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										Partner GNAT Script
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last updated:  03-09-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 03-09-2020 Millisecond Software

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BACKGROUND INFO 	
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This script implements a partner Go-Nogo Association Task (GNAT) using the category 'partner' as the target category.

In general, the GNAT procedure uses the Go-Nogo framework of responding to signal and noise stimuli to investigate implicit bias 
towards a target category. In contrast to reaction time based tests of implicit bias (e.g. Implicit Association Test), 
the GNAT framework mainly focuses on accuracy data and specifically d prime measures (measures of sensitivity to distinguish
signals from noise in signal detection theory) to infer implicit bias. 

For example, a positive association of 'partner' (the target signal) is suggested if the dprime measure in the condition
'Partner-Good' (aka both 'partner' and good attributes are signals) is greater than the dprime measure in the condition 'Partner-Bad' 
(aka both 'partner' and bad attributes are signals).											
											
																						
This script implements the Partner GNAT procedure (study 2) described in:

Lee, S., Rogge, R. D., & Reis, H. T. (2010). Assessing the seeds of relationship decay: Using implicit evaluations to detect 
the early stages of disillusionment. Psychological Science, 21(6), 857-864.

This script calculates d'prime values.

Adjustments to z-scores as described by:
Gregg, A. & Sedikides, C. (2010). Narcissistic Fragility:
Rethinking Its Links to Explicit and Implicit Self-esteem, Self and Identity, 9:2, 142-161 (p.148)

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TASK DESCRIPTION	
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Participants are asked to categorize attributes and partner-related items (e.g words  "supportive", "partner name") 
into predetermined categories via keystroke presses. The basic task is to press the Spacebar if an item (e.g. supportive")
belongs to the category currently being tested (e.g. "Constructive"") and to do nothing if it doesn't.
For practice, participants sort items into categories "Constructive", and "Destructive".
For the test, participants are asked to sort categories into the paired/combined categories (e.g. 
"Partner OR Constructive"). When an item belongs to either one of these two categories, 
participants should press the Spacebar.

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DURATION 
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the default set-up of the script takes appr. 5 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: 'partnergnat_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. 
										
stimulusitem:						the presented stimuli in order of trial presentation
response:							the participant's response (scancode of response buttons)
correct:							accuracy of response: 1 = correct response; 0 = otherwise
latency: 							the response latency (in ms); measured from: onset of stimuli

(2) Summary data file: 'partnergnat_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)
								
Note: z-score calculations: adjustments (see Gregg & Sedikides, 2010, p.148)
If the hit rate  FA rate is 0 => 0.005 is used instead (aka 0.005 is added to the hitFA rate)
IF the hit rate  FA rate is 1.0 => 0.995 is used instead (aka 0.005 is subtracted from the hitFA rate)

values.pg_hits,values.pg_falsealarms,
values.pb_hits,values.pb_falsealarms,
expressions.pg_hr,expressions.pg_fr,expressions.pg_z_hr,expressions.pg_z_fr,expressions.pg_dprime,
expressions.pb_hr,expressions.pb_fr,expressions.pb_z_hr,expressions.pb_z_fr,expressions.pb_dprime, expressions.dprime_Diff
								

pg_hits: 							number of Hits for the partner/good pairing
pg_falsealarms: 					number of false alarms for the partner/good pairing
pb_hits: 							number of Hits for the partner/bad pairing
pb_falsealarms: 					number of false alarms for the partner/bad pairing

pg_hr:								hitrate for partner/good pairing
pg_fr:								false alarm rate for partner/good pairing
pg_z_hr:							z-value of hitrate for partner/good pairing
pg_z_fr:							z-value of false alarm rate for partner/good pairing

pg_dprime:							d' for partner/good pairing
										=> Range (in this script): 
										-5.1516586840152740479 <= dprime <= 5.1516586840152740479 (=perfect performance)

pb_hr:								hitrate for partner/bad pairing
pb_fr:								false alarm rate for partner/bad pairing
pb_z_hr:							z-value of hitrate for partner/bad pairing
pb z-fr:							z-value of false alarm rate for partner/bad pairing

pb_dprime:							d' for partner/bad pairing
										=> Range (in this script): 
										-5.1516586840152740479 <= dprime <= 5.1516586840152740479 (=perfect performance)

dprime_Diff:						the difference in dprime btw. 'partner-good' and 'partner-bad'
									=> if d prime for 'partner-good' is larger than for 'partner-bad' (positive difference):
									participant more closely associated Partner with Good than with Bad attributes
									=> if d prime for 'partner-good' is smaller than for 'partner-bad' (negative difference):
									participant more closely associated Partner with Bad than with Good attributes								

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EXPERIMENTAL SET-UP 
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* 2 Practice Blocks of 16 trials (8 go/8 nogo): good  -> bad
-> items are randomly sampled 
* 2 test blocks (order counterbalanced by groupnumber): 
-> testing of paired categories "partner OR good" vs. "partner OR bad" 
-> items are randomly sampled
-> 70 trials: 20 partner (go trials), 20 attribute go trials, 30 attribute no-go trials
	
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STIMULI
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can be edited under section Editable Stimuli

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INSTRUCTIONS 
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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:

	intertrialinterval			default is 400ms
	responsetimeout				default is 600ms