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						JUMPING TO CONCLUSION (JTC) - BEADS TASK ("Jar Task")
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 10-28-2014
last updated: 01-14-2016 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Copyright © 01-14-2016 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script runs the Jumping to Conclusion (JTC) Beads Test similar to the one described in:

Garety, P. A., Hemsley, D. R. & Wessely, S. (1991). Reasoning in deluded schizophrenic and paranoid
patients : Biases in performance on a probabilistic inference task. Journal of Nervous and Mental Disease,
179, 194-201.

The JTC Beads Task is a probabilistic reasoning task.		

Millisecond Software thanks Sarah Reeve for assistance with this script!	


											  *Task*
Participants are presented with 2 jars (A and B) with different ratios of red to blue beads (15:85).
They are told that the computer selects one jar and draws beads from it with replacement.
The computer will draw one bead at a time and always return the bead to the jar before it draws the next bead.
The participant's task is decide which jar the computer selected.
By default, participants can ask for as many beads as they need to make a decision (number of max. drawings can be limited).
A sequence of small red and blue beads at the bottom of the screen reminds participants of all the beads drawn up to this 
point.
											  


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

(1) Raw data file: 'JTC_Beadtask_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 
/type_drawing:					"random" vs. "predetermined" (can be set under section Editable Values)
/max_drawings:					"unlimited" vs. an integer e.g. /nr_drawing = 20 (can be set under section Editable Values)
/feedback:						true (1) = participants receive feedback at the end
								false (0) = participants receive no feedback at the end (can be set under section Editable Values)
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) 
/jarA:							stores the ratio of red to blue beads in jar A (default: "85R:15B")
/jarB:							stores the ratio of red to blue beads in jar B (default: "15R:85B")
/targetjar:						"A" or "B" (counterbalanced by groupnumber)
/bead:							1 = high probability bead; 2 = low probability bead
stimulusitem:					the presented stimuli in order of trial presentation
response:						the participant's response
latency: 						the response latency (in ms)
/rt_start:						stores the latency (in ms) from start of task until the Spacebar is pressed to see the first bead
/rt_drawing:					stores the latency (in ms) from presentation of first bead to pressing 'D' (decision)
/selectedjar:					stores the jar participant selects
/decision:						"correct" vs. "incorrect"
/count_drawings:				counts the number of beads drawn
/beadsequence:					stores the bead sequence (e.g. R, R, B, R, R, R, ....)

(2) Summary data file: 'JTC_Beadtask_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)
/type_drawing:					"random" vs. "predetermined" (can be set under section Editable Values)
/max_drawings:					"unlimited" vs. an integer e.g. /nr_drawing = 20 (can be set under section Editable Values)
/feedback:						true (1) = participants receive feedback at the end
								false (0) = participants receive no feedback at the end (can be set under section Editable Values)
/jarA:							stores the ratio of red to blue beads in jar A (default: "85R:15B")
/jarB:							stores the ratio of red to blue beads in jar B (default: "15R:85B")
/targetjar:						"A" or "B" (counterbalanced by groupnumber)
/selectedjar:					stores the jar participant selects
/decision:						"correct" vs. "incorrect"
/count_drawings:					counts the number of beads drawn
/rt_drawing:					stores the latency (in ms) from presentation of first bead to pressing 'D' (decision)
/meanRT_drawing:  				mean latency (in ms) of trial.beaddrawing
/medianRT_drawing:				median latency (in ms) of trial.beaddrawing
/beadsequence:					stores the bead sequence (e.g. R, R, B, R, R, R, ....)

EXPERIMENTAL SET-UP

The default design of this JTC task is consistent with the "draws to decision" methologies:
Participants can request as many beads as they need to make a decision.
!HOWEVER, the number of drawings can be limited via an editable parameter (parameters.max_drawings).
Go to section Editable Parameters and edit parameters.max_drawings.

Bead Sequence: the default bead sequence is randomly determined (with replacement).
If a predetermined sequence is needed, go to 
a) section Editable Parameters and edit parameters.type_drawing accordingly
b) section Editable Lists and edit the drawing sequence under list.beadsequence_predetermined accordingly

Feedback is optional. By default, participants receive feedback at the end.
To change: Go to section Editable Parameters and edit parameters.feedback

Target Jar A/B are counterbalanced by groupnumber:
odd groupnumbers are assigned to TargetJar A
even groupnumbers are assigned to TargetJar B

STIMULI
Jar images: the default images with this script contain 100 beads in each jar (85 of one color, 15 of the other).
Alternative images provided:
* with opaque jars with 85:15
* with ratio 60:40
(go to Editable Stimuli to change the images).

INSTRUCTIONS
The provided instructions are provided by Millisecond Software and 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:

/jarA:					stores the ratio of red to blue beads in jar A (default: "85R:15B")
/jarB:					stores the ratio of red to blue beads in jar B (default: "15R:85B")
							Note: 	*if these default ratios are changed, the images under item.jars need to be edited accordingly
									*if these default ratios are changed, list.beadsequence_random might have to edited accordingly
								
/color1:				sets bead color1; the predominant color in jar A (default: red)
/color2:				sets bead color2; the predominant color in jar B (default: blue)
							Note: if these default colors are changed, the images under item.jars need to be edited accordingly

/type_drawing:			"random" vs. "predetermined" (default: "random")
						!Note: if "predetermined" go to 'Editable Lists' and edit list.beadsequence_predetermined
						(default list from Garety et al, 1991, condition 2) as well as set parameters.max_drawings below
						
/max_drawings:			"unlimited" vs. an integer e.g. /nr_drawing = 20 (default: "unlimited")
							Note: if the number of maximum beads is limited, the instructions under item.instructions may need to be edited accordingly

/feedback:				true = participants receive feedback at the end (default)
						false = participants receive no feedback at the end

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