Top-down attentional control in Parkinson's disease: salient considerations

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Cognitive dysfunction is a hallmark of Parkinson's disease (PD).
• Deficits resemble those seen in patients with lateral prefrontal cortex (pFC) lesions, suggesting impaired top-down attentional control.
• Direct evidence for this failure in PD has been lacking.

Purpose of the Study:

• To provide direct evidence for a failure of top-down attentional control in Parkinson's disease.
• To investigate the role of bottom-up attention to dimensional salience in PD cognitive deficits.

Main Methods:

• An attentional set-shifting task was administered to patients with PD and healthy controls.
• Performance was assessed based on trials to criterion when shifting attention between dimensions of varying salience.

Main Results:

• Parkinson's disease patients required more trials to shift attention to low-salient dimensions compared to controls.
• Conversely, PD patients required fewer trials to shift to high-salient dimensions.
• This indicates a disproportionate influence of bottom-up attention to salient information in PD.

Conclusions:

• The findings provide the first direct evidence for a failure of top-down attentional control in Parkinson's disease.
• Results suggest that cognitive deficits in PD stem from an over-reliance on bottom-up attentional capture by salient stimuli.
• This impairment resembles deficits observed after catecholamine depletion in the pFC.