Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 08, 2020
Last Modified: January 10, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements a Choice Reaction Time Task, a subset of the Cognitive Drug Research Computerized Assessment System (COGDRAS).
Nicholl, C.G. et al (1995). THE COGNITIVE DRUG RESEARCH COMPUTERIZED ASSESSMENT SYSTEM IN SPEED OF THE ESSENCE? THE EVALUATION OF EARLY DEMENTIA. INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, VOL. 10: 199-206.
2 minutes
Participants are asked to press a certain response key (here: Q) whenever the word YES appears in the middle of the screen or press another response key (here: P) whenever the word NO appears.
1. Test
- 20 trials (editable parameters)
- half the trial present YES, the other half NO (order is randomly determined, see list.trialselector)
Trial sequence:
- word YES/NO appears (wait for response) -> random iti (1000-2500ms) -> word YES....
provided by Millisecond - can be edited under section Editable Stimuli
The word YES/NO - size can be set under section Editable Parameters
provided by Millisecond - can be edited under section Editable Instructions
File Name: choicereactiontime_cogdras_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 |
| crtAcc | The overall proportion correct responses in the Choice Reaction Time test (across yes/no trials) |
| crtRT | The mean response time (in ms) of correct responses in the Choice Reaction Time test (across yes/no trials) (measured from onset of word 'YES'/'NO' in the center of the screen) |
File Name: choicereactiontime_cogdras_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 |
| countTrials | Custom counter of test trials (those that present word "YES") |
| stimulusItem | The presented stimuli in order of trial presentation |
| response | The participant's response (scancode of response buttons) 16 = Q |
| responseLabel | "yes" or "no" |
| correct | 1 = correct response 0 = error response |
| latency | The response latency (in ms); measured from: onset of word YES |
| iti | The intertrial interval (in ms) run at the end of the current trial |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Stimsize |
||
| stimSize | The proportional sizing of the yes/no-word on screen | 20% |
Experimental Design Parameters |
||
| nrTestTrials | The number of test trials run | 20 |
Response Keys |
||
| leftKey | The left response key (here: Q) | "Q" |
| rightKey | The right response key (here: P) | "P" |
| yesKey | The assignment of left/right key to the yesKey (here Q); left keys will appear on the left on touch screens | parameters.leftKey |
| noKey | The assignment of left/right key to the noKey (here P); right keys will appear on the right on touch screens | parameters.rightKey |