Rhesus monkeys employ a procedural strategy to reduce working memory load in a self-ordered spatial search task

Area of Science:

• Cognitive Neuroscience
• Primate Behavior
• Animal Cognition

Background:

• Nonhuman primates often use distance-minimizing strategies in foraging and spatial tasks.
• Spatial sequencing may reduce cognitive and physical demands.
• A computerized self-ordered spatial search (SOSS) task, adapted from human neuropsychology, assesses spatial memory.

Purpose of the Study:

• To assess the spatial self-ordered spatial search (SOSS) performance of rhesus monkeys.
• To determine if employing a distance-minimizing search path enhances accuracy in SOSS.
• To investigate the relationship between strategy use and spatial working memory demands.

Main Methods:

• Adapted a computerized self-ordered spatial search (SOSS) memory task for rhesus monkeys.
• Developed a novel strategy score to quantify distance-minimizing behavior, independent of task difficulty.
• Analyzed SOSS performance data from 21 rhesus monkeys over two years.

Main Results:

• A distance-minimizing search strategy was significantly associated with improved accuracy in the SOSS task.
• This association was observed both within individual monkeys over time and across different training levels.
• Trials with errors were linked to a failure to utilize the distance-minimizing strategy.

Conclusions:

• Rhesus monkeys' adoption of a distance-minimizing search strategy enhances accuracy on the SOSS task.
• This strategy effectively reduces demands on spatial working memory resources in a laboratory setting.
• Findings suggest that spatial sequencing strategies are crucial for optimizing performance in spatial memory tasks.