Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 11, 2017
Last Modified: January 15, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements a version of a 4 Choice Reaction Time Task similar to the one described in:
Armstrong et al (2012). Mild Dehydration Affects Mood in Healthy Young Women. The Journal of Nutrition: Ingestive Behavior and Neurosciences. Feb;142(2):382-8. doi: 10.3945/jn.111.142000. Epub 2011 Dec 21
2.5 minutes
4 boxes are presented on the screen in a horizontal array. Each box has an assigned response key (by default, the response keys are matched spatially to the position of their assigned boxes: DFJK). After a fixed amount of time, one of the boxes turns red and participants are asked to press the corresponding response key as fast as possible.
1. Practice Block: 10 practice trials with feedback
by default, the positions of the red box is randomly determined with replacement (see section Editable Lists)
error feedback provided
2. Testblock: 100 trials (default; can be adjusted under section Editable Parameters)
by default, the positions of the red box is randomly determined with replacement (see section Editable Lists)
Trial Sequence:
4 gray boxes (default: 500ms; parameters.soa; fixed)-> onset of red box -> waits for response to continue
Two latencies recorded:
1) 'latency' measured from onset of trial (with onset of the 4 gray boxes)
2) values.rt measured from onset of red box
Error Categories:
premature Errors: all responses with values.rt < parameters.prematureErrorWindow (measured from onset of red box)
If participant responds BEFORE red box appears, values.rt will be negative and automatically scored as a prematureError.
timeoutErrors: all responses with values.rt > parameters.timeoutErrorWindow (measured from onset of red box)
incorrectChoiceErrors: all responses that are valid (aka: no premature Error nor a timeoutError) BUT
the incorrect response button was pressed
provided by Millisecond - can be edited under section EDITABLE INSTRUCTIONS
File Name: fourchoicereactiontimetask_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 |
| totalTrialCount | Number of test trials run |
| propCorrect | Proportion correct responses (correct in terms of response button and timing of response) |
| meanRT | The average reaction time (in ms) of correct responses |
| std | The standard deviation (in ms) of correct response reaction times |
| propPrematureErrors | Proportion of Premature Errors relative of total number of trials |
| propTimeoutErrors | Proportion of Timeout Errors relative of total number of trials |
| propIncorrectChoices | Proportion of IncorrectChoices (otherwise valid) relative of total number of trials |
File Name: fourchoicereactiontimetask_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 |
| totalTrialCount | Number of test trials run |
| position | 1, 2, 3, or 4 => screen position of the stim from left to right |
| response | The participant's response (scancode of response button) 32 = D (left middle finger) 33 = F (left index finger) 36 = J (right index finger) 37 = K (right middle finger) |
| selectedPosition | The selected position based on keyboard press |
| latency | The response latency (in ms) measured from start of trial (onset of the 4 gray boxes) |
| rt | Stores the latency measured from onset of red box ( negative latencies => response was made before ONSET of red box) |
| prematureError | 1 = premature error was made (premature error: rt < parameters.prematureErrorWindow) 0 = otherwise |
| timeoutError | 1 = a timeout error was made (timeout error: rt > parameters.timeoutErrorWindow) 0 = otherwise |
| incorrectChoice | 1 = a valid (neither premature nor timeout response) but incorrect response was made 0 = otherwise |
| acc | The correctness of the response 1 => valid (no premature response nor late response) AND correct choice of response button 0 => otherwise |
| countPrematureErrors | Counts incorrect premature responses (responses made BEFORE appearance of red box and those made AFTER within the prematureErrorWindow) |
| countTimeoutErrors | Responses made after parameters.timeoutErrorWindow |
| countIncorrectChoices | Counts the number of valid responses (neither premature nor late) that are incorrect response choices |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| pos1X | The first horizonal box position from the left in canvas width percentages (0% at the far left of canvas - 100% far right of canvas) | |
| pos2X | The second horizonal box position from the left in canvas width percentages | |
| pos3X | The third horizonal box position from the left in canvas width percentages | |
| pos4X | The fourth horizonal box position from the left in canvas width percentages | |
| stimHeight | Height of the boxes in canvas height percentages Response Keys (from left to right) | 5% |
| responseKey1 | The first response button ("D"); furthest left | |
| responseKey2 | The second response button ("F") | |
| responseKey3 | The third response button ("J") | |
| responseKey4 | The fourth response button ("K"); furthest right Duration Parameters (in ms) | |
| soa | Response Stimulus Interval in ms (interval between onset of gray boxes and onset of red box) | 500ms |
| prematureErrorWindow | Responses made before the end of this window (measured in ms fro m onset of red box)are scored as premature errors ( ALL responses BEFORE appearance of red box are automatically considered premature) | 100 |
| timeoutErrorWindow | Responses made after this response window (measured from onset of red box in ms) are considered 'timeOut Errors' Example: if a response is made 1000ms AFTER onset of red box, the response is scored as a timeout error. | 1000ms |
| readyDuration | Duration (in ms) of getting ready trial | 5000ms |
| feedbackDuration | Duration (in ms) of feedback during the practice trials Trial Numbers | 1000ms |
| maxTrials | Number of trials to run | 100 |