Affiliations: [a] Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, USA | [b] Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA | [c] Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
Correspondence:
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Corresponding author: Joseph M. Furman, Department of Otolaryngology, 203 Lothrop Street, Suite 500, Pittsburgh, PA 15213, USA. Tel.: +1 412 647 2115; Fax: +1 412 647 2080; E-mail: furmanjm@upmc.edu
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.
