180 | Electrophysiological alterations during action semantic processing in Parkinson’s disease

Disorders of the Nervous System

Author: Mariano Nicolás Díaz Rivera | Email: Marianonicodr@gmail.com

Mariano Nicolás Díaz Rivera , Lucía Amoruso , Agustina Birba , Adolfo García

1° Centro de Neurociencias Cogntivas, Universidad de San Andrés

Assessments of action semantics consistently reveal markers of Parkinson’s disease (PD). However, neurophysiological signatures of the domain remain under-examined in this population, especially in conditions that allow patients to process stimuli without stringent time constraints. To bridge this gap, we assessed event-related potentials and time-frequency modulations in healthy individuals (HPs) and PD patients during a delayed-response semantic judgment task involving related and unrelated action-picture pairs. Both groups had slower response times for unrelated trials compared to related ones, but they exhibited discrepant electrophysiological patterns. HPs presented significantly greater N400 amplitudes as well as theta enhancement and mu desynchronization for unrelated relative to related trials. Conversely, N400 and theta modulations were abolished in the patients, who further exhibited a contralateralized cluster in the mu range. None of these patterns were associated with the participants’ cognitive status. Taken together, our results suggest that PD involves multidimensional neurophysiological disruptions during action-concept processing, even under task conditions that elicit canonical behavioral effects. New constraints thus emerge for translational neurocognitive models in this population.