Visual Search Task - Threatening Stimuli

Technical Manual

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

Created: January 24, 2014

Last Modified: January 31, 2023 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a Visual Search paradigm used in a 'Threat' context.

References

Becker. M.W. (2009). Panic Search: Fear Produces Efficient Visual Search for Nonthreatening Objects. Psychological Science, 20, 435-437.

this script runs with placeholder stimuli

Duration

22 minutes

Description

After the presentation of one of three cue types (happy, fearful, neutral) participants are presented a search screen with 3, 6 or 9 pictures randomly arranged in a circle and are asked to indicate as fast as possible whether a target picture (e.g. picture of a house) is present or not.

Procedure

Design: 3 cue types (happy, fearful, neutral) x 3 set sizes (3, 6, 9) x 2 trialTypes (target present vs. target absent), tested within

By default, the 3 cue types are run in a blocked design with 108 trials each (Becker, 2009) => 18 trials per setSize x trialType condition
The order of the blocks is counterbalanced by groupnumber (see EXPERIMENT).
Set size, trialType, and distribution of distractors/targets are randomized within each block.

cues: randomly sampled (without replacement) from 6 possible pictures per cue type; after 6 random drawings the pool resets.
targets: randomly sampled (without replacement) from 38 targets (default); after 38 random drawings the pool resets.
distractors: randomly sampled (without replacement) from 46 distractors (default); after 46 random drawings the pool resets.

Practice: this script offers a practice block of parameters.practiceTrials trials (default: 10).
It runs parameters.practiceTrials in a mixed design and provides error feedback.

In this script, the task could also be run in a mixed design by setting parameters.blockedCues = false (section Editable Parameters)

Stimuli

This script runs with PLACEHOLDER STIMULI. Insert your stimuli under item.cue1/item.cue2/item.cue3 and
item.distractors and item.targets.

Targets and distractors are arranged in a circle with 9 possible positions.
To fine tune presentation of the distractor/target display circle on different monitors, check
section Editable Parameters -> parameters.pictureHeight/parameters.radiusScreenProportion

Instructions

Instructions are provided by Millisecond and are not original to Becker (2009).
They can be easily edited under section Editable Instructions

Summary Data

File Name: visualsearch_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
propCorrectOverall Proportion correct across all test trials
meanRTOverall Mean correct latency (in ms) across all test trials
propCorrectCue1 Proportion correct across all cue1 test trials
meanRTCue1 Mean correct latency (in ms) across all cue1 test trials
propCorrectCue2 Proportion correct across all cue2 test trials
meanRTCue2 Mean correct latency (in ms) across all cue2 test trials
propCorrectCue3 Proportion correct across all cue3 test trials
meanRTCue3 Mean correct latency (in ms) across all cue3 test trials

Raw Data

File Name: visualsearch_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
cueCondition 1 = happy, 2= fearful, 3 = neutral
trialType Targetpresent vs. targetAbsent
setSize Stores current setSize
cueItem Stores the current cue
target Stores the current target item
response The participant's response (scancode of response button)
reponseKey The translated response scancode
responseType Hit, Miss, FA (False Alarm), CR (Correct Rejection)
correct The correctness of the response (1 = correct; 0 = otherwise)
latency The response latency in ms; measured from onset of images
stimuliLocations Stores the distractor/target itemnumbers and their circle positions (position 1 => 12 o'clock position, then clockwise)

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
responseKeyTargetPresent The target present responseKey , the left response key"Y"
responseKeyTargetAbsent The target absent responseKey , the right response key"N"
blockedCues True: the three cue types are run in a blocked design (default -> Becker, 2009)
false: the three cue types are run in a mixed design
trialNumber The number of visual searches per block
fontSize The font height (percentage of canvas height) of the Ready cue 10%
fontSizeFixation The font height (percentage of canvas height) of the fixation cross 5%
cueHeight The height of the cue picture (percentage of canvas height)
fine-tune display of target/distractor circle by editing these parameters below
30%
pictureHeight The height of the target/distractor pictures (percentage of canvas height) 15%
radiusScreenProportion The radius of the circle proportional to canvas height
Duration Parameters
0.4
readyDuration Duration of ready hint in ms 750ms
cueDuration Duration of cues in ms 300ms
fixationDuration Duration of fixation cross in ms 600ms