Interaction of stimulus dimensions in concept and choice processes

Four major types of interaction of stimulus dimensions based on perceptual research are described: integral, configural, separable, and asymmetric separable. Implications of these interactions for concept and choice processes are discussed. With regard to concept learning, it is argued that integral or configural interactions are desirable within the set of relevant and within the set of irrelevant dimensions used to generate stimuli, but that relevant dimensions should be separable from irrelevant dimensions. With regard to choice processes, integral or configural dimensions produce choices based on ordinary distance relations or equivalent parallel processing of dimensions. With separable dimensions, however, serial processing is at least possible; and such processing can lead to choices in which the subset of stimuli and the order of processing of dimensions affects the choice outcomes.     

The role of configuration and target discriminability in a visual search task

Ss sorted through decks of cards bearing five-element patterns, separating those in which all five were identical from those in which one of the five was different from the remaining four. Sorting time depended on the configuration and size of the pattern in which the elements were arranged but was independent of the goodness of these patterns. It was concluded that Ss did not attend to the patterns themselves, but just to the elements comprising them in searching for the discrepant element. The differences owing to the patterns appear to be due in part to the compactness of the configurations.     

The effect of redundant stimulus elements on visual discrimination as a function of element heterogeneity,equal discriminability,and position uncertainty

Garner and Lee (1962) showed no gain in visual discrimination accuracy with addition of redundant stimulus elements. Eriksen and Lappin (1965) showed a substantial gain. One experiment reported here indicates that the discrepancy is not due to the fact that the earlier experiment used heterogeneous stimulus elements. A second experiment indicated that the gain in discrimination accuracy does occur when the additional stimulus elements have the same discriminability as the original elements. It also showed that position uncertainty itself has no effect on the gain with redundant elements, but is a convenient procedural device for maintaining fixation and thus equal element discriminability. Three models of perceptual independence fit the data.     

The effect of stimulus element redundancy on speed of discrimination as a function of state and process limitation

The effect of spatially repeated stimulus elements on the speed of discrimination, measured in a sorting task, was determined under conditions of low stimulus visibility (state limitation) and high stimulus similarity (process limitation). A significant increase in speed of sorting stimuli was found when the stimuli were state limited but not when process limited, even though base speeds were the same in both cases. It is concluded that element redundancy will improve discrimination performance only when the need for the improvement is a state limitation.     

Physical and cognitive dimensions in stimulus comparison

Two experiments were carried out using a same-different task with sets of four stimuli varying orthogonally in three dimensions. Sameness was defined by each of the three dimensions in turn, as well as by physical identity. Two types of dimensions, physical and cognitive, were studied. In Experiment 1, the numerals 6, 10, VI, and X, which vary in Length, System, and Name, were used. With simultaneous presentation, order of difficulty was from the physical dimension of Length to the cognitive dimension of Name. While overall difficulty was related to dimensional discriminability, internal evidence suggested that Name was not a dimension in the same sense as Length is, and that some stimulus pairs were simply easier to process than others, regardless of the response required (e.g., short stimulus pairs and Arabic numerals). With sequential presentation, Name was processed as fast as System, due largely to the fact that much faster responding occurred when an Arabic numeral was the second stimulus. Thus, with sequential presentation, Name provides a processing mechanism not provided by physical dimensions. In Experiment 2, the numerals 3, 4, 6, and 7, which vary in Magnitude, Oddness, and Curvilinearity, were used. The cognitive dimension of Magnitude was pro cessed most rapidly, and numerical distance between pairs of numbers dominated the results for “same” responses, regardless of the sameness rule used. Again, evidence was found for fast processing of some stimulus pairs (e.g., 3 4), regardless of the response required. Overall, these experiments are interpreted as indicating that cognitive factors such as stimulus familiarity may override aspects of physical discriminability with many dimensions and stimuli, that, even though a cognitive dimension can be used to generate a logically proper set of stimuli, it does not necessarily act as other, more physical dimensions do, and that clarification of the functional role of a dimension is more important than attempts to locate stages.     

Continuity in Emotion Knowledge from Preschool to Middle-Childhood and Relation to Emotion Socialization

This longitudinal study examined the preschool correlates of middle school children's knowledge of emotional display rules. Participants included 50 children (29 girls) who were seen at preschoolage and again 4 years later. A total of 91% of the children were Caucasian, 4.5% were Mexican American, and 4.5% were Asian American. During the preschool period, measures included children's knowledge of facial expressions, knowledge of emotion-eliciting situations, and emotional role-taking ability. In addition, the rate at which their mothers explained the causes of emotions was assessed. Four years later, the children's knowledge of emotional display rules was assessed. The display rule measures included expression regulation knowledge (i.e., whether the children altered the facial expression relative to the internal feeling without providing a motive), self-protective display rules, and prosocial display rules. Results revealed that preschoolers' situation knowledge was a negative predictor of expression regulation knowledge and that emotional role-taking was inversely related to knowledge of self-protective display rules. The results also demonstrated that the rate at which mothers' explained emotions to their children as preschoolers was positively associated with expression regulation knowledge and knowledge of prosocial display rules.     

Exploration of the Factor Structure of ADHD in Adolescence through Self,Parent, and Teacher Reports of Symptomatology

Factor analytic studies of attention-deficit/hyperactivity disorder (ADHD) in children and adults have shown that second-order and bifactor models better represent ADHD symptoms than two- or three-factor models, yet there is far less evidence for a bestfitting model of ADHD in adolescence. Thus, the current study examined the factor structure of ADHD in adolescence and further evaluated the external validity of the best fitting model. Participants were 588 adolescents (22 % female; 366 with a childhood ADHD diagnosis; mean age 15.9 years) from the 8-year assessment of the Multimodal Treatment Study of Children with ADHD (MTA). ADHD symptoms were assessed via adolescent self-report, parent report, and teacher report on the SNAP-IV scale. Potential factor structures for the 18 symptoms of ADHD were tested for each informant, which included traditional one-factor, two-factor, and three-factor models of ADHD, as well as second-order factor (specific factors loading onto general factor) and bifactor (items loading onto both specific and general factors) models. Unique associations between external criteria and the identified factors of each informant’s best fitting model were examined. Although several of the proposed models exhibited good fit, the second-order two-factor model best accounted for ADHD in adolescence according to self-report and parent report, and the second-order three-factor model was optimal according to teacher report. Several key measurement issues emerged for the hierarchical bifactor models, such as numerous Heywood cases and out-of-bound parameter estimates, which rendered them unfit as optimal representations of ADHD in adolescence. These findings and the implications of the best fitting model of ADHD in adolescence suggest that a possible reorganization of this disorder may eventually aid clinicians in the accurate diagnosis of ADHD in adolescents.     

Evolution of kin recognition mechanisms in a fish

Animal Cognition - Both selection and phylogenetic history can influence the evolution of phenotypic traits. Here we used recently characterized variation in kin recognition mechanisms among six...     

The Role of Teachers' Social-Emotional Competence in Their Beliefs About Peer Victimization

One hundred fifty preservice teachers and 25 in-service teachers were surveyed to examine whether mental representations of relationships, confidence about managing bullying, empathy toward victims, and emotional expressiveness were associated with their peer victimization-related beliefs. Teachers' confidence about managing bullying was positively associated with their prosocial peer beliefs. In addition, the belief that the distress that children experience as a result of being victimized should be dismissed was negatively related to teachers' positive representations. Teachers' reports of positive emotional expressiveness were negatively related to normative, assertive, avoidance, and dismissive victimization-related beliefs and positively related to prosocial peer beliefs. In contrast, teachers' reports of negative emotional expressiveness were negatively related to prosocial peer beliefs and avoidance victimization-related beliefs. In-service teachers reported slightly higher positive expressiveness than preservice teachers did. Minority teachers reported higher scores for positive expressiveness, empathy, and lower negative classroom expressiveness than nonminority teachers did. Implications of these findings for practice are discussed.