The Chimp Test, also known as the Ayumu chimpanzee memory task, is a famous cognitive test that flashes numbers on a grid and then covers them. The task is to click the covered tiles in numerical order. While most adult humans struggle when the count exceeds 7 or 8 numbers, a young chimpanzee named Ayumu completed the test with up to 9 numbers in a fraction of a second, achieving nearly 80% accuracy. This guide explores the neuroscience behind this phenomenon and how you can optimize your own spatial recall.
The Cognitive Trade-Off Hypothesis
Why can chimpanzees recall spatial locations so much faster and more accurately than humans? Kyoto University researchers proposed the Cognitive Trade-Off Hypothesis.
As humans evolved complex language, symbolic thought, and advanced planning abilities, our brains repurposed neural networks in the prefrontal cortex and parietal lobes. Chimpanzees retained a highly efficient, short-term eidetic memory (photographic memory), which is essential for survival in the wild, such as mapping tree branches and detecting predators. In humans, this instant visual indexing was sacrificed to make room for linguistic processing and semantic categorization.
Human Limits in Working Memory
In cognitive psychology, the human working memory capacity is often defined by Miller's Law, which suggests that the average adult can hold approximately 7 items (plus or minus 2) in active memory. For spatial grids like the Chimp Test, this capacity drops slightly due to the complexity of spatial coordination.
- Phonological Loop: Human working memory relies heavily on subvocalization (repeating numbers in your head). This process is slow compared to instant visual recognition.
- Decay Time: Unrehearsed information in human short-term memory decays within 15 to 30 seconds.
How to Train and Improve Your Score
While humans do not possess the same raw photographic memory capacity as chimpanzees, we can use cognitive strategies to bypass our working memory bottlenecks:
- Chunking: Group numbers into clusters. For example, memorize the position of 1, 2, and 3 as a single triangle shape, 4, 5, and 6 as a straight line, and the remaining numbers individually.
- Visual Pathing: Instead of memorizing individual grid positions, trace a continuous line or path with your eyes connecting the numbers in order before you click. Your brain processes this single continuous path more easily than separate coordinates.
- The Method of Loci: Associate the spatial locations on the screen with a familiar mental map, such as the corners of a room.
Test your memory capacity
Challenge yourself on the Chimp Test to see where you stand relative to human and primate averages.