Competition for priority in processing increases prefrontal cortex's involvement in top-down control: an...

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Attention Research

Background:

• Task-irrelevant information can influence prefrontal cortex (PFC) involvement in attentional control.
• Prior studies suggest PFC engagement rises with increased salience, task-relatedness, or emotionality of irrelevant information.
• The hypothesis posits that PFC activation intensifies when irrelevant information competes for processing priority.

Purpose of the Study:

• To investigate how task-irrelevant information's competition for processing priority affects PFC activity.
• To examine the impact of frequency, conflict, and levels of conflict on PFC engagement.
• To differentiate the roles of distinct PFC subregions in attentional control under varying conflict conditions.

Main Methods:

• Event-related functional magnetic resonance imaging (fMRI) was employed.
• An oddball variant of the Stroop task was utilized to manipulate task-irrelevant information.
• Manipulations included varying the frequency of irrelevant information, presence of color conflict, and number of conflict levels.

Main Results:

• Posterior-dorsolateral PFC (DLPFC) and posterior-inferior PFC showed increased activity with infrequent irrelevant information, peaking with color conflict.
• Mid-DLPFC activity increased specifically with color conflict, particularly when conflict occurred at multiple levels.
• Anterior cingulate cortex (ACC) responded primarily to response-level conflict, with a smaller region sensitive to non-response conflict.

Conclusions:

• Posterior DLPFC and PIPFC likely bias processing in posterior systems.
• Mid-DLPFC appears involved in biasing working memory content.
• ACC is primarily associated with response-related conflict processing.