Impaired proactive cognitive control in Parkinson's disease

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Adaptive control, crucial for goal-directed behavior, is often studied in Parkinson's disease (PD) with mixed findings.
• Proactive control involves anticipating and preparing for upcoming demands, while reactive control manages immediate conflicts.

Purpose of the Study:

• To compare reactive and proactive cognitive control in individuals with Parkinson's disease (PD) versus healthy controls.
• To investigate the neural underpinnings of these control mechanisms using electroencephalography (EEG).

Main Methods:

• A numerical Stroop task was administered to 30 PD patients and 30 age-matched healthy controls.
• Electroencephalographic (EEG) activity was recorded using 128 channels.
• Stimulus-response (S-R) learning effects were controlled to isolate adaptive control mechanisms.

Main Results:

• Participants with PD demonstrated distinct impairments in both proactive and reactive control compared to controls.
• PD patients showed reduced ability in proactive adaptation and less effective conflict resolution during reactive control.
• Midline-frontal theta power correlated with successful control in healthy individuals, suggesting a neural marker.

Conclusions:

• Parkinson's disease is associated with a general impairment of proactive cognitive control.
• Reactive control effectiveness in PD is also diminished, though evidence was less conclusive.
• Controlling for S-R learning is vital for accurate assessment of adaptive control in neurological conditions.