Self-motion-induced eye movements: effects on visual acuity and navigation

2005 ◽  
Vol 6 (12) ◽  
pp. 966-976 ◽  
Author(s):  
Dora E. Angelaki ◽  
Bernhard J. M. Hess
1996 ◽  
Vol 16 (3) ◽  
pp. 253-253
Author(s):  
Anita J. Simmers ◽  
Lyle S. Gray ◽  
Barry Winn
Keyword(s):  

1999 ◽  
Vol 126 (4) ◽  
pp. 495-500 ◽  
Author(s):  
K. V. Thilo ◽  
Thomas Probst ◽  
Adolfo M. Bronstein ◽  
Yatsuji Ito ◽  
Michael A. Gresty

Author(s):  
Agnes Wong

One main reason that we make eye movements is to solve a problem of information overload. A large field of vision allows an animal to survey the environment for food and to avoid predators, thus increasing its survival rate. Similarly, a high visual acuity also increases survival rates by allowing an animal to aim at a target more accurately, leading to higher killing rates and more food. However, there are simply not enough neurons in the brain to support a visual system that has high resolution over the entire field of vision. Faced with the competing evolutionary demands for high visual acuity and a large field of vision, an effective strategy is needed so that the brain will not be overwhelmed by a large amount of visual input. Some animals, such as rabbits, give up high resolution in favor of a larger field of vision (rabbits can see nearly 360°), whereas others, such as hawks, restrict their field of vision in return for a high visual acuity (hawks have vision as good as 20/2, about 10 times better than humans). In humans, rather than using one strategy over the other, the retina develops a very high spatial resolution in the center (i.e., the fovea), and a much lower resolution in the periphery. Although this “foveal compromise” strategy solves the problem of information overload, one result is that unless the image of an object of interest happens to fall on the fovea, the image is relegated to the low-resolution retinal periphery. The evolution of a mechanism to move the eyes is therefore necessary to complement this foveal compromise strategy by ensuring that an object of interest is maintained or brought to the fovea. To maintain the image of an object on the fovea, the vestibulo-ocular (VOR) and optokinetic systems generate eye movements to compensate for head motions. Likewise, the saccadic, smooth pursuit, and vergence systems generate eye movements to bring the image of an object of interest on the fovea. These different eye movements have different characteristics and involve different parts of the brain.


2020 ◽  
Vol 237 (04) ◽  
pp. 502-505
Author(s):  
Noemie Schwob ◽  
Anja Palmowski-Wolfe

Abstract Objective Investigating the correlation between subjective and objective VA (visual acuity) elicited with a newly developed computerised optokinetic nystagmus (OKN) suppression test (“SpeedWheel”) in adults. Methods SpeedWheel presented alternating black/white stripes moving horizontally across a LED screen. Seven VA steps were induced with Bangerter filters placed onto spectacle frames. Magnified eye movements were projected from infrared cameras inside the frames and displayed onto a smartphone. Dots whose size increased in logarithmic steps were superimposed to suppress OKN. Suppression of OKN resulted in the SpeedWheel acuity which was then correlated to Snellen acuity as measured with the Freiburg Acuity test. Results 28 eyes from 14 individuals were tested. FrACT-E correlated well to SpeedWheel (r: 0.89; p < 0.001). Snellen acuity was never lower than 0.14 LogMAR of SpeedWheel values. Bangerter filters showed greater mean difference to both methods indicating that this filter is not as predictable as suggested by the filter value. Conclusion SpeedWheel offers a fast (< 80 sec) and reliable alternative option to measure objective VA.


1998 ◽  
Vol 79 (3) ◽  
pp. 1461-1480 ◽  
Author(s):  
Markus Lappe ◽  
Martin Pekel ◽  
Klaus-Peter Hoffmann

Lappe, Markus, Martin Pekel, and Klaus-Peter Hoffmann. Optokinetic eye movements elicited by radial optic flow in the macaque monkey. J. Neurophysiol. 79: 1461–1480, 1998. We recorded spontaneous eye movements elicited by radial optic flow in three macaque monkeys using the scleral search coil technique. Computer-generated stimuli simulated forward or backward motion of the monkey with respect to a number of small illuminated dots arranged on a virtual ground plane. We wanted to see whether optokinetic eye movements are induced by radial optic flow stimuli that simulate self-movement, quantify their parameters, and consider their effects on the processing of optic flow. A regular pattern of interchanging fast and slow eye movements with a frequency of 2 Hz was observed. When we shifted the horizontal position of the focus of expansion (FOE) during simulated forward motion (expansional optic flow), median horizontal eye position also shifted in the same direction but only by a smaller amount; for simulated backward motion (contractional optic flow), median eye position shifted in the opposite direction. We relate this to a change in Schlagfeld typically observed in optokinetic nystagmus. Direction and speed of slow phase eye movements were compared with the local flow field motion in gaze direction (the foveal flow). Eye movement direction matched well the foveal motion. Small systematic deviations could be attributed to an integration of the global motion pattern. Eye speed on average did not match foveal stimulus speed, as the median gain was only ∼0.5–0.6. The gain was always lower for expanding than for contracting stimuli. We analyzed the time course of the eye movement immediately after each saccade. We found remarkable differences in the initial development of gain and directional following for expansion and contraction. For expansion, directional following and gain were initially poor and strongly influenced by the ongoing eye movement before the saccade. This was not the case for contraction. These differences also can be linked to properties of the optokinetic system. We conclude that optokinetic eye movements can be elicited by radial optic flow fields simulating self-motion. These eye movements are linked to the parafoveal flow field, i.e., the motion in the direction of gaze. In the retinal projection of the optic flow, such eye movements superimpose retinal slip. This results in complex retinal motion patterns, especially because the gain of the eye movement is small and variable. This observation has special relevance for mechanisms that determine self-motion from retinal flow fields. It is necessary to consider the influence of eye movements in optic flow analysis, but our results suggest that direction and speed of an eye movement should be treated differently.


PLoS Biology ◽  
2007 ◽  
Vol 5 (12) ◽  
pp. e331 ◽  
Author(s):  
Xaq Pitkow ◽  
Haim Sompolinsky ◽  
Markus Meister

Author(s):  
Jonathan Adamson ◽  
Thomas Waterfield

‘It is midnight and you are called to see a thirteen-year-old boy who has been brought to the paediatric emergency department with a 24-hour history of swelling and redness of his left eye. He has had a ‘runny nose’ for a couple of days. He is systemically well. His upper and lower lids are red and swollen such that his eye is not open fully, though you elicit normal eye movements when you open his eye. Pupils are equal and reactive with no afferent pupillary defect. Visual acuity and colour vision are normal on examination.’ In this article, we consider the approach to preseptal and orbital cellulitis in children including the initial assessment and management options.


2014 ◽  
Vol 112 (10) ◽  
pp. 2470-2480 ◽  
Author(s):  
Andre Kaminiarz ◽  
Anja Schlack ◽  
Klaus-Peter Hoffmann ◽  
Markus Lappe ◽  
Frank Bremmer

The patterns of optic flow seen during self-motion can be used to determine the direction of one's own heading. Tracking eye movements which typically occur during everyday life alter this task since they add further retinal image motion and (predictably) distort the retinal flow pattern. Humans employ both visual and nonvisual (extraretinal) information to solve a heading task in such case. Likewise, it has been shown that neurons in the monkey medial superior temporal area (area MST) use both signals during the processing of self-motion information. In this article we report that neurons in the macaque ventral intraparietal area (area VIP) use visual information derived from the distorted flow patterns to encode heading during (simulated) eye movements. We recorded responses of VIP neurons to simple radial flow fields and to distorted flow fields that simulated self-motion plus eye movements. In 59% of the cases, cell responses compensated for the distortion and kept the same heading selectivity irrespective of different simulated eye movements. In addition, response modulations during real compared with simulated eye movements were smaller, being consistent with reafferent signaling involved in the processing of the visual consequences of eye movements in area VIP. We conclude that the motion selectivities found in area VIP, like those in area MST, provide a way to successfully analyze and use flow fields during self-motion and simultaneous tracking movements.


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