Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 09, 2020
Last Modified: January 10, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements a Memory Scan 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 view an initial triplet of digits (presented serially, one after other). They then view a series of 18 digits and have to decide whether the digit was one of the three by pressing a Yes or a No-key.
(1) Target Digit Learning
- three digits are randomly (without replacement) selected from 1-9
this script places the following constraint on the sampling process:
The last sampled digit cannot be the third of three consecutive digits.
Example: targetdigit = 4, targetdigit2 = 3
=> the third targetdigit cannot be 2 nor 5.
- each digit is presented for 2500ms (duration parameters editable, see section Editable Parameters)
(2) MS Test
- 18 trials: digits 1-9 are randomly selected
trial 1-9 randomly samples digit 1-9 (without replacement); trial 10-18 randomly samples 1-9 (without replacement)
=> 6 target trials; 12 foil trials (target:foil = 1:2)
- digits are presented as long as needed to make response
provided by Millisecond - can be edited under section Editable Stimuli
The size of the presented digits can be set under section Editable Parameters
provided by Millisecond - can be edited under section Editable Instructions
File Name: memoryscan_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 |
| msAcc | Proportion correct recognition (across old and new words) in Immediate Word Recognition Test |
| msRT | Mean response time (in ms) of correct responses (across old and new words) during recognition phase in Immediate Word Recognition Test |
| msHitRT | Mean response time (in ms) of correct responses for old words only |
| rHIT | The hitrate (proportion correct responses for old words => participant said 'yes' to old words) |
| rFA | The false alarm rate (proportion of incorrect responses for new words => participants said 'yes' to new words) |
| msAPrime | Non-parametric measure of sensitivity in Immediate Word Recognition Test Range: 0 (all incorrect responses) - 0.5 (random responses) - 1 (all correct responses) For Aprime measure see Stanislaw, H. & Todorov, N. (1999). Calculation of signal detection theory measures. Behavior Research Methods, Instruments, & Computers, 1999, 31 (1), 137-149. Nicholl et al (1995) used the non-parametric signal theory index (SI) presented by Frey and Colliver (1973) with a range of -1 (all incorrect) to 1 (all correct) |
File Name: memoryscan_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 |
| trialCode | Name of the current trial |
| targetDigits | The three target digits |
| stimulusItem | The presented digits |
| response | The participant's response (scancode of response buttons) 16 = Q 25 = P 57 = spacebar |
| responseLabel | "yes" vs. "no" |
| responseCategory | "Hit" (pressed yes-key for a target digit) "Miss" (pressed no-key for a target digit) = omission error "CR" (pressed no-key for a foil digit) = correct rejection "FA" (pressed yes-key for a foil digit) = commission error |
| correct | Accuracy of response: 1 = correct response; 0 = otherwise |
| latency | The response latency (in ms); measured from: onset of words |
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 | 18 |
Duration Parameters |
||
| firstStimDelay | The delay (in ms) of the first stim after pressing spacebar to start | 1000 |
| soa | Stimulus onset asynchrony (in ms) of the target triplets | 2500 |
| stimDuration | The duration (in ms) that each target digit is presented stimDuraton cannot exceed SOA | 2500 |
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 |