Short-term haptic memory for three-dimensional objects.

In 8 experiments college students felt 32 geometric objects and were tested in a signal-detection framework to same or distractor items. Retention intervals and intervening experiences were also manipulated following initial touching. In all instances performance was high, and there was no evidence of a decline in haptic sensitivity over the retention intervals employed. These surprising results were interpreted as consistent with the 1985 contention of Klatzky, Lederman, and Metzger that the haptic modality constitutes an expert system.

Early social isolation of the domestic cat: responses to separation from social and nonsocial rearing stimuli.

The relative contributions of social-rearing stimuli (a mother and/or a littermate) and nonsocial-rearing stimuli (a brooder) to the formation and decline of infant kitten attachments were assessed by counting the frequency of distress cries produced by separation from the following rearing conditions: (1) mother-littermate; (2) mother-only; (3) brooder-littermate; and (4) brooder-only. Four male and 4 female kittens were reared in each condition. Each kitten was separated from its rearing condition once a week, from 2 until 5 weeks of age, and placed in open field for 15 min. The frequency of distress cries in both littermate-reared groups did not significantly differ throughout the experiment. The frequency was consistently high until 5 weeks of age when distress cries were significantly reduced. The frequency of distress cries consistently increased in the mother-only-reared kittens with repeated separations, but consistently decreased in the brooder-only-reared kittens. The results were interpreted as being commensurate with the social conditions at the time of separation.

The effects of social isolation on the behavior of juvenile domestic cats.

The effects of social isolation on the behavior of juvenile domestic cats were assessed by rearing 4 male and 4 female infant kittens in each of the following rearing conditions: (1) mother-littermate; (2) mother-only; (3) brooder-littermate; and (4) brooder-only. They were then tested twice a week individually and twice a week socially from 2 to 6 1/2 months of age in a playroom, utilizing multiple categories of behavior. The mother-only-reared juveniles were hyperactive in both object play (when tested individually) and social play. The brooder-only-reared kittens displayed enhanced socially directed behavior and were generally hypergregarious, whereas the brooder-littermate-reared kittens displayed retarded social behavior. Observations indicated that littermate-deprived kittens did not learn social communication skills and that some prolonged separation effects existed for littermate-reared kittens. The results suggest that the determinants of social play are more complex than the determinants of object play.

A signal-detection determination of the two-point supraliminal difference limen on three different body areas.

This investigation was designed to determine the relationship between the tactual two-point threshold and the two-point supraliminal difference limen. The yes/no method was employed and three localities were tested. The results confirmed the hypothesis that as the initial two-point threshold increases, the two-point supraliminal difference limen also increases. No significant differences were obtained between the right and the left sides of each body area tested and only on the hand was a reliable difference obtained between the first 9 and second 9 sessions. This difference was interpreted in terms of a peripheral fatigue phenomenon.