Cholinergic modulation of hippocampal CA1 basal-dendritic long-term potentiation

Extensive research suggests that long-term potentiation (LTP) may serve as a cellular mechanism for memory and that alterations in synaptic plasticity may underlie the gross memory impairments observed in patients with Alzheimer's disease. Cholinergic facilitation of hippocampal LTP in the behaving rat is a useful model for the study of the effects of anticholinesterase or other drugs on synaptic plasticity. Field excitatory postsynaptic potentials were recorded from the hippocampal CA1 region following excitation of the basal dendrites in behaving male Long-Evans rats. LTP was induced by a high-frequency train (200 Hz for 0.5s duration) following injection of the acetylcholinesterase inhibitor eserine sulfate (0.5 mg/kg, i.p.), specific muscarinic M1 receptor antagonist pirenzepine (21.2 microg/microl, i.c.v.), or saline (i.p. or i.c.v.). Pirenzepine was found to block basal-dendritic LTP when LTP was induced during walking, but not when LTP was induced during immobility. Eserine facilitated LTP when induction occurred during either immobility or walking. The present study demonstrates that an anticholinesterase enhances LTP in CA1 of the behaving rat, and that facilitation of basal-dendritic LTP during walking is mediated by muscarinic M1 receptors.     

The Human Being in the Context of Nature: Philosophical Anthropology and Natural Sciences in Hedwig Conrad-Martius

The most original aspect of Hedwig Conrad-Martius’ research is her interpretation of nature, performed through the phenomenological method. She pinpoints the very essences of the natural phenomena, discovering entelechies inside them and a trans-physical dimension. She reads the evolution of nature in a new way, against the deterministic interpretation of it. Inside nature one can discover many levels, qualitatively different. The human being participates to all of them, but his/her peculiarity is linked to the mental–spiritual life.     

Mental workload and visual impairment: differences between pupil, blink, and subjective rating

This research has two aims: (a) To study the concurrent validity of three measures of mental workload, NASA TLX rating scale, pupil dilation and blink rate, testing the hypothesis that they will provide convergent results using a single-task, and dissociative results for dual-task; and (b) To analyse their capability to predict visual search impairment. These three measures were analyzed in the same cognitive tasks in single-task and dual-task (cognitive task and visual search) conditions in a within-subjects experiment with twenty-nine participants. Mental workload measures showed concurrent validity under single-task condition, but a complex pattern of results arose in the dual-task condition: it is suggested that NASA TLX would be a subjective addition of the rating of each task; pupil dilation would measure the average arousal underlying the cognitive tasks; and the blink rate would produce opposite effects: whereas mental workload of cognitive tasks would increase blink rate, visual demand would inhibit it. All three measures were good predictors of visual impairment. The soundness of these measures is discussed with regard to the applied field of driving and other activities.     

Sensitization and habituation of motivated behavior in overweight and non-overweight children

The rate of habituation to food is inversely related to energy intake, and overweight children may habituate slower to food and consume more energy. This study compared patterns of sensitization, as defined by an initial increase in operant or motivated responding for food, and habituation, defined by gradual reduction in responding, for macaroni and cheese and pizza in overweight and non-overweight 8- to 12-year-old children. Non-overweight children habituated faster to both foods than overweight children (p = .03). All children recovered motivated responding for a new food (chocolate). Overweight children consumed more energy than non-overweight children (p = .0004). Children who showed a sensitization in responding consumed more food (p = .001), and sensitization moderated the effect of overweight on habituation, with slower habituation for overweight children who sensitized (p < .001). This study replicates previous data on overweight/non-overweight differences in habituation of food and energy intake, and provides new information that individual differences in sensitization and habituation of motivated responding to obtain food may be associated with a sustained motivation to eat, resulting in greater energy intake.     

Mothers' Parenting and Young Economically Disadvantaged Children's Relational and Overt Bullying

We examined links between mothers' parenting and children's relational bullying and overt bullying in a sample of children attending a Head Start program. Mothers completed surveys and face-to-face interviews. Head Start teachers completed assessments on children. Results indicated that a small percentage of children in the sample was rated by teachers as engaging in relational bullying “frequently to almost always,” and slightly over half of the sample was rated by teachers as engaging in relational bullying “occasionally to about half of the time.” Similar results were found for the frequency with which children engaged in overt physical bullying. Regarding mothers' parenting, maternal empathy was most strongly correlated with both children's relational bullying and overt physical bullying. In addition, mothers' inappropriate developmental expectations for children and mothers' need to exert power over children rather than grant them independence were related to children's relational bullying. A composite variable for mothering predicted 11% of the variance in children's relational bullying. No gender differences were found for children's relational bullying and children's overt bullying.     

Familiarity can increase stereotyping

Two experiments show that repeated exposure to information about a target person reduces individuation and thereby increases stereotyping of the target person based on social group memberships. The effect is not due to familiarity-induced liking (the mere exposure effect), nor is it mediated by increased accessibility of the target’s social category, nor by increases in perceived social judgeability. The results are most consistent with the use of feelings of familiarity as a regulator of processing mode, such that familiar objects receive less systematic or analytic processing. In everyday life, frequent exposure to another person ordinarily produces not only familiarity but also liking, individuated knowledge, and friendship, factors that may effectively limit stereotyping. But when previous exposure is unconfounded from these other factors, its effect can be to increase stereotyping.