title: Interference between postural control and spatial vs. non-spatial auditory reaction time tasks in older adults.
abstract: This study investigated whether spatial aspects of an information processing task influence dual-task interference. Two groups (Older/Young) of healthy adults participated in dual-task experiments. Two auditory information processing tasks included a frequency discrimination choice reaction time task (non-spatial task) and a lateralization choice reaction time task (spatial task). Postural tasks included combinations of standing with eyes open or eyes closed on either a fixed floor or a sway-referenced floor. Reaction times and postural sway via center of pressure were recorded. Baseline measures of reaction time and sway were subtracted from the corresponding dual-task results to calculate reaction time task costs and postural task costs. Reaction time task cost increased with eye closure (p = 0.01), sway-referenced flooring (p < 0.0001), and the spatial task (p = 0.04). Additionally, a significant (p = 0.05) task x vision x age interaction indicated that older subjects had a significant vision X task interaction whereas young subjects did not. However, when analyzed by age group, the young group showed minimal differences in interference for the spatial and non-spatial tasks with eyes open, but showed increased interference on the spatial relative to non-spatial task with eyes closed. On the contrary, older subjects demonstrated increased interference on the spatial relative to the non-spatial task with eyes open, but not with eyes closed. These findings suggest that visual-spatial interference may occur in older subjects when vision is used to maintain posture.
authors.affiliation: Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Susan I
authors.initials: SI
authors.lastname: Fuhrman
authors.affiliation: Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Redfern
authors.affiliation: Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: J Richard
authors.initials: JR
authors.lastname: Jennings
authors.affiliation: Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Furman
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D056228:Feedback, Sensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010470:Perceptual Masking / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011897:Random Allocation; D011930:Reaction Time; D013017:Sound Localization / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D013037:Spatial Behavior / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
keywords: Posture; aging; dual-task; spatial orientation; spatial task