Inhibition of Return - IOR

Technical Manual

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

Credits:
Millisecond thanks Dr.Fillmore for his generous support in developing this script!

Created: January 29, 2013

Last Modified: January 05, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

Inhibition of Return (IOR) is considered an important part of visual search behavior by biasing attention towards unexplored locations. This script implements a visual cued target detection paradigm to study IOR. The implemented procedure is based on Abroms & Fillmore (2004).

References

Abroms, B.D. & Fillmore, M.T. (2004). Alcohol-Induced Impairment of Inhibitory Mechanisms Involved in Visual Search. Experimental and Clinical Psychopharmacology, 12, 243–250.

Duration

30 minutes

Description

Participants are asked to press a key when they see a white star (target) in a box either to the left or the right of a center box. Before the target is presented, either the left or the right box is briefly "lit" (=cue) to shift attention towards cued location and is then followed by a briefly "lit" center square to shift attention back to the center location.

After a certain timeframe (min. 300ms) btw. cue and target, participants tend to be SLOWER to attend to the cued location (aka detect the star) => 'Inhibition of Return' Effect

Procedure

Design:
2 cue-target associations (target in same box as cue, target in opposite box as cue) x
5 SOAs (stimulus onset asynchronies; time between onset of cue and onset of target)

Experimental Block:
- presents 200 trials each for same/different condition (=> 40 per SOA)
- presents 100 catch trials (no target presentations, the target trials ends after 1000ms)
- after 250 trials a rest trial is presented for 60s (default); 10s before rest trial is over
a beep alerts participants that rest is coming to an end.

Practice Block:
- runs 30 trials

Trial Sequence:
cue-presentation trials:
-> present fixation cross for 500ms (0-500ms)
-> then present the slightly gray boxes for 500ms (500-1000ms)
-> then "light" up the left (or right) box for 20ms (1000-1020ms) <= SOA starts at 1000ms
-> present the original slightly gray boxes for 10ms before (1020-1030ms)
-> lightening the centersquare for 20ms (1030-1050)
-> present the original slightly gray boxes for values.soa_remaining (=SOA-50ms)

target-presentation trials:
-> present the target for max 1000ms
trial either ends automatically after the responsetimeout of 1000ms or if participant responds; whichever comes first


•catch trials: latencies can either be measured from onset of cues OR from onset of the 'imaginary' target
(similarly to the target trials, done by Abroms & Fillmore, 2004); see parameters.measureCatchResponsesFromCueOnset

Stimuli

Physical Stimuli Dimensions
Abroms & Fillmore (2004) report specific cm dimensions of their stimuli. By default, this script codes
the dimensions of the stimuli in % of the screen height.
Go to EDITABLE CODE -> Editable Values and change parameters.runAbsoluteSizing to change to mm measurements

Instructions

Instructions are not originals. Customize under EDITABLE CODE -> Editable Instructions

Summary Data

File Name: inhibitionofreturnn_summary*.iqdat

Data Fields

NameDescription
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
computer.touch 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities
computer.hasKeyboard 0 = no external keyboard detected; 1 = external keyboard detected
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
propErrorsSame Proportion Erros for Same test trials
propErrorsDifferent Proportion Erros for Different test trials
propErrorsCatch Proportion Errors for Catch trials (when participant responded but should not have)
meanrtSame The mean latency (in ms) of correctly responding in Same test trials
meanrtDiff The mean latency (in ms) of correctly responding in Different test trials
meanrtCatch The mean latency (in ms) of correctly responding in Catch test trials
catch latencies: measured from onset of 'imaginary' target (default) OR from onset of cue
(which one depends on chosen setting of measureCatchResponsesFromCueOnset)

Raw Data

File Name: inhibitionofreturn_raw*.iqdat

Data Fields

NameDescription
build Inquisit version number
computer.platform Device platform: win | mac |ios | android
computer.touch 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities
computer.hasKeyboard 0 = no external keyboard detected; 1 = external keyboard detected
date Date the session was run
time Time the session was run
subject Participant ID
group Group number
session Session number
blockcode The name the current block (built-in Inquisit variable)
blocknum The number of the current block (built-in Inquisit variable)
trialcode The name of the currently recorded trial (built-in Inquisit variable)
trialnum The number of the currently recorded trial (built-in Inquisit variable)
trialnum is a built-in Inquisit variable; it counts all trials run
even those that do not store data to the data file.
condition Different, same, catch
currentsoa The SOA of the current trial
targetDuration Parameter: max duration of target trials (max time that star is presented, default: 1000ms)
response The participant's response (scancode of response button)
57 = spacebar press
0 = no response
correct The correctness of the response (1 = correct; 0 = incorrect)
latency The response latency (in ms)
same/different: measured from onset of target
catch: measured from onset of imaginary target (default) OR from onset of cue
(which one depends on chosen setting of measureCatchResponsesFromCueOnset)

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
Design
measureCatchResponsesFromCueOnset 1 (true): catch anticipatory responses are measured from cue onset (different from Abroms & Fillmore, 2004)
0 (false): catch anticipatory responses are measured as in Abroms & Fillmore, 2004 (default)
false
Color Parameters
canvasColor Display color of the actively used portion of the screen (the 'canvas')
if set to a color other than the screenColor, you can distinguish the active canvas
from the inactive portion of the screen
black
screenColor Color of the screen not used by the canvas ('inactive screen')black
defaultTextColor Default color of text itemswhite
Sizing Parameters
squareHeightPerc Size of the boxes relative to canvas height20%
starHeightPerc Size of the star relative to canvas height10%
distancePerc The distance btw. the left and right box relative to canvas width25%
fontHeight The size of the fixation cross relative to canvas height10%
Timing Parameters
targetDuration Duration of target (in ms)1000
iti Duration of intertrial interval (in ms)500
restDuration The duration of the rest trial (in ms)60000
Response Key
responseKey The default response key (" " = [space])" "