Chimp Test vs Number Memory: Which Tests Working Memory Better?

The Chimp Test and Number Memory both measure working memory, but they target fundamentally different subsystems in your brain. Understanding this distinction helps you train smarter and build comprehensive memory capacity.

The Chimp Test: Visuospatial Working Memory

In the Chimp Test, numbers appear briefly on a grid, then are hidden. You must click their positions in ascending order from memory. This engages:

• Visuospatial sketchpad — your brain's scratch pad for spatial information
• Spatial encoding — converting screen positions into mental maps
• Rapid visual processing — the numbers appear for only a fraction of a second
• Sequential motor planning — clicking positions in the correct order

The task mirrors what primates do naturally: rapidly scan an environment and remember where things are. Chimpanzees are famously better at this than humans, which is why the test bears their name.

Number Memory: Verbal Working Memory

In Number Memory, a number appears on screen for a few seconds and you must type it back from memory. This engages:

• Phonological loop — your brain's system for rehearsing verbal/numeric information
• Subvocal rehearsal — "saying" the number in your head to keep it active
• Sequential encoding — remembering the order of digits
• Chunking ability — grouping digits into meaningful units (e.g., 1492 as a year)

This is the classic digit span test used in psychology since the 1880s. It remains one of the most reliable measures of verbal working memory capacity.

Both tests map neatly onto Alan Baddeley's influential model of working memory, which identifies separate subsystems:

1. Phonological loop — handles verbal and numeric information (Number Memory)
2. Visuospatial sketchpad — handles spatial and visual information (Chimp Test)
3. Central executive — coordinates attention between systems (both tests)
4. Episodic buffer — integrates information from both systems (both tests)

This model explains why you can be excellent at one test and mediocre at the other. The subsystems are genuinely independent, with different neural bases and different capacity limits.

Neither test is objectively better—they measure different things. However, each has advantages:

Chimp Test Advantages

• Tests rapid encoding — the brief display time demands fast spatial processing
• Less susceptible to strategies — you cannot easily "chunk" spatial positions
• More novel for most people — less practiced, so scores reflect raw ability
• Engages visual processing — combines memory with perceptual speed

Number Memory Advantages

• More standardized — digit span is one of psychology's most validated measures
• Clearer improvement path — chunking and rehearsal strategies produce large gains
• More practical transfer — daily life is full of numbers to remember
• Higher ceiling with training — memory athletes memorize 100+ digits using techniques

Recommendation

Test both. If your Chimp Test score significantly exceeds your Number Memory score (or vice versa), you have identified a working memory imbalance worth addressing. Training your weaker subsystem will produce larger gains than further training your strong one.

Week Structure

Chimp Test Improvement Tips

• Focus on the flash — train yourself to absorb the entire grid in one glance rather than scanning left to right
• Build spatial chunks — group nearby numbers into clusters (1-2-3 are in the top left)
• Use consistent scan patterns — always process the grid the same way
• Practice speed over accuracy initially — build rapid encoding before pushing capacity

Number Memory Improvement Tips

• Chunk aggressively — group digits into 2-4 digit chunks (7, 3, 8, 2 becomes 73, 82)
• Use rhythm — rehearse chunks with a musical cadence
• Create associations — 1776 is a year, 365 is days in a year
• Practice the phonological loop — say numbers aloud during practice to strengthen subvocal rehearsal

The Chimp Test and Number Memory are complementary working memory exercises that target different brain systems. A complete memory training program includes both, because real-world demands draw on both spatial and verbal memory constantly. Test both today, identify your weaker channel, and give it extra attention. Your working memory is only as strong as its weakest subsystem.