Influence of Target Distance and Acceleration Level on Eye Movements Evoked by Lateral Acceleration Steps

1995 ◽  
Vol 115 (sup520) ◽  
pp. 65-67 ◽  
Author(s):  
Claire C. Gianna ◽  
Michael A. Gresty ◽  
Adolfo M. Bronstein
2002 ◽  
Vol 88 (5) ◽  
pp. 2880-2885 ◽  
Author(s):  
Hui-Hui Zhou ◽  
Min Wei ◽  
Dora E. Angelaki

The geometry of gaze stabilization during head translation requires eye movements to scale proportionally to the inverse of target distance. Such a scaling has indeed been demonstrated to exist for the translational vestibuloocular reflex (TVOR), as well as optic flow–selective translational visuomotor reflexes (e.g., ocular following, OFR). The similarities in this scaling by a neural estimate of target distance for both the TVOR and the OFR have been interpreted to suggest that the two reflexes share common premotor processing. Because the neural substrates of OFR are partly shared by those for the generation of pursuit eye movements, we wanted to know if the site of gain modulation for TVOR and OFR is also part of a major pathway for pursuit. Thus, in the present studies, we investigated in rhesus monkeys whether initial eye velocity and acceleration during the open-loop portion of step ramp pursuit scales with target distance. Specifically, with visual motion identical on the retina during tracking at different distances (12, 24, and 60 cm), we compared the first 80 ms of horizontal pursuit. We report that initial eye velocity and acceleration exhibits either no or a very small dependence on vergence angle that is at least an order of magnitude less than the corresponding dependence of the TVOR and OFR. The results suggest that the neural substrates for motor scaling by target distance remain largely distinct from the main pathway for pursuit.


1997 ◽  
Vol 114 (1) ◽  
pp. 124-129 ◽  
Author(s):  
C. C. Gianna ◽  
Michael A. Gresty ◽  
Adolfo M. Bronstein

2006 ◽  
Vol 95 (4) ◽  
pp. 2530-2540 ◽  
Author(s):  
Hui Meng ◽  
Dora E. Angelaki

To stabilize objects of interest on the fovea during translation, vestibular-driven compensatory eye movements [translational vestibulo-ocular reflex (TVOR)] must scale with both target distance and eccentricity. To identify the neural correlates of these properties, we recorded from different groups of eye movement–sensitive neurons in the prepositus hypoglossi and vestibular nuclei of macaque monkeys during lateral and fore-aft displacements. All neuron types exhibited some increase in modulation amplitude as a function of target distance during high-frequency (4 Hz) lateral motion in darkness, with slopes that were correlated with the cell's pursuit gain, but not eye position sensitivity. Vergence angle dependence was largest for burst-tonic (BT) and contralateral eye-head (EH) neurons and smallest for ipsilateral EH and position-vestibular-pause (PVP) cells. On the other hand, the EH and PVP neurons with ipsilateral eye movement preferences exhibited the largest vergence-independent responses, which would be inappropriate to drive the TVOR. In addition to target distance, the TVOR also scales with target eccentricity, as evidenced during fore-aft motion, where eye velocity amplitude exhibits a “V-shaped ” dependence and phase shifts 180° for right versus left eye positions. Both the modulation amplitude and phase of BT and contralateral EH cells scaled with eye position, similar to the evoked eye movements during fore-aft motion. In contrast, the response modulation of ipsilateral EH and PVP cells during fore-aft motion was characterized by neither the V-shaped scaling nor the phase reversal. These results show that distinct premotor cell types carry neural signals that are appropriately scaled by vergence angle and eye position to generate the geometrically appropriate compensatory eye movements in the translational vestibulo-ocular reflex.


1991 ◽  
Vol 1 (4) ◽  
pp. 357-371
Author(s):  
Trevor Hine

The kinematics of the horizontal VOR for near fixation demand that VOR gain should change dependent on the target distance and the orientation of the head with respect to the target, or, equivalently, the amount of ocular vergence and the asymmetry of this vergence. Across two experiments, the gain of the VOR was measured in the right eye of humans who rotated their heads to the right or left while viewing a target placed either 22, 32.5 or 200 cm from the center of head rotation, in conditions with and without visual feedback. When tbe eye was in-line with the target, the measured VOR gain was up to 43% greater than when the eye was in an eccentric position. However, in the eccentric position, higher VOR gains were achieved with visual feedback of the target than without feedback, indicative of a visual component in the compensatory eye movement. Also, by changing the posture of the left eye but keeping the right eye constant, the VOR gain in the right eye was changed substantially during a subsequent head rotation. Hence, the positions of both eyes in their orbits determine the gain of the VOR in each eye.


2000 ◽  
Vol 53 (4) ◽  
pp. 1061-1080 ◽  
Author(s):  
Keith Rayner ◽  
Gretchen Kambe ◽  
Susan A. Duffy

2000 ◽  
Vol 59 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Rudolf Groner ◽  
Marina T. Groner ◽  
Kazuo Koga

2007 ◽  
Vol 12 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Géry d'Ydewalle ◽  
Wim De Bruycker

Abstract. Eye movements of children (Grade 5-6) and adults were monitored while they were watching a foreign language movie with either standard (foreign language soundtrack and native language subtitling) or reversed (foreign language subtitles and native language soundtrack) subtitling. With standard subtitling, reading behavior in the subtitle was observed, but there was a difference between one- and two-line subtitles. As two lines of text contain verbal information that cannot easily be inferred from the pictures on the screen, more regular reading occurred; a single text line is often redundant to the information in the picture, and accordingly less reading of one-line text was apparent. Reversed subtitling showed even more irregular reading patterns (e.g., more subtitles skipped, fewer fixations, longer latencies). No substantial age differences emerged, except that children took longer to shift attention to the subtitle at its onset, and showed longer fixations and shorter saccades in the text. On the whole, the results demonstrated the flexibility of the attentional system and its tuning to the several information sources available (image, soundtrack, and subtitles).


2019 ◽  
Vol 24 (4) ◽  
pp. 297-311
Author(s):  
José David Moreno ◽  
José A. León ◽  
Lorena A. M. Arnal ◽  
Juan Botella

Abstract. We report the results of a meta-analysis of 22 experiments comparing the eye movement data obtained from young ( Mage = 21 years) and old ( Mage = 73 years) readers. The data included six eye movement measures (mean gaze duration, mean fixation duration, total sentence reading time, mean number of fixations, mean number of regressions, and mean length of progressive saccade eye movements). Estimates were obtained of the typified mean difference, d, between the age groups in all six measures. The results showed positive combined effect size estimates in favor of the young adult group (between 0.54 and 3.66 in all measures), although the difference for the mean number of fixations was not significant. Young adults make in a systematic way, shorter gazes, fewer regressions, and shorter saccadic movements during reading than older adults, and they also read faster. The meta-analysis results confirm statistically the most common patterns observed in previous research; therefore, eye movements seem to be a useful tool to measure behavioral changes due to the aging process. Moreover, these results do not allow us to discard either of the two main hypotheses assessed for explaining the observed aging effects, namely neural degenerative problems and the adoption of compensatory strategies.


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