Vestibular stimulation affects dichotic lexical decision performance.
We report an experimental attempt to shift, by vestibular stimulation, healthy subjects' right ear advantage (REA) in a dichotic listening (DL) task with words and nonwords as stimuli. Forty right-handed men performed the task under two different conditions, once while sitting in a stationary turning chair (baseline) and once during sinusoidal rotation. In this latter condition, every other stimulation was received during maximal left-to-right (i.e., clockwise), every other during maximal right-to-left (i.e., counterclockwise) acceleration. There was a reliable REA for lexical decision accuracy in the baseline and right-to-left trials but not during left-to-right rotation. While right ear performance was unaffected by rotation, there were more correct lexical decisions to left ear targets exclusively during left-to-right turns (one-tailed P = 0.05). Since there were no parallel shifts in auditory thresholds under the different conditions, this effect is not due to any hypothetical auditory-vestibular interactions on a primary sensory level. The improvement in left ear DL performance, although small in our study, is comparable to the symptom-alleviating effect of caloric vestibular stimulation in patients with left-sided hemispatial neglect and interpreted as a consequence of a rotation-induced attentional shift towards the left hemispace.
Schüeli
H
H
Department of Neurology, University Hospital Zurich, Switzerland.
Henn
V
V
Brugger
P
P
D000328:Adult; D000704:Analysis of Variance; D003657:Decision Making / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D018466:Gravity Sensing / Q000502:physiology; D006801:Humans; D008297:Male; D000091402:Prohibitins; D012399:Rotation; D013067:Speech Perception / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000502:physiology*