Anterior medial prefrontal cortex exhibits activation during task preparation but deactivation during task execution

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Brain Function

Background:

• The anterior prefrontal cortex (PFC) is involved in various cognitive functions.
• The medial part of the anterior PFC is part of the default mode network (DMN), typically deactivated during goal-directed tasks.
• Dynamic allocation of attentional resources may influence anterior medial PFC (MPFC) activity.

Purpose of the Study:

• To investigate how dynamic allocation of attentional resources affects activity in the anterior MPFC.
• To examine MPFC activity patterns during different phases of a working memory task.

Main Methods:

• Event-related functional magnetic resonance imaging (fMRI) was used.
• Participants performed a face working memory task with distinct preparation and execution periods.
• Task set formation for face memory versus ignoring faces was manipulated.

Main Results:

• The anterior MPFC showed activation during the task preparation period when forming a face memory task set.
• The anterior MPFC exhibited deactivation during the task execution period within the same trial.
• This pattern was observed specifically when participants were engaged in face memory.

Conclusions:

• The anterior MPFC plays a role in task set formation, not task execution, in this face working memory paradigm.
• Deactivation of the anterior MPFC during execution suggests attentional resources are allocated elsewhere.
• Anterior MPFC activation and deactivation are influenced by the dynamic allocation of processing resources.