No sequence dependent modulation of the Simon effect in Parkinson's disease. Export

@article{citeulike:345963, abstract = {This study sought to evaluate impaired response tendencies and modulation of automatic processes in Parkinson's disease (PD), utilising a saccadic Simon task with stimulus-response (S-R) compatibility determined on the basis of cue shape. The appearance of either a circle or a square in one of two boxes presented peripherally required the generation of a leftward or rightward horizontal saccade, respectively. These goal-directed responses were considered behaviourally relevant to an examination of visuospatial performance. Although response times are typically faster when stimulus and response are spatially compatible than when they are not, sequence-dependent modulation of this effect results in large differences between S-R compatible and S-R incompatible trials when stimulus and response are spatially compatible in the preceding trial, and reduced or absent differences when stimulus and response are spatially incompatible in the preceding trial. Unlike control subjects, PD patients demonstrated significantly shorter saccadic latencies overall, compared to a baseline condition involving endogenously-driven saccades. Patients also responded erroneously to cue stimuli with greater frequency. Analyses of both saccadic latency and errors to cue demonstrated a Simon effect (relatively faster response for S-R compatible trials), irrespective of the preceding trial. This suggests impaired modulation of the Simon effect in PD, consistent with predictions of inhibitory dysfunction, or impaired episodic memory. These results demonstrate the pivotal role of the basal ganglia in the regulation of context-dependent neural activity.}, address = {Experimental Neuropsychology Research Unit, Department of Psychology, School of Psychology, Psychiatry and Psychological Medicine, Clayton Campus, Monash University, Victoria 3800, Australia; Mental Health Research Institute, Parkville, 3052, Victoria, Australia.}, author = {Fielding, Joanne and Georgiou-Karistianis, Nellie and Bradshaw, John and Millist, Lynette and White, Owen}, citeulike-article-id = {345963}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.cogbrainres.2005.05.015}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/15996856}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=15996856}, doi = {10.1016/j.cogbrainres.2005.05.015}, issn = {0926-6410}, journal = {Brain Res Cogn Brain Res}, keywords = {basal, compatibility, ganglia, leakage, memory, parkinsons, saccades, simon}, month = {September}, number = {1}, pages = {251--260}, posted-at = {2005-10-08 23:39:40}, priority = {2}, title = {No sequence dependent modulation of the Simon effect in Parkinson's disease.}, url = {http://dx.doi.org/10.1016/j.cogbrainres.2005.05.015}, volume = {25}, year = {2005} }

TY - JOUR ID - citeulike:345963 L3 - citeulike-article-id:345963 N2 - This study sought to evaluate impaired response tendencies and modulation of automatic processes in Parkinson's disease (PD), utilising a saccadic Simon task with stimulus-response (S-R) compatibility determined on the basis of cue shape. The appearance of either a circle or a square in one of two boxes presented peripherally required the generation of a leftward or rightward horizontal saccade, respectively. These goal-directed responses were considered behaviourally relevant to an examination of visuospatial performance. Although response times are typically faster when stimulus and response are spatially compatible than when they are not, sequence-dependent modulation of this effect results in large differences between S-R compatible and S-R incompatible trials when stimulus and response are spatially compatible in the preceding trial, and reduced or absent differences when stimulus and response are spatially incompatible in the preceding trial. Unlike control subjects, PD patients demonstrated significantly shorter saccadic latencies overall, compared to a baseline condition involving endogenously-driven saccades. Patients also responded erroneously to cue stimuli with greater frequency. Analyses of both saccadic latency and errors to cue demonstrated a Simon effect (relatively faster response for S-R compatible trials), irrespective of the preceding trial. This suggests impaired modulation of the Simon effect in PD, consistent with predictions of inhibitory dysfunction, or impaired episodic memory. These results demonstrate the pivotal role of the basal ganglia in the regulation of context-dependent neural activity. IS - 1 JF - Brain Res Cogn Brain Res SN - 0926-6410 AD - Experimental Neuropsychology Research Unit, Department of Psychology, School of Psychology, Psychiatry and Psychological Medicine, Clayton Campus, Monash University, Victoria 3800, Australia; Mental Health Research Institute, Parkville, 3052, Victoria, Australia. EP - 260 TI - No sequence dependent modulation of the Simon effect in Parkinson's disease. VL - 25 SP - 251 KW - basal KW - compatibility KW - ganglia KW - leakage KW - memory KW - parkinsons KW - saccades KW - simon AU - Fielding, Joanne AU - Georgiou-Karistianis, Nellie AU - Bradshaw, John AU - Millist, Lynette AU - White, Owen PY - 2005/09// UR - http://dx.doi.org/10.1016/j.cogbrainres.2005.05.015 ER -