Short-term memory, attentional control and brain size in primates.

Area of Science:

• Comparative psychology
• Neuroscience
• Evolutionary biology

Background:

• Brain size variability in primates is often linked to socio-ecological factors.
• Previous studies found no correlation between short-term memory and external cognitive demands in primates.

Purpose of the Study:

• To investigate the relationship between primate short-term memory performance and brain size.
• To determine if domain-specific brain regions or overall brain size better predict short-term memory abilities.

Main Methods:

• Analyzed interspecific variation in short-term memory test performance across 41 primate species.
• Examined correlations with total brain size and encephalization quotient.
• Assessed the predictive power of specific brain region sizes on performance.

Main Results:

• Short-term memory performance strongly correlated with total brain size, especially after removing small sample sizes.
• Encephalization quotient did not predict performance.
• Sizes of brain regions associated with memory did not outperform overall brain size.

Conclusions:

• Primate short-term memory performance is linked to domain-general cognitive abilities, not domain-specific adaptations.
• Total brain size is a better predictor of cognitive performance than previously thought.
• Refinements to the delayed response test are suggested to better isolate short-term memory.