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										*TIME PERCEPTION BIAS TEST*
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
last updated:  03-12-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 03-12-2020 Millisecond Software

Millisecond thanks Joe Vitriol and Dr. Gordon Moskowitz for their help with this script
and for sharing the original geometric shapes used!

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BACKGROUND INFO 	
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This script implements a time perception bias test. The test is based on the assumption that
people overestimate the duration of items that heighten their arousal.

The implemented procedure is based on:

Gordon B. Moskowitz, G.B., Olcaysoy Okten, I. & Gooch, C.M. (2015).
On Race and Time. Psychological Science, 26, 1783-1794.
DOI: https://doi.org/10.1177/0956797615599547 (Experiment1)

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TASK DESCRIPTION	
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People tend to overestimate the duration of items that heighten their arousal.
In this script, people are asked to estimate the duration of items from 2 categories that
frequently elicit anxiety: spiders and dogs, and a control category (shoes) that is
assumed to be arousal neutral.

Each target item is presented after a geometric shape. The geometric shapes act as the 'standard' stimuli 
and are always presented for the same fixed duration (here: 600ms). 
The target items, on the other hand, are presented for variable durations (with the same number of 
durations being longer and shorter than the standard). 
Participant are asked to decide whether the target stimuli were presented for a longer or 
shorter duration than the preceding standard. 
The proportion of longer judgements is taken as a measure of time bias for arousal-neutral (baseline bias) and
potentially arousal-positive targets.

Note: Control and target categories can easily be altered.

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DURATION 
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the default set-up of the script takes appr. 15 minutes to complete

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

(1) Raw data file: 'timeperceptionbiastest_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 such as feedback trials. Thus, trialnum 
										may not reflect the number of main trials run per block.
										
values.countBlocks:					tracks the number of test blocks run										
values.countTrials:					tracks the number of trials run within a block (resets for each block)

values.compCategory:				stores the current comparison category presented									
stimulusitem:						standard stimulus presented
values.compStim:					the current comparison stimulus presented


parameters.standardDuration:		the duration (in ms) of the standard object (here: geometric figure) (default: 600ms)
									during the test trials (demo trials = 1000ms, default)

values.compDuration:				stores the current comparison duration (in ms)
response:							the participant's response (scancode of response button: 31 = S; 38 = L)
values.responseCategory:			1 = longer judgment; 0 = otherwise
latency: 							the response latency (in ms); measured from offset of comparison stimulus


(2) Summary data file: 'timeperceptionbiastest_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)
																	
parameters.standardDuration:		the duration (in ms) of the standard object (here: geometric figure) (default: 600ms)
									during the test trials									

expressions.propLonger:						proportion of "longer" judgment across all trials and blocks

item.comparisonControlLabel.item.1:			the control category (here: SHOES)
expressions.propLonger_control:				overall proportion of "longer" judgments for control items
expressions.propLonger_control1:			proportion of "longer" judgments for control comp duration 1 (default: 300ms)
expressions.propLonger_control2:			proportion of "longer" judgments for control comp duration 2 (default: 380ms)
expressions.propLonger_control3:			proportion of "longer" judgments for control comp duration 3 (default: 480ms)
expressions.propLonger_control4:			proportion of "longer" judgments for control comp duration 4 (default: 600ms)
expressions.propLonger_control5:			proportion of "longer" judgments for control comp duration 5 (default: 760ms)
expressions.propLonger_control6:			proportion of "longer" judgments for control comp duration 6 (default: 960ms)
expressions.propLonger_control7:			proportion of "longer" judgments for control comp duration 7 (default: 1200ms)

item.comparisonTargetALabel.item.1:			the targetA category (here: SPIDERS)
expressions.propLonger_targetA:				overall proportion of "longer" judgments for targetA items
expressions.propLonger_targetA1:			proportion of "longer" judgments for targetA comp duration 1 (default: 300ms)
expressions.propLonger_targetA2:			proportion of "longer" judgments for targetA comp duration 2 (default: 380ms)
expressions.propLonger_targetA3:			proportion of "longer" judgments for targetA comp duration 3 (default: 480ms)
expressions.propLonger_targetA4:			proportion of "longer" judgments for targetA comp duration 4 (default: 600ms)
expressions.propLonger_targetA5:			proportion of "longer" judgments for targetA comp duration 5 (default: 760ms)
expressions.propLonger_targetA6:			proportion of "longer" judgments for targetA comp duration 6 (default: 960ms)
expressions.propLonger_targetA7:			proportion of "longer" judgments for targetA comp duration 7 (default: 1200ms)

item.comparisonTargetBLabel.item.1:			the targetB category (here: DOGS)
expressions.propLonger_targetB:				overall proportion of "longer" judgments for targetB items
expressions.propLonger_targetB1:			proportion of "longer" judgments for targetB comp duration 1 (default: 300ms)
expressions.propLonger_targetB2:			proportion of "longer" judgments for targetB comp duration 2 (default: 380ms)
expressions.propLonger_targetB3:			proportion of "longer" judgments for targetB comp duration 3 (default: 480ms)
expressions.propLonger_targetB4:			proportion of "longer" judgments for targetB comp duration 4 (default: 600ms)
expressions.propLonger_targetB5:			proportion of "longer" judgments for targetB comp duration 5 (default: 760ms)
expressions.propLonger_targetB6:			proportion of "longer" judgments for targetB comp duration 6 (default: 960ms)
expressions.propLonger_targetB7:			proportion of "longer" judgments for targetB comp duration 7 (default: 1200ms)


* separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section
"DATA" and follow further instructions


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EXPERIMENTAL SET-UP 
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Method of Constant Stimuli:
each target category uses a fixed set of durations that are presented in a randomized order.

1. Demo/Practice:
- 5 trials to get familiarized with the set-up
- stimuli are selected from random object/animal categories

2. Test:
- 4 blocks (editable, under section Editable Parameters
- each blocks presents: 
	- 21 control trials (here: shoes), 21 target A (here: spiders), 21 target B (here: dogs) 
	(number of trials are editable under section Editable Parameters) => 63 trials per block
	- each comparison trial randomly (without replacements) selects from 7 fixed durations: 300,380,480,600,760,960,1200 (in ms)
		=> 3 shorter than standard, 1 at standard, 3 above standard (for each category)
		=> 3 repetitions of each comparison duration per category per block => 12 repetitions of each comparison duration per category across 4 blocks
		The minimum recommended number of comparison duration repetitions per category is 10.
	- trial order is random

Trial Sequence:
standard (randomly selected geometric shape) for 600ms 
-> comparison stimuli for variable duration -> Judgment via keypress (S = shorter; L = longer)
-> ITI (default: 1000ms)	

Note:
By default each block repeats the same stimuli as the one before; stimuli are randomly selected
To avoid repeats, add as many items to the respective item elements (under editable stimuli) as trials should be run overall,
across all blocks for each condition (e.g. use 84 stimuli instead of 21 for target A for no repeats across blocks)

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STIMULI
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- geometric shapes generously shared by Dr. Gordon Moskowitz
- images of shoes, spiders, dogs were collected from the internet
and converted in black and white pics in Paint.Net

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INSTRUCTIONS 
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provided by Millisecond Software - can be edited under section Editable Instructions

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EDITABLE CODE 
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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:

Trial/Block Numbers:
Note: trial numbers should be divisible by the number of comp durations run (default: 7)
/controlTrials:							number of control (control) trials (default: 21)
/targetATrials:							number of target A trials (default: 21)
/targetBTrials:							number of target B trials (default: 21)
/maxBlocks:								number of blocks to run (default: 4)

Note: 
The minimum recommended total number of comparison duration repetitions per category is 10.
The default settings run a total of 12 repetitions per category.


/standardDuration:						the duration (in ms) of the standard object (here: geometric figure) (default: 600ms)
/standardDuration_demo:					the duration (in ms) of the standard object during the demo trials (default: 1000ms)
/ITI:									the intertrial interval (in ms) between response and presentation of the next standard stim
/readyDuration:							the duration (in ms) of the 'get ready' trial

/shorterDurationResponsekey:			the key used to make "shorter" judgements (default: "S"); left response key			
/longerDurationResponsekey:				the key used to make "longer" judgements (default: "L"); right response key