Interactive effects of deprivation in the albino rat

The interactive effects of feeding and drinking schedules were investigated in three experiments. Twenty-four hour water-deprived rats consumed their entire obligatory water intake prior to feeding, whereas 24-hr food-deprived rats consumed only small quantities of food prior to drinking. This drinking was apparently due to a shift of water stores rather than an actual negative water balance. Experiment 3 investigated the effects of 24, 48, or 72 hr of water, food, or total deprivation. Water-deprived rats did not adequately suppress food intake and became thirstier than totally deprived rats. The effects of total deprivation were essentially identical to those of food deprivation. These experiments indicate the degree to which deprivation schedules impose restrictions on the reinforcement parameters of behavioral experiments.     

Learned taste aversions in rats as a function of delay,speed, and duration of rotation

Rats fed a saccharin solution and then rotated on a turntable showed an aversion to the saccharin solution on later testing. In the first experiment, the rats learned to avoid saccharin with delays of as much as 9 hr between drinking the saccharin and the start of rotation. The second experiment showed that the critical determinant of aversiveness of rotation was number of rotations. The rats avoided saccharin as much after rotation at high speeds for short durations as after rotation at low speeds for long durations.     

Increment thresholds against pulsed and steady backgrounds

Cornsweet and Pinsker reported that ΔL/L was constant at all values of L for briefly pulsed fields (ΔL was the luminance increment required for discriminating which of two nearby flashed fields was brighter). We obtain the same result when the subject must detect which of two briefly (4-msec) flashed backgrounds contains an increment at its center. However, when the background and increment are flashed at a longer duration (200 msec) ΔL/L decreases with increasing L as is obtained with a steady background. Two previous models which handle earlier work do not readily accommodate this result; we suggest a theoretical approach that does.     

Measuring the duration of perception

An analysis is presented of ways in which the total duration of perception of transient visual stimuli may be determined by means of psychophysical judgments of the simultaneity (or relative precedence) of two sensory events. This analysis yields a new method for measuring the duration of perception that only requires judgments of the simultaneity of the offset of one visual target with the onset of another (“offset-onset” judgments), and is thus free of differential biases between onset-onset and offset-onset judgments of simultaneity which could be involved in previous measurements. When three or more perceived durations need to be determined, the new method is more efficient than earlier methods; it requires measurement of only one PSE in order to evaluate one response duration as compared to two PSEs per response duration for previous methods. We also describe ways of determining the presence of some kinds of biases and quantitatively evaluating the magnitude of bias in the new method, as well as bias in onset-onset or offset-offset judgments of simultaneity alone; such evaluations of differential bias were not possible for the earlier methods. An experimental example of a bias analysis is described. No significant biasing effects were detected in the measures of perceived duration that were extracted as either retinal location or background luminance was changed, although background luminance itself markedly influenced the values of perceived duration.     

JAPANESE AND AMERICAN PERSONAL VALUES SOME CROSS-CULTURAL FINDINGS

Comparaison d'échantillons appariés d'étudiants japonais et américains (niveau lycée et collège universitaire) relativement aux six valeurs que mesure L'inventaire Survey of Personal Values. On a d'abord testé la comparabilité des “valeurs” dans la langue originale de L'inventaire et dans la traduction japonaise: L'analyse factorielle des items traduits et les corrélations calculées entre L'inventaire en japonais et un choix d'échelles japonaises de personnalité donnent des garanties à cet égard. Chez les étudiants japonais des deux sexes et des deux niveaux scolaires, on trouve des moyennes plus faibles pour ce qui est de L'orientation pratique de L'esprit, la réussite et la variété, et des moyennes plus élevées pour L'ordre et L'orientation vers un but. Ainsi, les Japonais accordent moins d'importance aux considérations matérialistes (réussite individuelle, changement ou diversité) mais ils donnent plus de valeur à un mode de vie organisé et routinier et au fait de chercher systématiquement à réaliser des buts bien définis. Les résul-tats de la présente recherche recoupant des recherches antérieures, font apparaître une grande ressemblance entre les deux pays, dans la structure de la personnalité.     

Firearm violence and the effects of gun control legislation

Two gun control laws designed to reduce different types of violent crimes were evaluated. In 1981, East St. Louis, IL, imposed stricter penalties for individuals who carry firearms outside their homes for protection (individuals could keep firearms in their homes). This law had only a temporary impact in reducing firearm use in assaults and robberies. In Evanston, IL, a slightly different approach was taken with legislation that banned handguns in the entire city (i.e., individuals could not keep handguns within their homes). A temporary reduction in firearm assaults occurred a few months before the gun law took effect. The implications of these findings are discussed.     

Are visual-perceptual and visual-motor skills separate abilities?

This study explored the independence of visual-perceptual and visual-motor abilities. Scores on the Motor-free Visual Perception Test were correlated by Pearson's method with scores on tests that weight the visual-perceptual, motor, and visual-motor components differently. Small but significant correlations were found between the Motor-free Visual Perception Test and tests of visual-motor integration, but there was no relationship between the motor-free test and tests of motor ability. These findings support the premise that tests of visual perception, visual-motor integration, and motor ability measure different skills.     

Sociability and Social Withdrawal in Childhood: Stability and Outcomes

The stability and long-term correlates of both social withdrawal and sociability were investigated in a longitudinal study of normal children in kindergarten through the fifth grade. Both observational and peer assessment indices of withdrawal and sociability were considered; furthermore, a distinction was made between observed active versus passive solitude. Of particular interest was whether social withdrawal in early childhood was predictive of subsequent internalizing problems, as assessed by self-reports of social competence, overall self-worth, loneliness, and depression as well as teacher ratings of shy/anxious behavior, in later childhood. Results indicated a modest degree of stability for observed social withdrawal but not for observed sociability, nor for active or passive forms of solitude. Somewhat higher stability correlations were obtained for peer assessments of both sociability and withdrawal. In terms of predictive outcomes, significant relations were found between early social withdrawal in kindergarten and Grade 2 and subsequent internalizing problems in Grades 4 and 5, although the pattern of results was mixed. These data suggest that social withdrawal in early childhood may be predictive of risk for internalizing difficulties in later childhood.