Thiamin deprivation in ventromedial hypothalamic hyperphagic rats: anorexia, specificity of food aversion, and a dietary consideration.

The anorexic consequence of thiamin deprivation was investigated in ventromedial hypothalamic (VMH) hyperphagic rats under either high-fat or low-fat thiamin-free diet conditions. The low-fat diet maintained feeding significantly longer in thiamin-deprived VMH rats than in intact rats, whereas the hig-fat diet sustained feeding in thiamin-deficient intact rats and accelerated anorexia onset in vitamin B1 deprived VMH rats. This effect was noted under both ad lib and pair-feeding conditions. Thiamin-deprived VMH rats subjected to weight control developed anorexia sooner than intact subjects regardless of the diet employed. The VMH rats fed a high-fat diet failed to resume feeding after thiamin readministration, which was interpreted as a permanent aversion to this diet. The relation between dietary intake and conditioned taste aversion is discussed with reference to the VMH and intact rat.     

Approach and withdrawal analysis of the effects of hypothalamic stimulation and lesions in rats.

In a paradigm in which rats would both initiate and terminate hypothalamic stimulation, "purely" rewarding lateral hypothalamic and "purely" aversive medial hypothalamic electrodes were identified. Subjects were then given a series of tests designed to assess the effects of brain stimulation on approach and withdrawal behaviors. Lateral hypothalamic stimulation facilitated approach behavior and suppressed withdrawal behaviors, whereas medial hypothalamic stimulation produced largely the opposite effects. No serious motor deficits due to stimulation were detected with either type of electrode. In a second experiment, the approach-withdrawal effects of bilateral lateral hypothalamic lesions were tested and found to suppress approach behaviors and facilitate withdrawal behaviors. Other neurological examinations revealed motor deficits, but these deficits do not account for the specific pattern of results observed on the approach-withdrawal tests. These approach-withdrawal phenomena are interpreted in terms of altering a natural balance between approach and withdrawl behavior facilitating systems in the lateral and medial hypothalamus, respectively.     

BEHAVIORAL ASSESSMENT FOR PEDIATRIC INTENSIVE CARE UNITS1

Two studies were conducted to analyze behaviors of staff and patients on a Pediatric Intensive Care Unit (PICU). In the first study, behavioral observation procedures were employed to assess patient state, physical position, affect, verbal behaviors, visual attention and activity engagement, and staff verbal behavior. On the average, one-third of the patients were judged to be conscious and alert but markedly nonengaged with their environment. In the second study, a member of the hospital staff provided alert patients with individual activities to determine whether a simple environmental manipulation could positively affect behavior of children in intensive care. Employing a reversal design, the activity intervention was found to increase attention and engagement and positive affect, and to decrease inappropriate behavior. Both studies demonstrate that behavioral assessment procedures can provide an empirical basis for designing PICU routines affecting children's psychosocial status, and, thus, complement current procedures designed to provide quality medical care.     

Learning family therapy: The dilemmas of an individual therapist

Individual therapists who begin doing family therapy often encounter some special difficulties directly related to their prior training and experience. Some therapeutic techniques of individual therapy, such as understanding and explaining the patient's problems on the basis of faulty parenting, must be relinquished and alternative means of alleviating guilt must be adopted. In doing family therapy individual therapists must adapt to the fact that they are less important than they are used to being and have less control over content and emotional tone of sessions. They must change their conceptions about the importance of privacy and secrecy. This article discusses some of the problems encountered when one is not thoroughly committed to a family therapy approach to treatment. Countertransference difficulties, problems stemming from wanting change, and the differing nature of the gratifications in the two therapeutic modalities are other topics discussed.     

Direct Open Supervision: A Team Approach

Created in the absence of one-way mirror facilities, Direct Open Supervision combines elements of live supervision with team participation in training family therapists. The theory and application of this approach to direct supervision are described.     

Preservation of global order equivalence

Psychological data frequently can only be gives rank-order significance. This paper investigates and characterizes those cluster methods suitable for use in such a situation. The work is carried out in an abstract order theoretic setting but a relation is shown to earlier models due to Jardine and Sibson as well as Matula. It deals with that portion of the clustering process that starts with a dissimilarity measure defined on a set P and produces a nested sequence of reflexive symmetric relations on P.     

The role of attribution in the experience of crowding

The theory that the subjective experience of crowding results from an attribution of arousal process was examined. Specifically, it was predicted that subjects who were aroused by having their personal space violated would experience less crowding if they were led to believe that some other environmental factor was responsible for the arousal. Groups of subjects were placed in a room in which their personal space was either violated or not violated. Some subjects were told that either an arousing or a relaxing subliminal noise would be played into the room. (Actually there was no noise.) Other subjects were told nothing about subliminal noise. The subjects worked on a number of tasks and were then asked to report how crowded they felt. The noise manipulation had no effect on subjects' performance nor on feelings of crowdedness when their personal space was not being violated. However, when there was a violation of personal space, subjects who felt the noise would arouse them reported being less crowded and performed better than subjects in the relaxing noise or no explanation conditions. It was suggested that subjects attributed their arousal to the “arousing noise” and hence felt less crowded.     

Focus of attention, chronic expectancy, and responses to a feared stimulus.

An attentional model of fear-based behavior is proposed and a study that tested the model is reported. It was predicted that among subjects with moderate fear of snakes, heightened self-attention during an approach attempt would cause increased awareness of existing anxiety, followed by one of two courses of events: Subjects who believed that they could do the behavior in spite of their fear were expected to redirect their attention to the behavior--goal comparison and exhibit no behavioral deficit. Subjects who doubted their ability to do the behavior were expected to divert their attention from the behavior--goal comparison and to withdraw behaviorally from the approach attempt. The results of the study support this reasoning. Discussion centers on relationships between the proposed model and previous theory.     

Temporal control of behavior and the power law

The performance of rats and pigeons under fixed-interval schedules was studied in two experiments. The duration of postreinforcement pause was a declining proportion of fixed-interval duration. For pigeons this was true both when the duration of the reinforcer was fixed and when it was increased in direct proportion to increases in fixed-interval duration; the longer reinforcer durations did, however, lengthen the postreinforcement pause at higher schedule values. A quantitative analysis of data from Experiments 1 and 2 and from other studies showed that fractional exponent power functions described the relationship between postreinforcement pause and fixed-interval value; similar functions have previously been observed in studies of temporal differentiation. It was concluded that power functions reflect a direct causal, rather than artifactual, relationship between performance and the temporal requirements of reinforcement schedules.