Infant sensitivity to figural coherence in biomechanical motions

Two experiments assessed infant sensitivity to figural coherence in point-light displays moving as if attached to the major joints of a walking person. Experiment 1 tested whether 3- and 5-month-old infants could discriminate between upright and inverted versions of the walker in both moving and static displays. Using an infant-control habituation paradigm, it was found that both ages discriminated the moving but not the static displays. Experiment 2 was designed to clarify whether or not structural invariants were extracted from these displays. The results revealed that (1) moving point-light displays with equivalent motions but different topographic relations were discriminated while (2) static versions were not, and (3) arrays that varied in the amount of motion present in different portions of the display were also not discriminated. These results are interpreted as indicating that young infants are sensitive to figural coherence in displays of biomechanical motion.     

Self-reinforcement: Impact of instructions,criterion setting,and tangible rewards

This investigation was designed to ascertain the effects of instructions, criterion setting, and the presence of tangible rewards on the self-reinforcement process. Fifty-two third- and fourth-grade subjects were assigned to one of four treatment groups: (a) stringent instructions/criterion setting/tangible reward, (b) stringent instructions/criterion setting/no tangible reward, (c) nonstringent instructions/criterion setting/tangible reward, and (d) nonstringent instructions/no tangible reward. In the stringent-instruction conditions, subjects received social reinforcement for selecting stringent performance criteria, whereas in the non-stringent-instruction conditions, social reinforcement was withheld. Subjects in the tangible-reward groups were allowed to select a prize following the successful completion of their self-selected work performance. Subjects in the no-tangible-reward groups received no prizes for their work. All subjects performed an arithmetic task in which the number of correct problems completed, number of problems attempted, and time at task served as dependent variables across five reinforcement and two extinction trials. The results suggest that the condition of stringent instructions, criterion setting, and tangible reward was more effective in producing behavior change than the other three conditions. Perceived task difficulty and previous achievement on arithmetic task performance were shown to affect criteria selected and mathematical performance. The results are discussed in light of the contributory role of instructions, criterion setting, and tangible rewards on the self-reinforcement procedure.This study is based on a doctoral dissertation submitted to the Faculty of Arts and Sciences at the University of Pittsburgh by Helen L. Evans. Dr. Russell T. Jones was the dissertation committee chairperson. It was partially funded by an American Psychological Association Minority Fellowship awarded to the first author. Special thanks are extended to the committee members, Drs. Lloyd Bond, Robert Glaser, Johnny Matson, and Samuel M. Turner, for their assistance. The authors would like to thank Thomas DeVoge, Paul Karoly, and Samuel M. Turner for reading and commenting on an early draft of this study. Portions of this paper were presented at the 1982 APA convention.     

A possible proximity effect on human grip strength

A double-blind experiment with 58 adults tested the hypothesis that proximity to sugar reduces human grip strength. An analysis of variance supported the hypothesis.     

Effects of family therapy for substance abuse: A systematic review of recent research

One of the most serious psychosocial problems worldwide is substance abuse because of its repercussions not only on the physical and psychological health of the abuser but also on their relational functioning. Among the well-established therapeutic approaches for the treatment of substance abuse is family therapy, which, in addition to influencing personal variables, promotes changes in family dynamics. The main objective of this study is to review the scientific literature published from 2010 to the present on the efficacy and effectiveness shown by family-based treatment approaches for substance use problems both in adolescent and adult samples. In addition, the effect on secondary variables such as family functioning and behavioral problems is evaluated. The empirical evidence accumulated in the last decade and reviewed in the present study indicates that the incorporation of family members in the treatment of substance abuse produces benefits by diminishing consumption and improving family functioning. Limitations of this study and of the research reviewed are discussed and directions for future research are provided.     

A tool to act blind? Object-assisted eye-covering as a self-handicapping behavior and social play signal in Balinese long-tailed macaques

Animal Cognition - Self-handicapping behaviors evolved as honest signals that reliably reflect the quality of their performers. In playful activities, self-handicapping is described as...     

Exploratory study of best friendship dissolution characteristics and psychological difficulties during early adolescence

Few studies have evaluated best friendship dissolutions and especially the circumstances surrounding the dissolutions. In this exploratory study of young adolescents (N = 273, M_age = 11.83 years; 51% boys), we investigate young adolescents' experiences with two types of best friendship dissolution (complete dissolutions, downgrade dissolutions) and two characteristics of such experiences: initiation status (self- versus friend-initiation) and emotional reactions (degree of happiness, anger, sadness, and embarrassment). We also consider whether these characteristics of best friendship dissolutions are related to psychological difficulties (loneliness, depressive symptoms). Results indicated that most young adolescents perceive their friends initiated their recent complete and downgrade dissolutions. When young adolescents did initiate their complete dissolutions, however, they reported less negative (anger) and more positive (happiness) emotional responses. Initiation status was not related to psychological difficulties, but variability in several types of emotional responses (e.g., embarrassment) was related to variability in loneliness and depressive symptoms. Findings underscore the importance of considering not only the type of dissolution, but also the circumstances surrounding dissolutions, during early adolescence.