Colour imperception in unilateral hemisphere-damaged patients.

Effects of memory load on hemispheric asymmetries of colour memory

“…This finding is in agreement with other studies showing a RH advantage in colour detection (Pirot et al, 1977), colour matching (Bernasek & Haude, 1993;Levy & Trevarthen, 1981;Pennal, 1977;Tokar et al, 1989), and hue discrimination (Basso et al, 1976;Davidoff, 1976;Hannay, 1979;Scotti & Spinnler, 1970). The RH advantage was especially pronounced when 12 colour items had to be memorised (HML).…”

“…A right-hemisphere (RH) advantage has been shown in behavioural studies investigating colour detection (Pirot, Pulton, & Sutker, 1977), colour matching (Bernasek & Haude, 1993;Levy & Trevarthen, 1981;Pennal, 1977;Tokar, Matheson & Haude, 1989), and colour or hue discrimination (Basso, Faglioni, & Spinnler, 1976;Davidoff, 1976;Hannay, 1979;Scotti & Spinnler, 1970). However, a prerequisite to detect a RH advantage in those tasks is that colour stimuli are not easily nameable or involve verbal response (Levy & Trevarthen, 1981).…”

Hemispheric differences in the perception of gratings

“…The absence of hemispheric differences observed in our study, however, makes it plausible that gratings are processed at a low level of sensory information processing, where a pattern is analyzed by both hemispheres. Thus, our data confirm the notion that hemispheric asymmetry does not appear in the perception of simple features of a visual pattern such as contour, luminance, sound volume, grating, and touch (Beaton & Blakemore, 1981;Dimond & Beaumont, 1974;Moscovitch, 1979;Moscovitch et al, 1976;Rotkin et al, 1977;Scotti & Spinnler, 1970;Sergent, 1982Sergent, , 1983Wood, 1975). According to these authors, hemispheric asymmetry comes into play only at subsequent processing stages, at which higher order features, such as phonemes, words, or facial features, are identified.…”

“…According to some authors, functional differentiation takes place at an early processing stage (Hellige & Webster, 1979;Pennal, 1977;Pirot, Pulton, & Sutker, 1977). Others believe that it occurs only in the processing of the more complex features, for example, visuospatial or semantic features (Moscovitch, 1979;Moscovitch, Scullion, & Christie, 1976;Rotkin, Greenwood, & Gazzaniga, 1977;Scotti & Spinnler, 1970;Sergent, 1983). These divergent findings, as well as the electrophysiological data suggesting that grating is processed at the lower levels of the nervous system, have induced us to investigate hemispheric differences in grating perception.…”

Results of Colour Vision Tests in Alcoholic and in Mentally Disordered Subjects

“…Liver damages cause an acquired blue-yellow de fectiveness of colour vision, even without al coholism [Dittrich and Neubauer, 1967], Also without interference of alcoholism, some mental disorders can provoke a bad performance at colour vision tests (organic damages to the brain [Scotti and Spinnler, 1970]; schizophrenia [Kaplan and Lynch, 1945]; conversion hysteria [Krill and New ell, 1968], etc. ); as alcoholism often damages the liver and the mental condition, dyschromatopsia can sometimes be secondary, as it is the case in concomitant diabetes.…”