Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: September 14, 2017
Last Modified: January 29, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the Millisecond Road Sign Reaction Time Task inspired by the Road Sign Reaction Time Task described in:
Edwards J., Ross , L.A., Wadley, V.G., Clay, O.J., Crowe, M., Roenker, D.L., Ball, K.K. (2006). The useful field of view test: Normative data for older adults. Archives of Clinical Neuropsychology, 21, 275–286.
The Millisecond Road Sign Reaction Time Task can be used with touchscreens OR the mouse.
7 minutes
Participants see sets of three or six traffic signs (sets are sampled from four different signs: left arrow, right arrow, bicycle, pedestrian) that are all crossed out by a red cross. After a random delay (1000-6000ms, steps of 1000ms), the cross is removed from one of the signs, and participant has to choose amongst 4 different responses: - left arrow => move a car icon to the left - right arrow => move a car icon to the right - bicycle => press a bicycle stop sign icon - pedestrian => press a pedestrian stop sign icon
by default, the test is run in a blocked design (N=3 vs. N=6, with N=3 always preceding N=6 block). To run N=3 and N=6 trials in a randomized mixed design, change parameters.runBlockedDesign under section Editable Parameters.
by default, the test is run in a blocked design (N=3 vs. N=6).
To run N=3 and N=6 trials in a randomized mixed design, change parameters.runBlockedDesign under section Editable Parameters.
1. Response Practice:
- 20 trials that present only 1 sign (5 trials per sign); only correct responses terminate trial
- order of signs is randomized
- if no valid response is detected within 5s, a response reminder (summary of possible responses) is presented on screen
- after the first 20 practice trials, the script checks performance:
if performance is below a cut-off value (default: 90%, see editable parameters.practice1MinACC),the block is repeated
if performance is still below cut-off after the second block (default; see editable parameters.maxPractice1Blocks),
the script aborts.
2. Task Practice:
- 12 trials that run the test set-up but with only 2 signs and with feedback
- each of the four signs is presented as a target 3 times and 3 times as a distractor
- order of targets is randomized
- signs are randomly assigned to two of 12 possible screen locations
- delays (of cross removal) are randomly selected from 1000-6000ms (see list.delays)
3. Test: with N = 3
- 12 trials with sets of 3 signs (no feedback)
- each of the four signs is presented 3 times as a target 3 and 6 times as distractors
- each non-target sign is presented as a distractor twice with each target and never in the same combination:
Example: target left turn
presented with:
1: right turn, bicycle
2: right turn, pedestrian
3: pedestrian, bicycle
- order of trials is randomized
- signs are randomly assigned to three of 12 possible screen locations
- delays (of cross removal) are randomly selected from 1000-6000ms (see list.delays)
5. Test: with N = 6
- 12 trials with sets of 6 signs (no feedback)
- each target is presented 3 times
- !!!Distractor Selection (2 signs in each display have to be repeats):
- distractor 1-3: sample from the non-target options (without replacement)
- distractor 4-5 (repeated signs): sample from all options (without replacement)
=> it's randomly determined whether the target sign is one of the 'double' signs.
=> the frequency of each sign is not controlled for the N=6 trials
- order of trials is randomized
- signs are randomly assigned to six of 12 possible screen locations
- delays (of cross removal) are randomly selected from 1000-6000ms (see list.delays)
6. mixed design block (only run if parameters.runBlockedDesign is turned to false)
- 24 trials: 12 with N=3 and 12 with N = 6, randomized order
Trial Sequence:
fixation cross (until clicked with mouse)-> pretrialpause (default: 1000ms)
-> 3 (6) signs appear, all crossed out -> random delay: 1000-6000ms
-> one cross is removed: target -> waits for response
( responses are collected from onset of stimuli, a valid response terminates the set-up
even if the target has been revealed yet. These trials are noted as "premature responses")
Screen Location of Signs:
- screen locations are randomly sampled from 12 possible screen locations (arranged in a 3 rows x 4 columns matrix)
provided by Millisecond - can be edited under section Editable Stimuli
The signs are 4 traffic signs commonly used in the United States but can easily be exchanged.
provided by Millisecond as html files.
To edit instructions, edit the html files directly.
File Name: millisecondroadsigntest_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 |
| propCorrectPractice1 | The final proportion initially correct responses during practice 1 |
| aborted | 1 = script was aborted after practice 1; 0 = script was not aborted after practice 1 the following summary variables are based on correct responses made after onset of target The script considers all correct responses made after onset of target including those trials where a premature response was also registered |
| propCorrectOverall | Proportion correct across all test trials |
| meanRTOverall | Mean latency (in ms) of correct responses across all test trials |
| propCorrectStims3 | Proportion correct across all test trials with N = 3 |
| meanRTStims3 | Mean latency (in ms) of correct responses across all test test trials with N = 3 |
| propCorrectStims6 | Proportion correct across all test trials with N = 6 |
| meanRTStims6 | Mean latency (in ms) of correct responses across all test test trials with N = 6 |
| sumPrematureResponses | The sum of all premature responses (responses before the cross was removed) |
| sumPrematureResponsesSigns3 | The sum of all premature responses (responses before the cross was removed) in the 3 sign condition |
| sumPrematureResponsesSigns6 | The sum of all premature responses (responses before the cross was removed) in the 6 sign condition |
File Name: millisecondroadsigntest_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 |
| runBlockedDesign | True (1): the test is split into 2 blocks: first block runs N=3; second block runs N=6 (default) false (0): N=3 and N=6 trials are run in a mixed design |
| n | Stores the current set size tested |
| delay | Stores the currently randomly sampled target delay in ms (1000-6000ms) |
| target | Stores the current target image distractor1- |
| distractor5 | Store the current distractor images |
| response | The participant's response (recorded touchscreenmouse response) |
| values.responseCategory | Description of response "left move", "right move", "stop-bicycle" "stop-pedestrian" |
| correct | Accuracy of response: 1 = correct response made after removal of cross; 0 = otherwise |
| propCorrectPractice1 | Proportion initially correct responses during practice 1 |
| valid | 0 = invalid response (e.g. too early) 1 = valid response |
| validrt | Valid response time (in ms); measured from onset of unslashed target -> "early response": response was made too early (during practice session 2) |
| latency | The response latency (in ms) of the last measured response; measured from: onset of stims |
| prematureResponse | Number of times participant responded before cross was removed during the current trial |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| runBlockedDesign | True (1): the test is split into 2 blocks: first block runs N=3; second block runs N=6 (default) false (0): N=3 and N=6 trials are run in a mixed design | |
| minHorizontalChangePX | Any horizontal mouse movements (in pixels) smaller than this value is ignored and not processed as a response (default: 100 pixels). | |
| picSize | The proportional size of the images if picSize is increased list.xcoordinates/list.ycoordinates need to be updated accordingly | 20% |
| maxPractice1Blocks | The maximum number of response practice blocks run if performance is too low | 2 |
| practice1MinAcc | The minimum proportion correct that terminates practice 1 (response practice) | |
| pretrialPause | The pause (in ms) after pressing the fixation cross and presentation of signs | 1000ms |
| responseReminder | During practice (response learning) a response reminder is presented after this duration (in ms) ) | 5000ms |