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.     

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.     

Reminiscence and strategies of performance in rotary pursuit tracking

The maximum speed at which man detects and corrects errors is analyzed on the pursuit rotor. During the prerest performance, scores of about 220 msec. are found, for both extravertive and introvertive subjects. During the postrest performance a crossover effect appeared: extraverts had scores near 60 msec., while introverts did not surpass 100 msec. The results are discussed in the framework of Eysenck and Frith's (1977) theory of reminiscence.     

Repression and Coping Styles in Asthmatic Patients

The objectives of this study were to (a) determine prevalence of the dispositional repressive coping style as well as other situational coping styles in a sample of asthmatic patients and (b) to analyze the capacity of these styles to predict subsequent morbidity (emergency room visits or hospitalizations due to asthma) during a 12-month follow-up. A sample of 75 adult asthmatic patients was selected and information about sociodemographics, asthma severity, and patient’s perception of illness severity was collected. Repressive coping style was defined by a combination of scores obtained on the Trait Anxiety Inventory and the Marlowe-Crowne Social Desirability Scale. Coping styles were assessed with the dispositional version of the Coping Orientation to Problems Experienced Inventory. Eighteen patients (24%) were classified as repressors. Repressor asthmatics obtained scores significantly lower on Emotion-Focused Coping compared to non-repressors (F _(1,72) = 5.15, p = .026). Patients who perceived their asthma as severe reported to use Emotion-Focused Coping more than those who judged it as mild or moderate (F _(2,71) = 4.83, p = .011). A higher use of Denial (an Emotion-Focused strategy of coping) explained 8% of variance of the frequency of emergency room visits during the 12-month follow-up. The prevalence of repressive coping style in the asthmatic population is similar to that registered in other populations of chronic patients, and it is also associated with the tendency to report a lower use of strategies traditionally considered as maladaptive. The use of Emotion-Focused Coping strategies seems to be related to a worse perception of the physical status, and among this group of strategies, Denial also could favor a poor clinical course in bronchial asthma.     

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.     

Functional networks involved in spatial learning strategies in middle-aged rats

Our aim was to assess the way that middle-aged rats solve spatial learning tasks that can be performed using different strategies. We assessed the brain networks involved in these spatial learning processes using Principal Component Analysis. Two tasks were performed in a complex context, a four-arm radial maze, in which each group must use either an allocentric or an egocentric strategy. Another task was performed in a simple T-maze in which rats must use an egocentric strategy. Brain metabolic activity was quantified to evaluate neural changes related to spatial learning in the described tasks. Our findings revealed that two functional networks are involved in spatial learning in aged rats. One of the networks, spatial processing, is composed of brain regions involved in the integration of sensory and motivational information. The other network, context-dependent processing, mainly involves the dorsal hippocampus and is related to the processing of contextual information from the environment. Both networks work together to solve spatial tasks in a complex spatial environment.     

Effects of Modeling the Heterogeneity on Inferences Drawn from Multilevel Designs

This article uses Monte Carlo techniques to examine the effect of heterogeneity of variance in multilevel analyses in terms of relative bias, coverage probability, and root mean square error (RMSE). For all simulated data sets, the parameters were estimated using the restricted maximum-likelihood (REML) method both assuming homogeneity and incorporating heterogeneity into multilevel models. We find that (a) the estimates for the fixed parameters are unbiased, but the associated standard errors are frequently biased when heterogeneity is ignored; by contrast, the standard errors of the fixed effects are almost always accurate when heterogeneity is considered; (b) the estimates for the random parameters are slightly overestimated; (c) both the homogeneous and heterogeneous models produce standard errors of the variance component estimates that are underestimated; however, taking heterogeneity into account, the REML-estimations give correct estimates of the standard errors at the lowest level and lead to less underestimated standard errors at the highest level; and (d) from the RMSE point of view, REML accounting for heterogeneity outperforms REML assuming homogeneity; a considerable improvement has been particularly detected for the fixed parameters. Based on this, we conclude that the solution presented can be uniformly adopted. We illustrate the process using a real dataset.     

Test-retest reliability of the Frankfurt Complaint Questionnaire

Long-term reliability of the Frankfurt Complaint Questionnaire (FCQ) was investigated in two follow-up studies of participants with psychosis using a test-retest method. In the first study (N = 56), the duration of the follow-up ranged from 6 months to 2 years; Spearman rho was .62 for the abridged (18 items) Spanish version of the questionnaire. In Study 2 (N = 21), in participants with stable schizophrenia, the follow-up ranged from 8 to 11 years; test-retest Spearman rho was .83 for the French version of the questionnaire. Subjective experiences could constitute, in psychosis-prone people, traits or markers of psychotic vulnerability.     

Psychometric properties of the d2 selective attention test in a sample of premature and born-at-term babies

The psychometric properties of the d2 Selective Attention Test are analyzed in two samples of premature ( n = 63) and born-at-term ( n = 78) children. The reliability coefficients (internal consistency) reached values of around .90. Principal components analysis revealed a three-factor structure, which accounts for 58% of the variance, and thus coincides with the number of factors presented in the manual of the Spanish adaptation of the test but not with their composition. Results suggest that the d2 test has adequate psychometric properties both for the global sample and for each sub-sample.