Personality correlates of heroic rescue during the holocaust

This study investigated the extent to which personality variables can be used to discriminate non-Jewish heroes of the Holocaust from bystanders and from a comparison group of prewar European immigrants who left their countries of origin prior to World War II. Eighty verified rescuers, 73 bystanders, and 43 immigrants were administered measures of locus of control, autonomy, risk taking, social responsibility, tolerance/authoritarianism, empathy, and altruistic moral reasoning. A three-group discriminant function analysis was able to correctly classify 80.2% of the sample by a combination of personality and demographic variables. When the bystanders and immigrants, who differed very little from each other, were grouped together and compared to the rescuers, the personality variables alone correctly classified 93.1% of the sample. Implications regarding the relationship between personality and altruistic behavior, as well as suggestions for future research are discussed.     

Concurrent second-order schedules: some effects of variations in response number and duration

To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second-order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed-interval schedule, with one further response completing the fixed-interval schedule. The fixed-ratio and fixed-interval requirements comprising the first-order operant units were systematically and independently varied under three pairs of concurrent variable-interval schedules to produce differences in the first-order response and duration requirements (response and duration differentials). These manipulations produced consistent changes in response, time, and operant-unit biases. A 1:4 response differential biased the time and operant-unit measures towards the smaller fixed ratio, but to a degree less than the imposed response differential. The response-based biases favored the larger fixed ratio. Duration differentials of 4:1 and 8:1 biased the response and operant-unit measures towards the shorter fixed interval, again less than the imposed duration differential, but the time biases remained close to zero. Both sorts of differentials acted to bias operant-unit completions more systematically than the other measures, but undermatching to the differentials occurred. The undermatching appears to have arisen from a pattern of fix and sample (in which visits to the less preferred alternative involved only a single completed operant unit) under combinations of unequal operant-unit requirements and reinforcer rates. The response and time bias measures appeared to arise as by-products of the changes in operant-unit completions.     

Audio-visual simultaneity judgments

The relative spatiotemporal correspondence between sensory events affects multisensory integration across a variety of species; integration is maximal when stimuli in different sensory modalities are presented from approximately the same position at about the same time. In the present study, we investigated the influence of spatial and temporal factors on audio-visual simultaneity perception in humans. Participants made unspeeded simultaneous versus successive discrimination responses to pairs of auditory and visual stimuli presented at varying stimulus onset asynchronies from either the same or different spatial positions using either the method of constant stimuli (Experiments 1 and 2) or psychophysical staircases (Experiment 3). The participants in all three experiments were more likely to report the stimuli as being simultaneous when they originated from the same spatial position than when they came from different positions, demonstrating that the apparent perception of multisensory simultaneity is dependent on the relative spatial position from which stimuli are presented.     

Perceptual limits on low-dimensional models of Munsell reflectance spectra

Some experimental and theoretical approaches to surface-colour perception depend on approximating surface reflectance spectra by low-dimensional models. In the psychophysical experiment reported here, observers had to discriminate between patterns of Munsell surfaces and their spectral approximations under either the same or different illuminants. The approximations were produced by principal component analysis, by independent component analysis, and by artificial neural networks trained with a supervised-learning rule. In all experimental conditions, observers required, on average, at least 5 basis functions for discrimination performance to be at chance, thus placing a lower limit on the dimensionality of models of Munsell reflectance spectra.     

Minimalist surface-colour matching

Some theories of surface-colour perception assume that observers estimate the illuminant on a scene so that its effects can be discounted. A critical test of this interpretation of colour constancy is whether surface-colour matching is worse when the number of surfaces in a scene is so small that any illuminant estimate is unreliable. In the experiment reported here, observers made asymmetric colour matches between pairs of simultaneously presented Mondrian-like patterns under different daylights. The patterns had either 49 surfaces or a minimal 2 surfaces. No significant effect of number was found, suggesting that illuminant estimates are unnecessary for surface-colour matching.     

The look of love: gaze shifts and person perception

Gaze direction is a vital communicative channel through which people transmit information to each other. By signaling the locus of social attention, gaze cues convey information about the relative importance of objects, including other people, in the environment. For the most part, this information is communicated via patterns of gaze direction, with gaze shifts signaling changes in the objects of attention. Noting the relevance of gaze cues in social cognition, we speculated that gaze shifts may modulate people's evaluations of others. We investigated this possibility by asking participants to judge the likability (Experiment 1) and physical attractiveness (Experiment 2) of targets displaying gaze shifts indicative of attentional engagement or disengagement with the participants. As expected, person evaluation was moderated by the direction of gaze shifts, but only when the judgment under consideration was relevant to participants. We consider how and when gaze shifts may modulate person perception and its associated behavioral products.     

Differences in Individual Approaches: Communication in the Familial Breast Cancer Consultation and the Effect on Patient Outcomes

This multicenter study aimed to assess (i) whether individual clinical geneticists and genetic counselors vary in their communication skills and (ii) whether this variation in communication impacts on patient outcomes, such as anxiety, depression, genetics knowledge, and satisfaction. One hundred and fifty women from high-risk breast cancer families attending their first genetic counseling consultation completed pre and post-consultation self-report questionnaires. The consultations were audiotaped and transcribed verbatim. Univariate analyses showed highly significant differences between individual clinical geneticists and genetic counselors in: facilitating understanding (p 0.001); facilitating active involvement (p 0.001); facilitating partnership building (p = 0.003); addressing emotional concerns (p 0.001); and discussing prophylactic mastectomy (p = 0.017). Multivariate linear regressions showed that this variation in communication resulted in a greater change in patients depression 4 weeks after the counseling session (p = 0.017). These findings suggest clinical geneticists and genetic counselors have achieved some standardization in communicating information, but showed diversity in their facilitation skills. Communication skills may be a useful area to explore further in this field.     

Infants' enumeration of actions: numerical discrimination and its signature limits

Are abstract representations of number – representations that are independent of the particular type of entities that are enumerated – a product of human language or culture, or do they trace back to human infancy? To address this question, four experiments investigated whether human infants discriminate between sequences of actions (jumps of a puppet) on the basis of numerosity. At 6 months, infants successfully discriminated four‐ versus eight‐jump sequences, when the continuous variables of sequence duration, jump duration, jump rate, jump interval and duration, and extent of motion were controlled, and rhythm was eliminated. In contrast, infants failed to discriminate two‐ versus four‐jump sequences, suggesting that infants fail to form cardinal number representations of small numbers of actions. Infants also failed to discriminate between sequences of four versus six jumps at 6 months, and succeeded at 9 months, suggesting that infants’ number representations are imprecise and increase in precision with age. All of these findings agree with those of studies using visual–spatial arrays and auditory sequences, providing evidence that a single, abstract system of number representation is present and functional in infancy.     

An on-line task for contrasting auditory processing in the verbal and nonverbal domains and norms for younger and older adults

Contrasting linguistic and nonlinguistic processing has been of interest to many researchers with different scientific, theoretical, or clinical questions. However, previous work on this type of comparative analysis and experimentation has been limited. In particular, little is known about the differences and similarities between the perceptual, cognitive, and neural processing of nonverbal environmental sounds and that of speech sounds. With the aim of contrasting verbal and nonverbal processing in the auditory modality, we developed a new on-line measure that can be administered to subjects from different clinical, neurological, or sociocultural groups. This is an on-line task of sound to picture matching, in which the sounds are either environmental sounds or their linguistic equivalents and which is controlled for potential task and item confounds across the two sound types. Here, we describe the design and development of our measure and report norming data for healthy subjects from two different adult age groups: younger adults (18–24 years of age) and older adults (54–78 years of age). We also outline other populations to which the test has been or is being administered. In addition to the results reported here, the test can be useful to other researchers who are interested in systematically contrasting verbal and nonverbal auditory processing in other populations.     

The Relative Contribution of Sibling Deviance and Peer Deviance in the Prediction of Substance Use Across Middle Childhood

This study investigated the quality of sibling relationships and sibling deviancy in a sample of children at-risk for substance use and antisocial behavior. Based on a history of empirical and theoretical models suggesting strong associations between children's development in the context of relationships and the emergence of delinquency and drug use, this research extends previous efforts by including sibling relationships in this developmental model, linking siblings with later substance use. Sibling relationship quality as well as peer deviance were examined using a multirater, multimethod assessment procedure. We tested 3 constructs (deviancy, warmth, and conflict) related to sibling behavior. Only sibling deviance and peer deviance directly predicted substance use. When both sibling deviance and peer deviance were examined as predictors of changes in substance use over time, only sibling deviance was significant. Implications for the development of substance use behavior in middle childhood are discussed.