Failure to replicate visual discrimination learning with a 1-min delay of reward

Two experiments were carried out in an attempt to replicate Lett's (1974) demonstration of visual discrimination learning with a 1-min delay of reward. In Experiment 1, controls for olfactory cues were introduced by testing animals in different orders from day to day and by reversing the positions of the discrimination chambers within days; also, secondary reinforcement effects were precluded by the use of opaque rather than transparent doors to the discrimination chambers. No evidence of learning was found either in a group of rats returned to the home cage during the delay or in a group left in the apparatus during the delay. It was hypothesized that the failure to find improvement in Experiment 1 might have resulted from either the controls for odor cues or from a lack of memory retrieval cues provided by the apparatus. In Experiment 2, both of these hypotheses were tested and neither was supported. The Lett group in Experiment 2 was run according to the exact procedures used by Lett and still no learning was demonstrated. It was concluded that further demonstrations of visual discrimination learning with a 1-min delay of reward will be necessary for the acceptance of the validity of this phenomenon.     

Lifting movements in the size-weight illusion

The occurrence of the size-weight illusion is related to the manner in which-objects are lifted. When the SWI occurs, the larger of two objects of equal objective weight is usually lifted with greater acceleration, deceleration, and maximum velocity than the smaller one, but to approximately the same height. These differences are not present when the cans feel equally heavy. The relationship of lifting movements to judgments is consistent with the known behavior of proprioceptors which provide sensory input about muscular and movement events.     

The effects of prior task experience in the modeling situation

An investigation was made into the effects of observers' previous experience with the experimental task on acquisition and subsequent performance of modeled task behavior. The task was socially neutral and the subjects were second grade boys and girls. Recall of modeled actions increased with prior experience, indicating greater acquisition. This finding supports Bandura's (1973) assertion that task familiarity may enhance attentiveness to the model. Contrary to previous research, performance of imitation did not decrease with experience. The present performance results are possibly due to the ambiguity of the preexperience and novelty of the experimental task.     

The inheritance of cognitive interest styles among twins

Through twin studies, research in behavioral genetics has demonstrated significant genetic components in many personality traits. Less research has been done on inheritance of vocational interest preferences, partially because of the lack of a wholistic conceptual model for understanding the relationships among diverse occupational interests. With the development of scales for the Strong Vocational Interest Blank (SVIB) to measure the six cognitive interest styles propounded by Holland, a parsimonious and comprehensive mapping of the occupational world was available and lent itself to the study of measuring inheritance of vocational preferences among twins. Median intraclass correlations for 409 pairs of monozygotic males, tested with the SVIB, was r = .50; for 570 pairs of monozygotic females, r = .55; for 237 pairs of dizygotic males, r = .27; and for 370 pairs of dizygotic females, r= .27.     

Theory of the invisible group applied to individual and group-as-a-whole interpretations

The theory of the Invisible Group explains the dynamics of groups in terms of four separate systems, hierarchically and isomorphically related, which enable the therapist to view group from four different perspectives and to interpret four different dimensions of group process. Person and member interpretations apply to aspects of the individual system; group-role and group-as-a-whole interpretations apply to aspects of the group system. Clinical examples illustrate how the psychotherapist can modify the dynamics of the group at the individual or at the group-as-a-whole level by modifying interpretations.     

A family‐therapy approach to child abuse: countering resistance

Abusing and high-risk families have been seen over three years at a new treatment resource with a family therapy orientation. The families present with established resistance to any treatment intervention and many have defeated a succession of previous helping agencies. Initial typology and treatment strategies are described with the aim of more systematic selection of therapeutic techniques.     

The aggressive behaviour of personality disordered patients and its relation to personality and perceptual motor performance

The present study investigates the relationship between the frequency of aggressive behaviour of patients in a therapeutic community and socialization, extraversion and perceptual-motor rule-breaking. The subjects were 33 males and 24 females who had been rated by two observers in regard to frequency of aggressive behaviour during the initial part of their stay in the community. Principal component analysis revealed two fairly pure factors, referred to as verbal and physical aggression. In females both factors correlated significantly with extraversion, lack of role-taking ability and perceptual-motor rule-breaking. No significant correlations were obtained in the male sample except that physical aggression correlated positively with perceptual-motor rule-breaking.     

Audiovisual presentation demonstrates that selective adaptation in speech perception is purely auditory

MRC Institute of Hearing Research, University of Nottingham, Nottingham NG72RD, England Both auditory and phonetic processes have been implicated by previous results from selective adaptation experiments using speech stimuli. It has proved difficult to dissociate their individual contributions because the auditory and phonetic structure of conventional acoustical stimuli are mutually predictive. In the present experiment, the necessary dissociation was achieved by using an audiovisual adaptor consisting of an acoustical [b?] synchronized to a video recording of a talker uttering the syllable [g?]. This stimulus was generally identified as one of the dentals [d?] or [??]. It produced an adaptation effect, measured with an acoustical [b?-d?] test continuum, identical in size and direction to that produced by an acoustical [b?]—an adaptor sharing its acoustical structure—and opposite in direction to that produced by an acoustical [d?]—an adaptor sharing its perceived phonetic identity. Thus, the result strongly suggests that auditory rather than phonetic levels of processing are influenced in selective adaptation.