William J. Gehring

Lateral prefrontal damage affects processing selection but not attention switching

Authors:

  • William J. Gehring

  • Robert T. Knight

Date: 2002

PubMed: 11958971

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Abstract:

A challenge for cognitive neuroscience is to determine how the prefrontal cortex (PFC) contributes to the cognitive control operations that oversee thought and action. We studied the effects of damage to the lateral PFC in two types of attentional control. Subjects performed a choice reaction time task that required attention switching and processing selection. The performance of individuals with PFC or parietal cortex damage was compared with that of age-matched and young control subjects. Damage to the lateral PFC did not significantly impair the switch from attending to one color to attending to another. PFC damage did, however, significantly increase the effects of distractor stimuli, implicating the lateral PFC in processing selection. Individual subjects' performance suggested that the left inferior posterior PFC was the most critical for processing selection. Our data are consistent with the view that the lateral PFC contributes to the top-down control of the information flow along pathways from sensory input to motor output.

Prefrontal-cingulate interactions in action monitoring

Authors:

  • William J. Gehring

  • Robert T. Knight

Date: 2000

PubMed: 10769394

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Abstract:

We found that medial frontal cortex activity associated with action monitoring (detecting errors and behavioral conflict) depended on activity in the lateral prefrontal cortex. We recorded the error- related negativity (ERN), an event-related brain potential proposed to reflect anterior cingulate action monitoring, from individuals with lateral prefrontal damage or age-matched or young control participants. In controls, error trials generated greater ERN activity than correct trials. In individuals with lateral prefrontal damage, however, correct-trial ERN activity was equal to error-trial ERN activ- ity. Lateral prefrontal damage also affected corrective behavior. Thus the lateral prefrontal cortex seemed to interact with the anterior cingulate cortex in monitoring behavior and in guiding compensatory systems.