Testing for symmetry in the conditional discriminations of language-trained chimpanzees

If subjects are taught to match Stimulus A to B and then, without further training, match B to A, they have passed a test of symmetry. It has been suggested that non-humans' lack of success on symmetry tests might be overcome by giving them a history of symmetry exemplar training, that is, by directly teaching a large number of conditional relations (e.g., AB, CD, EF,...) and also directly training the "reverse" of these relations (e.g., BA, DC, FE,...). The chimpanzee subjects of the present study, Sherman, Austin, and Lana, had already received extensive symmetry exemplar training as a result of attempts to teach a selection-based language system of lexigrams. The present study systematically subjected 2 of these chimps (Sherman and Lana), for the first time, to standard symmetry tests in controlled conditions. Both chimps failed the tests, even when their correct responses on test trials were reinforced. The findings do not support the exemplar training hypothesis, and cast doubt upon whether the chimps can pass tests of stimulus equivalence.     

Individual differences in collinearity judgment as a function of angular position

Previous research indicates that perceived orientation and/or alignment of segments and points can vary as a function of the angular position of the stimulus elements. Several studies show that the variability of the responses is least and accuracy of judgment is greatest where segments and dots are aligned with a cardinal axis. Additionally, some report assimilation of judgments toward the nearest cardinal axis--that is, the segments (or dots) are seen as being closer to the horizontal or vertical than is true. The present research confirms that judgments of collinearity are least variable and most accurate when the segment being judged is aligned with a cardinal axis. However, we do not find any consistent tendency for cardinal axis assimilation. Plotting the collinearity error (delta) as a function of angular position (phi), we find a distinctive profile of oscillation for each subject. Furthermore, subjects who were evaluated in two sessions showed very similar profiles of delta oscillation from Day 1 to Day 2. Harmonic analysis indicated a wide-ranging pattern of significant components. The components at the 4th harmonic and below were more likely to be significant, but each subject showed differential loadings in terms of which of the components were significant, as well as in the sign and amplitude of significant components. These results may reflect idiosyncratic fixation tendencies, or individual differences in the design of neural mechanisms that encode the angular positions of stimuli.     

Dimensions of fatigue in different working populations

Perceived fatigue related to work has often been measured in one dimension. The main purpose of the present study was to validate a proposed five-factor model of perceived fatigue in a new sample. 597 persons, employed in five occupations with different types of work loads, rated their fatigue after work. The ratings were subjected to analyses of linear structural equation models. The results suggest a slightly revised model for perceived fatigue, still with the five dimensions: Lack of energy, Physical exertion, Physical discomfort, Lack of motivation and Sleepiness. As expected, the rating profiles describing fatigue states differed between the five occupations. On the basis of these results, a revised version of the Swedish Occupational Fatigue Inventory (SOFI) is presented.     

Psychosocial Treatment Strategies in the MTA Study: Rationale, Methods, and Critical Issues in Design and Implementation

The Collaborative Multimodal Treatment Study of Children with Attention Deficit Hyperactivity Disorder (ADHD), the MTA, is the first multisite, cooperative agreement treatment study of children, and the largest psychiatric/psychological treatment trial ever conducted by the National Institute of Mental Health. It examines the effectiveness of Medication vs. Psychosocial treatment vs. their combination for treatment of ADHD and compares these experimental arms to each other and to routine community care. In a parallel group design, 579 (male and female) ADHD children, aged 7–9 years, 11 months, were randomly assigned to one of the four experimental arms, and then received 14 months of prescribed treatment (or community care) with periodic reassessments. After delineating the theoretical and empirical rationales for Psychosocial treatment of ADHD, we describe the MTA's Psychosocial Treatment strategy applied to all children in two of the four experimental arms (Psychosocial treatment alone; Combined treatment). Psychosocial treatment consisted of three major components: a Parent Training component, a two-part School Intervention component, and a child treatment component anchored in an intensive Summer Treatment Program. Components were selected based on evidence of treatment efficacy and because they address comprehensive symptom targets, settings, comorbidities, and functional domains. We delineate key conceptual and logistical issues faced by clinical researchers in design and implementation of Psychosocial research with examples of how these issues were addressed in the MTA study.Deceased     

Regulation of Negative Affect During Mother–Child Problem-Solving Interactions: Adolescent Depressive Status and Family Processes

Despite recent suggestions that depression can be conceptualized as a disorder of affect regulation, relatively little research has focused on affect regulation skills in depressed individuals. This paper investigated whether depressed adolescents (N = 25) differ from nondepressed adolescents (N 25) on two indices of affect regulation (i.e., duration of negative affective states and reciprocity of maternal negative affect) as well as whether these indices are related to microsocial family interactional processes. Analyses revealed that depressed teens differed from their nondepressed peers with regard to duration of negative affective states but not in their likelihood of reciprocating negative affect. Additionally, indices of adolescent affect regulation were related to family interactional processes. Duration of depressive affect was positively associated with maternal display of facilitative behavior contingent on adolescent depressive behavior. Duration of aggressive behavior was inversely related to maternal problem-solving responses to aggressive behavior. Finally, adolescent reciprocity of maternal depressive and aggressive behaviors was strongly associated with mothers' reciprocity of adolescents' negative affective behavior.     

Reinforcing variability in adolescents with autism

Five adolescents with autism, 5 adult control participants, and 4 child controls received rewards for varying their sequences of responses while playing a computer game. In preceding and following phases, rewards were provided at approximately the same rate but were independent of variability. The most important finding was that, when reinforced, variability increased significantly in all groups. Reinforced variability could provide the necessary behavioral substrate for individuals with autism to learn new responses.     

The treatment of relevant and irrelevant outgroups in minimal group situations with crossed categorizations

Among a sample of Belgian high school boys, the author attempted to determine on the basis of social identity theory (H. Tajfel & J. C. Turner, 1979) whether an outgroup's relevancy in intergroup comparisons influences the amount of intergroup discrimination. Relevancy was manipulated by the use of 2 trivial categorization dimensions that were orthogonally crossed. In 1 of the crossed categorization conditions, this procedure resulted in the formation of 4 groups, whereas in the 2nd condition, only 2 of these groups were effectively formed. Nevertheless, the participants in both conditions were instructed to evaluate 4 groups--either 4 actual groups (1st condition) or 2 actual and 2 hypothetical groups (2nd condition). In both conditions, the intergroup evaluations exhibited the same pattern--that is, they did not differentiate their ingroups from the partly overlapping groups but were clearly biased against the double outgroup.     

Suggesting strategies improves creative visual synthesis

An experiment assessed whether a figural or an interpretative strategy can enhance creative visual synthesis. 45 undergraduates were presented a set of simple figures and asked to imagine combining them to obtain a whole pattern corresponding to a creative product. In the figurative condition participants were instructed to combine figures in unusual ways; in the interpretative condition they were induced to look for unusual meanings embedded in the combinations; in the control condition no strategy was suggested. Results showed that certain strategies induced a more flexible visual synthesis.