Prefrontal neurons of opposite spatial preference display distinct target selection dynamics

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Primate Neurophysiology

Background:

• Neurons in the primate dorsolateral prefrontal cortex (dlPFC) exhibit selectivity for attended target locations across both visual hemifields.
• The precise interaction and roles of dlPFC neurons selective for opposite hemifields in target selection and attention allocation remain incompletely understood.

Purpose of the Study:

• To investigate whether dlPFC neurons with selectivity for opposite hemifields directly compete or play distinct roles during attention allocation.
• To elucidate the functional differentiation of neuronal populations within the dlPFC during attention tasks involving distracters.

Main Methods:

• Neuronal recordings were conducted in the right dlPFC of two macaques performing an attention task.
• Monkeys allocated attention to a target in one hemifield while ignoring a distracter in the opposite hemifield.
• Neuronal responses were analyzed during target discrimination and a control task involving fixation spot changes.

Main Results:

• 49% of recorded dlPFC neurons showed target location selectivity.
• Neurons selective for contralateral targets (58%) discriminated targets from distracters faster than ipsilateral neurons (42%).
• Contralateral neurons maintained target-distracter discrimination even when stimuli were task-irrelevant, unlike ipsilateral neurons, suggesting independent processing.

Conclusions:

• Contralateral and ipsilateral dlPFC neurons may represent distinct components of the prefrontal circuitry for attention allocation.
• The presence of a contralateral distracter significantly reduced responses to attended targets, indicating inhibitory interactions within dlPFC circuitry.