The Spatial Memory Test: Visuospatial Working Memory, Explained

In Keel's spatial memory test, you observe a sequence of locations highlighted on a grid, then reproduce the sequence from memory. The grid size and sequence length vary, adapting to maintain an appropriate level of challenge. You are asked to hold and manipulate spatial information over a short retention interval — the defining task of visuospatial working memory.

This format is adapted from the Corsi Block Tapping Test, developed by Philip Corsi in the 1970s and subsequently refined by neuropsychologist Brenda Milner's group. It is a standard component of comprehensive neuropsychological evaluations and is included in the Cambridge Neuropsychological Test Automated Battery (CANTAB), a widely used digital cognitive assessment platform.

Spatial memory engages a distributed network: the hippocampus encodes the sequence; the parietal lobes process spatial relationships and location; the prefrontal cortex holds the sequence in working memory during the retention interval. Unlike verbal working memory (which engages primarily left hemisphere language networks), visuospatial working memory relies heavily on right hemisphere and posterior cortex.

This distinction matters clinically. The hippocampus and entorhinal cortex — regions central to spatial memory — are among the earliest sites of amyloid plaque and tau tangle accumulation in Alzheimer's disease. Spatial disorientation (getting lost in familiar places) is a well-documented early symptom. A daily spatial memory task thus probes one of the most disease-relevant circuits in a relatively direct way.

The spatial navigation system — sometimes called the 'cognitive map' — is centered in the hippocampus and entorhinal grid cells. In Alzheimer's disease, grid cell disruption precedes widespread memory decline by years. Several research groups have shown that subtle spatial navigation deficits can be detected in APOE4 carriers and in people with early amyloid accumulation, before they meet any clinical criteria for impairment.

Keel's spatial memory test is not a clinical Alzheimer's screen and cannot diagnose anything. But it does probe the same neural circuits that are vulnerable early — which is precisely why tracking changes in spatial memory over time, rather than taking a single snapshot, may have value for people monitoring their cognitive health.

Spatial memory is particularly sensitive to sleep. REM sleep — the stage most reliably disrupted by alcohol, stress, and some sleep medications — plays a specific role in consolidating spatial memories and maintaining hippocampal function. A night with fragmented or reduced REM sleep predictably suppresses spatial recall the following day.

Age-related decline in spatial memory is real and measurable, but it is gradual. The key question your trend line answers: is your spatial memory declining faster than expected for your age, or at the normal slow rate? A single low score never answers this. Months of data do.