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.     

A system for the assessment of human performance in concurrent verbal and manual control tasks

A multipurpose laboratory system incorporating a voice interactive terminal and graphic display system is described. The facility is designed to investigate some aspects of human performance on concurrent verbal and tracking tasks. The results of a pilot study showing decrements in dual-task performance are reported.     

Assessment of the relative importance of S+ and S− in rats using differential training on intercurrent discriminations

The present studies assessed the degree of stimulus control exerted by S+ and S? without confoundings of stimulus novelty and stimulus ambiguity. In Experiment 1, rats were trained on two intercurrent simultaneous discrimination problems with nine times more training given on one than the other. Then the animals were given transfer tests with re-paired stimuli. The results showed that S? exerts greater stimulus control than S+ in a two-choice simultaneous discrimination. Experiment 2 provided a test of the possibility that the relative degree of control by S? varies with different amounts of training. Three groups were trained on two intercurrent simultaneous discrimination problems; each group was given 7, 11, or 15 times more training on one problem than the other. Then transfer tests were given with re-paired stimuli. Again the results showed that S? exerts greater stimulus control than S+ in a two-choice simultaneous discrimination.     

Mental imagery and pictorial memory

Previous research has failed to show consistent effects upon memory performance of individual differences in the use of mental imagery. A test of pictorial memory was devised which varied the ease with which the stimulus patterns could be verbally encoded. A factor analysis related performance in this task to a variety of other individual characteristics. The recall of material which could not be readily verbalized defined a factor within the solution which showed significant loadings of age and performance in the Progressive Matrices, but not of subjective ratings of the vividness of experienced imagery. The recall of material which could be readily verbalized did not contribute to the factorial structure of the results. It was concluded that the two sorts of pictorial material are remembered in quite different ways.     

Low-cost equipment for schedule generation I: Fixed- and random-ratio schedules

The use of complementary metal oxide semiconductor (CMOS) technology to produce fixed-ratio and random-ratio schedules is described. Such a technology implies several advantages over traditional methods of construction, especially with respect to cost and complexity. Suitable interfaces for linking with everyday laboratory equipment are also described.     

Parents’ postnatal depressive symptoms and their children's academic attainment at 16 years: Pathways of risk transmission

The aim of the study was to examine whether parents’ increased postnatal depressive symptoms predicted children's academic attainment over time and whether the parent–child relationship, children's prior academic attainment, and mental health mediated this association. We conducted secondary analyses on the Avon Longitudinal Study of Parents and Children data (12,607 mothers, 9,456 fathers). Each parent completed the Edinburgh-Postnatal Depression Scale at 8 weeks after the child's birth (predictor) and a questionnaire about the mother–child and father–child relationship at 7 years and 1 month (mediator). The children's mental health problems were assessed with the teacher version of the Strengths and Difficulties Questionnaire at 10–11 years (mediator). We used data on the children's academic attainment on UK Key Stage 1 (5–7 years; mediator) and Key Stage 4 (General Certificate of Secondary Education 16 years) (outcome). We adjusted for the parents’ education, and child gender and cognitive ability. The results revealed that parents’ depressive symptoms at 8 weeks predicted lower academic performance in children at 16 years. Mothers’ postnatal depressive symptoms had an indirect effect through children's mental health problems on academic outcomes at 16 years via negative mother–child relationship, and prior academic attainment. There was a significant negative indirect effect of fathers’ postnatal depressive symptoms on academic attainment at 16 years via negative father–child relationship on child mental health. The findings suggest that the family environment (parental mental health and parent–child relationship) and children's mental health should be potential targets for support programmes for children of depressed parents.