Neuronal activity in dorsomedial frontal cortex and prefrontal cortex reflecting irrelevant stimulus dimensions

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Primate Behavior

Background:

• Previous studies suggest dorsomedial frontal cortex (DMF) and prefrontal cortex (PF) neurons encode stimulus location.
• It remains unclear if this encoding is dependent on the behavioral relevance of location in conditioned tasks.

Purpose of the Study:

• To investigate whether DMF and PF neurons encode stimulus location independently of its relevance to an instrumentally conditioned behavior.
• To differentiate between location encoding as a general property versus a task-specific contingency.

Main Methods:

• Recorded neural activity from DMF and PF neurons in two rhesus monkeys.
• Monkeys performed an operant eye-movement task where only stimulus color and shape were relevant.
• Stimulus location varied randomly and was behaviorally irrelevant.

Main Results:

• A significant proportion of DMF and PF neurons encoded stimulus location.
• This encoding persisted even when stimulus location was not a relevant feature for the task.
• Location encoding was observed despite the absence of any task where location controlled behavior.

Conclusions:

• Neural encoding of stimulus location in DMF and PF is not contingent on its behavioral relevance.
• These findings suggest that location encoding is an intrinsic property of these neuronal populations.
• The results challenge the notion that observed neural activity solely reflects learned task contingencies.