title: Human ocular torsion and perceived roll responses to linear acceleration.
abstract: We investigated if human ocular torsion (OT) and perceived roll (PR) are elicited in response to either dynamic interaural linear acceleration or dynamic roll tilt of the gravito-inertial force (GIF). We expanded a previous study [26] that measured only OT across a limited frequency-range (from 0.35 Hz to 1 Hz) by simultaneously measuring OT and PR at three very low (0.01, 0.02 and 0.05 Hz) and one high (1 Hz) frequencies. Three experimental conditions were investigated: (1) Y-Upright with acceleration along the interaural (Y) axis while upright, (2) Y-Supine with acceleration along the Y-axis while supine, and (3) Z-RED with acceleration along the rostro-caudal Z) axis with right-ear-down (RED). OT was measured by video-oculography, while PR was measured by use of a somatosensory bar. OT and PR were qualitatively different. Large OT responses were measured for Y-Upright and Y-Supine, while large perceived roll responses were observed for Y-Upright and Z-RED. OT for Z-RED was small, and PR for Y-Supine was absent. In conclusion, OT and PR appear governed by qualitatively different neural mechanisms. OT appears mostly influenced by central low-pass filtering of interaural graviceptor cues, while PR appears mostly influenced by roll tilt of the GIF.
authors.affiliation: Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA. lionel.zupan@meei.harvard.edu
authors.forename: Lionel H
authors.initials: LH
authors.lastname: Zupan
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Merfeld
mesh_terms: D000054:Acceleration; D000328:Adult; D005128:Eye Diseases / Q000503:physiopathology*; D005260:Female; D018466:Gravity Sensing / Q000502:physiology*; D006801:Humans; D008297:Male; D009949:Orientation / Q000502:physiology; D010037:Otolithic Membrane / Q000502:physiology; D011434:Proprioception; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012399:Rotation; D016683:Supine Position; D014102:Torsion Abnormality