Infants' ability to use luminance information to individuate objects

Recent research indicates that infants first use form and then surface features as the basis for individuating objects. However, very little is known about the underlying basis for infants' differential sensitivity to form than surface features. The present research assessed infants' sensitivity to luminance differences. Like other surface properties, luminance information typically reveals little about an object. Unlike other surface properties (e.g. pattern, color), the visual system can detect luminance differences at birth. The outcome of two experiments indicated that 11.5-month-olds, but not 7.5-month-olds, used luminance differences to individuate objects. These results suggest that it is not the age at which infants can detect a feature, but the nature of the information carried by the feature, that determines infants' capacity to individuate objects.     

Eighteen month test-retest stability of the youth self report in a sample of Catalonian adolescents

The aim of this study is to assess the test-retest stability of the Spanish version of Youth Self Report after 18 mo. for a sample of 357 Catalonian high school students (158 boys and 199 girls). At Time 2 the girls' scores increased on Delinquent and Aggressive Behavior scales and, therefore on Externalizing scores. At Time 2 the boys' scores increased on Attention Problems and Delinquent Behavior and decreased on Anxious/Depressed, Social Problems, and Internalizing scales. Significant differences in the remaining scales were not observed. The test-retest intraclass correlations for the broad-band scales ranged between .62 (Internalizing) and .68 (Externalizing) and for the narrow-band scales between .37 and .67. The correlations for girls and boys were similar but slightly higher for girls on Anxious/Depressed and Thought Problems.     

Sex-specific differences in olfactory sensitivity for putative human pheromones in nonhuman primates

In humans, the volatile C19-steroids androsta-4,16-dien-3-one (AND) and estra-1,3,5(10),16-tetraen-3-ol (EST) have been shown to modulate autonomic nervous system responses, and to cause hypothalamic activation in a gender-specific manner. Using two conditioning paradigms, the authors here show that pigtail macaques and squirrel monkeys of both sexes were able to detect AND and EST at concentrations in the micromolar and mM range, respectively. Male and female spider monkeys, in contrast, differed markedly in their sensitivity to these two odorous steroids, with males not showing any behavioral responses to the highest concentrations of AND tested and females not responding to the highest concentrations of EST. These data provide the first examples of sex-specific bimodal distributions of olfactory sensitivity in a nonhuman primate species.     

Social power increases implicit prejudice

The effects of power on implicit and explicit attitudes towards racial groups were examined. In Study 1, participants who had power showed a stronger facilitation of positive words after exposure to White faces, and negative words after exposure to Black faces, compared to participants who did not have power. In Study 2, powerful participants, compared to controls and powerless participants, showed more positive affective responses to Chinese pictographs that followed White compared to Black faces. Power did, however, not affect explicit racial attitudes. In Study 3, powerful participants showed greater racial prejudice toward Arabs in an Implicit Association Test than did powerless participants. This effect was driven by the power of the perceiver rather than the power of the target. Implications of these findings are discussed.     

Applying memories of reinforcement outcomes mainly to Pavlovian conditioning

A theory devised initially on the basis of instrumental reward schedule data, such as the PREE, was extended to deal with various Pavlovian findings. These Pavlovian findings include blocking, unblocking, relative validity, positive and negative patterning, renewal, reinstatement, reacquisition, and inhibition. In addition, the sequential model was discussed in relation to the rule-learning view of Hulse and Dorsky (1977) employing data from a report by Bloom and Capaldi (1961).     

Lists of Spanish sentences with equivalent predictability, phonetic content, length, and frequency of the last word

This paper presents a pool of Spanish sentences designed for use in cognitive research and speech processing in circumstances in which the effects of context are relevant. These lists of sentences are divided into six lists of 25 equivalent high-predictability sentences and six lists of 25 low-predictability sentences according to the extent to which the last word can be predicted by the preceding context. These lists were also equivalent in phonetic content, length and frequency of the last word. These lists are intended for use in psycholinguistic research with Spanish-speaking listeners.     

Psychometric Evidence of a Multidimensional Measure of Prosocial Behaviors for Spanish Adolescents

Prior theories and scholars rarely distinguished between distinct forms of prosocial behaviors (i.e., actions intended to benefit others) and most scholars operationalize prosocial behaviors as a global construct. Furthermore, stringent tests of psychometric properties of prosocial behavior measures are rare, especially in countries other than the United States. The present study was designed to examine the structure and functions of a multidimensional measure of prosocial behaviors in youth from Spain. Six hundred and 66 adolescents (46% girls; M age = 15.33 years, SD = 0.47 years) from Valencia, Spain, completed the Prosocial Tendencies Measure-Revised (PTM-R), measures of sympathy, perspective taking, and a global measure of prosocial behavior. Results showed that the hypothesized 6-factor structure of the PTM-R had good fit, the best fit model as compared to alternative models, and that there were several unique patterns of relations between specific forms of prosocial behaviors and sympathy, perspective taking, and the global measure of prosocial behavior. Furthermore, although there were significant gender differences in some forms of prosocial behaviors, the structure of the PTM-R was equivalent across gender. Discussion focuses on the implications for theories and measurement of prosocial behaviors.