Social learning in Cartilaginous fish (stingrays Potamotrygon falkneri)

Social learning is considered one of the hallmarks of cognition. Observers learn from demonstrators that a particular behavior pattern leads to a specific consequence or outcome, which may be either positive or negative. In the last few years, social learning has been studied in a variety of taxa including birds and bony fish. To date, there are few studies demonstrating learning processes in cartilaginous fish. Our study shows that the cartilaginous fish freshwater stingrays (Potamotrygon falkneri) are capable of social learning and isolates the processes involved. Using a task that required animals to learn to remove a food reward from a tube, we found that observers needed significantly (P < 0.01) fewer trials to learn to extract the reward than demonstrators. Furthermore, observers immediately showed a significantly (P < 0.05) higher frequency of the most efficient “suck and undulation” strategy exhibited by the experienced demonstrators, suggesting imitation. Shedding light on social learning processes in cartilaginous fish advances the systematic comparison of cognition between aquatic and terrestrial vertebrates and helps unravel the evolutionary origins of social cognition.     

SPSS and SAS programs for comparing Pearson correlations and OLS regression coefficients

Several procedures that use summary data to test hypotheses about Pearson correlations and ordinary least squares regression coefficients have been described in various books and articles. To our knowledge, however, no single resource describes all of the most common tests. Furthermore, many of these tests have not yet been implemented in popular statistical software packages such as SPSS and SAS. In this article, we describe all of the most common tests and provide SPSS and SAS programs to perform them. When they are applicable, our code also computes 100 × (1 ? α)% confidence intervals corresponding to the tests. For testing hypotheses about independent regression coefficients, we demonstrate one method that uses summary data and another that uses raw data (i.e., Potthoff analysis). When the raw data are available, the latter method is preferred, because use of summary data entails some loss of precision due to rounding.     

Substitutes for leadership in anaesthesia teams and their impact on leadership effectiveness

In this study we aim to increase our understanding of leadership in anaesthesia teams by investigating the relationship between substitutes for leadership, leadership behaviour, and team performance in situations with varying levels of routine and standardization. The present study relied on video recordings of 12 anaesthesia teams in a simulated setting with the occurrence of a nonroutine event. Clinical team performance was measured by the speed of adequate team reaction to this event. The leadership behaviours observed were coded either as content oriented (e.g., information transmission) or structuring (e.g., assigning tasks). Results showed that leadership behaviour changed depending upon the level of routine of a situation, the degree of standardization, and, to some extent, on the experience of team members. Leadership tends to be positively related to team performance during nonroutine and low standardized situations but negatively related to team performance in routine and highly standardized situations. Furthermore, leadership is only slightly related to team member experience. This study improves our understanding of influences of substitutes for leadership on successful leadership behaviour in anaesthesia teams. The findings also lead to suggestions for both further research and the enhancement of team leadership in critical care.     

Hemispheric lateralization in aging: Interest of the verbal-manual concurrency paradigm

ABSTRACT

Introduction: The aim of this study was to evaluate whether the classic asymmetry seen in hemispheric functioning is modified in older adults by using a verbal-manual concurrency task. Method: Thirty-five right-handed participants divided into two groups according to age (15 older participants, mean age: 68 ± 8 years, without cognitive decline and 20 younger participants, mean age: 23 ± 2 years) had to perform a 30-second uni-manual tapping task, in both a single task (tapping alone) and dual task (tapping and performing a letter fluency task together) condition. Results: In younger participants, the letter fluency task disrupted the right hand more than the left hand whereas, in older participants, the letter fluency task disrupted both hands equally. Conclusion: These results should be considered preliminary data using a behavioral dual task condition, which might be useful for studying lateralized hemispheric functioning and the processes of divided attention during aging.     

A Group of Sexually Abused Adolescents' Perceptions of their Future Life-Roles: An Exploratory Study

Sexual abuse of adolescents can have detrimental effects on their perceptions of their different future life-roles. We investigated such perceptions of students with a history of sexual abuse (n=163) as well as typically developing others (n=237). Participants completed the Life-role Inventory of the then called Human Sciences Research Council (Langley, 1990). Between-group comparisons were carried out. Adolescents with a history of sexual abuse reported negative perceptions of themselves fulfilling some of their roles in the future, being committed to these roles and attaching value to them, compared to typically developing others.     

Modifying driver behaviour with passenger feedback

A feedback programme was employed to help drivers improve their safety behaviour based on the idea that particular types of driver error result from contingency traps as defined by Fuller [Journal of Applied Behaviour Analysis, 24 (1991) 73]. Two drivers and their single respective passengers participated. For each driver, repeated in-car observations were made of four unsafe driving behaviours. Two of these were sequentially targeted in the behavioural intervention that involved the passengers providing informational feedback to their driver. Both drivers showed a marked improvement across the targeted behaviours. The study demonstrated the applicability of behaviour analysis to the traffic domain and the efficacy of individual feedback as a behavioural tool for positive behaviour modification.     

Perceptions of Self and Relationship with Parents in Aggressive and Nonaggressive Rejected Children

This study examined the perceptions of self and the attachment relationship to parents in aggressive and nonaggressive rejected children, as compared to children with an average or popular sociometric status. Participants were 216 children from grades 3 and 4. They completed peer nomination measures, the Self-Perception Profile for Children (SPPC), and the Security Scale (mother and father form). Results generally confirmed the assumption that only the nonaggressive rejected children perceive themselves as less competent and worthy as a person than the more popular children. Aggressive rejected children did not report lower feelings of global self-worth or competence, although they did report lower levels of social acceptance. Furthermore, rejected-nonaggressive children perceived the relationship with their father (but not with their mother) as less secure than did the more popular children. Logistic regression analyses suggested that the linkage between felt security with father and rejected-nonaggressive status was mediated by children's self-worth. Implications for attachment theory and for the hypothesized heterogeneity among rejected children are discussed.     

Perceiving minority members as individuals: the effects of relative group size in social categorization

According to the account by comparative distinctiveness, minorities draw attention by virtue of their relative size, leading to more individuation and more stereotyping of their members. Using the ‘Who said what?’ paradigm by Taylor, Fiske, Etcoff, and Ruderman ( 1978 ) in Klauer and Wegener's ( 1998 ) modified version, relative group size of gender categories and age categories was varied in a pilot study and a main experiment, respectively. In the pilot study, memory for discussion statements and in both studies, memory for individuating information increased as subgroup size decreased. Rating measures obtained in the main experiment revealed most stereotyping of minority members. The findings thereby support major predictions of the account by comparative distinctiveness, but demonstrate dissociations between different modes of category‐based processing, i.e. category memory, reconstructive category use, and stereotyping. Copyright © 2002 John Wiley & Sons, Ltd.