Implicit task switching in Parkinson's disease is preserved when on medication.

Jacob A Yaffe,Yair Zlotnik,Gal Ifergane,Shelly Levy-Tzedek,Diego Kaski

doi:10.1371/journal.pone.0227555

Jacob A Yaffe, Yair Zlotnik + Show 3 more

Open Access

https://doi.org/10.1371/journal.pone.0227555

Copy DOI

Abstract

People with Parkinson’s disease have been shown to have difficulty switching between movement plans. In the great majority of studies, the need to switch between tasks was made explicitly. Here, we tested whether people with Parkinson’s disease, taking their normal medication, have difficulty switching between implicitly specified tasks. We further examined whether this switch is performed predictively or reactively. Twenty five people with Parkinson’s disease continuously increased or decreased the frequency of their arm movements, inducing an abrupt–but unaware–switch between rhythmic movements (at high frequencies) and discrete movements (at low frequencies). We tested whether that precipitous change was performed reactively or predictively. We found that 56% of participants predictively switched between the two movement types. The ability of people with Parkinson’s disease, taking their regular medication, to predictively control their movements on implicit tasks is thus preserved.

Highlights

Parkinson’s disease (PD) is a progressive neurodegenerative disease [1]
We found that the gradual change in movement frequency induced an unaware abrupt change from a discrete to a rhythmic movement type, and vice versa
Our goals in the current study were to test: (1) whether patients with PD, taking their regular medication, are able to switch between two movement plans of the upper limb when the ID Age Gender UPDRS motor score

Summary

Introduction

Parkinson’s disease (PD) is a progressive neurodegenerative disease [1]. Considered the second most common neurodegenerative disease after Alzheimer’s disease, PD effects approximately 7.5 million people worldwide [2]. It has been documented that people with PD have difficulties switching between movement plans [12], such as walking initiation and turning [13,14], or trying to perform a predetermined sequence of actions [15], and that transitioning between tasks (e.g., rising from a chair) is associated with an increased risk of falling [7]. In the tasks reviewed above, as well as others documenting a difficulty for patients with PD in switching between tasks [16,17,18,19], the need to change one’s movement plan is explicitly clear. Participants were asked to continuously change the frequency of their arm movements

Participants

Results

Discussion

Study limitations