Individual use of judgmental dimensions and hemispheric specificity.

The present study investigated the relationship of hemispheric functional specificity to a subject's use of judgmental dimensions when discriminating temporal and spatial visual stimuli using a multidimensional scaling (MDS) paired-comparison paradigm. The major purposes of the study were: To identify the judgmental dimensions used in discriminating unidimensional (temporal or spatial) and multidimensional (combinations of temporal and spatial parameters) stimuli presented to the two visual hemifields; to study the relationship of the use of judgmental dimensions to the visual hemifields; to investigate whether the use of judgmental dimensions in discriminating unidimensional stimuli can be used to predict their use in discriminating multidimensional stimuli. Subjects used two dimensions in discriminating the spatial and temporal unidimensional stimuli: A dimension whose scaling paralleled the physically interval-scaled stimuli; a dimension, in which the extreme values were located on one end of the scale, while the mid-values are located at the other end of the scale. There is significantly greater use of the spatial dimension when spatial stimuli are presented to the left visual field (LVF) then when presented to the right visual field (RVF). Conversely, there is significantly greater use of the temporal dimension when temporal stimuli are presented to the RVF then when they are presented to the LVF. Three perceptual dimensions were used to judge multidimensional stimuli: Spatial-to-temporal; stimulus quality; apparent movement. Two groups of subjects were identified who differed in their relative use of the temporally and spatially scaled unidimensional stimuli presented to the RVF. These two groups differed with respect to their relative use of a spatial-to-temporal dimension when multidimensional stimuli were presented to the RVF.