scholarly journals Suboptimal eye movements for seeing fine details

2017 ◽  
Author(s):  
Mehmet N. Ağaoğlu ◽  
Christy K. Sheehy ◽  
Pavan Tiruveedhula ◽  
Austin Roorda ◽  
Susana T. L. Chung
Keyword(s):  
Eye Movements ◽  
Visual Target ◽  
Ganglion Cells ◽  
State Of The Art ◽  
Imaging Technique ◽  
Orientation Discrimination ◽  
Retinal Ganglion ◽  
Response Characteristics ◽  
Eye Motion ◽  
Human Eyes

AbstractHuman eyes are never stable, even during attempts of maintaining gaze on a visual target. Considering transient response characteristics of retinal ganglion cells, a certain amount of motion of the eyes is required to efficiently encode information and to prevent neural adaptation. However, excessive motion of the eyes leads to insufficient exposure to the stimuli which creates blur and reduces visual acuity. Normal miniature eye movements fall in between these extremes but it is unclear if they are optimally tuned for seeing fine spatial details. We used a state-of-the-art retinal imaging technique with eye tracking to address this question. We sought to determine the optimal gain (stimulus/eye motion ratio) that corresponds to maximum performance in an orientation discrimination task performed at the fovea. We found that miniature eye movements are tuned, but may not be optimal, for seeing fine spatial details.

The structural and functional development of the retina in larval Xenopus

Development ◽  
1975 ◽  
Vol 33 (4) ◽  
pp. 915-940
Author(s):  
S. H. Chung ◽  
R. Victoria Stirling ◽  
R. M. Gaze
Keyword(s):  
Ganglion Cells ◽  
Single Layer ◽  
Plexiform Layer ◽  
Distinct Pattern ◽  
Inner Plexiform Layer ◽  
Retinal Ganglion ◽  
Response Characteristics ◽  
Functional Development ◽  
New Type ◽  
Plexiform Layers

The structural transformations of the larval Xenopus retina at successive stages of development, and concomitant changes in response characteristics of retinal ganglion cells, were studied using histological and electrophysiological techniques. The first sign of visually evoked electrical responses appears at about the time when the ganglion cells spread out into a single layer and shortly after the inner and outer plexiform layers become discernible. Initially giving simple ‘on’ responses, the cells progressively change their response characteristics and become ‘event’ units. Subsequently, ‘dimming’ units can be identified. Throughout larval life, response properties of these two types become more distinct from one another and approximate to those found in the adult. So do the arborization patterns of the dendritic trees of the ganglion cells. Two types of branching patterns are identifiable in Golgi preparations. Around metamorphic climax, a new type of ganglion cell appears, coinciding with the emergence of ‘sustained’ units electrophysiologically. After metamorphosis, the retina still grows both in thickness (mainly in the inner plexiform layer) and diameter. The three unit types change such that they come to show pronounced inhibitory effects from the peripheral visual field on the receptive field and each unit type acquires a distinct pattern of endogenous discharge.

Morphogenesis and physiogenesis of the retino-tectal connection in the chicken. II. the retino-tectal synapses

1976 ◽  
Vol 192 (1108) ◽  
pp. 353-370 ◽  
Keyword(s):  
Ganglion Cells ◽  
Field Potential ◽  
Preceding Paper ◽  
Early Response ◽  
Retinal Ganglion ◽  
Surface Mapping ◽  
Response Characteristics ◽  
Morphological Criteria ◽  
Response Burst ◽  
First Time

The preceding paper (Eager 1976) was concerned with the development of retinal ganglion cells and the maturation of photoreceptors. Here we discuss the formation of retino-tectal synapses as studied in terms of both morphology and physiology. The early response characteristics of the first and second postsynaptic tectal cells were also studied. The first retino-tectal synapses, sparse in number, were found with the electron microscope on the eleventh day of incubation. Strict criteria for their identification were employed. At the same stage postsynaptic potentials could be recorded for the first time. These potentials could be recognized as postsynaptic by the application of various techniques: combined ortho- and antidromic stimulation, variation of stimulus intensities, surface mapping, field potential profiles, and application of double shocks of varying intervals. From day twelve onward single unit recordings were also possible and confirmed these results. We were able to establish that morphological criteria for recognition of optic nerve synapses are also criteria for when they start to function. Tectal cells first respond with long-lasting repetitive discharges. Only a few days later the response burst has become shorter and is followed by post-excitatory inhibition. When retino-tectal synapses start to function the excitation is not confined to the superficial tectal cells, but reaches deeper neurons which are possibly tectal output cells. The results of this and the preceding paper (Eager 1976) indicate that the development of the retino-tectal connection in the chicken differs from that in the frog in several fundamental respects.

Role of Eye Movements in the Retinal Code for a Size Discrimination Task

2007 ◽  
Vol 98 (3) ◽  
pp. 1380-1391 ◽  
Author(s):  
Ronen Segev ◽  
Elad Schneidman ◽  
Joe Goodhouse ◽  
Michael J. Berry
Keyword(s):  
Eye Movements ◽  
Visual Information ◽  
Ganglion Cells ◽  
Multielectrode Array ◽  
Retinal Ganglion ◽  
Size Discrimination ◽  
Fixational Eye Movements ◽  
Stationary Objects ◽  
A Minor

The concerted action of saccades and fixational eye movements are crucial for seeing stationary objects in the visual world. We studied how these eye movements contribute to retinal coding of visual information using the archer fish as a model system. We quantified the animal's ability to distinguish among objects of different sizes and measured its eye movements. We recorded from populations of retinal ganglion cells with a multielectrode array, while presenting visual stimuli matched to the behavioral task. We found that the beginning of fixation, namely the time immediately after the saccade, provided the most visual information about object size, with fixational eye movements, which consist of tremor and drift in the archer fish, yielding only a minor contribution. A simple decoder that combined information from ≤15 ganglion cells could account for the behavior. Our results support the view that saccades impose not just difficulties for the visual system, but also an opportunity for the retina to encode high quality “snapshots” of the environment.

scholarly journals Comparison of optomotor and optokinetic reflexes in mice

2017 ◽  
Vol 118 (1) ◽  
pp. 300-316 ◽  
Author(s):  
Friedrich Kretschmer ◽  
Momina Tariq ◽  
Walid Chatila ◽  
Beverly Wu ◽  
Tudor Constantin Badea
Keyword(s):  
Eye Movements ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Head Movements ◽  
Retinal Ganglion ◽  
Optomotor Response ◽  
Optokinetic Response ◽  
Stimulus Velocity ◽  
Image Stabilization ◽  
Optokinetic Responses

During animal locomotion or position adjustments, the visual system uses image stabilization reflexes to compensate for global shifts in the visual scene. These reflexes elicit compensatory head movements (optomotor response, OMR) in unrestrained animals or compensatory eye movements (optokinetic response, OKR) in head-fixed or unrestrained animals exposed to globally rotating striped patterns. In mice, OMR are relatively easy to observe and find broad use in the rapid evaluation of visual function. OKR determinations are more involved experimentally but yield more stereotypical, easily quantifiable results. The relative contributions of head and eye movements to image stabilization in mice have not been investigated. We are using newly developed software and apparatus to accurately quantitate mouse head movements during OMR, quantitate eye movements during OKR, and determine eye movements in freely behaving mice. We provide the first direct comparison of OMR and OKR gains (head or eye velocity/stimulus velocity) and find that the two reflexes have comparable dependencies on stimulus luminance, contrast, spatial frequency, and velocity. OMR and OKR are similarly affected in genetically modified mice with defects in retinal ganglion cells (RGC) compared with wild-type, suggesting they are driven by the same sensory input (RGC type). OKR eye movements have much higher gains than the OMR head movements, but neither can fully compensate global visual shifts. However, combined eye and head movements can be detected in unrestrained mice performing OMR, suggesting they can cooperate to achieve image stabilization, as previously described for other species. NEW & NOTEWORTHY We provide the first quantitation of head gain during optomotor response in mice and show that optomotor and optokinetic responses have similar psychometric curves. Head gains are far smaller than eye gains. Unrestrained mice combine head and eye movements to respond to visual stimuli, and both monocular and binocular fields are used during optokinetic responses. Mouse OMR and OKR movements are heterogeneous under optimal and suboptimal stimulation and are affected in mice lacking ON direction-selective retinal ganglion cells.

Analysis of vertebrate eye movements following intravitreal drug injections. I. Blockade of retinal ON-cells by 2-amino-4-phosphonobutyrate eliminates optokinetic nystagmus

1988 ◽  
Vol 60 (3) ◽  
pp. 1010-1021 ◽  
Author(s):  
A. G. Knapp ◽  
M. Ariel ◽  
F. R. Robinson
Keyword(s):  
Visual Cortex ◽  
Eye Movements ◽  
Retinal Ganglion Cells ◽  
Optokinetic Nystagmus ◽  
Ganglion Cells ◽  
Directional Asymmetry ◽  
Retinal Ganglion ◽  
Binocular Stimulation ◽  
Vertebrate Eye ◽  
Stimulation Of

1. Horizontal optokinetic nystagmus (OKN) was examined in alert rabbits and cats following intravitreal injection of 2-amino-4-phosphonobutyrate (APB), an agent which selectively blocks the light-responsiveness of retinal ON-cells while having little effect on OFF-cells. The retinal actions of APB were assessed independently by electroretinography. 2. In five rabbits, doses of APB sufficient to eliminate the b-wave of the electroretinogram reduced drastically the ability of the injected eye to drive OKN at all stimulus speeds tested (1-96 degrees/s). Impairment of OKN was apparent within minutes of the injection, remained maximal for several hours, and recovered completely in 1-7 days. OKN in response to stimulation of the uninjected eye alone remained qualitatively and quantitatively normal. 3. Following administration of APB, OKN in response to binocular stimulation displayed a directional asymmetry. Stimuli moving in the preferred (temporal-to-nasal) direction for the uninjected eye became more effective than stimuli moving in the opposite direction, indicating that the injected eye could no longer contribute to binocular OKN. 4. When rabbits viewed stationary stimuli through the APB-treated eye alone, episodes of slow (less than 1 degrees/s) ocular drift were observed, similar to the positional instability seen when rabbits are placed in darkness or when the retinal image is stablized artifically (12). 5. APB had little effect on OKN in normal cats. In two cats that had previously received large lesions of the visual cortex, however, APB eliminated the ability of the injected eye to drive monocular OKN. The extent of the impairment was similar to that seen in rabbits. Because the cortex is thought to contribute more to OKN in cats than in rabbits, this result suggests that the optokinetic pathways disrupted by APB project subcortically. 6. This study demonstrates that the integrity of retinal ON-cells is required to sustain normal OKN. The results are consistent with additional anatomic and physiological evidence suggesting that a particular subclass of retinal ganglion cells, the ON-direction-selective cells, may provide a crucial source of visual input to central optokinetic pathways.

scholarly journals Nonlinear decoding of natural images from large-scale primate retinal ganglion recordings

2020 ◽  
Author(s):  
Young Joon Kim ◽  
Nora Brackbill ◽  
Ella Batty ◽  
JinHyung Lee ◽  
Catalin Mitelut ◽  
...  
Keyword(s):  
Visual Information ◽  
Large Scale ◽  
Ganglion Cells ◽  
State Of The Art ◽  
Fundamental Problem ◽  
The State ◽  
Natural Images ◽  
Retinal Ganglion ◽  
Neural Decoding ◽  
Sensory Stimuli

AbstractDecoding sensory stimuli from neural activity can provide insight into how the nervous system might interpret the physical environment, and facilitates the development of brain-machine interfaces. Nevertheless, the neural decoding problem remains a significant open challenge. Here, we present an efficient nonlinear decoding approach for inferring natural scene stimuli from the spiking activities of retinal ganglion cells (RGCs). Our approach uses neural networks to improve upon existing decoders in both accuracy and scalability. Trained and validated on real retinal spike data from > 1000 simultaneously recorded macaque RGC units, the decoder demonstrates the necessity of nonlinear computations for accurate decoding of the fine structures of visual stimuli. Specifically, high-pass spatial features of natural images can only be decoded using nonlinear techniques, while low-pass features can be extracted equally well by linear and nonlinear methods. Together, these results advance the state of the art in decoding natural stimuli from large populations of neurons.Author summaryNeural decoding is a fundamental problem in computational and statistical neuroscience. There is an enormous literature on this problem, applied to a wide variety of brain areas and nervous systems. Here we focus on the problem of decoding visual information from the retina. The bulk of previous work here has focused on simple linear decoders, applied to modest numbers of simultaneously recorded cells, to decode artificial stimuli. In contrast, here we develop a scalable nonlinear decoding method to decode natural images from the responses of over a thousand simultaneously recorded units, and show that this decoder significantly improves on the state of the art.

Distribution of bipolar input to midget and parasol ganglion cells in marmoset retina

2008 ◽  
Vol 25 (1) ◽  
pp. 67-76 ◽  
Author(s):  
BAHAR ERIKÖZ ◽  
PATRICIA R. JUSUF ◽  
KUMIKO A. PERCIVAL ◽  
ULRIKE GRÜNERT
Keyword(s):  
Ampa Receptor ◽  
Synaptic Input ◽  
New World ◽  
Ganglion Cells ◽  
World Monkey ◽  
Dendritic Tree ◽  
Retinal Ganglion ◽  
Response Characteristics ◽  
Different Types ◽  
Synaptic Markers

Different types of retinal ganglion cell show differences in their response properties. Here we investigated the question of whether these differences are related to the distribution of the synaptic input to the dendritic tree. We measured the distribution and density of synaptic input to the dendrites of midget and parasol ganglion cells in the retina of a New World monkey, the marmoset,Callithrix jacchus. Ganglion cells were retrogradely labeled by dye injection into parvocellular or magnocellular regions of the lateral geniculate nucleus and subsequently photo-filled. Presumed bipolar cell synapses were identified immunocytochemically using antibodies against the ribbon protein CtBP2 or the GluR4 subunit of the AMPA receptor. For all cells, colocalized immunoreactive puncta were distributed across the entire dendritic tree. The density of the presumed bipolar input to midget ganglion cells was comparable for both synaptic markers, suggesting that the AMPA receptor GluR4 subunit is expressed at all synapses between midget bipolar and midget ganglion cells. Midget ganglion cells had an average of nine colocalized immunoreactive puncta per 100 μm2dendritic surface, and parasol cells had an average of seven colocalized immunoreactive puncta per 100 μm2dendritic surface. The densities were comparable in different regions of the dendritic tree and were not influenced by the location of the cells with respect to the fovea. Our findings suggest that the differences in the response characteristics of midget and parasol cells are not due to differences in the density of synaptic input to their dendritic tree.

scholarly journals Decorrelation of retinal response to natural scenes by fixational eye movements

2015 ◽  
Vol 112 (10) ◽  
pp. 3110-3115 ◽  
Author(s):  
Irina Yonit Segal ◽  
Chen Giladi ◽  
Michael Gedalin ◽  
Michele Rucci ◽  
Mor Ben-Tov ◽  
...  
Keyword(s):  
Eye Movements ◽  
Retinal Ganglion Cells ◽  
Visual Information ◽  
Ganglion Cells ◽  
Natural World ◽  
Natural Scenes ◽  
Retinal Ganglion ◽  
Spatial Correlations ◽  
Fixational Eye Movements ◽  
Spatiotemporal Signal

Under natural viewing conditions the input to the retina is a complex spatiotemporal signal that depends on both the scene and the way the observer moves. It is commonly assumed that the retina processes this input signal efficiently by taking into account the statistics of the natural world. It has recently been argued that incessant microscopic eye movements contribute to this process by decorrelating the input to the retina. Here we tested this theory by measuring the responses of the salamander retina to stimuli replicating the natural input signals experienced by the retina in the presence and absence of fixational eye movements. Contrary to the predictions of classic theories of efficient encoding that do not take behavior into account, we show that the response characteristics of retinal ganglion cells are not sufficient in themselves to disrupt the broad correlations of natural scenes. Specifically, retinal ganglion cells exhibited strong and extensive spatial correlations in the absence of fixational eye movements. However, the levels of correlation in the neural responses dropped in the presence of fixational eye movements, resulting in effective decorrelation of the channels streaming information to the brain. These observations confirm the predictions that microscopic eye movements act to reduce correlations in retinal responses and contribute to visual information processing.

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