Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 17, 2016
Last Modified: January 02, 2024 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the Short Term Memory Binding Test (STMB); a task to assesses feature binding (here: color and shape of objects) in visual short-term memory.
The implemented procedure is based on:
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).
10 minutes
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)
Blocks:
- 3 blocks (color, shape, binding) - order of blocks is counterbalanced across participants by groupnumber
=> 6 different groupnumbers (1-6) run all possible orders of the three blocks
groupnumber1: binding -> color -> shape
groupnumber2: binding -> shape -> color
groupnumber3: color -> binding -> shape
groupnumber4: color -> shape -> binding
groupnumber5: shape -> binding -> color
groupnumber6: shape -> color -> binding
- each block runs 16 same and 16 different trials (total: 32) - order is randomly determined
- each block is preceded by 10 practice trials
(if parameters.allowPracticeRepeat == true => practice can be repeated if requested)
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 (4) 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 (4) randomly selected shapes (no shape repeats) in that color
- Display2 different: 2 randomly selected items 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 are not original to Brockmole et al (2008)
All stimuli are hexagonal shapes provided by Millisecond - 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 are not original to the task. They are provided by Millisecond
as htm/html pages and can be edited by changing the provided htm/html files.
To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac)
or Notepad (Windows).
File Name: shorttermmemorybindingtest_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| propCorrectBindingSame | Proportion correct responses in 'same' binding trials |
| meanRTBindingSame | Mean latency (in ms) of correct responses in 'same' binding trials |
| stdBindingSame | Standard Deviation (in ms) of latencies to correct responses in 'same' binding trials |
| propCorrectBindingDifferent | Proportion correct responses in 'different' binding trials |
| meanRTBindingDifferent | Mean latency (in ms) of correct responses in 'different' binding trials |
| stdBindingDifferent | Standard Deviation (in ms) of latencies to correct responses in 'different' binding trials |
| propCorrectShapeSame | Proportion correct responses of 'same' shape trials |
| meanRTShapeSame | Mean latency (in ms) of correct responses in 'same' shape trials |
| stdShapeSame | Standard Deviation (in ms) of latencies to correct responses in 'same' shape trials |
| propCorrectShapeDifferent | Proportion correct responses of 'different' shape trials |
| meanRTShapeDifferent | Mean latency (in ms) of correct responses in 'different' shape trials |
| stdShapeDifferent | Standard Deviation (in ms) of latencies to correct responses in 'different' shape trials |
| propCorrectColorSame | Proportion correct responses of 'same' color trials |
| meanRTColorSame | Mean latency (in ms) of correct responses in 'same' color trials |
| stdColorSame | Standard Deviation (in ms) of latencies to correct responses in 'same' color trials |
| propCorrectColorDifferent | Proportion correct responses of 'different' color trials |
| meanRTColorDifferent | Mean latency (in ms) of correct responses in 'different' color trials |
| stdColorDifferent | Standard Deviation (in ms) of latencies to correct responses in 'different' color trials |
File Name: shorttermmemorybindingtest_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockCode | Name of the current block |
| blockNum | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| phase | "practice" vs. "test" |
| 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)- built-in Inquisit variable 18 = E => same 23 = I => different |
| responseCat | The interpreted key response: "same", "different" (custom variable) |
| 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 |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| allowPracticeRepeat | True = practice trials can be repeated if requested by participant (default) false = participants only get to run practice trials once for each condition | |
| arraySize | The number of objects presented, available for 2-4 objects | 4 |
| arrayPresentationTime | The duration (in ms) that the array of objects is on screen | 1000ms |
| blankPresentationTime | The duration of the blank screen (in ms) between displays | 900ms |
| iti | Intertrial interval (in ms) | 1000ms |
| picSize | The size of object images in proportion to canvas size keyAssignment | 0% |
| leftKey | The left key (here: "E") | |
| rightKey | The right key (here: "I") by changing the above values of the keys, you can use different response keys | |
| sameKey | Stores the label of the 'same' key | it's the left response button "E" |
| sameKeyLocaton | Stores the location of the 'same' key | it's the left one |
| differentKey | Stores the label of the 'different' key | it's the right response button "I" |
| differentKeyLocation | Stores the location of the 'different' key by changing the above values, you can control the left/right assignment of the 'same' and 'different' response buttons | it's the right one |