Sources of Motion-Sensitivity Loss in Glaucoma

Falkenberg, Helle K.; Bex, Peter J.

doi:10.1167/iovs.06-0752

Cited by 29 publications

(28 citation statements)

References 72 publications

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“…Several human studies of motion perception and orientation discrimination have found data that are consistent with models of either increased baseline noise and/or increased multiplicative noise (that is, scaled by the magnitude of the signal) with age. 21,43,44 Further studies specifically designed to estimate internal noise within the aging form perception system are required to clarify these potential contributions to impaired oriented texture discrimination.…”

Section: Discussionmentioning

confidence: 99%

Shape Perception Is Altered by Normal Aging

Weymouth¹,

McKendrick²

2012

Invest. Ophthalmol. Vis. Sci.

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Section: Discussionmentioning

confidence: 99%

Shape Perception Is Altered by Normal Aging

Weymouth¹,

McKendrick²

2012

Invest. Ophthalmol. Vis. Sci.

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“…Equivalent noise analysis showed that the reduced sensitivity with eccentricity was primarily due to reduced sampling efficiency, with little increase in the level of internal noise, and that the fall-off with age was attributable to both sources of error. Compared with age-matched control observers, patients with POAG and AMD have similar levels of internal noise but significantly lower sampling efficiency (Falkenberg & Bex, 2007).…”

Section: Introductionmentioning

confidence: 94%

“…In patients with POAG and AMD, the loss is mostly attributable to a reduction in sampling efficiency. This suggests that retinal ganglion cells are non-functional rather than dysfunctional, at least in glaucoma (Falkenberg & Bex, 2007). …”

Section: Introductionmentioning

confidence: 99%

Kongsberg Vision Meeting 2009

Baraas¹,

Einevoll²

2009

SJOVS

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In Old World primates, the three cone photoreceptor classes provide the starting point for trichromatic vision. These cone classes are characterized by differences in spectral sensitivity, in density with respect to distance from the fovea, and in relative abundance across individuals (Hofer et al., 2005). How neural signals originating from the cones lead to colour perception is still not understood. For example, there is controversy over the chromatic structure of the receptive fields of the midget class of retinal ganglion cells, which give rise to the parvocellular visual pathway. To distinguish colours, the responses of different cone types must be compared. It is uncertain if the centres and surrounds of midget ganglion cell receptive fields are composed of inputs from only one cone type, or from cone mixtures. These options lead to different colour-coding schemes in the retina, and thus dictate how colour must be processed downstream. To solve this and other problems concerning visual perception, it would be useful to have a way to directly map the cone fields that initially define every receptive field.The main impediments to achieving this goal have been the inability to resolve and stimulate individual cones in the living retina. To begin to overcome these difficulties, we used an adaptive optics scanning laser ophthalmoscope (AOSLO) to visualize and stimulate the cones in vivo in the macaque (Roorda et al., 2002; Arathorn et al., 2007). We made extracellular recordings in the lateral geniculate nucleus to map the cones providing excitatory input to single parvocellular neurons, and assessed the efficacy of each cone's input for eliciting responses (Sincich et al., 2009). We found that parvocellular neurons can be mapped reliably by this method, and that the probability of evoking a spike with each stimulus flash varied considerably from cone to cone. This variability appeared to have two sources: a high sensitivity to the position of stimuli relative to each cone, and more variation in the synaptic weighting of cones than would be predicted if each class had a characteristic weight. For receptive field centres comprised of multiple cones, we also found that stimulation of just one of these cones leads to geniculate transmission with high probability. This result suggests that activation of a single cone within a large receptive field is sufficient for perception.Although our studies are at an early stage, cone imaging with an AOSLO, performed in conjunction with traditional electrophysiology, is a promising way to study the inputs to the visual system at the elemental level of the single cone. Receptive fields recorded at any level of the visual system can then be mapped by what they are truly made of -cone fields.

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“…them influences the decision making and action control in the process of human aging due to the increased level of internal noise in the visual system [1]. If the visual system neglects some of the available information [2], the visual signal/noise ratio will additionally deteriorate. Throughout the life cycle many aspects of vision and visual information processing decline and affect everyday task performance.…”

Section: Introductionmentioning

confidence: 99%

Human integration of motion and texture information in visual slant estimation

Tchamova

Dezert

Bocheva

et al. 2012

2012 6th IEEE INTERNATIONAL CONFERENCE INTELLIGENT SYSTEMS

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Abstract-The present research is aimed to: (i) characterize the ability of human visual system to define the objects' slant on the base of combination of visual stimulus characteristics, that in general are uncertain and even conflicting.(ii) evaluate the influence of human age on visual cues assessment and processing; (iii) estimate the process of human visual cue integration based on the well known Normalized Conjunctive Consensus and Averaging fusion rules, as well on the base of more efficient probabilistic Proportional Conflict Redistribution rule no.5 defined within Dezert-Smarandache Theory for plausible and paradoxical reasoning. The impact of research is focused on the ability of these fusion rules to predict in adequate way the behavior of individuals, as well as age-contingent groups of individuals in visual cue integration process.

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Sources of Motion-Sensitivity Loss in Glaucoma

Cited by 29 publications

References 72 publications

Shape Perception Is Altered by Normal Aging

Shape Perception Is Altered by Normal Aging

Kongsberg Vision Meeting 2009

Human integration of motion and texture information in visual slant estimation

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