Dot Memory Task

Background

The Dot Memory Task is a brief cognitive assessment of visuo-spatial memory, designed by Martin J. Sliwinski and colleagues in 2018 to be a portable test of short-term memory capacity and cognitive performance. Each trial of the task presents participants with a single 5x5 grid displaying three dots. For each dot display, participants have 3 seconds to encode the location of the dots for a later recall task. Before the recall task, participants work on a secondary visual search distractor task that asks them to select all the F's from a display of 'E's and 'F's for about 8 seconds to prevent rehearsal. The recall trials present an empty 5x5 grid, and participants are instructed to click on the dot locations that they remember.

Sliwinski et al (2018) report acceptable within-person reliability as well as good construct validity of the task and suggest that the brief assessment tool designed to be used in uncontrolled settings provides reliable results comparable to those made in controlled laboratory environments.

Task Procedure

After an animated demo to explain the task, the Millisecond Dot Memory Task runs two trial. Each trial starts with the encoding phase that presents a 5x5 grid with three dots. The grid locations of the dots are pre-determined and the same for each participant. Participants get 3 seconds to encode the dot locations.

The distractor phase starts immediately after the encoding phase. The script displays a 5x8 matrix filled with 'E's and 'F', and participants are asked to select all 'F's (by default there are 8). Letters can be selected (and un-selected) by clicking or touching the respective letters. Selected letters get highlighted. The distractor phase automatically ends after 8 seconds and the retrieval phase starts.

For each retrieval trial, the script provides an empty 5x5 matrix and instructs participants to select the matrix positions of the 3 dots. Any time participants touches an empty box, a dot is placed. Once 3 dots are placed, no further dots are accepted. Dots can be erased by touching a previously placed dot. The retrieval trial ends when participants select a 'done' button. The screen goes blank for 1000ms before the next trial is started.

What it Measures

The Dot Memory Task is a quick measure of visuo-spatial working memory.

Psychological domains

• Episodic Memory: Ability to encode and recall a specific event in time and space
• Visuospatial Memory: Ability to process, retain, and manipulate visual imagery and spatial layouts within the mind's eye.
• Associative Binding: Memory sub-process that links two unrelated pieces of information (dot & spatial location) into a unified mental representation
• Selective and Sustained Attention: Ability to maintain focus during the encoding phase

Main Performance Metrics

• Recall Error Score: The mean distance-related error placement score; main measure of visuo-spatial memory

Psychiatric Conditions

The Dot Memory Task has been used with the following clinical populations

• Multiple Sclerosis (MS)
• Chronic Pain and Rheumatological Conditions (e.g., Fibromyalgia)
• **Mild Cognitive Impairment (MCI) **

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Dot Memory Task.

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Shaw, R., Helmes, E., & Mitchell, D. (2006). Research: Age-related change in visual, spatial and verbal memory. Australasian Journal on Ageing, 25(1), 14-19.

Siedlecki KL. Investigating the structure and age invariance of episodic memory across the adult lifespan. Psychology and Aging. 2007; 22(2):251–268

Sliwinski et al (2018)