Coincident induction of long-term facilitation at sensory-motor synapses in Aplysia: presynaptic and postsynaptic factors

Induction of long-term synaptic changes at one synapse can facilitate the induction of long-term plasticity at another synapse. Here we show that if Aplysia sensory neuron (SN) somata and their remote motor neuron (MN) synapses are simultaneously exposed to serotonin (5HT) pulses, which at either site alone are insufficient to induce long-term facilitation (LTF), processes activated at these sites interact to induce LTF. Coincident induction of LTF requires: (1) that the synaptic pulse occurs within a brief temporal window of the somatic pulse and (2) that local protein synthesis occurs immediately at the synapse, followed by delayed protein synthesis at the soma. LTF at the SN-MN synapses can also be induced with cell-wide application of repeated pulses of 5HT. However, these two forms of LTF differ mechanistically: (1) coincident LTF requires protein synthesis in the postsynaptic motor neuron, whereas repeated 5HT LTF does not, and (2) repeated 5HT LTF is accompanied by intermediate-term (3 h) facilitation, whereas coincident LTF is not. Thus LTF expressed in the same temporal domain can result from different underlying mechanisms.     

A conceptual model of cultural predictors of anxiety among Japanese American and part-Japanese American adolescents

A model integrating Japanese ethnicity, cultural identity, and anxiety was developed and assessed in Japanese American and part-Japanese American high school seniors (N = 141). Using measures from the Hawaiian High Schools Health Survey, the model incorporated the State-Trait Anxiety Inventory, the Major Life Events Scale, and the Japanese Culture Scale (JCS). Japanese American adolescents scored higher on the JCS and reported fewer anxiety symptoms than part-Japanese American adolescents. Predictors for anxiety were being Japanese American versus part-Japanese American, income, and culturally intensified events. A significant interaction of behavior by self-identification was obtained. The model had good overall fit, suggesting that cultural identity formation may contribute to anxiety experienced particularly by adolescents of mixed heritage.     

Evaluating frequency proximity in stream segregation

Consecutive sounds of similar structure that are close in frequency or pitch are more likely to be perceived as part of the same sequence than those at greater frequency separations. The principle of grouping into such perceptual sequences, or auditory streams, is known as frequency proximity. However, the metric by which one frequency difference is judged to be greater or less than another in complex auditory scenes is not yet known. Two experiments explored the metric for frequency proximity. We presented repeating three-tone stimulus patterns at a rate where they are normally heard as two streams, one containing the highest tone and one containing the lowest. The middle tone joined one stream or the other depending on its frequency. Subjects reported the perceived allocation of the variable tone by responding on a 5-point scale. The frequency at which either of these two percepts was equally probable was found to be lower than a logarithmic midpoint or the midpoints on a cochlear map or the Mel scale; that is, it was unlike metrics arrived at by direct comparisons of tones. Further, the midpoint for high and low tones presented synchronously was lower than that for the same tones presented sequentially, demonstrating that in addition to a proximity factor, some additional factor or factors must operate differently when the lower and upper fixed tones are, or are not, presented simultaneously.     

Promoting parental compliance with home infant apnea monitor use

OBJECTIVE: To promote greater compliance in using prescribed infant apnea monitors among families with a medically at-risk infant. Eight consecutively referred non-compliant families were treated by a medical social worker who provided educational, behavioral prompting, and case management services. In six families results were evaluated with A-B single case research designs, and in two families A-B-A designs were used. Enhanced compliance followed intervention with all eight families. Clinically satisfactory compliance permitting the pediatrician to safely discontinue monitor use occurred in five of the eight families. Simple behavioral and case management interventions show great promise in promoting caregiver compliance with using home-based infant apnea monitors.     

Body checking and avoidance and the core features of eating disorders among obese men and women seeking bariatric surgery

This study examined two aspects of body checking and avoidance, and their relations to the core psychopathology of eating disorders (EDs), in severely obese men and women seeking bariatric surgery. A consecutive series of 260 (44 male and 216 female) gastric bypass candidates were administered measures to assess body checking and avoidance, binge eating, restraint, and overevaluation of weight and shape. The majority of patients reported regularly pinching areas of their body to check for fatness and avoided wearing clothing that made them particularly aware of their body. Significant associations were observed between checking and restraint, and between avoidance and binge eating. Both checking and avoidance behaviors were significantly associated with overevaluation of weight and shape. The positive associations between each of the two behaviors (body checking and avoidance) with overevaluation of weight/shape remained significant even after controlling for the effects of avoidance on body checking and vice versa. Stepwise multiple regression analyses revealed that binge eating, body checking, and avoidance behaviors made significant unique contributions and jointly accounted for 22-25% of the variance in overevaluation of weight and shape, respectively. This study documents the presence of eating disorder psychopathology among severely obese patients seeking bariatric surgery. The findings support the view that body checking and avoidance behaviors are manifestations of overevaluation of weight and shape and disordered eating.     

Plantinga’s Reformed Epistemology: What’s the Question?

Alvin Plantingas Warranted Christian Belief is without questionone of the central texts of the Reformed epistemology movement. Critiques of Plantingas defence have been both multiple and varied. As varied as these responses are, however, it is my contention that many of them amount to the same thing. It is the purpose of this paper to offer an overview of the main lines of attack that have been directed as Plantingas project, and thereafter to show how many, if not most, of these objections can be understood as versions or aspects of the same criticism, what I call the Inadequacy Thesis.     

The social context of imitation in infancy

Infants increasingly generalize deferred imitation across environmental contexts between 6 and 18 months of age. In three experiments with 126 6-, 9-, 12-, 15-, and 18-month-olds, we examined the role of the social context in deferred imitation. One experimenter demonstrated target actions on a hand puppet, and a second experimenter tested imitation 24h later. When the second experimenter was novel, infants did not exhibit deferred imitation at any age; when infants were preexposed to the second experimenter, all of them did. Imitating immediately after the demonstration also facilitated deferred imitation in a novel social context at all ages but 6 months. Infants' pervasive failure to exhibit deferred imitation in a novel social context may reflect evolutionary selection pressures that favored conservative behavior in social animals.