Short Term Memory Binding Test (STMB)

Background

The Short-Term Memory Binding (STMB) Test is a cognitive-behavioral assessment that measures the brain's ability to join and hold separate features of an object—such as its shape and color—together in temporary memory. James R. Brockmole and colleagues published the task in 2008 to determine whether age-related difficulty with remembering visual material could be caused by impairments in forming relational associations amongst pieces of visual information ('feature binding') rather than a simple reduction in visual memory capacity. In their study they tested memory for colors ("do the shapes have the same colors as before?) and memory for shapes ("are the shapes the same as before?") separately and in a combined condition ("are these the same objects -in color AND shape

• as before?"). Their results supported that healthy aging resulted in reduced memory capacity but not in deteriorating feature binding. The deteriorating ability to bind features in short-term memory was later shown by Mario A. Parra and his colleagues (2009) to be an early marker for Alzheimer Disease and could be used to isolate Alzheimer’s-specific pathology from healthy aging or other conditions like depression.

Task Procedure

The Millisecond STMB procedure is based on the published paradigm by Brockmole et al (2008). The test consists of three blocks: Color-only, Shape-only and Binding. The order of the task is counterbalanced by running the task with one of six different groupnumbers.

In the 'Color-only' condition, participants are shown an array of 4 shapes (always the same shape) in four different colors presented in a random arrangement on the screen for a short duration. After a short delay, another set of 4 shapes (same shape as before) in four different colors are presented in a random arrangement for a short duration. Participants are asked to decide, whether the shapes show the same colors as in the previous array (Note: if different, two colors have been replaced by new ones).

In the 'Shape-only' condition, participants are shown an array of 4 different shapes (all in the same color) presented in a random arrangement on the screen for a short duration. After a short delay, another set of 4 shapes (same color as before) are presented in a random arrangement for a short duration. Participants are asked to decide, whether the shapes are the same as in the previous array (Note: if different, two shapes have been replaced by new ones).

In the 'Binding' condition, participants are shown an array of 4 different shapes in four different colors presented in a random arrangement on the screen for a short duration. After a short delay, another set of 4 shapes in four colors (the same colors as before, but potentially not for the same shapes as before) are presented in a random arrangement for a short duration. Participants are asked to decide, whether the objects (in shape AND color) are the same as in the previous array (Note: if different, two shapes have swapped colors).

In each condition, the first array of objects is presented for 1000ms, followed by a blank screen for 900ms before the second array is presented. After the response, an intertrial interval of 1000ms separates each trial from the next.

All conditions run 32 trials (a random order of 16 'same' and 16 'differen't ones) and are preceded by practice block of 10 practice trials. During practice, participants receive performance feedback.

What it Measures

The Short-Term Memory Binding (STMB) Test is a sensitive measure of well the brain links visual features in short-term memory

Psychological domains

• Short-Term and Working Memory: Ability to hold (and manipulate) information in temporary storage
• Conjunctive Binding: Ability to integrate fragmented pieces of data (e.g., color and shape) into a unified mental representation
• Visuospatial Perception: Ability to accurately perceive visual items, spatial configurations, and abstract lines.
• Selective Attention: Ability to focus the target features while ignoring external distractions
• Sustained Attention: Ability to maintain a consistent focus across multiple rapid trials without experiencing an immediate drift in vigilance.

Main Performance Metrics

• dPrime: Measures of Sensitivity to Change in Shapes-only, Color-only and Binding conditions
• Proportional Binding Cost: Difference in dPrime Measures for Shapes-only (Baseline) and Binding conditions relative to dPrime Shapes-only (Baseline)

Psychiatric Conditions

The STMB is used for many patient groups to help distinguish observable memory problems from Alzheimer's Disease (AD). Generally, only patients with AD or suspected AD tend to show binding performance issues.

• Alzheimer's Disease (AD)
• Frontotemporal Dementia (FTD)
• Dementia associated with Parkinson’s Disease
• Major Depressive Disorder (MDD)

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Short Term Memory Binding Test (STMB).

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Jarrold, C., Phillips, C., & Baddeley, A. (2007). Binding of visual and spatial short-term memory in Williams syndrome and moderate learning disability. Developmental Medicine & Child Neurology, 49(4), 270-273.

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).

Parra, M., Abrahams, S., Logie, R., Méndez, L., Lopera, F., & Della Sala, S. (2010). Visual short-term memory binding deficits in familial Alzheimer’s disease. Brain, 133(9), 2702-2713.

Logie, R., Brockmole, H., & Jaswal, J. (2011). Feature binding in visual short-term memory is unaffected by task-irrelevant changes of location, shape, and color. Memory & Cognition, 39(1), 24-36.