Color constancy and the functional significance of McCollough effects

Vladusich, Tony; Broerse, Jack

doi:10.1016/s0893-6080(02)00085-0

Cited by 3 publications

(6 citation statements)

References 91 publications

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“…An additional limitation of previous models (Broerse et al, 1999 ; Grossberg et al, 2002 ; Vladusich and Broerse, 2002 ) is their assumption that the LCA is triggered only by achromatic boundaries. In fact, chromatic aberration (and specifically the LCA) also occurs at iso-luminance chromatic boundaries, where there are no achromatic boundaries (Figure 1 ).…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies that proposed neuronal mechanisms to compensate for chromatic aberration (Hay et al, 1963 ; Broerse et al, 1999 ; Grossberg et al, 2002 ; Vladusich and Broerse, 2002 ) related these mechanisms to long-term after-effects, such as the ME—a long-term orientation-contingent color after-effect (McCollough, 1965 ). Vladusich and Broerse ( 2002 ) proposed a learning neuronal model that inhibits the fringes at luminance boundaries (caused by chromatic aberrations). Grossberg et al ( 2002 ) proposed a learning mechanism whose primary function is to adaptively align the representations of the boundaries and surfaces, which are shifted due to the process of binocular fusion.…”

Section: Discussionmentioning

confidence: 99%

“…In our opinion, there are two main arguments against the idea that ME models can completely explain neuronal compensation to LCA. The first limitation of the above models (Broerse et al, 1999 ; Grossberg et al, 2002 ; Vladusich and Broerse, 2002 ) is that they assume that the magnitude of LCA effect depends solely on the magnitude of the luminance edge. However, the LCA effect also depends on additional optical factors, such as the pupil aperture (DeValois and DeValois, 1991 ), whose size changes dynamically in response to the level of ambient illumination and accommodation.…”

Section: Discussionmentioning

confidence: 99%

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Neuronal Mechanism for Compensation of Longitudinal Chromatic Aberration-Derived Algorithm

Barkan

Spitzer

2018

Front. Bioeng. Biotechnol.

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The human visual system faces many challenges, among them the need to overcome the imperfections of its optics, which degrade the retinal image. One of the most dominant limitations is longitudinal chromatic aberration (LCA), which causes short wavelengths (blue light) to be focused in front of the retina with consequent blurring of the retinal chromatic image. The perceived visual appearance, however, does not display such chromatic distortions. The intriguing question, therefore, is how the perceived visual appearance of a sharp and clear chromatic image is achieved despite the imperfections of the ocular optics. To address this issue, we propose a neural mechanism and computational model, based on the unique properties of the S-cone pathway. The model suggests that the visual system overcomes LCA through two known properties of the S channel: (1) omitting the contribution of the S channel from the high-spatial resolution pathway (utilizing only the L and M channels). (b) Having large and coextensive receptive fields that correspond to the small bistratified cells. Here, we use computational simulations of our model on real images to show how integrating these two basic principles can provide a significant compensation for LCA. Further support for the proposed neuronal mechanism is given by the ability of the model to predict an enigmatic visual phenomenon of large color shifts as part of the assimilation effect.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Neuronal Mechanism for Compensation of Longitudinal Chromatic Aberration-Derived Algorithm

Barkan

Spitzer

2018

Front. Bioeng. Biotechnol.

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“…There is evidence in support of a purely local (primary visual cortex) basis of ME 28,29,30 as well as indications of involvement of more complex integrational processes. Thus, previous studies [31][32][33][34] have shown that ME reveals adaptive (compensation-correction) mechanisms of color constancy. According to Dodwell and Humphrey, 35 the ME represents an error-correction mechanism (error correcting device) whose role is reducing discrepancies between the external environment and the internal representation, which may be mediated by top-down neural processes.…”

Section: Introductionmentioning

confidence: 89%

“…We acknowledge that studies on medication naïve patients are warranted to fully examine the ME in schizophrenia. The patients group was heterogenous in terms of hospitalization status, comprising both inpatients (16) and outpatients (34). The choice of the patients was determined by 2 main factors: their ability to participate in the FA and ME tasks and the availability of the relatives who were willing to take part in the study.…”

Section: Limitationsmentioning

confidence: 99%

The McCollough Effect and Facial Emotion Discrimination in Patients With Schizophrenia and Their Unaffected Relatives

Surguladze

Chkonia

Kezeli³

et al. 2010

Schizophrenia Bulletin

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Abnormalities in visual processing have been found consistently in schizophrenia patients, including deficits in early visual processing, perceptual organization, and facial emotion recognition. There is however no consensus as to whether these abnormalities represent heritable illness traits and what their contribution is to psychopathology. Fifty patients with schizophrenia, 61 of their first-degree healthy relatives, and 50 psychiatrically healthy volunteers were tested with regard to facial affect (FA) discrimination and susceptibility to develop the color-contingent illusion [the McCollough Effect (ME)]. Both patients and relatives demonstrated significantly lower accuracy in FA discrimination compared with controls. There was also a significant effect of familiality: Participants from the same families had more similar accuracy scores than those who belonged to different families. Experiments with the ME showed that schizophrenia patients required longer time to develop the illusion than relatives and controls, which indicated poor visual adaptation in schizophrenia. Relatives were marginally slower than controls. There was no significant association between the measures of FA discrimination accuracy and ME in any of the participant groups. Facial emotion discrimination was associated with the degree of interpersonal problems, as measured by the Schizotypal Personality Questionnaire in relatives and healthy volunteers, whereas the ME was associated with the perceptual-cognitive symptoms of schizotypy and positive symptoms of schizophrenia. Our results support the heritability of FA discrimination deficits as a trait and indicate visual adaptation abnormalities in schizophrenia, which are symptom related.

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Chromatic aberration and the roles of double-opponent and color-luminance neurons in color vision

Vladusich¹

2007

Neural Networks

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Color constancy and the functional significance of McCollough effects

Cited by 3 publications

References 91 publications

Neuronal Mechanism for Compensation of Longitudinal Chromatic Aberration-Derived Algorithm

Neuronal Mechanism for Compensation of Longitudinal Chromatic Aberration-Derived Algorithm

The McCollough Effect and Facial Emotion Discrimination in Patients With Schizophrenia and Their Unaffected Relatives

Chromatic aberration and the roles of double-opponent and color-luminance neurons in color vision

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