Ontogeny of sex differences in defensive burying behavior in rats: effect of social isolation

The aim of the present experiments was to clarify sex differences in socio-developmental factors that affected defense behavior in rats. Sex differences in the defensive burying behavior of rats, and related social factors, were explored in three developmental stages: juvenile, puberty, and adult; 30, 50, and 80 days of age, respectively. The duration of burying, digging into bedding material, stretch-attend postures, and crouch/freezing were measured in a shock-prod test. For males, the duration of burying was longer in the juvenile and pubertal stages than in adulthood. For females, no age differences in the duration of burying were found. Males showed longer burying durations than females in both the juvenile and pubertal stages. For both sexes, the highest duration of digging was found in the juvenile stage, and females showed longer durations of digging than males. Both male and female rats isolated during the juvenile stage, from 26 to 40 days of age, showed smaller durations of burying behavior compared to pair-reared rats. This effect of juvenile isolation was maintained among both adult males and females even when they were returned to pair rearing after isolation. Isolation during adulthood, from 66 to 80 days of age, increased burying behavior in males, but decreased it in females. The durations of digging, stretch-attend postures, and crouch/freezing were not affected by isolation. The decrease in defensive burying and its increase resulting from isolation in adult male rats, suggest that the emergence of adult-like social relationships in males suppressed the duration of burying. Male and female rats isolated during the juvenile stage maintained lower levels of burying, suggesting that social experience as juveniles is important for the emergence of defensive burying behavior.     

Changes in feeding and foraging patterns as an antipredator defensive strategy: a laboratory simulation using aversive stimulation in a closed economy.

The effects of the risk of electric shock on the meal patterns of rats living in an operant chamber were investigated. Rats could obtain food by working on a response lever that provided reinforcement according to chained fixed-ratio continuous reinforcement schedules that allowed the animals control over meal size. Using a two-compartment operant chamber with a safe nesting area and manipulanda area with a grid floor, shock could be correlated with responding on the schedule. Shocks (less than or equal to 1.25 per hour) were scheduled to occur randomly throughout the day, independent of the rat's behavior. Shock caused a reorganization of meal patterns such that the animals took less frequent but larger meals. This pattern reduced the time the animals spent at risk without compromising caloric balance. Similar changes in feeding pattern were obtained in both hooded and albino rats. Exposure to shock in a separate chamber did not produce these behavioral modifications. The magnitude of shock-induced alterations of meal patterns was greater with chained fixed-ratio 90 continuous reinforcement than with chained fixed-ratio 10 continuous reinforcement. Additionally, the rats seemed to be able to reduce food intake but increase caloric efficiency, such that the reduced food intake did not have deleterious effects on maintenance of body weight. These behavioral modifications reduced the number of shocks received from that which would have been expected if meal pattern changes had not occurred. We suggest that this technique may provide a useful laboratory simulation of the impact that the risk of predation has on foraging behavior.     

死亡提醒效应：概念、测量及来自多领域的证据

死亡提醒效应是指由于死亡提醒而引起的世界观防御或自尊寻求。对死亡提醒效应的测量主要考察死亡提醒后,被试在世界观防御或自尊寻求上的反应。死亡提醒效应在健康、消费、司法、政治及和平领域均有所体现,并对现实生活富有启示作用。未来研究应细化世界观的概念,并借鉴本土文化中的生死观。     

Histrionic Personality Disorder, Physical Attractiveness, and Social Adjustment

Histrionic personality disorder (HPD) is the only DSM-IV personality disorder (PD) explicitly linked to a person's physical appearance. This study examined the HPD–attractiveness link in a mixed-sex sample of college students. Consistent with expectations, HPD women were rated higher in attractiveness than women with other PDs or no PD. However, a parallel HPD–attractiveness link was not found in men. Subsequent analyses indicated that, relative to less attractive HPD women, more attractive HPD women (a) had a more varied and supportive social network, (b) exhibited more negative behaviors in important relationships, and (c) showed greater use of immature defenses, and less reliance on image-distorting, self-sacrificing, and mature defenses. Similar attractiveness–defense relationships were found in HPD men, but parallel results did not emerge for men in the other two domains. Implications of these findings are discussed, and suggestions for future studies are offered.     

A passion of the soul: an introduction to pain for consciousness researchers

Pain is an important focus for consciousness research because it is an avenue for exploring somatic awareness, emotion, and the genesis of subjectivity. In principle, pain is awareness of tissue trauma, but pain can occur in the absence of identifiable injury, and sometimes substantive tissue injury produces no pain. The purpose of this paper is to help bridge pain research and consciousness studies. It reviews the basic sensory neurophysiology associated with tissue injury, including transduction, transmission, modulation, and central representation. In addition, it highlights the central mechanisms for the emotional aspects of pain, demonstrating the physiological link between tissue trauma and mechanisms of emotional arousal. Finally, we discuss several current issues in the field of pain research that bear on central issues in consciousness studies, such as sickness and sense of self.     

The Wall: On the psychology of the reunification of Germany

The fall of the Berlin Wall, which separated West Germans and East Germans for decades, led to emotional catastrophe among the reunited peoples. The authors conducted a psychological research program in Berlin to analyze individual and interpersonal processes in the reunification. They describe four categories used to pinpoint different (largely unconscious) levels of coping and defense strategies used to deal with the changes: control, splitting, symbiosis, and integration.Thomas Krauss, Dr. phil., is a family therapist and teaching supervisor. From 1985–1990 he worked as scientific employee at the Free University Berlin. Angelika Fass, Dr. phil., is a family therapist and teaching supervisor. From 1986–1991 she worked as scientific employee (research and lecturer) at the Technical University in Berlin. Reprint requests should be sent to the authors at Markt 2, D-29493 Schnackenburg, Germany.Translation by Ann Brandt.     

Involvement of reactive oxygen species in emotional stress: A hypothesis based on the immobilization stress-induced oxidative damage and antioxidant defense changes in rat brain,and the effect of antioxidant treatment with reduced glutathione

We examined the oxidative damage and antioxidant defense changes with immobilization-induced emotional stress in the rat brain. Though superoxide dismutase activity remained unchanged, brain peroxidation was significantly accelerated by the immobilization stress. Membrane fluidity study with spin labeling in brain cortical membrane showed that immobilization stress induced an increase in microviscosity of membrane layer near the surface and in the ordering of membrane proteins but a decrease in microviscosity at the core of the membrane bilayer. The Na, K-ATPase activity decreased whereas the levels of some monoamines and their metabolites increased along with their metabolic rate. The administration of reduced glutathione showed a protective effect on the immobilization stress-induced stomach bleeding, oxidative damage and abnormal changes in the brain antioxidant defenses. Based on these results and on previous reports, we hypothesize that immobilization stress may induce the formation of reactive oxygen species which weakens the brain antioxidant defenses and induces oxidative damage. The antioxidant administration of reduced glutathione provides further evidence to support the above hypothesis, and also may provide clues in the search for a rational therapy to emotional stress. A possible correlation of emotional stress to aging is also discussed.     

A Norwegian translation of the Plutchik questionnaire for psychological defense

The reliability and validity of the Norwegian translation of Plutchik's Life Style Index (LSI) have been tested in a material of 704 individuals, 471 men and 233 women. The results showed low internal consistency for most of the subscales (Alpha ranging from 0.43 to 0.68). Several of the scales were also significantly correlated. Factor analyses showed that some of them loaded on common factors, indicating low specificity of the scales. Further, the validity of the test was not confirmed.     

The insanity defense: Legal standards and clinical assessment

Although the insanity defense is used infrequently, it has received significant attention from legal and mental health professionals. In this article, we review the historical development of insanity defense standards and describe the standards currently employed in the United States. We present a model for evaluating a defendant's mental nonresponsibility, and we briefly discuss the legal standards and procedures for the assessment of insanity acquittees for release. Throughout the article, we discuss some scientific, ethical, and jurisprudential issues associated with the insanity defense and nonresponsibility evaluations.     

Defensive aggression in terns: Discrimination and response to individual researchers

The defensive responses of roseate terns (Sterna dougallii) were studied during the middle of the breeding season when all reproductive stages (incubation, chick-hatching, chick-rearing) were represented, to determine the factors affecting levels of nest defense and whether terns responded differently towards a familiar versus an unfamiliar researcher. Defensive aggression generally varied as a function of researcher identity, time of day, section or location in the colony and nest density. These variables explained from 60 to 66% of the variation in defensive aggression. More terns mobbed one researcher with more dive attacks than the other researcher. Terns were more aggressive in areas where the chicks had just hatched and were most vulnerable. © 1993 Wiley-Liss, Inc.