Chromatic and achromatic contrast sensitivity were measured in a human observer, 2 normal macaque monkeys, and 3 monkeys with severe toxicant-induced damage to the parvocellular projecting retinogeniculate pathway (P cell-deficient monkeys). Damage to the P pathway was produced by the oral administration of acrylamide monomer (Eskin and Merigan, 1986). Contrast sensitivity was measured in all s...

RECEPTIVE FIELDS OF MONKEY GEIUCULATE CELLS IN THE DARK ADAPTED STATE. T.N.Wiesel & D.H.Hubel. Dept. of F’harm.,Harvard Med. School, Boston. Twelve cells in the dorsal layers of the lateral geniculate body of the Rhesus monkey were examined with monochromatic light-spot stimulation in both the light and dark adapted state. All cells had their receptive fields 3O to 18Ofrom the fovea. Four cells...

We have recorded the responses of single cells in the lateral geniculate nucleus (LGN) and striate cortex of the macaque monkey. The response characteristics of neurons at these successive visual processing levels were examined with isoluminant gratings, cone-isolating gratings, and luminance-varying gratings. The main findings were: (i) Whereas almost all parvo- and konio-cellular LGN cells ar...

According to opponent-colors theory, a reddish surround induces greenness in a central test field. Color-appearance measurements verify this with a long-wavelength reddish surround (660 nm) but not with a short-wavelength reddish surround (440 nm). Surprisingly, a short-wavelength reddish surround shifts the appearance of a test toward redness. Four possible explanations are: (1) stray light fr...

purpose : to investigate the discriminative ability of contrast sensitivity (cs), color vision and best corrected visual acuity (bcva) in detecting functional losses in diabetic participants with and without retinopathy methods : in this cross sectional study we examined 105 patients in khatam-al-anbia eye hospital of mashhad university of medical sciences including 70 diabetic patients (35 wit...

To shed light on the perceptual basis of the color white, we measured settings of unique white in a dark surround. We find that settings reliably show more variability in an oblique (blue-yellow) direction in color space than along the cardinal axes of the cone-opponent mechanisms. This is against the idea that white perception arises at the null point of the cone-opponent mechanisms, but one a...

We present a new vectorial total variation method that addresses the problem of color consistent image filtering. Our approach is inspired from the double-opponent cell representation in the human visual cortex. Existing methods of vectorial total variation regularizers have insufficient (or no) coupling between the color channels and thus may introduce color artifacts. We address this problem ...

We extended our detection model of achromatic spatial vision (Rovamo, J., Mustonen, J., & Näsänen, R. (1994a). Modelling contrast sensitivity as a function of retinal illuminance and grating area. Vision Research, 34, 1301-1314) to colour vision by taking into account the fact that due to the spatio-chromatic opponency of retinal ganglion cells and dorsal lateral geniculate nucleus (dLGN) neuro...

Does it matter if you speak with a regional accent? Speaking immediately reveals something of one's own social and cultural identity, be it consciously or unconsciously. Perceiving accents involves not only reconstructing such imprints but also augmenting them with particular attitudes and stereotypes. Even though we know much about attitudes and stereotypes that are transmitted by, e.g. skin c...

for Chapter A MULTI-STAGE COLOR MODEL REVISITED: IMPLICATIONS FOR A GENE THERAPY CURE FOR RED-GREEN COLORBLINDNESS Katherine Mancuso, Matthew C. Mauck, James A. Kuchenbecker, Maureen Neitz, and Jay Neitz In 1993, DeValois and DeValois proposed a “multi-stage color model” to explain how the cortex is ultimately able to deconfound the responses of neurons receiving input from three cone types in ...