title: A novel computational model to probe visual search deficits during motor performance.
abstract: Successful execution of many motor skills relies on well-organized visual search (voluntary eye movements that actively scan the environment for task-relevant information). Although impairments of visual search that result from brain injuries are linked to diminished motor performance, the neural processes that guide visual search within this context remain largely unknown. The first objective of this study was to examine how visual search in healthy adults and stroke survivors is used to guide hand movements during the Trail Making Test (TMT), a neuropsychological task that is a strong predictor of visuomotor and cognitive deficits. Our second objective was to develop a novel computational model to investigate combinatorial interactions between three underlying processes of visual search (spatial planning, working memory, and peripheral visual processing). We predicted that stroke survivors would exhibit deficits in integrating the three underlying processes, resulting in deteriorated overall task performance. We found that normal TMT performance is associated with patterns of visual search that primarily rely on spatial planning and/or working memory (but not peripheral visual processing). Our computational model suggested that abnormal TMT performance following stroke is associated with impairments of visual search that are characterized by deficits integrating spatial planning and working memory. This innovative methodology provides a novel framework for studying how the neural processes underlying visual search interact combinatorially to guide motor performance.
  
  
  
  Visual search has traditionally been studied in cognitive and perceptual paradigms, but little is known about how it contributes to visuomotor performance. We have developed a novel computational model to examine how three underlying processes of visual search (spatial planning, working memory, and peripheral visual processing) contribute to visual search during a visuomotor task. We show that deficits integrating spatial planning and working memory underlie abnormal performance in stroke survivors with frontoparietal damage.
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, South Carolina.
authors.forename: Tarkeshwar
authors.initials: T
authors.lastname: Singh
authors.affiliation: Department of Communication Sciences and Disorders, University of South Carolina, Columbia, South Carolina; and.
authors.forename: Julius
authors.initials: J
authors.lastname: Fridriksson
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, South Carolina.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Perry
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, South Carolina.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Tryon
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, South Carolina.
authors.forename: Angela
authors.initials: A
authors.lastname: Ross
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, South Carolina.|Physical Therapy Program, University of South Carolina, Columbia, South Carolina.
authors.forename: Stacy
authors.initials: S
authors.lastname: Fritz
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, South Carolina; therter@sc.edu.
authors.forename: Troy M
authors.identifier: 0000-0001-7466-1619
authors.initials: TM
authors.lastname: Herter
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000209:etiology*; D003198:Computer Simulation; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009048:Motor Skills / Q000502:physiology*; D010775:Photic Stimulation; D011596:Psychomotor Disorders / Q000209:etiology*; D013223:Statistics as Topic; D020521:Stroke / Q000150:complications*; D014145:Trail Making Test; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: computational model; saccades; stroke; visual search; visuomotor