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.     

Modulation of behavioral inhibition in appetitive extinction following manipulation of adrenal steroids in rats: implications for involvement of the hippocampus.

Corticosterone, the principal glucocorticoid in the rat, binds selectively to the CA1 pyramidal neurons of the hippocampus where the hormone has been demonstrated to exert a moderate chronic suppression of spontaneous activity. In the first experiment of the current study, the functional behavioral significance of this hormone--brain interaction was investigated in the extinction of an appetitive runway response in normal rats and those with lesions of the hippocampus. During extinction, half of the animals in each group were given daily subcutaneous injections of corticosterone. Whie the classical retardation effect of hippocampal lesions on appetitive extinction was replicated, hormone treatment was without effect in normal or hippocampally damaged subjects. The absence of a hormone effect in normals was primarily attributed to a saturated limited-binding system operating in the normal animal. Experiment 2 tested this notion, repeating the first experiment, with adrenal-ectomized (ADX), ADX + corticosterone replacement, and normal groups of animals. Adrenalectomy produced a striking facilitation of extinction which was speculated to be the result of a hyperactive inhibitory neural organ free from an inhibitory endocrine feedback. Corticosterone treatment normalized the progress of extinction in ADX animals, providing support for the afore-mentioned speculation. In the normal animal, it appears that a stress-induced surge in hormone level interacts with a limited-capacity neural binding to produce a transient dynamic range of behavioral disinhibition, perhaps promoting persistence during initial stages of frustrative nonreward in moderate stress tasks.     

Evidence that probing the vaginal cervix is analgesic in rats, using an operant paradigm.

Probing against the vaginal cervix (CP) suppresses responses to noxious stimulation in rats. The first experiment rules out the possibility that this effect is due to CP-induced immobilization. All rats first learned to press a panel, thus terminating noxious skin shock. Then they either received CP (experimentals) or did not (controls) when they pressed the panel during skin shock that was inescapable. The controls soon showed extinction of the panel-press response, whereas the experimentals continued pressing the panel and obtaining CP, for significantly more trials. The rats thus performed an operant response for CP at a time before CP could have blocked their movement. The second experiment argues against the possiblity that CP exerts its effect by "distracting" the rats from the skin shock. The rats received inescapable skin shock which continued for 7 sec after each panel-press response. During this shock one group received CP, and another received perineal probing ("distraction" control). The panel-press latency was significantly shorter in the CP group than in the perineal group. Latency in a control group, in which shock was terminated as soon as the rats pressed the panel, did not differ significantly from the CP group. Latency in another control group, in which the shock persisted for 7 sec after the rats pressed the panel with no probing being applied, was not significantly different from that of the perineal-probing group but was significantly longer than latency in the CP group. Thus the present studies suggest that CP is indeed analgesic and that this effect of CP is mediated by neither movement inhibition nor distraction.     

ANALYSIS OF THE CONSISTENCY OF OBJECTIVE MEASURES OF SEXUAL AROUSAL IN WOMEN

Eight adult women volunteers viewed the same erotic film in two different sessions. Their resulting genital responses were recorded simultaneously by three different measures: vaginal pressure pulse, vaginal blood volume, and labial temperature change. During the erotic stimulation, the vaginal pressure pulse and labial responses always increased, and the vaginal blood volume response increased on all but two occasions. Although there was considerable intersubject variability in each genital measure, all three measures were found to have some intrasubject consistency over sessions with respect to either their response amplitudes or patterns, with labial temperature being the most consistent on both parameters. The relationship between the response patterns of the three measures during the film was also relatively consistent across sessions, as was the correspondence between subjective ratings of arousal and both vaginal pressure pulse and labial responses but not vaginal blood volume response. To overcome the problem of considerable intrasubject variability of response amplitudes, it was suggested that the inclusion in the data analysis of several parameters of response patterns, which were relatively stable over sessions, might facilitate the evaluation of a treatment.     

EVALUATION OF BIOFEEDBACK IN THE TREATMENT OF BORDERLINE ESSENTIAL HYPERTENSION1

Direct biofeedback of blood pressure was compared with frontal EMG biofeedback and with self-instructed relaxation for the treatment of essential hypertension in a controlled group outcome study. Patients were followed up for four months after the end of treatment. Generalization of treatment effects was assessed through pre- and posttreatment measurements of blood pressure under clinical conditions in a physician's office. There were no significant reductions in diastolic blood pressure. The systolic blood pressure (SBP) of the patients receiving blood pressure biofeedback decreased 8.1 mm mercury (p = 0.07) and the SBP of the patients in the relaxation condition decreased 9.5 mm mercury (p = 0.05). In the generalization measures, there were significant reductions in SBP for the relaxation group. The results are discussed in terms of the general lack of replicability within the area of biofeedback treatment of hypertension.     

Effects of medial preoptic-anterior hypothalamic lesions on development of sociosexual behavior in dogs

Bilateral medial preoptic-anterior hypothalamic lesions in adult male dogs eliminate or impair copulatory behavior and reduce urine-marking responses but do not affect aggressive behavior. The present study examined the emergence of the adult forms of these same male sociosexual behavioral patterns when the lesions are made prior to puberty. The subjects were allowed to interact with male peers during development. Animals with lesions had reduced frequence of juvenile mounting and an almost total absence of male copulatory activity in adulthood. Urine-marking and aggressive behavior in the juvenile and adult periods were not affected by the lesions. The findings reveal a sparing of function with regard to urine-marking but not sexual behavior.     

OVERJUSTIFICATION EFFECTS IN TOKEN ECONOMIES

This study tested the relevance to clinical token economies of the overjustification hypothesis that tangible reward interferes with intrinsic interest in target behaviors and causes such behaviors to be less probable following a period of reinforcement than preceding such a period. The study was carried out in an ongoing token economy for chronic psychiatric patients. Alternated over an 8-week period were weeks of token and no-token reward for one of the program's target behaviors, toothbrushing. Two different amounts of token reward were employed in order to examine whether reward magnitude might influence the presence or extent of overjustification effects. Little evidence was found for the presence of overjustification effects in token economies. However, maintenance of toothbrushing was greater in no-token weeks following weeks of low amounts of token reward than in no-token weeks following weeks of higher amounts of reward. The importance of such complex functional relationships is discussed.     

Employer Preferences for the Form and Substance of Employment Application Cover Letters

This study investigates the effect some principal characteristics of employment application cover letters have on personnel officers. A sample of personnel executives from 100 major companies was queried as to their perception of the desirability of 12 common cover letter characteristics. The results indicate that the personnel officers do not consistently perceive letters in the manner suggested by the existing literature. Some characteristics are shown to elicit negative responses from personnel officers, and thus should be avoided by job applicants. Several characteristics are strongly preferred by the sample surveyed. The model for an employment cover letter derived from this study should enhance the applicant's chances for a favorable response, or at least prevent letter forms which might detract therefrom.     

Egocentrism and inefficiency in the communication of families containing schizophrenic members

Conceptual and methodological shortcomings of research on family and interactional psychopathology are owing mainly to the use of vague and ill-defined concepts of communication. Based on a theory of language use and communication within general social and cognitive psychology (e.g., Heider, Mead, Piaget, Rometvet) Blakar has outlined a methodology by which interaction is analyzed in terms of how and to what extent the participants (families) manage or fail to cope with the various prerequisites for successful communication under varying situational conditions. A study illustrating this program is presented: The interaction of twelve families, six with (Group S) and six without (Group N) a schizophrenic member, is analyzed in Blakar's communication conflict situation with respect to the members' ability to decenter and take the perspective of each other. Group S proved significantly more egocentric, their egocentric attitudes resulting, as would be expected, in very inefficient communication. Moreover, Group S were not able to adapt their pattern of communication to the changing situational requirements. Finally, the subtle interplay between the capacities and behavior of the individual members and the family system is illustrated: the egocentrism of the members resulted in "closed systems," and the closed systems hindered adequate feedback, forcing the members to decenter.