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Full-Text Articles in Medicine and Health Sciences
Striatum In Stimulus-Response Learning Via Feedback And In Decision Making., Nole M Hiebert, Andrew Vo, Adam Hampshire, Adrian M Owen, Ken N Seergobin, Penny A Macdonald
Striatum In Stimulus-Response Learning Via Feedback And In Decision Making., Nole M Hiebert, Andrew Vo, Adam Hampshire, Adrian M Owen, Ken N Seergobin, Penny A Macdonald
Brain and Mind Institute Researchers' Publications
Cognitive deficits are recognized in Parkinson's disease. Understanding cognitive functions mediated by the striatum can clarify some of these impairments and inform treatment strategies. The dorsal striatum, a region impaired in Parkinson's disease, has been implicated in stimulus-response learning. However, most investigations combine acquisition of associations between stimuli, responses, or outcomes (i.e., learning) and expression of learning through response selection and decision enactment, confounding these separate processes. Using neuroimaging, we provide evidence that dorsal striatum does not mediate stimulus-response learning from feedback but rather underlies decision making once associations between stimuli and responses are learned. In the experiment, 11 males …
Human Premotor Areas Parse Sequences Into Their Spatial And Temporal Features., Katja Kornysheva, Jörn Diedrichsen
Human Premotor Areas Parse Sequences Into Their Spatial And Temporal Features., Katja Kornysheva, Jörn Diedrichsen
Brain and Mind Institute Researchers' Publications
Skilled performance is characterized by precise and flexible control of movement sequences in space and time. Recent theories suggest that integrated spatio-temporal trajectories are generated by intrinsic dynamics of motor and premotor networks. This contrasts with behavioural advantages that emerge when a trained spatial or temporal feature of sequences is transferred to a new spatio-temporal combination arguing for independent neural representations of these sequence features. We used a new fMRI pattern classification approach to identify brain regions with independent vs integrated representations. A distinct regional dissociation within motor areas was revealed: whereas only the contralateral primary motor cortex exhibited unique …
Effector-Independent Motor Sequence Representations Exist In Extrinsic And Intrinsic Reference Frames., Tobias Wiestler, Sheena Waters-Metenier, Jörn Diedrichsen
Effector-Independent Motor Sequence Representations Exist In Extrinsic And Intrinsic Reference Frames., Tobias Wiestler, Sheena Waters-Metenier, Jörn Diedrichsen
Brain and Mind Institute Researchers' Publications
Many daily activities rely on the ability to produce meaningful sequences of movements. Motor sequences can be learned in an effector-specific fashion (such that benefits of training are restricted to the trained hand) or an effector-independent manner (meaning that learning also facilitates performance with the untrained hand). Effector-independent knowledge can be represented in extrinsic/world-centered or in intrinsic/body-centered coordinates. Here, we used functional magnetic resonance imaging (fMRI) and multivoxel pattern analysis to determine the distribution of intrinsic and extrinsic finger sequence representations across the human neocortex. Participants practiced four sequences with one hand for 4 d, and then performed these sequences …