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).
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 |