caa a22 4500 44535111X CHVBK 20180317142844.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s00221-011-2566-6 doi (NATIONALLICENCE)springer-10.1007/s00221-011-2566-6 Extraction of visual motion information for the control of eye and head movement during head-free pursuit [Elektronische Daten] [Rochelle Ackerley, Graham Barnes] We investigated how effectively briefly presented visual motion could be assimilated and used to track future target motion with head and eyes during target disappearance. Without vision, continuation of eye and head movement is controlled by internal (extra-retinal) mechanisms, but head movement stimulates compensatory vestibulo-ocular reflex (VOR) responses that must be countermanded for gaze to remain in the direction of target motion. We used target exposures of 50-200ms at the start of randomised step-ramp stimuli, followed by >400ms of target disappearance, to investigate the ability to sample target velocity and subsequently generate internally controlled responses. Subjects could appropriately grade gaze velocity to different target velocities without visual feedback, but responses were fully developed only when exposure was >100ms. Gaze velocities were sustained or even increased during target disappearance, especially when there was expectation of target reappearance, but they were always less than for controls, where the target was continuously visible. Gaze velocity remained in the direction of target motion throughout target extinction, implying that compensatory (VOR) responses were suppressed by internal drive mechanisms. Regression analysis revealed that the underlying compensatory response remained active, but with gain slightly less than unity (0.85), resulting in head-free gaze responses that were very similar to, but slightly greater than, head-fixed. The sampled velocity information was also used to grade head velocity, but in contrast to gaze, head velocity was similar whether the target was briefly or continuously presented, suggesting that head motion was controlled by internal mechanisms alone, without direct influence of visual feedback. Springer-Verlag, 2011 Expectation nationallicence Extra-retinal nationallicence Head movement nationallicence Prediction nationallicence Smooth pursuit nationallicence Vestibulo-ocular reflex nationallicence Ackerley Rochelle Faculty of Life Sciences, University of Manchester, Moffat Building, Sackville Street, PO Box 88, M60 1QD, Manchester, UK aut Barnes Graham Faculty of Life Sciences, University of Manchester, Moffat Building, Sackville Street, PO Box 88, M60 1QD, Manchester, UK aut Experimental Brain Research Springer-Verlag 210/3-4(2011-05-01), 569-582 0014-4819 210:3-4<569 2011 210 221 https://doi.org/10.1007/s00221-011-2566-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-011-2566-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ackerley Rochelle Faculty of Life Sciences, University of Manchester, Moffat Building, Sackville Street, PO Box 88, M60 1QD, Manchester, UK aut NATIONALLICENCE 700 1- Barnes Graham Faculty of Life Sciences, University of Manchester, Moffat Building, Sackville Street, PO Box 88, M60 1QD, Manchester, UK aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 210/3-4(2011-05-01), 569-582 0014-4819 210:3-4<569 2011 210 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer