Discrimination learning in a foraging situation

Rats were allowed to forage in a simulated natural environment made up of eight food sources (patches) each containing a fixed number of pellets. Two of the eight contained an extra supply of peanuts. The peanut patches were signaled by an olfactory/visual cue located at the bottom of the ladder leading to the patch. In successive phases the number of sessions per day, height of the patches, and availability of peanuts were manipulated. Subjects showed evidence of discrimination learning under these conditions, although the degree of discriminatory behavior varied as a function of environmental manipulations. Assessment of behavior within foraging sessions showed that subjects systematically changed their patterns of utilization of patches across time. Sampling or exploration, as well as food reinforcement, seem implicated in these results.     

FADING TEACHER PROMPTS PROM PEER-INITIATION INTERVENTIONS FOR YOUNG CHILDREN WITH DISABILITIES

This study examined a system for fading teacher prompts to children who served as peers in peer-initiation interventions for young children with disabilities. A teacher taught peers to direct social initiations to children with disabilities, provided verbal prompts for those initiations, and introduced a system that provided peers with visual feedback about the social interactions of the children with disabilities. She then systematically withdrew the verbal prompts to peers, and subsequently faded the visual feedback system. Peer initiations increased when the intervention began and resulted in increases in social interaction for the children with disabilities. As the teacher systematically faded the prompts and visual feedback to the peers, social interaction continued at the levels found during intervention and was maintained during a short maintenance period.     

Diathesis-stress models of psychopathology: A quantitative genetic perspective

When genetics is considered in diathesis-stress models of psychopathology, it is often assumed that heredity provides the diathesis and environmental factors are responsible for the stressor. We discuss two quantitative genetic models relevant to the diathesis-stress construct. One model focuses on genotype-environment interaction, which is the usual way in which genetic influence is represented in diathesis-stress models. A second model—genotype-environment correlation—provides an alternative that represents both genetic and environmental influences relevant to the development of psychopathology. Implications of these models for clinical research are discussed.     

The accuracy of maternal self-reports: Agreement between reports on a computer simulation compared with observed behaviour in the supermarket

The validity of maternal self-reports about their parenting behaviour is evaluated with two studies. In both studies, the mothers were observed shopping in the supermarket with their 2-year-old children. One week later they responded to multiple choice questions on a computer that simulated the experience of shopping with their children. The exact agreement between the two types of data was then assessed. The results from the first study involving 28 mothers revealed some agreement, although it was generally low. In an effort to increase the level of agreement, the computer simulation was revised to allow multiple responses and to clarify some of the simulation vigenettes. A replication study resulted in a considerably higher level of agreement for 22 mothers. Implications of this method for researchers and practitioners are discussed.     

Family interaction and child psychopathology: A comparison of two observation strategies

We examined two systems of assessing family interactions that are in common usage: a home based observation of free parent-child interaction and a clinic based observation of a structured mother-child problem solving discussion. Participants were 18 depressed, 27 conduct disordered and 16 comparison children and their mothers. Results indicated that: 1) these observations may yield very different data about child, and to a lesser extent, parent behavior, 2) parental affect in the clinic was related to their level of aversive behaviour in the home, 3) levels of both aversive and positive behavior for children and their mothers were correlated within each setting, 4) accuracy of diagnostic classifications made on the basis of the observational data were highest for comparison and conduct disordered children, but lowest for depressed children observed in the clinic, and 5) the inclusion of data on mothers' behavior increased classification accuracy for conduct disordered children only.     

Imitation among infants in a day-care center and the development of locomotion

To examine the relationship between imitation and locomotor development among peers during infancy, we observed free play in a class of infants in a day-care center over a one-year period. The analysis included 16 infants (mean age was 8.3 months (SD=2.3) at the beginning of the observation) and 5 caregivers. The longitudinal data were divided into the crawling, cruising, and walking periods, and the imitation of object manipulation that took place among the infants during each period was analyzed. With the development of locomotion, peer-to-peer imitation became frequent. Infants who had acquired the ability to walk demonstrated imitation more frequently in triadic interactions than in dyadic interactions. Imitation took place between infants, but it was often mediated by caregivers rather than directly between infants. The results suggest that the acquisition of locomotor skills is a link in a developmental cascade from motor development to infant peer interaction. However, it is reasonable to interpret the results as indicating that the development of locomotion does not directly affect infant interactions in isolation, but rather that walking increases both the sharing and manipulation of objects with caregivers and proximity to peers, and their combined effects form a cascade.     

Social support from weak ties: Insight from the literature on minimal social interactions

When people face difficult life events, such as cancer or bereavement, they fare better when they receive support. These “experiencers” are likely to seek and receive support from a wide range of people, from close others to acquaintances. Indeed, the social support literature has long acknowledged the value of having a diverse support network. Research suggests that experiencers often perceive “weak ties” (i.e., acquaintances) as sources of support, and that experiencers sometimes prefer to get support from weak ties rather than strong ties. Providing support can be challenging for all kinds of supporters, however weak ties may be more likely than strong ties to allow worries about their inability to provide effective support to stop them from providing any support at all, thus depriving experiencers of opportunities for additional support. In this paper, we focus on the fact that often the provision of support occurs via a social interaction. We draw on the social psychology literature on minimal social interactions to suggest reasons why potential weak tie supporters might doubt their ability to provide effective support, and to generate advice to encourage potential supporters to reach out. Finally, we suggest future areas of research, with the ultimate goal of helping to expand the support that is available for people experiencing difficult life events.     

Arguers as editors

People use editorial criteria to decide whether to say or to suppress potential arguments. These criteria constitute people's standards as to what effective and appropriate arguments are like, and reflect general interaction goals. A series of empirical investigations has indicated that the standards fall into three classes: those having to do with argument effectiveness, those concerned with personal issues for arguer and target, and those centered on discourse quality. The essay also sketches the affinities certain types of people have for the different criteria.     

Three-term contingency patterns in mother-child verbal interactions during first-language acquisition

Selections from a large longitudinal data set of verbal interactions between a mother and her child are presented. Two sets of three-term contingency sequences that seemed to reflect maternal rewards and corrections were noted. Both the antecedents as well as the immediate consequences of maternal interventions are presented to explore training and learning processes. The observed frequencies of three-step sequences are compared to those expected based upon Markov-chain logic to substantiate the patterning of the interactions. Behavioral conceptualizations of the learning process are supported by these analyses, although their sufficiency is questioned. It is suggested that maternal rewards and corrections should be integrated with perceptual, cognitive, and social learning conceptualizations in a skill-learning approach to explain the complexity of language transmission and acquisition processes.     

Dark adaptation of foveal cones during the cone-plateau period

Following substantial bleaching by "white" light, absolute threshold, relative spectral sensitivity and sensation of hue of monochromatic lights were measured at the central fovea during the cone-plateau period. The absolute-threshold level was found to increase and then decrease markedly, the relative spectral sensitivity remained invariant, while the sensation of hues of monochromatic lights from the long- and middle-wave regions of the spectrum changed toward hues of shorter wavelengths.