Tomassini, A;
Pollak, TA;
Edwards, MJ;
Bestmann, S;
(2019)
Learning from the past and expecting the future in Parkinsonism: Dopaminergic influence on predictions about the timing of future events.
Neuropsychologia
, 127
pp. 9-18.
10.1016/j.neuropsychologia.2019.02.003.
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Abstract
The prolonged reaction times seen in Parkinson's disease (PD) have been linked to a dopaminergic-dependent deficit in using prior information to prepare responses, but also have been explained by an altered temporal processing. However, an underlying cognitive mechanism linking dopamine, temporal processing and response preparation remains elusive. To address this, we studied PD patients, with or without medication, and age-matched healthy individuals using a variable foreperiod task requiring speeded responses to a visual stimulus occurring at variable onset-times, with block-wise changes in the temporal predictability of visual stimuli. Compared with controls, unmedicated patients showed impaired use of prior information to prepare their responses, as reflected by slower reaction times, regardless of the level of temporal predictability. Crucially, after dopamine administration normal performance was restored, with faster responses for high temporal predictability. Using Bayesian hierarchical drift-diffusion modelling, we estimated the parameters that determine temporal preparation. In this theoretical framework, impaired temporal preparation under dopaminergic depletion was driven by inflexibly high decision boundaries (i.e. participants were always extremely cautious). This indexes high levels of uncertainty about temporal predictions irrespectively of stimulus onset predictability. Our results suggest that dopaminergic depletion in PD affects the uncertainty of predictions about the timing of future events (temporal predictions), which are crucial for the anticipatory preparation of responses. Dopamine, which is affected in PD, controls the ability to predict the timing of future events.
| Type: | Article |
|---|---|
| Title: | Learning from the past and expecting the future in Parkinsonism: Dopaminergic influence on predictions about the timing of future events |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.neuropsychologia.2019.02.003 |
| Publisher version: | https://doi.org/10.1016/j.neuropsychologia.2019.02... |
| Language: | English |
| Additional information: | © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/). |
| Keywords: | Dopamine, Drift-diffusion model, Motor preparation, Parkinson's Disease, Temporal expectation, Temporal processing, Uncertainty |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Clinical and Movement Neurosciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10069417 |
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