___________________________________________________________________________________________________________________ INSPECTION TIME TASK ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 12-05-2014 last updated: 02-04-2025 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-04-2025 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script runs an Inspection Time task; a task used to study the early stages of visual processing. The implemented task is based on: Deary, I.J., Enrico Simonotto, E., Meyer, M., Marshall, A., Ian Marshall, I., Goddard, N. & Wardlawf, J.M. (2004). The functional anatomy of inspection time: an event-related fMRI study. NeuroImage, 22, 1466– 1479. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants see stimuli that have one long and one short arm. The stimuli are presented for variable durations before they are covered by a mask. Participants have to decide whether the long arm was left or right and press corresponding response keys. Participants are told that reaction time is unimportant. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 18 minutes to complete __________________________________________________________________________________________________________________ DATA OUTPUT DICTIONARY ___________________________________________________________________________________________________________________ The fields in the data files are: (1) Raw data file: 'inspectiontimetask_raw*.iqdat' (a separate file for each participant) build: The specific Inquisit version used (the 'build') that was run computer.platform: the platform the script was run on (win/mac/ios/android) display.refreshRate: the vertical refresh rate of the current monitor NOTE: Deary et al (2004) used the following durations: 6, 12, 19, 25, 31, 37, 44, 50, 62, 75, 87, 100, 125, 150, 200 ms on a monitor with a vertical refresh rate = 160Hz !!! Most monitors have a vertical refresh rate of 60Hz and therefore it won't be possible to present any stimuli at 6 or 12 ms. One these computers it takes about 17ms (minimum) to refresh the screen (thus 17ms is the minimum that can be used on 60Hz monitors). date, time: date and time script was run subject, group, with the current subject/groupnumber session: with the current session id blockCode, blockNum: the name and number of the current block (built-in Inquisit variable) trialCode, trialNum: the name and number of the currently recorded trial (built-in Inquisit variable) Note: trialNum is a built-in Inquisit variable; it counts all trials run; even those that do not store data to the data file such as feedback trials countTrials: counts all stim trials stimDuration: duration (in ms) of current stim stimDuration_condition1-15 (depending on stimDuration) location: 1 = right long arm; 2 = left long arm stimulusItem: the presented stimuli in order of trial presentation response: the participant's response (scancode of response buttons) 30 = A 38 = L correct: accuracy of response: 1 = correct response; 0 = otherwise latency: the response latency (in ms); measured from: onset of stims (2) Summary data file: 'inspectiontimetask_summary*.iqdat' (a separate file for each participant) inquisit.version: Inquisit version run computer.platform: the platform the script was run on (win/mac/ios/android) display.refreshRate: the vertical refresh rate of the current monitor NOTE: Deary et al (2004) used the following durations: 6, 12, 19, 25, 31, 37, 44, 50, 62, 75, 87, 100, 125, 150, 200 ms on a monitor with a vertical refresh rate = 160Hz !!! Most monitors have a vertical refresh rate of 60Hz and therefore it won't be possible to present any stimuli at 6 or 12 ms. One these computers it takes about 17ms (minimum) to refresh the screen (thus 17ms is the minimum that can be used on 60Hz monitors). startDate: date script was run startTime: time script was started subjectId: assigned subject id number groupId: assigned group id number sessionId: assigned session id number elapsedTime: time it took to run script (in ms); measured from onset to offset of script completed: 0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run) propcorrect_stim1: proportion correct responses for stim duration 1 (here: 6ms) (the same for all 15 stim durations) __________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ (1) 15 stimulus presentation durations tested with 20 repetitions (default). Deary et al (2004) used the following durations: 6, 12, 19, 25, 31, 37, 44, 50, 62, 75, 87, 100, 125, 150, 200 ms on a monitor with a vertical refresh rate = 160Hz !!! Most monitors have a vertical refresh rate of 60Hz and therefore it won't be possible to present any stimuli at 6 or 12 ms. One these computers it takes about 17ms (minimum) to refresh the screen. (set durations under section EDITABLE CODE -> Editable Values) (2) The stimuli duration times are selected randomly without replacement (method of constant stimuli). (3) The long arm is located on the left for 50% of the trials (4) Practice block for 25 randomly durations (number of trials can be edited) Trial Sequence: (1) Cue ('+') for 500ms (editable) (2) Interstimulus interval: Blank screen for 600ms (editable) (3) Stimulus for variable duration (4) Mask for 500ms (editable) (5) Trial continues until response is made (6) Intertrial interval (blank screen) for 500ms (editable) ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ Stimuli are provided by Millisecond Software. They can be replaced under section EDITABLE CODE -> Editable stimuli. The target stimulus was created in such a way, that the long arm is twice the length of the short arm (which equals the length of the crossbar) Note: The size of the target stimulus in this script is coded in terms of canvas screen %. In order to achieve, a size that is roughly equal to the one used by Deary et al (2004), go to stim picture.stim and follow instructions. ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ Instructions are provided by Millisecond Software in the form of htm pages. Instructions can be edited directly in file "IT_intro.htm" or replaced entirely. ___________________________________________________________________________________________________________________ EDITABLE CODE ___________________________________________________________________________________________________________________ check below for (relatively) easily editable parameters, stimuli, instructions etc. Keep in mind that you can use this script as a template and therefore always "mess" with the entire code to further customize your experiment. The parameters you can change are: //Design Parameters: / trialsPerDuration = 20 //number of trials per stimulusduration (default: 20) //!!!Note: if that number is changed, list.stimDurations/list.stimDuration_condition //(section Editable Lists) need to be changed accordingly //=> 15 stimDurations x 20 trials/stimDuration = 300 trials total / nrPracticeTrials = 25 //number of practice trials in this script. //Note: the durations are selected at random. //SIZING PARAMETERS //sizing Parameters in RELATIVE measurements relative to CANVAS HEIGHT //NOTE: to run the script with ABSOLUTE screen measurements, go to 'defaults' and set //canvasSize to absolute measurements OR directly change the size of the stims //under elements picture.stim / stimPicHeightPct = 26% //default height (in screen height %) (default: 26%) //Note: Deary et al (2004): long arm = 5cm (short arm and cross bar = 2.5cm) //you can set the height of the stim directly under element picture.stim / cueFontSizePct = 10% //default height (in screen height %) of the cue (default: 10%) //Timing Parameters / readyDuration = 2000 //duration in ms of get-ready-trial (default: 2000) / cueDuration = 500 //duration of cue in ms (default: 500) / cueIsi = 600 //cue(offset)-stim(onset) Interstimulus Interval in ms (default: 600) / maskDuration = 500 //duration of mask in ms (default: 500) / iti = 500 //inter trial interval in ms (measured from response to onset of cue) (default: 500ms) //stores the 15 stimulus presentation durations in ms //Note: Deary et al (2004) used: 6, 12, 19, 25, 31, 37, 44, 50, 62, 75, 87, 100, 125, 150, 200 ms //on a monitor with a vertical refresh rate = 160Hz //!!! Most monitors have a vertical refresh rate of 60Hz and therefore it won't be possible //to present any stimuli at 6 or 12 ms. One these computers it takes about 17ms //to refresh the screen. / stimDuration1 = 6 / stimDuration2 = 12 / stimDuration3 = 19 / stimDuration4 = 25 / stimDuration5 = 31 / stimDuration6 = 37 / stimDuration7 = 44 / stimDuration8 = 50 / stimDuration9 = 62 / stimDuration10 = 75 / stimDuration11 = 87 / stimDuration12 = 100 / stimDuration13 = 125 / stimDuration14 = 150 / stimDuration15 = 200 //Response Keys: / responseKeyLeft = "A" / responseKeyRight = "L"