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										TIME PERCEPTION BIAS TEST
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 05-09-2017
last updated: 06-01-2017 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Script Copyright © 06-01-2017 Millisecond Software

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


BACKGROUND INFO 

											*Purpose*
This script implements a time perception bias test similarly to the one described in Experiment 1 by:

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


											  *Task*
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.


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

(1) Raw data file: 'timeperceptionbiastest_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) 
/countTrials:					tracks the number of trials run within a block (resets for each block)
/countBlocks:					tracks the number of test blocks run
/compCategory:					stores the current comparison category presented									
stimulusitem:					standard stimulus presented
/compStim:						the current comparison stimulus presented
/compDuration:					stores the current comparison duration (in ms)
response:						the participant's response (scancode of response button: 31 = S; 38 = L)
/response:						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)*

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)

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

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

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

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


EXPERIMENTAL SET-UP

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)


STIMULI
- 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


INSTRUCTIONS
provided by Millisecond Software - can be 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:

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 scancode of the key used to make "shorter" judgements (default: 31)
/shorterDurationResponsekeyLabel:		the label of the key used to make "shorter" judgements (default: "S")
/longerDurationResponsekey:				the scancode of the key used to make "longer" judgements (default: 38)				
/longerDurationResponsekeyLabel:		the label of the key used to make "longer" judgements (default: "L")

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