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										SHORT TERM MEMORY BINDING TEST (STMB)
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 10-17-2016
last updated: 04-19-2017 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Script Copyright © 04-19-2017 Millisecond Software


BACKGROUND INFO 

											*Purpose*
This script implements the Short Term Memory Binding Test by:

Brockmole, JR, Parra, MA, Della Sala, S, Logie RH (2008). Do binding deficits account for age-related decline in visual working memory?
Psychon Bull Rev.;5:543–547 (Experiment 2).

The STMB test assesses feature binding in short-term memory.


											  *Task*
Participants view 2 displays of 2-4 objects (default: 4) distributed over 9 possible screen locations, one after the other. 
These displays consist of the same objects (arranged differently in each display), or they differ by two items.
The task is to decide whether the second display presents the same objects as the first display - despite different object locations.
If the same objects are presented in display2, participants are asked to press a 'same' response key (default: E-key); 
if the object array is altered in display2, participants are asked to press a 'different' response key (default: I-key).

There are 3 different feature conditions: color, shape, and binding condition, tested in blocked format.

Color Condition: the presented objects are the same shape but differ in color (for 'different' trials: 2 of the objects get assigned new colors)
Shape Condition: the presented objects are different shapes but of the same color (for 'different' trials: 2 of the objects get assigned new shapes)
Binding Condition: the presented objects are different shapes, presented in different colors (for 'different' trials: 2 of the objects swap colors)

  

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

(1) Raw data file: 'shorttermmemorybindingtest_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) 
/array:							1 (display1) vs. 2 (display2)
/congruency:					'same' vs. 'different'
/image1-image4:					store the current image files used for object1-object4
response:						the participant's response (scancode of response button; 18=E; 23=I)
correct:						the correctness of the response (1 = correct; 0 = incorrect)
latency: 						the response latency (in ms)
/shape1:						stores the shape number (1-8) for object #1
/color1:						stores the color (1-8) for object #1
/location1:						stores the location (1-9) for object #1
/location1x:					stores the x-coordinate for object #1 (corresponds to location assignment)
/location1y:					stores the y-coordinate for object #1 (corresponds to location assignment)
(same for objects 2-4)
/change1:						helper variable: stores the object number of the first object that will change in different trials
/change2:						helper variable: stores the object number of the second object that will change in different trials
/countDiffs:					counts the differences in the presented images (helper variable) -> 'different'=> 2; 'same' => 0


(2) Summary data file: 'shorttermmemorybindingtest_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)

/propCorrect_binding_same:		proportion correct responses in 'same' binding trials
/meanRT_binding_same:			mean latency (in ms) of correct responses in 'same' binding trials
/SD_binding_same:				Standard Deviation (in ms) of latencies to correct responses in 'same' binding trials
/propCorrect_binding_different:	proportion correct responses in 'different' binding trials
/meanRT_binding_different:		mean latency (in ms) of correct responses in 'different' binding trials
/SD_binding_different:			Standard Deviation (in ms) of latencies to correct responses in 'different' binding trials

/propCorrect_shape_same:		proportion correct responses of 'same' shape trials
/meanRT_shape_same:				mean latency (in ms) of correct responses in 'same' shape trials
/SD_shape_same:					Standard Deviation (in ms) of latencies to correct responses in 'same' shape trials
/propCorrect_shape_different:	proportion correct responses of 'different' shape trials
/meanRT_shape_different:		mean latency (in ms) of correct responses in 'different' shape trials
/SD_shape_different:			Standard Deviation (in ms) of latencies to correct responses in 'different' shape trials

/propCorrect_color_same:		proportion correct responses of 'same' color trials
/meanRT_color_same:				mean latency (in ms) of correct responses in 'same' color trials
/SD_color_same:					Standard Deviation (in ms) of latencies to correct responses in 'same' color trials
/propCorrect_color_different:	proportion correct responses of 'different' color trials
/meanRT_color_different:		mean latency (in ms) of correct responses in 'different' color trials
/SD_color_different:			Standard Deviation (in ms) of latencies to correct responses in 'different' color trials

* 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
- 3 blocks (color, shape, binding) - order of blocks is counterbalanced across participants by groupnumber
- each block runs 16 same and 16 different trials (total: 32) - order is randomly determined

Trials: all blocks
- Display1 (1000ms) -> Blank (900ms) -> Display2 (until response) -> ITI (1000ms) - Timings can be edited under section Editable Parameters
- arraysize is 4 (default - can be changed to 2-3 under section Editable Parameters)
- objects can appear in 9 different screen locations (the active screen canvas is squared in this script)
- display 1 object positions: randomly determined (without replacement)
- display 2 object positions: position of objects in display2 are randomly determined (with the constraint that all objects appear in positions not used in display1)
- objects can be presented in 8 different shapes and 8 different colors

Color: 
- Display1: randomly selects one shape and presents the shape in randomly selected colors (no color repeats)
- Display2 different: 2 randomly selected objects get new colors (colors were not previously used)

Shape: 
- Display1: randomly selects one color and presents the object in randomly selected shapes (no shape repeats)
- Display2 different: 2 randomly selected objects get new shapes (shapes were not previously used)

Binding: 
- Display1: randomly selects shapes and colors (no shape and color repeats)
- Display2 different: 2 randomly selected objects swap colors


STIMULI
Stimuli are not original to Brockmole et al (2008)
All stimuli are hexagonal shapes provided by Millisecond Software - the shapes can 
be edited under section Editable Stimuli.
The colors used in this script are: red, green, blue, purple, pink, turquoise, black, yellow and orange
Size can be edited under section Editable Parameters

INSTRUCTIONS
Instructions are not original to Brockmole et al (2008) - they are provided by Millisecond Software and presented via
htm-files that can be edited in a separate text editor such as Notepad (Windows) or TextEdit (Mac)

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:

/arraySize:									the number of objects presented, available for 2-4 objects (default: 4)
/arrayPresentationTime:						the duration (in ms) that the array of objects is on screen (default: 1000ms)
/blankPresentationTime:						the duration of the blank screen (in ms) between displays (default: 900ms)
/ITI:										intertrial interval (in ms) (default: 1000ms)
/picSize:									the size of object images in proportion to canvas size (default: 0%)

Keyassignment:

/leftKey:									the scancode for the left key (default: 18) 
/rightKey:									the scancode for the right key (default: 23)  
/leftKey_label:								the corresponding label of the left key (here: "E")
/rightKey_label:							the corresponding label of the right key (here: "I")
Note: by changing the above values of the keys, you can use different response keys

/sameKey:									stores the scancode of the 'same' key (default: it's the left response button)
/sameKey_label:								stores the label of the 'same' key (default: it's the left response button "E")
/sameKey_location:							stores the location of the 'same' key (default: it's the left one)
/differentKey:								stores the scancode of the 'different' key (default: it's the right response button)
/differentKey_label:						stores the label of the 'different' key (default: it's the right response button "I")
/differentKey_location:						stores the location of the 'different' key (default: it's the right one)
Note: by changing the above values, you can control the left/right assignment of the 'same' and 'different' response buttons

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