Return to the Visual Search Task page
						
									       VISUAL SEARCH
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 01-24-2014
last updated: 08-15-2016 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Script Copyright © 08-15-2016 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script implements the Visual Search paradigm as described in:

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

											  *Task*
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.

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:							Inquisit build
computer.platform:				the platform the script was run on
date, time, subject, group:		date and time script was run with the current subject/groupnumber 
blockcode, blocknum:			the name and number of the current block
trialcode, trialnum: 			the name and number of the currently recorded trial
									(Note: not all trials that are run might record data; by default data is collected unless /recorddata = false is set for a particular trial/block) 
stimulusitem:					the presented stimuli in order of trial presentation
response:						the participant's response
correct:						the correctness of the response (1 = correct; 0 = incorrect)
latency: 						the response latency (in ms)
/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
correct:						the correctness of the response
latency: 						the response latency in ms
/responsetype:					Hit, Miss, FA (False Alarm), CR (Correct Rejection)
/Hit:							1 = it's a hit; 0 = it's not a hit
/FA:							1 = it's a false alarm; 0 = it's not a false alarm
/Miss:							1 = it's a miss; 0 = it's not a miss
/CR :							1 = it's a correct rejection; 0 = it's not a correct rejection
/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)

script.startdate:				date script was run
script.starttime:				time script was started
script.subjectid:				subject id number
script.groupid:					group id number
script.elapsedtime:				time it took to run script (in ms)
computer.platform:				the platform the script was run on
/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 scancode of the target present responsekey (default: 21)
/responsekey_targetpresent_label: 			the label of the target present responsekey (default: "Y")
/responsekey_targetabsent					the scancode of the target absent responsekey (default: 49)
/responsekey_targetabsent_label: 			the label of the target absent responsekey (default: "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 (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)

Copyright © Millisecond Software. All rights reserved.
Contact | Terms of Service | Security Statement | Employment