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									PARAMETRIC Go/NoGo TASK (PGNG)
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 12-02-2013
last updated: 01-21-2016 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Copyright © 01-21-2016 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script implements the Parametric Go/NoGo task as described in:

Langenecker SA, Zubieta J-K, Young EA, Akil H, Nielson KA. (2007). A task to manipulate attentional load, set-shifting, 
and inhibitory control: Convergent validity and test-retest reliability of the Parametric Go/No-go test. 
Journal of Clinical and Experimental Neuropsychology, 29 (8), 842–853.

and the original e-prime version "Parametric Go/No-go/Stop test (version 9.13)" by Dr. Langenecker 
(http://sitemaker.umich.edu/slangen/downloads)

The original e-prime script contains several conditions that are not described in Langenecker et al (2007) (e.g. Stop 
Signal conditions). This script implements all conditions run by the original e-prime script. Comments will point out which 
conditions correspond to the conditions (referred to as "levels") run by Langenecker et al (2007). Each condition in this script 
will be run by a block (see under EXPERIMENTAL BLOCKS) that can be added or deleted from the experiment 
(look for instructions under EXPERIMENT) to customize.  Targets in this script are r, s, t as used in the e-prime script 
(as opposed to x, y, z used in the article). Trial sequences are translated from the e-prime script into Inquisit. 
Instructions and practice trials are also adapted to run in Inquisit.

											  *Task*
Participants are presented with a constant stream of letters. A subset of the letters require a response, e.g.
pressing the Spacebar (= Go trials), otherwise no response is required (=NoGo trials). Participants work 
through different tasks that differ in difficulty to identify a "true" Go trial (context can turn a Go stimulus
into a NoGo stimulus).


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

(1) Raw data file: 'PGNG_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) 
/previoustarget:					stores the previous target stimulus
stimulusitem:						the presented stimulus
response:							the participant's response (scancode)
correct:							the correctness of the response
latency: 							the response latency (measured at onset of stimulus)
/stimulusduration:					current stimulus duration
/stopsignalduration:				duration of current stop signal

summary variables for all levels:

2TA = 2 targets, static Go/NoGo task
2TAB = 2 targets, contextual Go/NoGo task ("Level2" -> Langenecker et al, 2007)
2TAC = 2 targets, stopsignal Go/NoGo task

3TA = 3 targets, static Go/NoGo task ("Level1" -> Langenecker et al, 2007)
3TAB = 3 targets, contextual Go/NoGo task  ("Level3" -> Langenecker et al, 2007)
3TAC = 3 targets, stopsignal Go/NoGo task

/count_distractors2TA:						counts the number of times a distractor is presented for static 2 target block (= 2TA)
/countcorrect_distractors2TA:				counts the number of correct responses to distractors for static 2 target block (= 2TA)
(same for remaining 2T conditions)

/count_distractors3TA:						counts the number of times a distractor is presented for static 3 target block (= 3TA) ("Level1" -> Langenecker et al, 2007)
/countcorrect_distractors3TA:				counts the number of correct responses to distractors for static 3 target block (= 3TA)
(same for remaining 3T conditions)

/count_targets2TA:							counts the number of times a target is presented for static 2 target block (= 2TA)
/countcorrect_targets2TA:					counts the number of correct responses to targets for static 2 target block (= 2TA)
(same for remaining 2T conditions)

/count_targets3TA:							counts the number of times a target is presented for static 3 target block (= 3TA) ("Level1" -> Langenecker et al, 2007)
/countcorrect_targets3TA:					counts the number of correct responses to targets for static 3 target block (= 3TA)
(same for remaining 3T conditions)

/count_lures2TB:							counts the number of times a lure is presented for contextual 2 target block (= 2TA) ("Level2" -> Langenecker et al, 2007)
/countcorrect_lures2TB:						counts the number of correct responses to lures for contextual 2 target block (= 2TA)
(same for remaining 2T conditions)

/count_lures3TB:							counts the number of times a lure is presented for contextual 3 target block (= 3TA) ("Level3" -> Langenecker et al, 2007)
/countcorrect_lures3TB:						counts the number of correct responses to lures for contextual 3 target block (= 3TA)
(same for remaining 2T conditions)

/sumrt_targets2TA-
/sumrt_targets3TC:							sums up latencies of correct responses to targets in conditions 2TA-3TC

(2) Summary data file: 'PGNG_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)

2 targets (A = static; B = contextual; C = stop signal)
/PCTT_2TA-					
/PCTT_2TC:			percent correct target detection for 2 targets 
/PCIT_2TB-
/PCIT_2TC:			percent correct target suppression for 2 targets

3 targets (A = static; B = contextual; C = stop signal)
/PCTT_3TA-
/PCTT_3TC:			percent correct target suppression for 3 targets
/PCIT_3TB-
/PCIT_3TC:			percent correct target suppression for 3 targets

2 targets (A = static; B = contextual; C = stop signal)
/RTT_2TA-
/RTT_2TC:			simple mean processing speed of correct target trials for 2 targets

3 targets (A = static; B = contextual; C = stop signal)
/RTT_3TA-
/RTT_3TC:			simple mean processing speed of correct target trials for 3 targets

EXPERIMENTAL SET-UP:
* 6 conditions
(A) 3 conditions with 2 targets: r, s
		(a) static targets: targets are always targets (= Go trials)
		(b) context-based targets: targets become lures (= NoGo trials) IF they repeat => block.2t_context, LEVEL 2 (Langenecker et al, 2007)
		(c) stopsignal targets: targets become lures (=NoGo trials) IF followed by stop sign
(B) 3 conditions with 3 targets: r, s, t
		(a) static targets: targets are always targets (= Go trials) => block.3t_static, LEVEL 1 (Langenecker et al, 2007)
		(b) context-based targets: targets become lures (= NoGo trials) IF they repeat => block.3t_context, LEVEL 3 (Langenecker et al, 2007)
		(c) stopsignal targets: targets become lures (=NoGo trials) IF followed by stop sign

* Go trials: "valid" target trials
* NoGo trials: all distractor trials (all letters other than r, s, t) AND lure trials (targets turned lures)
* all letters are presented in prefixed orders (same as in original e-prime script)

Trial Presentation:
- stimulus is presented for 500ms (default) with a 0ms interstimulus interval (default)
- participants have the entire 500ms to respond
- by default, stimuli are presented in black on a white background (Langenecker et al, 2007a)
- the size of the stimuli can be adjusted via an editable parameter (parameters.fontsize_target)
- the default presentation font in this script is Arial

PRACTICE
Each task is preceded by a practice session that is modeled after the practice session used in the original
e-prime script by Langenecker (letter sequences are different)

INSTRUCTIONS
The instruction slides for the Inquisit PGNG.iqx script by Millisecond Software are based on instruction 
slides provided by Dr. Langenecker with the original e-prime script. Nevertheless, the slides provided by Millisecond 
Software for the PGNG.iqx script differ from the originals. Feel free to edit these slides or use the originals.

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:

/responsekey:							scancode of the response key
											Note: scancodes under Tools -> Keyboard Scancodes (default: 57)
													original response key was 'n' (scancode: 49)
/responsekey_label:						label of the response key (default: )
/fontsize_target:						fontsize of the targets in screen height percentages (default: 10%)
/fixationcross_height:					size of the fixation cross that starts the letter sequence

/stimulusduration_test:					presentation duration of the targets during the test session (default: 500ms)
												Note: the stimulus presentation time for targets will
												vary in the Stop Signal conditions 
												(-> list.stimulusdurations_2TC; list.stimulusdurations_3TC)
/isi:									duration of the interstimulusinterval (default: 0ms) 
												Note: Langenecker et al (2007) do not use an interstimulusinterval
/fixationcrossduration:					duration of fixation cross at start of letter sequence
/testinstruction_duration:				duration of test instructions

/showsummary:							true = a performance summary is presented to participants at the end of the script (default)
										false = the performance summary is not presented

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