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*PARAMETRIC Go/NoGo TASK (PGNG)*
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 12-02-2013
last updated: 06-30-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 06-30-2020 Millisecond Software
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BACKGROUND INFO
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This script implements the Parametric Go/NoGo task, a task to manipulate attentional load, set-shifting,
and inhibitory control as a measure of executive functioning.
The implemented procedure is based on:
1. 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.
2. 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).
The default procedure of this script runs the 3 levels described by Langenecker et al (2007).
Additional conditions can be run - go to section EXPERIMENT for more information.
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TASK DESCRIPTION
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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).
Level 1 (3 targets, static rule ): press spacebar for 's','r', and 't'; otherwise wait
Level 2 (2 targets, repeat rule): press spacebar for 's' and 'r' IF they don't repeat the last target letter;
otherwise wait
Level 3 (3 targets, repeat rule): press spacebar for 's', 'r' and 't'. IF they don't repeat the last target letter;
otherwise wait.
The levels are run in ascending difficulty.
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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: 'pgng_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
session: 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.
trialtype: 1 = distractor (non-target trial)
2 = target trial
3 = lure trial (presents a target but should not elicit a response)
stimulusduration: current stimulus duration
stopsignalduration: duration of current stop signal in ms
previoustarget: stores the previous target stimulus
stimulusitem: the presented stimulus
response: the participant's response (scancode of response key)
57 = spacebar
0 = no response
correct: the correctness of the response (1 = correct; 0 = otherwise)
latency: the response latency (measured at onset of stimulus) in ms
(2) Summary data file: 'pgng_summary*.iqdat' (a separate file for each participant)
inquisit.version: Inquisit version run
computer.platform: the platform the script was run on (win/mac/ios/android)
startDate: date script was run
startTime: time script was started
subjectid: assigned subject id number
groupid: assigned group id number
sessionid: assigned session id number
elapsedTime: time it took to run script (in ms); measured from onset to offset of script
completed: 0 = script was not completed (prematurely aborted);
1 = script was completed (all conditions run)
pctCorrect_overall: overall percent correct responses (across target and nontarget trials)
RTT_overall: overall mean target response time (=correctly hitting spacebar for a target) in ms
=> measure of processing speed
PCTT_overall: overall percent target identification (correctly hitting spacebar for a target)
=> percent correct responses for target trials
=> measure of sustained attention and set maintenance
pctCommissionError_overall: overall percent commission errors (=incorrectly hitting spacebar for a non target)
=> percent error responses for distractors and lures
*By Condition:*
//2TA - 2 targets, static (targets are always targets)
pctCorrect_2TA: percent correct for 2 targets, static condition (across target and nontarget trials)
RTT_2TA: mean target response time (=correctly hitting spacebar for a target) in ms for 2 targets, static condition
=> measure of simple processing speed
PCTT_2TA: percent target identification (correctly hitting spacebar for a target) for 2 targets, static condition
=> measure of sustained attention and set maintenance
pctCommissionError_2TA: percent commission errors (=incorrectly hitting spacebar for a non target) for 2 targets, static condition
=> proportion error responses for distractors and lures
//2TB - 2 targets, targets are context dependent
pctCorrect_2TB: percent correct for 2 targets, context condition (across target and nontarget trials)
RTT_2TB: mean target response time (=correctly hitting spacebar for a target) in ms for 2 targets, context condition
=> measure of simple processing speed
PCTT_2TB: percent target identification (correctly hitting spacebar for a target) for 2 targets, context condition
=> measure of sustained attention and set maintenance
pctCommissionError_2TB: percent commission errors (=incorrectly hitting spacebar for a non target) for 2 targets, context condition
PCIT_2TB: percent successfully suppressed responses to lures for 2 targets, context condition
=> no responses to target letters that are not targets according to the repeating rule
=> measure of response inhibition
//2TC - 2 target, stop signal condition
pctCorrect_2TC: percent correct for 2 targets, stopSignal condition (across target and nontarget trials)
RTT_2TC: mean target response time (=correctly hitting spacebar for a target) in ms for 2 targets, stopSignal condition
=> measure of simple processing speed
PCTT_2TC: percent target identification (correctly hitting spacebar for a target) for 2 targets, stopSignal condition
=> measure of sustained attention and set maintenance
pctCommissionError_2TC: percent commission errors (=incorrectly hitting spacebar for a non target) for 2 targets, stopSignal condition
PCIT_2TC: percent successfully suppressed responses to lures for 2 targets, stopSignal condition
=> no responses to target letters that are not targets according to the stop signal rule
=> measure of response inhibition
(same for the 3 Target Conditions)
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EXPERIMENTAL SET-UP
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* 6 conditions
(A) 3 conditions with 2 targets: r, s
(a) 2TA: static targets: targets are always targets (= Go trials) - NOT RUN BY DEFAULT
(b) 2TB: context-based targets: targets become lures (= NoGo trials) IF they repeat => block.2t_context,
LEVEL 2 (Langenecker et al, 2007)
(c) 2TC: stopsignal targets: targets become lures (=NoGo trials) IF followed by stop sign - NOT RUN BY DEFAULT
(B) 3 conditions with 3 targets: r, s, t
(a) 3TA: static targets: targets are always targets (= Go trials) => block.3t_static,
LEVEL 1 (Langenecker et al, 2007)
(b) 3TB: context-based targets: targets become lures (= NoGo trials) IF they repeat => block.3t_context,
LEVEL 3 (Langenecker et al, 2007)
(c) 3TC: stopsignal targets: targets become lures (=NoGo trials) IF followed by stop sign - NOT RUN BY DEFAULT
* 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)
ADD/Delete Conditions:
To add or delete conditions (or change the order in which they are run),
go to section EXPERIMENT for further instructions
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INSTRUCTIONS
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The instructions for the Inquisit PGNG.iqx script by Millisecond Software are based on instruction
slides provided by Dr. Langenecker with the original e-prime script.
The instructions are provided as html/htm pages and can be edited by changing
the provided html/htm files.
To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac)
or Notepad (Windows).
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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:
/responsekey: the response key (default: " " -> spacebar)
original response key was 'n'
/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
