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Description
Chasing prey or foraging requires evaluating distant stimuli, transforming this information into an action plan, and adjusting ongoing behavior in a timely manner. The evolutionary expansion of the frontal cortex is considered responsible for enhanced behavioral flexibility and an extended spatiotemporal radius of potential actions, enabling us to make mid-movement decisions about distant goals.
The primary motor cortex (M1) and the dorsal premotor cortex (PMd) are two frontal areas known for their critical roles in selecting, planning, and executing arm reaches. These two brain areas differ in evolutionary age, with PMd emerging later than M1. Here we ask whether this difference translates into distinct action-planning horizons when rhesus monkeys approach distant targets during locomotion. Specifically, we hypothesize that PMd, being a more recent evolutionary acquisition, plays a greater role than M1 in representing and selecting targets beyond reach.
To test this, we recorded neural activity from M1 and PMd in three rhesus macaques as they chose between two potential targets while walking towards them.
Our findings show that PMd is involved in selecting distant action goals and can update preferred target representations based on the targets’ value during the ongoing approach behavior. In contrast, M1 is primarily involved in arm movements for locomotion. We conclude that the two brain regions play different roles in adaptive full-body foraging behavior, corresponding to different action horizons: within reach for M1, and beyond reach for PMd, opening new perspectives on the organization of the frontal-lobe action-associated brain regions during ecologically relevant behaviors.
