Fronto-striatal grey matter contributions to discrimination learning in Parkinson’s disease

Frontiers in Computational Neuroscience

Trevor W Robbins²  James M Shine³  Simon J. G Lewis³  Sanne ede Wit⁴  Michael eHornberger⁵  Claire eO'Callaghan⁷  Ahmed A Moustafa⁸ 

[1] ARC Centre of Excellence in Cognition and its Disorders, Sydney;Behavioural and Clinical Neuroscience Institute and Department of Psychology, University of Cambridge, Cambridge, UK;Brain and Mind Research Institute, University of Sydney;Cognitive Science Center Amsterdam and Department of Clinical Psychology, University of Amsterdam;Department of Clinical Neurosciences, University of Cambridge;Neuroscience Research Australia, Sydney;School of Medical Sciences, University of New South Wales, Sydney;School of Social Sciences and Psychology, the Marcs Institute for Brain and Behaviour, University of Western Sydney;

关键词: Discrimination Learning;    Parkinson’s disease;    Computational modelling;    Voxel-based morphometry (VBM);    goal-directed learning;    fronto-striatal;   

DOI  :  10.3389/fncom.2013.00180

来源: DOAJ

【 摘 要 】

Discrimination learning deficits in Parkinson’s disease (PD) have been well established. Using both behavioural patient studies and computational approaches, these deficits have typically been attributed to dopamine imbalance across the basal ganglia. However, this explanation of impaired learning in PD does not account for the possible contribution of other pathological changes that occur in the disease process, importantly including grey matter loss. To address this gap in the literature, the current study explored the relationship between fronto-striatal grey matter atrophy and learning in PD. We employed a discrimination learning task and computational modelling in order to assess learning rates in non-demented PD patients. Behaviourally, we confirmed that learning rates were reduced in patients relative to controls. Furthermore, voxel-based morphometry imaging analysis demonstrated that this learning impairment was directly related to grey matter loss in discrete fronto-striatal regions (specifically, the ventromedial prefrontal cortex, inferior frontal gyrus and nucleus accumbens). These findings suggest that dopaminergic imbalance may not be the sole determinant of discrimination learning deficits in PD, and highlight the importance of factoring in the broader pathological changes when constructing models of learning in PD.

【 授权许可】

Unknown