Internet use in the contemporary media environment

Although a significant amount of research has focused on traditional media choice and use, and even on some ‘new’ media, these studies have either neglected the Internet and World Wide Web or were conducted prior to their recent popularity. This study offers a novel exploration of individuals' use of three Internet functions (information retrieval, information giving, and conversation capabilities) in the context of the use of other communication media. Data from 684 individuals demonstrate that the Internet is a multidimensional technology used in a manner similar to other, more traditional media. Specifically, conversation features of the Internet align with mediated interpersonal technologies (the telephone and electronic mail), whereas the Internet's information‐retrieval and information‐giving features are used in ways similar to mass media channels (newspapers, television, and books and magazines). In addition, needs fulfilled by these channels cluster in ways consistent with past research, regardless of the technologies employed to meet them.     

In Vivo Hippocampal Acetylcholine Release During Exposure to Acute Stress

Hippocampal extracellular acetylcholine (ACh) and choline levels were evaluated using in vivo microdialysis in male Fischer 344 rats before, during, and following an 80-min exposure to two different stress conditions. Measurements were taken in rats restrained and immersed in a water bath containing either 37 degreesC (normothermic-restraint) or 20 degreesC (cold-restraint) water. Results were compared to normothermic-freely-moving rats. Cold-restrained rats displayed decreased ACh levels during cold exposure relative to both normothermic-restrained and normothermic-freely-moving rats. By the end of the cold exposure period and following removal from cold, ACh levels had returned to near-baseline values. Normothermic-restrained rats had levels similar to those of normothermic-freely-moving rats, except for a marked increase in ACh following removal from restraint. Cold-restrained rats displayed a gradual elevation in choline levels during cold stress, followed by a gradual decline after stress termination, whereas both normothermic-restrained and normothermic-freely-moving rats displayed gradual decreases during the microdialysis session. These findings demonstrate that central cholinergic neurotransmission can be altered by the application of, and removal from, acute stressors. In addition, the results suggest a possible relationship between the magnitudes of both the stressor and its cholinergic consequences.     

Methylphenidate-induced obsessive-compulsive symptoms in an elderly man

An 82-year-old man with treatment-resistant depression and early Alzheimer's disease was started on methylphenidate. Significant obsessive-compulsive behavior ensued but diminished over several weeks when methylphenidate was replaced by fluvoxamine. The patient had no prior psychiatric history, but he had a sister with obsessive-compulsive disorder. It appears that methylphenidate precipitated the patient's pathological behavior.     

The effects of testosterone on cognition in elderly men: a review

In this article, the literature examining the relationship between testosterone and various cognitive domains in elderly men is reviewed. The review focuses on the role of endogenous testosterone levels and the effects of androgen depletion and replacement. The cognitive domains most commonly linked to testosterone include memory and visuospatial function. Indeed, the literature suggests that in certain conditions (ie, hypogonadism, cognitive impairment) testosterone levels may be significantly associated with memory and visuospatial function, but not other cognitive functions. Studies with larger sample sizes and more sensitive cognitive measures are indicated, as questions remain about the potential role of testosterone as a cognitive enhancer.     

Clamped Corticosterone (B) Reveals the Effect of Endogenous B on Both Facilitated Responsivity to Acute Restraint and Metabolic Responses to Chronic Stress

To determine the effects of both corticosterone (B) and chronic stressors on acute ACTH responses to restraint, young male rats were exposed to streptozotocin-induced diabetes, cold (5-7 degreesC) or intracerebroventricular (icv) neuropeptide Y (NPY) for 5 d and then exposed to restraint within 2 h after lights on. Two groups of rats were studied: intact and adrenalectomized replaced with B pellets that maintained plasma B in the normal mean 24-h range of intact rats. In addition to ACTH and B responses to restraint on d 5, body weight, food intake, fat depots, glucose and other hormones were measured to determine the role of stress-induced elevations in B on energy balance. ACTH responses to restraint were normal in intact rats subjected to diabetes or cold. By contrast, there was no ACTH or B response to restraint in NPY-infused intact rats. All 3 groups of chronically stimulated adrenalectomized rats with clamped B had facilitated ACTH responses to restraint compared to their treatment controls. Overall food intake increased in all groups of stressed rats; however, augmented intake occurred only during the light in intact rats and equally in the light and dark in B-clamped rats. White adipose depot weights were decreased by both diabetes and cold and increased by NPY in intact rats; the decreases with cold and increases with NPY were both blunted and changes in fat stores were not significant in adrenalectomized, B-clamped rats. We conclude that: 1. diabetes- and cold-induced facilitation of restraint-induced afferent input to hypothalamic control of the hypothalamo-pituitary-adrenal (HPA) axis is opposed in intact rats by the elevated feedback signal of B secretion; 2. NPY does not induce facilitation of afferent stress pathways; 3. chronic stimulation of the HPA axis induces acute hyperresponsiveness of hypothalamic neurons to restraint provided that the afferent input of this acute stimulus is not prevented by B feedback; 4. stimulus-induced elevations in B secretion result in day-time feeding; 5. insensitivity of both caloric efficiency and white fat stores to chronic stress in adrenalectomized, B-clamped rats results from loss of normally variable B levels.     

Are the interpersonal and identity disturbances in the borderline personality disorder criteria linked to the traits of affective instability and impulsivity?

This study examines the degree to which two putative biologically influenced personality traits, affective instability and impulsive aggression, are associated with some of the interpersonal and intrapsychic disturbances of borderline personality disorder (BPD) and with choice of defense mechanism. In a sample of 152 personality disorder patients, affective instability and impulsive aggression were measured. Defense mechanisms were assessed in 140 of these patients using the Defensive Style Questionnaire (DSQ). The correlations between the traits of affective instability and impulsive aggression and the eight DSM-III-R criteria for borderline personality disorder and 20 DSQ defenses were examined. Affective instability was significantly correlated with the DSM-III-R criteria of identity disturbance, chronic emptiness or boredom, inappropriate anger, suicidality, and the affective instability criteria. It also was associated with the defenses of splitting, projection, acting out, passive aggression, undoing, and autistic fantasy. Impulsive aggression was related to unstable interpersonal relationships, inappropriate anger and impulsiveness and with the defense of acting out. It was negatively correlated with the defenses of suppression and reaction formation. A number of the interpersonal and experiential disturbances and defense mechanisms that are features of BPD are associated with the traits of affective instability and impulsive aggression among patients with personality disorders.     

Intercultural Study of Personal Space: A Case Study

The study of intercultural differences in personal space attempts to identify factors that could be helpful in guiding people from different cultures to live and work together in international ventures. The objective of this research was to measure interpersonal distance in a cross-cultural environment. Twenty-three participants classified in 4 cultural groups answered an 11-questions interview where the personal distance and orientation between seated interactants were measured. Results showed that Anglo Saxons used the largest zone of personal space, followed by Asians, then Caucasians, and, as expected, Mediterraneans and Latinos used the shortest distance. Where Latinos adopt a face-to-face position, Caucasians tend to orient themselves to the side of the interviewer, which has an impact on interpersonal communication.