title: Changes in spinal excitability during dual task performance.
abstract: The authors investigated how the nervous system responds to dual task performance. Because dual tasking is associated with greater postural challenges, it was hypothesized that spinal excitability would be reduced when simultaneously performing 2 tasks. For this experiment, participants maintained a lying or standing posture with or without performing a concurrent cognitive task (i.e., reacting to an auditory tone). Spinal excitability was assessed by eliciting the soleus Hoffmann reflex (H-reflex). Results indicated that the H-reflex was 6.4 ± 2.3% smaller (p = .011) when dual compared to single tasking. The reduced H-reflex amplitude, indicating a depressed spinal excitability, when dual tasking is suggested to reflect a neural strategy that individuals adopt to maintain postural stability when cognitive resources are divided between 2 concurrent tasks.
authors.affiliation: Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada.
authors.forename: Tyler B
authors.initials: TB
authors.lastname: Weaver
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Janzen
authors.forename: Allan L
authors.initials: AL
authors.lastname: Adkin
authors.forename: Craig D
authors.initials: CD
authors.lastname: Tokuno
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D003071:Cognition / Q000502:physiology; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D011187:Posture / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013131:Spine / Q000502:physiology*; D055815:Young Adult