key if the target was a gun ('E') and another if it was a tool (e.g 'I'). In this script, there is no response deadline for the response.
Design:
2 prime types (here: male black faces vs. male white faces) X 2 target types (here: tool vs. gun), tested within participants
1. Practice: learning to categorize the targets correctly
- minimum of 4 blocks of 12 trials (=all 12 targets), order of targets is randomized
If proportion correct is < targetPracticePerformance (0.90, default) during the last practice block, additional practice blocks
automatically start until the criterium of targetPracticePerformance is achieved
(or until the max. number of practice blocks has run; default: 10)
- feedback is provided: if incorrect response -> the image of the target is presented again for further study
- participants only advance to the test if they reach targetPracticePerformance during the last practice block run
Payne (2001) presented 48 practice trials without a specified 'targetPracticePerformance' that had to be reached
Practice Trial Sequence:
target (200ms) -> mask (until response) -> feedback (reinforces learning by presenting the same target once more for error response) until spacebar press -> ITI (500ms)
2. Test
- 192 trials = each of the four 'prime type x target type' combinations runs 48 trials (order of trials is randomized)
• per 'prime type x target type' combination:
- each prime is presented 4 times, order is randomized
- each target is presented 8 times, order is randomized
- Pairing:
each randomly selected face prime is paired with a randomly selected target of the appropriate category
(no constraints applied on the random pairing of primes and targets)
Example: in trial.prime1_target2: each of 12 black face primes are randomly paired with a tool target
Test Trial Sequence:
prime (200ms) -> target (200ms) -> mask (until response) -> ITI (500ms)
Key Assignment:
key assignment to tool/gun is counterbalanced by groupnumber
odd groupnumbers: 'gun' with right key on keyboard ("E") vs. 'tool' with left key on keyboard ("I")
even groupnumbers: 'tool' with right key on keyboard ("E") vs. 'gun' with left key on keyboard ("I")
Estimates of Controlled/Automatic Components:
In this script the focus is on gun (target1) identifications following different primes
congruent condition: prime1-target1 pairs (black faces preceding guns) => allows the estimate of hit rate for gun identifications
incongruent condition: prime1-target2 pairs (black faces preceding tools) => allows the estimate of false alarm rate for gun identification
https://bkpayne.web.unc.edu/research-materials/
- can be edited under section Editable Stimuli
provided by Millisecond - they are not original to Payne (2001)
The instructions can be easily edited under section Editable Instructions
File Name: weaponsidtask_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| 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 |
| primeDuration | Duration (in ms) of prime presentation (default: 500ms = SOA) ! if primeDuration was set to be longer than SOA, the script automatically set the primeDuration = SOA |
| soa | Stimulus onset asynchrony (in ms) of prime and target (default: 500ms) |
| list.practiceAcc.mean | Stores the mean practice performance of the last/final practice block |
| countPracticeBlocks | Stores the number of practice blocks run |
| advance | 0 = no, script was aborted after practice due to low categorization performance during practice 1 = participant advanced to test session the following summary variables are based on ALL responses regardless of accuracy and timing constraints |
| propCorrectAll | Proportion correct of ALL trial responses |
| meanRTAll | Mean latency of ALL trials |
| efficiency | Proportion correct of all trial responses in relation to the average response time = propCorrectAll/meanRTAll ! for the remaining summary variables only responses with minRT <= latencies <= maxRT are considered for accuracy and latencies statistics |
| propCorrect | Overall proportion correct |
| meanRT | Overall mean latency (in ms) of correct responses |
| meanlnRT | Mean of the ln-transformed latencies of correct responses across all conditions |
| accPrime1Target1 | Proportion correct responses in prime1 -> target1 (here: black -> gun condition) |
| rtPrime1Target1 | Mean latency (in ms) of correct responses in prime1 -> target1 (here: black -> gun condition) |
| lnRTPrime1Target1 | Mean of the ln-transformed latencies of correct responses in prime1 -> target1 (here: black -> gun condition) |
| accPrime1Target2 | Proportion correct responses in prime1 -> target2 (here: black -> tool condition) |
| rtPrime1Target2 | Mean latency (in ms) of correct responses in prime1 -> target2 (here: black -> tool condition) |
| lnRTPrime1Target2 | Mean of the ln-transformed latencies of correct responses in prime1 -> target2 (here: black -> tool condition) |
| accPrime2Target1 | Proportion correct responses in prime2 -> target1 (here: white -> gun condition) |
| rtPrime2Target1 | Mean latency (in ms) of correct responses in prime2 -> target1 (here: white -> gun condition) |
| lnRTPrime2Target1 | Mean of the ln-transformed latencies of correct responses in prime2 -> target1 (here: white -> gun condition) |
| accPrime2Target2 | Proportion correct responses in prime2 -> target2 (here: white -> tool condition) |
| rtPrime2Target2 | Mean latency (in ms) of correct responses in prime2 -> target2 (here: white -> tool condition) |
| lnRTPrime2Target2 | Mean of the ln-transformed latencies of correct responses in prime2 -> target2 (here: white -> tool condition) "list.ACC_prime1target1.itemCount", "list.ACC_prime1target2.itemCount", "list.ACC_prime2target1.itemCount", "list.ACC_prime2target2.itemCount": store the number of data points considered for summary statistics |
File Name: weaponsidtask_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockCode | Name of the current block |
| blockNum | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| primeDuration | Duration (in ms) of prime presentation (default: 500ms = SOA) ! if primeDuration was set to be longer than SOA, the script automatically set the primeDuration = SOA |
| soa | Stimulus onset asynchrony (in ms) of prime and target (default: 500ms) |
| compatibility | 1 = prime-target pairing compatible 0 = prime-target pairing incompatible This script template makes the following prime-target compatibility-assumptions compatible pairings: prime1-target1; prime2-target2 incompatible pairings: prime1-target2; prime2-target1 |
| primeType | Here: "black" vs. "white" |
| targetType | Here: "GUN" vs. "TOOL" |
| prime | Stores the currently presented prime image |
| target | Stores the currently presented target image |
| response | The participant's response: scancode of response button (default: 18 = E; 23 = I) 18 = E = left 23 = I = right |
| responseCategory | Translation of scancode into response category (here: "tool", "gun") |
| correct | Accuracy of response: 1 = correct response; 0 = otherwise |
| latency | The response latency (in ms); measured from: onset of target until response |
| list.practiceAcc.mean | Stores the mean practice performance of the current block |
| countPracticeBlocks | Stores the number of practice blocks run |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| minPracticeBlocks | The minimum number of practice blocks run | 4 |
| maxPracticeBlocks | The maximum number of practice blocks run before the script aborts because categorization performance is too low | 10 |
| targetPracticePerformance | Proportion correct that participant has to reach during last practice block to continue on to task to eliminate a limit, set targetPracticePerformance = -1 | 90% |
| soa | Stimulus onset asynchrony (in ms) of prime and target | 200ms |
| primeDuration | Duration (in ms) of prime presentation ! if primeDuration is set to be longer than SOA, the script automatically sets the primeDuration = SOA | 200ms = SOA |
| targetDuration | Duration (in ms) of target before it is replaced by a mask | 200ms |
| iti | Duration (in ms) of intertrial interval after response and before a new trial starts | 500ms |
| readyDuration | Duration (in ms) of the 'get ready' trial | 5000ms |
| primeSize | The size of the prime pictures proportional to canvas height | 40% |
| targetSize | The size of the target pictures proportional to canvas height responseKeys | 20% |
| leftKey | The left response key (here: E) | |
| rightKey | The right response key (here: I) the assignment of left and right response key to tool vs. gun is counterbalanced by groupnumber odd groupnumbers: left response key is used to identify gun, right response key is used for tool even groupnumbers: right response key is used to identify gun, left response key is used for tool RT cut-offs for summary statistics | |
| minRT | Latencies < minRT are not considered for summary statistics | 100ms |
| maxRT | Latencies > maxRT are not considered for summary statistics | 1000ms |