Saturation of red: A prothetic continuum

A battery of procedures was used to scale the saturation of colors produced by mixtures of red and gray papers. By direct magnitude estimation, the apparent saturation was found to grow as the1.7 power of the percentage of red in the mixture. The power law was confirmed by the cross-modality matching of loudness to saturation. The inverse continuum, paleness, was also scaled. Saturation appears to be a prothetic continuum because the category scale is curved and the subjective size of the jnd increases as saturation increases.     

Regression effect in psychophysical judgment

Psychophysical judgment, like all other kinds of judgment, involves a matching or equating of two different domains. When the judgment involves the matching of values on two perceptual continua, the observer tends, on the average, to constrict the range of his adjustments on whichever variable is placed under his control. When the observer adjusts each variable in turn, two different regression lines are produced. This regression effect presumably occurs whenever the results of the matching judgments yield less than a perfect correlation. Illustrative examples are given for the continua, loudness, vibration, brightness, and duration.     

Emotional trauma in rats: Age as a factor in recovery

Old (7 months of age) and young (2 months) male rats were divided into groups matched for spontaneous exploratory activity and for age. Experimental rats in the two age categories were then traumatized by giving them a 90 volt shock to the feet for two sec. on only one occasion. It was shown that nearly all the young rats recovered from the trauma within 5 weeks, as measured by brief exploratory activity and defecation, while at the end of 6 months the old rats still had not recovered. These results point up the greater resiliency of young animals, and the need for caution in the interpreting of research and theories on early experience.     

CULTURAL AND PHYSIOLOGICAL INFLUENCES UPON SPATIAL-PERCEPTUAL PROCESSES IN WEST AFRICA1 – PART I

Influences culturelles et physiologiques sur les processus spatio-perceptifs dans L'Ouest africain. 1^re partie. — Plusieurs études ont été réalisées dans le Sierra Leone pour tester la validité de certaines hypothèses relatives aux effets d'une culture tribale et d'un trouble endocrinien (Kwashiorkor) sur le développement de la dépendance vis-à-vis du champ et L'acquisition d'aptitudes spatio-perceptives. La première partie traite de la construction d'un test de tridimensionnalité, des variables culturelles et d'une expérience d'enseignement de la tridimensionnalité. La seconde partie présentera L'étude des variables endocriniennes et L'analyse factorielle pour L'ensemble des résultats.