Fitts law: Modelling upper limb movements in Huntington's disease and the impact of visual cue restriction

Abstract

Event Abstract Back to Event Fitts law: Modelling upper limb movements in Huntington's disease and the impact of visual cue restriction Jessica L. Despard1, Bleydy Dimech-Betancourt1, Anne-Marie Ternes1, Govinda Poudel1, Andrew Churchyard2 and Nellie Georgiou-Karistianis1 1 Monash University, School of Psychology and Psychiatry, Australia 2 Monash Medical Centre, Australia Background: Huntington’s disease (HD) is an inherited neurodegenerative disorder associated with a triad of symptoms, impairing cognitive, affective and motor functions. Although voluntary motor deficits are attributed to movement slowing, and performance inaccuracies, we predict that basal ganglia dysfunction would result in impaired motor planning, exacerbated by the absence of visual cues. Methods: We recruited n=9 pre-symptomatic HD (pre-HD), n=9 early symptomatic HD (symp-HD) and n=9 matched control individuals to complete a reciprocal aiming task incorporating Fitts’ law. The task comprised 2 targets presented on a touchscreen computer, requiring participants to make reciprocal movements between the targets. After 10 movements, the cues were removed, and participants were asked to continue their movements based on their recollection of target location. This enabled the quantification of movement time and movement planning, via the manipulation of task difficulty according to target size and distance. Results: As expected, symp-HD showed prolonged movement times compared with controls; however, this effect did not reach statistical significance, nor was the effect intensified by the removal of visual cues. Furthermore, movement planning was impaired in symp-HD compared with controls and pre-HD, evident by prolonged dwell times (time stationary between movements), as a function of task difficulty. Dwell time however, was not exacerbated in the absence of visual cues. Performance accuracy, as determined by constant and variable error, was comparable across all groups. Discussion: These findings support the hypothesis that neuropathology of HD leads to a deficiency in motor planning. This suggests that dwell time may be a more reliable measure of the motor deficit observed in HD, than either movement time or accuracy alone. Keywords: Huntington Disease, Fitts’ law, Basal Ganglia, Movement, Motor planning Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Motor Citation: Despard JL, Dimech-Betancourt B, Ternes A, Poudel G, Churchyard A and Georgiou-Karistianis N (2013). Fitts law: Modelling upper limb movements in Huntington's disease and the impact of visual cue restriction. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00011 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Oct 2013; Published Online: 25 Nov 2013. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jessica L Despard Bleydy Dimech-Betancourt Anne-Marie Ternes Govinda Poudel Andrew Churchyard Nellie Georgiou-Karistianis Google Jessica L Despard Bleydy Dimech-Betancourt Anne-Marie Ternes Govinda Poudel Andrew Churchyard Nellie Georgiou-Karistianis Google Scholar Jessica L Despard Bleydy Dimech-Betancourt Anne-Marie Ternes Govinda Poudel Andrew Churchyard Nellie Georgiou-Karistianis PubMed Jessica L Despard Bleydy Dimech-Betancourt Anne-Marie Ternes Govinda Poudel Andrew Churchyard Nellie Georgiou-Karistianis Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.