• cortex
  • Further, the magnitude of this perceptual suppression effect has been shown to correlate with the concentration of γ-aminobutyric acid or GABA, an inhibitory neurotransmitter in visual cortex. (wikipedia.org)
  • The cortical area MT (medial temporal cortex, also known as V5) plays a significant role in motion processing, and deactivation of this region using Transcranial magnetic stimulation can affect perception of motion. (wikipedia.org)
  • retinal
  • To test the retinal dopaminergic hypothesis, which posits deficient blue color perception in ADHD, resulting from hypofunctioning CNS and retinal dopamine, to which blue cones are exquisitely sensitive. (biomedcentral.com)
  • Accommodative and vergence responses of the typically developing visual system are generated using a combination of cues, including retinal blur and disparity. (arvojournals.org)
  • cortical
  • This counterintuitive finding is likely a perceptual correlate of center-surround mechanisms in cortical area MT. We now show that schizophrenic patients exhibit abnormally weak center-surround suppression in motion, an abnormality that is most pronounced in patients with severe negative symptoms. (jneurosci.org)
  • participants
  • This may be the result of perceiving an object in a dis-integrated way-seeing it in terms of its "parts" rather than as a "whole" leading to the possibility that the perceptual advantage observed in ASD participants result from altered visual integration ( Happé, 1996 ). (frontiersin.org)
  • spatial
  • This apparent variance in perception is influenced when it is viewed by different observers and when the background and central target patch are placed on "non-overlapping spatial frequency bands", as explained by Chubb et al. (wikipedia.org)
  • It has been suggested that this phenomenon, spatial suppression, is mediated by GABAergic center-surround antagonism in visual pathways. (jneurosci.org)
  • 1) "Spatial disorder of attention": an inability to perceive at any one time the several items of a visual scene. (bmj.com)
  • stimulus
  • 5. Visual reaction time may be defined as the interval between the onset of a stimulus and the initiation of the crewmember's response. (nasa.gov)
  • mechanisms
  • Here, we examine the integrity of suppressive center-surround mechanisms in motion perception of schizophrenic patients. (jneurosci.org)
  • Future studies should address possible underlying psychoanatomical mechanisms at "bottom up" and "top down" levels, and should specifically consider visual working memory and attention (including object based attention) as well as systems for identification of object structure and depth from binocular stereopsis, kinetic depth, motion parallax, eye movement signals, and other cues. (bmj.com)
  • psychophysical
  • To explore this claim we investigated visual integration in adults with ASD (diagnosed with Asperger's Syndrome) using two psychophysical tasks thought to rely on integrative processing-collinear facilitation and contour integration. (frontiersin.org)
  • In its simplest sense, a quantitative assessment profile of visual form discrimination by psychophysical responses is generated on a tangible computer readable medium. (patentsencyclopedia.com)
  • responses
  • The syndrome has six characteristics: photophobia eye strain poor visual resolution a reduced span of focus impaired depth perception poor sustained focus The scotopic sensitivity syndrome is diagnosed by interviewing the client and by observing responses to certain visual tasks such as interpreting geometric figures and reading. (wikipedia.org)
  • equally
  • Although the two central target patches are equally bright (identical in luminance) the one on a dark background appears lighter and the one on a lighter background appears darker. (wikipedia.org)
  • Nor was it purely visual, in which case both hands should have been affected equally (the right hand was worse). (bmj.com)
  • differ
  • An optical illusion (also called a visual illusion) is an illusion caused by the visual system and characterized by a visual percept that (loosely said) appears to differ from reality. (wikipedia.org)
  • illusion
  • The Chubb illusion is an optical illusion or error in visual perception in which the apparent contrast of an object varies substantially to most viewers depending on its relative contrast to the field on which it is displayed. (wikipedia.org)
  • Chubb and his colleagues researched this illusion by showing various combinations of foreground objects and background fields to human test subjects and asking them to rate the sharpness of the visual contrast in each foreground object. (wikipedia.org)
  • The Chubb illusion is similar to another visual illusion, the contrast effect. (wikipedia.org)
  • The Chubb illusion illustrates an error in contrast rather than luminance. (wikipedia.org)
  • A familiar phenomenon and example for a physical visual illusion is when mountains appear to be much nearer in clear weather with low humidity (Foehn) than they are. (wikipedia.org)
  • severe
  • There is evidence that these impairments may be more severe among patients with predominantly Negative symptoms, or those who are not medicated. (wikipedia.org)
  • Vibration - If vibration is sufficiently severe, visual performance will be degraded. (nasa.gov)
  • difficulty
  • They are intended to help people with the supposed perceptual processing difficulty known as Irlen Syndrome, also known as Scotopic Sensitivity Syndrome or visual stress. (wikipedia.org)
  • 3) Optic ataxia ( ataktos , Greek for "disorderly"): difficulty reaching under visual guidance despite normal limb strength. (bmj.com)
  • discrimination
  • Previous studies of color perception in ADHD, including our own [ 8 ], have focused on hue discrimination in ADHD. (biomedcentral.com)
  • An apparatus for quantitative assessment of visual form discrimination of a subject comprising a display device, an input device, a control device, and a tangible computer readable medium. (patentsencyclopedia.com)
  • cues
  • Loss of these cues along with other environmental consequences discussed below can degrade perception of object shape, distance, location and relative motion. (nasa.gov)
  • consequences
  • all patients had been clinically recovered and unmedicated for several months at the time of testing, suggesting that depression has ubiquitous consequences that may persist long after mood symptoms have receded. (jneurosci.org)
  • disorder
  • Major depressive disorder (MDD) is a mood disorder that is not traditionally considered to affect the visual system. (jneurosci.org)
  • The goal of this review is to explore a range of psychological and anatomical explanations for this striking visual disorder and to propose new directions for interpreting the findings in Bálint's syndrome and related cerebral disorders of visual processing. (bmj.com)
  • macular degeneration
  • 15. The composition of claim 1, wherein the composition is for improving the visual performance of a subject without age-related macular degeneration. (patentsencyclopedia.com)
  • 27. The method of claim 17, wherein performance of the method causes an improvement in visual performance of a subject without age-related macular degeneration. (patentsencyclopedia.com)
  • The purpose of this study was to evaluate the impact of supplemental macular carotenoids (including versus not including meso -zeaxanthin) in combination with coantioxidants on visual function in patients with nonadvanced age-related macular degeneration. (arvojournals.org)
  • Antioxidant supplementation in patients with nonadvanced age-related macular degeneration results in significant increases in macular pigment and improvements in CS and other measures of visual function. (arvojournals.org)
  • Pigment
  • 14. The composition of claim 1, wherein the composition is for improving the visual performance of a subject who has a normal level of macular pigment. (patentsencyclopedia.com)
  • 26. The method of claim 17, wherein performance of the method causes an improvement in visual performance of a subject who has a normal level of macular pigment. (patentsencyclopedia.com)
  • 28. The method of claim 17, wherein performance of the method causes an improvement in visual performance of a subject with an atypical "central dip" macular pigment distribution. (patentsencyclopedia.com)
  • processes
  • Collectively, the preceding findings indicate the need for further investigation of visual function and its regulation by attentional processes in ADHD. (biomedcentral.com)
  • syndrome
  • However, current research on the topic includes placebo controls, longitudinal studies, and cutting-edge brain mapping technology, all of which support the use of colour to alleviate the symptoms associated with Irlen Syndrome. (wikipedia.org)
  • She has also claimed that a treatment for scotopic sensitivity syndrome could help a number of incarcerated individuals and delinquent children. (wikipedia.org)
  • According to Helveston, the scotopic sensitivity syndrome and its treatment has, as a phenomenon, resulted in classic group behaviour and has the characteristics of a fad with a charismatic personality as a leader and the supporting evidence being mostly anecdotal. (wikipedia.org)
  • In the case of Bálint's syndrome, the visual world is perceived erratically, as a series of single objects. (bmj.com)
  • subjects
  • We tested whether disruption of these monitoring pathways on the thalamic level impairs the perceptual matching of visual input before and after an eye movement in human subjects. (frontiersin.org)
  • stimulation
  • The negative safety implications of the elaborate interior lighting features would appear to be minimal in terms of distraction and irritation whereas the safety benefits in this particularly long road tunnel, in terms of subjective feelings of visual stimulation is encouraging. (hcibib.org)
  • light
  • 2. Luminance Range (Contrast) - The extravehicular environment is marked by a wider range of light intensities than normally encountered on Earth. (nasa.gov)
  • system
  • Moreover, other brain functions that rely on transient information processed by the visual system may also be jeopardized. (jneurosci.org)
  • performance
  • This section discusses aspects of visual performance that are, or are likely to be, modified by space travel. (nasa.gov)
  • Altered sensory and perceptual experiences are also common, and a notable perceptual difference between individuals with ASD and controls is their superior performance in visual tasks where it may be beneficial to ignore global context. (frontiersin.org)
  • Disclosed is a composition comprising MZ for use as a dietary supplement or food additive for oral consumption for improving the visual performance of a human subject. (patentsencyclopedia.com)
  • 13. The composition of claim 1, wherein the composition is for improving the visual performance of a subject in photopic conditions with a level of illumination greater than 3 Cdm.sup. (patentsencyclopedia.com)
  • 17. A method of improving the visual performance of a human subject in need of such improvement, the method comprising the step of administering to the subject an effective amount of a composition comprising MZ for use as a dietary supplement or food additive for oral consumption. (patentsencyclopedia.com)
  • 25. The method of claim 17, wherein performance of the method causes an improvement in visual performance of the subject in photopic conditions. (patentsencyclopedia.com)
  • 29. A method of making a composition for human consumption, the composition to be consumed by a human subject for the purpose of improving visual performance, the method comprising the step of mixing an effective amount of MZ with an acceptable dietary diluent, excipient or carrier. (patentsencyclopedia.com)
  • One theory of macular pigment's (MP) presence in the fovea is to improve visual performance in glare. (arvojournals.org)
  • MP correlates with three aspects of visual performance in glare. (arvojournals.org)
  • The effects described, therefore, can be extended more confidently to real-world, practical visual performance benefits. (arvojournals.org)
  • Because the fovea yields the highest visual performance for nearly all parameters of vision, any factor that negatively impacts its function (i.e., glare) will result in noticeable decrements in visual performance. (arvojournals.org)
  • Conversely, any factor that promotes or protects foveal function would seemingly have noticeable visual performance benefits. (arvojournals.org)