Reward sensitivity predicts dopaminergic response in spatial neglect
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
It has recently been revealed that spatial neglect can be modulated by motivational factors including anticipated monetary reward. A number of dopaminergic agents have been evaluated as treatments for neglect, but the results have been mixed, with no clear anatomical or cognitive predictors of dopaminergic responsiveness. Given that the effects of incentive motivation are mediated by dopaminergic pathways that are variably damaged in stroke, we tested the hypothesis that the modulatory influences of reward and dopaminergic drugs on neglect are themselves related.
We employed a single-dose, double-blind, crossover design to compare the effects of Co-careldopa and placebo on a modified visual cancellation task in patients with neglect secondary to right hemisphere stroke. Whilst confirming that reward improved visual search in this group, we showed that dopaminergic stimulation only enhances visual search in the absence of reward. When patients were divided into REWARD-RESPONDERs and REWARD-NON-RESPONDERs, we found an interaction, such that only REWARD-NON-RESPONDERs showed a positive response to reward after receiving Co-careldopa, whereas REWARD-RESPONDERs were not influenced by drug. At a neuroanatomical level, responsiveness to incentive motivation was most associated with intact dorsal striatum.
These findings suggest that dopaminergic modulation of neglect follows an ‘inverted U’ function, is dependent on integrity of the reward system, and can be measured as a behavioural response to anticipated reward.
We employed a single-dose, double-blind, crossover design to compare the effects of Co-careldopa and placebo on a modified visual cancellation task in patients with neglect secondary to right hemisphere stroke. Whilst confirming that reward improved visual search in this group, we showed that dopaminergic stimulation only enhances visual search in the absence of reward. When patients were divided into REWARD-RESPONDERs and REWARD-NON-RESPONDERs, we found an interaction, such that only REWARD-NON-RESPONDERs showed a positive response to reward after receiving Co-careldopa, whereas REWARD-RESPONDERs were not influenced by drug. At a neuroanatomical level, responsiveness to incentive motivation was most associated with intact dorsal striatum.
These findings suggest that dopaminergic modulation of neglect follows an ‘inverted U’ function, is dependent on integrity of the reward system, and can be measured as a behavioural response to anticipated reward.
Date Issued
2020-01-01
Date Acceptance
2018-09-03
Citation
Cortex, 2020, 122, pp.213-224
ISSN
0010-9452
Publisher
Elsevier
Start Page
213
End Page
224
Journal / Book Title
Cortex
Volume
122
Sponsor
Imperial College Healthcare NHS Trust- BRC Funding
Grant Number
RDA03
Subjects
Science & Technology
Social Sciences
Life Sciences & Biomedicine
Behavioral Sciences
Neurosciences
Psychology, Experimental
Neurosciences & Neurology
Psychology
Attention
Motivation
Neglect
Reward
Dopamine
MEDIAL AGRANULAR CORTEX
UNILATERAL NEGLECT
AGONIST THERAPY
VISUAL NEGLECT
L-DOPA
ATTENTION
APATHY
HEMINEGLECT
STIMULATION
APOMORPHINE
Attention
Dopamine
Motivation
Neglect
Reward
1109 Neurosciences
1702 Cognitive Sciences
1701 Psychology
Experimental Psychology
Publication Status
Published
Date Publish Online
2018-10-18