Beta oscillation modulations of the orienting attention network effect correlate with dopamine-dependent motor symptoms of Parkinson's disease.

Attention impairment, a prevalent non-motor symptom in Parkinson's disease (PD), plays a crucial role in movement disorders. PD patients exhibit abnormalities in the attentional network related to alerting, orienting, and executive control. While dopamine medications have well-documented effects on motor function, their impact on attention networks and the underlying neural mechanisms involved in motor functions remain unclear. In this study, we utilized a modified attention network test to investigate the neural correlates underlying attention network effects measured by electroencephalography (EEG) in 29 PD patients, both on and off dopamine medication and examined their association with motor performance. Interestingly, we found that dopamine medication specifically modulated the orienting effect of the attention network. We analyzed event-related potential components, time-frequency oscillations, and brain network connectivity, as determined by the weighted phase lag index, within the orienting effect under different dopamine medication states. We observed that event-related desynchronization in the beta, event-related synchronization in the beta, and functional connectivity of the beta in the frontal, central, and parietal were regulated by dopamine medication in the orienting effect. We discovered an association between the attention network's orienting effect and motor performance alterations, which may be attributed to enhanced functional connectivity within the beta-brain network. Enhanced weighted phase lag index of the beta-brain network in the orienting effect may contribute to dopamine-dependent changes in motor performance. These preliminary findings provide insights into the EEG mechanisms that underlie the impact of the orienting effect in individuals with PD, shedding light on the influence of dopamine medication and its potential role in regulating top-down attention processes. These findings could help in the advancement of substitution strategies and may have the potential to address both motor and cognitive deficits in PD patients.