Wolfgang Becker and Reinhard Jürgens
- Published in print:
- 1992
- Published Online:
- March 2012
- ISBN:
- 9780195068207
- eISBN:
- 9780199847198
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195068207.003.0066
- Subject:
- Neuroscience, Sensory and Motor Systems
In this chapter, the authors addressed the question of the degree to which gaze saccades executed under natural conditions are modulated by concomitant head movements by creating a “quasi-natural” ...
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In this chapter, the authors addressed the question of the degree to which gaze saccades executed under natural conditions are modulated by concomitant head movements by creating a “quasi-natural” situation. Head-fixed saccades were compared to head-free saccades. The first experiment in this study cannot prove or disprove the validity of Bizzi's classical summation hypothesis for human gaze saccades confined to the oculomotor range. It rather demonstrates that the presence of a classical VOR is irrelevant for the velocity of such gaze saccades since the concurrent head movement starts too late and is too slow to impart to the saccade a significant gain in velocity in the event of a disconnected VOR. The second experiment confirms that the factor of greater importance for the dynamics of head-free saccades is the orbital eccentricity and direction of the EiH contribution to saccades.Less
In this chapter, the authors addressed the question of the degree to which gaze saccades executed under natural conditions are modulated by concomitant head movements by creating a “quasi-natural” situation. Head-fixed saccades were compared to head-free saccades. The first experiment in this study cannot prove or disprove the validity of Bizzi's classical summation hypothesis for human gaze saccades confined to the oculomotor range. It rather demonstrates that the presence of a classical VOR is irrelevant for the velocity of such gaze saccades since the concurrent head movement starts too late and is too slow to impart to the saccade a significant gain in velocity in the event of a disconnected VOR. The second experiment confirms that the factor of greater importance for the dynamics of head-free saccades is the orbital eccentricity and direction of the EiH contribution to saccades.
Henrietta L. Galiana, Daniel Guitton, and and Douglas P. Munoz
- Published in print:
- 1992
- Published Online:
- March 2012
- ISBN:
- 9780195068207
- eISBN:
- 9780199847198
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195068207.003.0082
- Subject:
- Neuroscience, Sensory and Motor Systems
Two primary issues are being studied in relation to the control of coordinated eye and head movements. The first one is the possible interaction of the vestibulo-ocular reflex (VOR) during the ...
More
Two primary issues are being studied in relation to the control of coordinated eye and head movements. The first one is the possible interaction of the vestibulo-ocular reflex (VOR) during the saccadic component of a gaze shift and the second one is the possible coordination of eye and head trajectors through shared access to a common premotor drive. This chapter presents an alternate view of central eye-head coordination, using global gaze error as a precursor of motoneural drives. The model of eye-head coupling is also conceptually justified in this chapter. Some simulation examples are presented, including the gaze shifts within and beyond the oculomotor range and coupling of eye and head trajectories.Less
Two primary issues are being studied in relation to the control of coordinated eye and head movements. The first one is the possible interaction of the vestibulo-ocular reflex (VOR) during the saccadic component of a gaze shift and the second one is the possible coordination of eye and head trajectors through shared access to a common premotor drive. This chapter presents an alternate view of central eye-head coordination, using global gaze error as a precursor of motoneural drives. The model of eye-head coupling is also conceptually justified in this chapter. Some simulation examples are presented, including the gaze shifts within and beyond the oculomotor range and coupling of eye and head trajectories.
