Simple Visual Reaction Time Task

Technical Manual

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Last Modified: January 07, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script runs a simple visual reaction time task.

Duration

4 minutes

Description

The participant gets presented a fixation cross that is followed after variable time intervals by a visual target stimulus (here: circle). The participant's task is to press the spacebar as soon as the target stimulus appears on the screen. Latency, mean latency, and latency standard deviation are recorded in the data file.

Procedure

• By default, the script runs 2 blocks of 20 trials each
• By default, the fixation cross as well as the target stimuli appear in the center of the screen. Changes can be made under
section Editable Parameter, including changing the script so that the target stimuli appear randomly in one of 9 screen positions.
• By default, the time intervals are randomly chosen from 2000ms, 3000ms, 4000ms, 5000ms, 6000ms, 7000ms, 8000ms
• By default, the fixation cross is black.
• By default, the color of the circle is red.
• By default, the color of the screen background is white.

Instructions

see section Editable Instructions

Summary Data

File Name: srtvisual_summary*.iqdat

Data Fields

NameDescription
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
trial.srtt.totalMeanLatency The mean latency across all trials.SRTT (in ms)
trial.srtt.totalMedianLatency The median latency across all trials.SRTT (in ms)
trial.srtt.totalMinLatency The fastest response across all trials SRTT (in ms)
trial.srtt.totalMaxLatency The slowest response across all trials SRTT (in ms)
trial.srtt.totalSDLatency The the standard deviation of the latency responses across all trials SRTT
trial.srtt.totalVarLatency The variance of the latency responses across all trials SRTT

Raw Data

File Name: srtvisual_raw*.iqdat

Data Fields

NameDescription
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
stimulusItem The first presented stimulus (=fixation cross)
focusx The x-coordinate of the fixation cross
focusy The y-coordinate of the fixation cross
focuscolor The color of the fixation cross
focussize The size of the fixation cross
stimulusItem The second presented stimulus (=target)
targetcolor The current color of the target circle
targetsize The current color of the target circle
targetx The x-coordinate of the target circle
targety The y-coordinate of the target circle
fixed 0= fixed position of target; 1 = random position of target
maxtrialnumber The number of trials in a block
trials.srtt.count Counts the SRTT trials run in a given block
stimInterval The current stimulus interval
latency The latency of the response (in ms)
trial.srtt.meanLatency The mean latency in the current block (in ms)
trial.srtt.medianLatency The median latency in the current block (in ms)
trial.srtt.minLatency The fastest response in the current block (in ms)
trial.srtt.maxLatency The slowest response in the current block (in ms)
trial.srtt.sdLatency The standard deviation of the latency responses in the current block
trial.srtt.varLatency The variance of the latency responses in the current block
trial.srtt.totalMeanLatency The mean latency across all trials.SRTT (in ms)
trial.srtt.totalMedianLatency The median latency across all trials.SRTT (in ms)
trial.srtt.totalMinLatency The fastest response across all trials SRTT (in ms)
trial.srtt.totalMaxLatency The slowest response across all trials SRTT (in ms)
trial.srtt.totalSDLatency The the standard deviation of the latency responses across all trials SRTT
trial.srtt.totalVarLatency The variance of the latency responses across all trials SRTT