Psychophysical studies of monkey vision—I. Macaque luminosity and color vision tests

Visual functions associated with rhesus visual pursuit tracking

“…This result is consistent with target sizes used in studies in which rhesus long wavelength sensitivity was suppressed relative to the human (9,10,(16)(17)(18). In other rhesus and human comparisons of photopic spectral sensitivity, much more agreement exists between human and rhesus in the spectral sensitivity range from 580 to 640 nm (6)(7)(8). However, all of these studies utilized test targets many times larger than the test target limits which we used for observing rhesus long wavelength insensitivity.…”

“…Microspectrophotometric (MSP) measurements of rhesus cone photopigments, measured indiscreetly from foveal and parafoveal retinal regions, compare favorably with psychophysical measurements of cone fundamentals (5). Measurements of rhesus photopic spectral sensitivity have been demonstrated to fit the human photopic functions with small departure in the short wavelength region generally attributed to differences in lens pigmentation (6)(7)(8). Human achromatic acuity is slightly better at high photopic luminance levels and rhesus acuity is better at scotopic acuity luminance levels (4).…”

“…However, all of these studies utilized test targets many times larger than the test target limits which we used for observing rhesus long wavelength insensitivity. Yet, in at least two studies (7,8) a small deficit in rhesus long wavelength sensitivity either appeared without comment or was noted and dismissed as incidental experimental variation.…”

Psychophysical Chromatic Mechanisms in Macaque Monkey

“…Psychophysical measurements of color-discrimination thresholds in humans have been critical in building models of such post-receptoral chromatic mechanisms (Stockman and Brainard, 2010), generating numerous hypotheses concerning the underlying physiology that could potentially be tested in monkeys. Although monkeys and humans show similar spectral sensitivity (De Valois et al, 1974) and have almost identical cone types (Schnapf et al, 1990), the two species have obvious differences in brain organization and cognitive ability; it is not clear that monkeys possess the same psychophysical chromatic mechanisms as humans. The results presented here provide the first direct link between psychophysical chromatic mechanisms observed in humans and physiological studies in monkeys and justify the use of monkeys as a model system to investigate color behavior characterized in people.…”

Spatial and Temporal Properties of Cone Signals in Alert Macaque Primary Visual Cortex

“…All experiments were performed according to National Institutes of Health guidelines for the use of animals and with the approval of the Harvard Medical School Standing Committee on the use of animals. Macaques are a useful model for human color vision because psychophysical data from them match those of humans (De Valois et al, 1974;Sandell et al, 1979); the psychophysical results on human color matching are well predicted from the spectral sensitivities of the macaque cones (Baylor et al, 1987). Moreover, using alert animals overcomes the effects of anesthesia, which alter motion tuning (Pack et al, 2001) and may interfere with color processing (Solomon et al, 2004).…”