Crowding: Effects of Group Size,Room Size,or Density?

The separate effects of group size, room size, and density (space per person) were investigated for subjects responding interactively or coactively to perceptual and cognitive tasks. The major findings are that crowding has greater effects on "feelings" and "interpersonal perceptions" than on task performance. Where crowding did have effects, they appeared to be mediated more by group size and, to some degree, room size than by density, especially for males. Female subjects appeared somewhat more density oriented than male subjects.     

Imitative Behavior as a Function of Success-Failure and Racial-Socioeconomic Factors1

This study examined whether success-failure experiences, race, and social class are related to the likelihood that young children will engage in imitative behavior. Black subjects imitated significantly more than white subjects on a pre-experimental measure of imitation. Analysis of a difference score between pre- and post-experimental measures of imitation indicated that prior success was associated with less imitation than failure or a neutral condition. In addition, a white model was imitated significantly more than a black model in both the failure and the success conditions, with little difference between models in the neutral condition. No significant difference was found between the nondeprived and deprived groups. The results were discussed in terms of an outer-directedness hypothesis.     

Periodicity pitch perception and its upper frequency limit in cats

We have established a procedure for behavioral assessment of periodicity pitch perception in the cat. This procedure requires the training of cats to make a differential response to two different pure tones, and then testing for the transfer of learning when complex stimuli known to produce periodicity pitch sensations in humans are substituted for the pure tones. Complex stimuli consisted of three to five harmonically related frequencies of the same amplitude and phase. Eight cats were the subjects of these experiments. Two of them were controls. It is demonstrated here that cats do perceive periodicity pitch. We also used this procedure to measure the upper frequency limit of periodicity pitch perception for two cats. The frequencies tested were 100, 200, 300, 400, 600, 800, 900, and 1,200 Hz. The data indicate that the upper frequency limit of periodicity pitch perception in the cat is on the order of 600 to 800 Hz. There is a trend of decreasing prominence of the perception of periodicity pitch as the component frequencies are increased. These results are parallel to the human psychophysical data.