Groton Maze Learning Test (GMLT)
Background
The Groton Maze Learning Test (GMLT) is a computerized measure of immediate- and delayed-term visuospatial memory, spatial learning efficiency, and processing speed. It was developed by Peter Snyder, Paul Maruff, and Robert Pietrzak in the early 2000s and is commercially available through the Cogstate Brief Battery. The modern Groton Maze Test is based on 'the stepping-stone maze' paradigm by Roger Barker from 1931 and the 'stylus-maze task' by Brenda Milner from 1965. The Groton Maze Test has reliably shown to be sensitive to cognitive changes and is used in aging research as well as a clinical assessment tool to identify executive dysfunction in vulnerable patient groups.
The main task in the Groton Maze Test is to find a 'hidden' 28-square pathway in a 10x10 grid that starts in the upper left corner and ends in the lower right corner of the grid. This pathway needs to be discovered following specific rules.
- Rule1: only move one box at a time
- Rule2: only move up or down, left or right (no diagonal moves allowed)
- Rule3: do not move backwards (unless for error corrections)
Each correct square that is selected (by mouse or touch) is briefly highlighted in green. Each error square is briefly highlighted in red, and participants should immediately correct the error by moving back to the last correct square to try again. After three consecutive errors, participants are forced by the program to return to the last correct square which gets visibly highlighted with a flashing '!' at that point. Participants are tested with the same maze 6 times, with the last round being an optional 'delayed' test. Each time participants work through the maze, they are timed, and errors are counted and classified as legal errors (LE), perseverative errors (PE) or rule-break errors (RbE). Legal Errors include the selection of each first wrong selection made (starting from a correct square), PE errors refer to the number of times participants keep selecting a second wrong square and RbR refer to the third consecutive error selections that is forcibly corrected.
The Millisecond implementation of the Groton Maze test provides five different pathways. All pathways consist of 28 squares with 11 corners. By default, the pathway is selected randomly. However, test administrators can opt to select specific pathways instead. Note that the Groton Maze Test does not run a practice session. To familiarize participants with the maze setup it is recommended to have participants play the 'Timed Chase Game', a computerized version of 'Capture-the-Flag' game first.
Task Procedure
After learning about the rules for the Groton Maze test, participants start the first round. To start the maze they must select the start square, marked by a blue dot, in the upper left corner of the 10x10 grid. If they miss selecting the start square, they are reminded to do so by the computer. Participants work through the square by trying to find all 'green' squares in the correct order by guessing and correcting mistakes until they successfully reach the goal square, marked by a yellow dot, in the lower right corner of the grid. Rounds 2-5 follow immediatly, one after the other. Each round tests the same underlying pathway thus participants can use their memory of previous attempts to guide their selections. Round 6 can be used as a delayed test of the maze and run after a specified delay period.
What it Measures
The Groton Maze Test measures immediate- and delayed-term visuospatial memory, spatial learning efficiency, and processing speed.
Psychological domains
- Complex Attention: Both parts require visual scanning, searching, and sustained attention.
- Processing Speed: Measured by the total time taken to complete the tasks, reflecting both mental and motor processing speeds.
- Executive Functioning: This is the primary domain measured by Part B, which requires set-shifting, a component of cognitive flexibility
Main Performance Metrics
- Legal Errors: number of first error moves that were legal (across all rounds 1-5)
- Perseverative Errors: number of repeated error moves (across all rounds 1-5)
- Rule-Break Errors: number of three consecutive errors made as well as illegal first errors ((across all rounds 1-5)
- Maze Efficiency Index: A summary score calculated as the mean number of correct moves per second across all trials.
Psychiatric Conditions
The following patient groups show impaired performance on the Groton Maze Test:
- Dementia
- Mild Cognitive Impairment (MCI)
- Attention-Deficit/Hyperactivity Disorder (ADHD)
- Schizophrenia
Test Variations
This script implements a version of the Groton Maze Test, a measure of immediate- and short-term visuospatial memory as described in Schroder et al (2004).
This script implements the Timed Chase Test (TCT), a simple test of visuomotor processing speed- as described in Schroder et al (2004).
References
Search Google Scholar for peer-reviewed, published research using the Inquisit Groton Maze Learning Test (GMLT).
Schroder, M.D, Snyder, P.J, Sielski, I. & Mayes, L. (2004). Impaired performance of children exposed in utero to cocaine on a novel test of visuospatial working memory. Brain and Cognition, 55, 409–412.
Pietrzak, R. H., Cohen, H., & Snyder, P. J. (2007). Learning efficiency and error monitoring in normal aging: An investigation using a novel hidden maze learning test. Archives of Clinical Neuropsychology, 22, 235–245.
Mathewson, K.J., Dywan, J., Snyder, P.J., Tays, W.J., & Segalowitz, S.J.(2008). Aging and electrocortical response to error feedback during a spatial learning task. Psychophysiology, 45, 936–948.