Spontaneous spatial mapping of learned sequence in chimpanzees: evidence for a SNARC-like effect

Area of Science:

• Cognitive Science
• Comparative Psychology
• Neuroscience

Background:

• Humans exhibit a spatial-numerical association, often representing numbers along a left-to-right spatial dimension.
• Understanding the evolutionary origins of such cognitive abilities requires examining non-human primates.

Purpose of the Study:

• To investigate whether chimpanzees, our closest living relatives, exhibit a similar spatial mapping of acquired numerical sequences as observed in humans.
• To explore the evolutionary roots of the spatial-numerical association.

Main Methods:

• Chimpanzees were trained on a sequential number task involving Arabic numerals presented in random locations.
• Test trials presented only numerals 1 and 9 horizontally, with varying spatial arrangements (1 left of 9, or 1 right of 9).
• Response times were measured to assess the influence of spatial arrangement on task performance.

Main Results:

• Chimpanzee performance was significantly affected by the spatial arrangement of numerals 1 and 9.
• Chimpanzees responded faster when 1 was positioned to the left of 9, consistent with the human left-to-right spatial-numerical mapping.
• This indicates a spontaneous spatial mapping of the learned numerical sequence.

Conclusions:

• Chimpanzees demonstrate a spontaneous spatial-numerical association for learned sequences, mirroring human cognitive patterns.
• This finding supports the hypothesis of shared evolutionary origins for spatial representations of numerical order between humans and chimpanzees.
• The study provides crucial insights into the deep evolutionary history of numerical cognition and spatial mapping.