Visual imagery scanning in young adults with intellectual disability.

Fifteen young adults with intellectual disability and 17 college students learned the locations of 5 landmarks on an island map and then scanned from one landmark to another. In the perception condition, the landmarks were visible; in the imagery condition, they were not. The rate of scanning over distance was similar for perception and imagery conditions, but overall scan times were slower in the imagery condition. Participants with intellectual disability required slightly more trials to learn the landmark locations and had generally slower scan times. Both groups were identical in rate of scanning for both perception and imagery conditions. Results suggest that persons with intellectual disability have no particular deficit in image inspection and, perhaps, relatively good imagery capacities.

Phonological and visuo-spatial working memory in individuals with intellectual disability.

Differences in the storage and rehearsal components of the phonological loop and visuo-spatial sketchpad were investigated in individuals with and without intellectual disability matched on memory span. The group with intellectual disability had specific difficulty in the rehearsal component of the phonological loop, as demonstrated by a weak word length effect compared to the group without intellectual disability. Groups did not differ in the storage component of the phonological loop as indexed by the phonological similarity effect. Also, groups did not differ in the storage or maintenance components of the visuo-spatial sketchpad, having comparable visual similarity and visual complexity effects. However, visual complexity task performance suggested that some aspects of visual processing surpass developmental level expectations for individuals with intellectual disability.

Converging on a richer understanding of human behavior and experience through a blending of cognitive and clinical psychology.

McClelland, Kemps, and Tiggemann's (this issue) use of experimental methods typically used in cognitive psychology to reduce the intensity of food cravings formed the basis for maintaining that an understanding of human experiences and behaviors requires a blending of cognitive and clinical psychological approaches. Clinical psychology can adapt cognitive models of information processing to understand the mechanisms underlying clinical phenomena and to create and evaluate effective interventions. Cognitive psychology should broaden its scope to include information relevant to clinical phenomena, such as desire, attitudes, self-regulation, and temperament. Only through a blending of these two fields will we converge on a richer understanding of human behavior and experience.

Sex differences in spatial ability: a lateralization of function approach.

The current study was designed to examine whether the extent of the male advantage in performance on a spatial task was determined by the extent to which the task was right-hemisphere dependent. Participants included 108 right-handed men and women who completed the mental rotation, waterlevel, and paperfolding tasks, all of which were presented bilaterally. The results partially supported the hypothesis. On the mental rotation task, men showed a right-hemisphere advantage, whereas women showed no hemispheric differences; however, no overall sex differences were observed. On the waterlevel task, men outperformed women, and both men and women showed a right-hemisphere advantage. On the paperfolding task, no sex or hemispheric differences were observed. Although the findings of the current study were mixed, the study provides a framework for examining sex differences across different types of spatial ability.