Learning to be inflexible: Enhanced attentional biases in Parkinson's disease.
Impaired attentional flexibility is considered to be one of the core cognitive deficits in Parkinson's disease (PD). However, the mechanisms that underlie this impairment are contested. Progress in resolving this dispute has also been hindered by the fact that cognitive deficits in PD are heterogeneous; therefore, it is unclear whether attentional impairments are only present in a subgroup of patients. Here, we demonstrate that what differentiates PD patients from age-matched controls is an inability to shift attention away from previously relevant information (perseveration) and an inability to shift attention towards previously irrelevant information (learned irrelevance). In contrast, there was no evidence that PD patients, compared to controls, were impaired in being able to appropriately attend to, or ignore, novel information. Furthermore, when patients were stratified according to their level of executive impairment, the executively impaired group showed a selective deficit in set formation compared to the unimpaired group, a behavioural pattern reminiscent of cortical dopamine depletion. Cumulatively, these results suggest that cognitive inflexibility in PD relates to a specific form of attentional dysfunction, in which learned attentional biases cannot be overcome.
Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK; Department of Experimental Psychology, University of Oxford, Oxford, UK. Electronic address: sean.fallon@psy.ox.ac.uk.
Sean James
SJ
Fallon
Computational Cognitive & Clinical Neuroimaging Laboratory, Imperial College London, UK.
Adam
A
Hampshire
John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, UK.
Roger A
RA
Barker
Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK; The Brain and Mind Institute, University of Western Ontario, CA, USA.
Adrian M
AM
Owen
D000368:Aged; D001288:Attention / Q000502:physiology; D000070379:Attentional Bias / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000523:psychology*; D012201:Reward; D012718:Set, Psychology
Attention; Irrelevance; Parkinson's disease; Reward; Set-shifting