TY - JOUR
T1 - Torsional and horizontal vestibular ocular reflex adaptation
T2 - Three-dimensional eye movement analysis
AU - Solomon, D.
AU - Zee, D. S.
AU - Straumann, D.
N1 - Funding Information:
Acknowledgements This study was supported by NIH EYO1849 and DC00165-02, Swiss National Science Foundation (32-51938.97/31-63465.00), and the ’Betty and David Koetser Foundation for Brain Research’. The authors would like to thank Adrian Lasker and Dale Roberts for their expert technical assistance.
PY - 2003/9
Y1 - 2003/9
N2 - This study used visual-vestibular conflict to effect short-term torsional and horizontal adaptation of the vestibulo-ocular reflex (VOR). Seven normal subjects underwent sinusoidal whole-body rotation about the earth-vertical axis for 40 min (±37°/s, 0.3 Hz) while viewing a stationary radial pattern fixed to the chair (x0 viewing). During adaptation and testing in darkness, the head was pitched either up or down 35° to excite both the horizontal and torsional VOR. The eyes were kept close to zero orbital elevation. Eye movements were recorded with a dual search coil in a three-field magnetic system. VOR gain was determined by averaging peak eye velocity from ten cycles of chair oscillation in complete darkness. The gain of the angular horizontal VOR (response to rotation about the head rostral-caudal axis) was significantly reduced after training in both head orientations. Angular torsional VOR gain (head rotation about the naso-occipital axis) was reduced in both head orientations, but this reached statistical significance only in the head down position. These results suggest that torsional and horizontal VOR gain adaptation, even when elicited together, may be subject to different influences depending upon head orientation. Differences between head up and down could be due to the relatively greater contribution of the horizontal semicircular canals with nose-down pitch. Alternatively, different VOR-adaptation processes could depend on the usual association of the head down posture to near viewing, in which case the torsional VOR is relatively suppressed.
AB - This study used visual-vestibular conflict to effect short-term torsional and horizontal adaptation of the vestibulo-ocular reflex (VOR). Seven normal subjects underwent sinusoidal whole-body rotation about the earth-vertical axis for 40 min (±37°/s, 0.3 Hz) while viewing a stationary radial pattern fixed to the chair (x0 viewing). During adaptation and testing in darkness, the head was pitched either up or down 35° to excite both the horizontal and torsional VOR. The eyes were kept close to zero orbital elevation. Eye movements were recorded with a dual search coil in a three-field magnetic system. VOR gain was determined by averaging peak eye velocity from ten cycles of chair oscillation in complete darkness. The gain of the angular horizontal VOR (response to rotation about the head rostral-caudal axis) was significantly reduced after training in both head orientations. Angular torsional VOR gain (head rotation about the naso-occipital axis) was reduced in both head orientations, but this reached statistical significance only in the head down position. These results suggest that torsional and horizontal VOR gain adaptation, even when elicited together, may be subject to different influences depending upon head orientation. Differences between head up and down could be due to the relatively greater contribution of the horizontal semicircular canals with nose-down pitch. Alternatively, different VOR-adaptation processes could depend on the usual association of the head down posture to near viewing, in which case the torsional VOR is relatively suppressed.
KW - Adaptation
KW - Eye movements
KW - Torsion
KW - Vestibulo-ocular reflex
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U2 - 10.1007/s00221-003-1460-2
DO - 10.1007/s00221-003-1460-2
M3 - Article
C2 - 12879182
AN - SCOPUS:0141453306
SN - 0014-4819
VL - 152
SP - 150
EP - 155
JO - Experimental Brain Research
JF - Experimental Brain Research
IS - 2
ER -