Return to the Visual Search Task (Threatening Stimuli) page
___________________________________________________________________________________________________________________	

									       VISUAL SEARCH
___________________________________________________________________________________________________________________

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 01-24-2014
last updated:  03-16-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 03-16-2020 Millisecond Software

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

Reference:

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

Note: this script runs with placeholder stimuli

___________________________________________________________________________________________________________________
TASK 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.

___________________________________________________________________________________________________________________	
DURATION 
___________________________________________________________________________________________________________________	
the default set-up of the script takes appr. 22 minutes to complete

___________________________________________________________________________________________________________________	
DATA FILE INFORMATION 
___________________________________________________________________________________________________________________	
The default data stored in the data files are:

(1) Raw data file: 'visualsearch_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)
date, time, 						date and time script was run 
subject, group, 					with the current subject/groupnumber
script.sessionid:					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. 
									
								
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)


(2) Summary data file: 'visualsearch_summary*.iqdat' (a separate file for each participant)

computer.platform:					the platform the script was run on (win/mac/ios/android)
script.startdate:					date script was run
script.starttime:					time script was started
script.subjectid:					assigned subject id number
script.groupid:						assigned group id number
script.sessionid:					assigned session id number
script.elapsedtime:					time it took to run script (in ms); measured from onset to offset of script
script.completed:					0 = script was not completed (prematurely aborted); 
									1 = script was completed (all conditions run)
									
propcorrect_overall:				proportion correct across all test trials
meanRT_overall:						mean correct latency (in ms) across all test trials
propcorrect_cue1:					proportion correct across all cue1 test trials
meanRT_cue1:						mean correct latency (in ms) across all cue1 test trials
propcorrect_cue2:					proportion correct across all cue2 test trials
meanRT_cue2:						mean correct latency (in ms) across all cue2 test trials
propcorrect_cue3:					proportion correct across all cue3 test trials
meanRT_cue3:						mean correct latency (in ms) across all cue3 test trials

___________________________________________________________________________________________________________________	
EXPERIMENTAL SET-UP 
___________________________________________________________________________________________________________________

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.

NOTE: 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 Software and are not original to Becker (2009).
They can be easily edited under section Editable Instructions

___________________________________________________________________________________________________________________	
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:

Responsekeys:
/responsekey_targetpresent: 			the target present responsekey (default: "Y"), the left response key
/responsekey_targetabsent: 				the target absent responsekey (default: "N"), the right response key

/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 (default: 10%)
/fontsize_fixation						the font height (percentage of canvas height) of the fixation cross (default: 5%)
/cueheight:								the height of the cue picture (percentage of canvas height) (default: 30%)


Note: fine-tune display of target/distractor circle by editing these parameters below:
/pictureheight:							the height of the target/distractor pictures (percentage of canvas height) (default: 15%)
/radiusscreenproportion:				the radius of the circle proportional to canvas height (default: 0.4)


Duration Parameters:
/readyduration:							duration of ready hint in ms (default: 750ms)
/cueduration:							duration of cues in ms (default: 300ms)
/fixationduration:						duration of fixation cross in ms (default: 600ms)