Effects of hippocampal injections of a novel ligand selective for the alpha 5 beta 2 gamma 2 subunits of the GABA/benzodiazepine receptor on Pavlovian conditioning

Benzodiazepine pharmacology has led to greater insight into the neural mechanisms underlying learning and anxiety. The synthesis of new compounds capable of modulating responses produced by these receptors has been made possible by the development of an isoform model of the GABA(A)/benzodiazepine receptor complex. In the current experiment, rats were pretreated with several concentrations of the novel ligand RY024 (an alpha 5 beta 2 gamma 2 -selective benzodiazepine receptor inverse agonist) in the hippocampus and were trained in a Pavlovian fear conditioning paradigm. RY024 independently produced fear-related behavior prior to training and, at the highest concentration, decreased the strength of conditioning observed 24 h after training. These data provide further evidence for the involvement of hippocampal GABA(A)/benzodiazepine receptors in learning and anxiety.     

Contact with maternal parent and siblings affects hunting behavior,learning, and central nervous system development in spiderlings of <Emphasis Type="Italic">Hogna carolinensis</Emphasis> (Araeneae: Lycosidae)

The purpose of this study was to determine the effects of early experience (rearing conditions) on the central nervous system (CNS) and behavior of spiderlings of Hogna carolinensis (Lycosidae). We were interested in whether or not spiderlings that were allowed to remain in contact with their maternal parent and siblings (enriched condition, EC) would exhibit differences in CNS development or subsequent behavior when compared with those reared in isolation (impoverished condition, IC). Spiderlings emerged from their egg sacs and climbed onto the dorsal surface of their mother's abdomen where they remained until their yolk supply was depleted (5 days). They dispersed on day 6 after emergence. We compared the ability of 16-day-old EC and IC spiderlings to capture prey in a linear runway and to learn a complex maze (spatial learning). We also compared certain aspects of CNS development (brain weight, total number of brain cells, volume of central body and protocerebral neuropil) in EC and IC spiderlings. Results indicated that EC subjects are more efficient at capturing moving prey (crickets) and exhibited improved performance (significantly fewer blind alley errors) in the maze. The volume of the protocerebral neuropil in 6-day-old EC animals increased 30% over a 5-day period after emergence as compared to IC animals of the same age. The volume of the central body of EC animals increased 34.8% over the same time period. On day 6 after emergence, the weight of the protocerebrum was significantly greater in EC versus IC subjects. There were no significant effects of rearing condition (EC vs IC) or age (1- and 6-day-old spiderlings) on the total number of nerve cells in the protocerebrum, suggesting that the difference in protocerebral weight was due primarily to differences in supporting glial tissues and neuropil matrix. In conclusion, the data suggest that early contact with the maternal parent and siblings is of vital importance to CNS development in lycosid spiderlings and can influence the capacity for spatial learning as well as the ability to capture prey. Electronic Publication     

Early and late mismatch negativity elicited by words and speech-like stimuli in children

In auditory perception the brain's attentional and preattentional mechanisms select certain stimuli for preferential processing and filter out irrelevant input. This study investigated nonattentive auditory processing in children. Event-related potentials (ERPs) provide a means to study neural correlates related to language and speech-sound processing. Mismatch negativity (MMN) is an ERP wave that indicates attention-independent perceptual change detection. In this study cortical ERPs were elicited by complex tones, naturally spoken words, and pseudowords, with each stimulus type containing equal acoustical elements. Tones elicited a bifurcated mismatch negativity (MMN), with early MMN (peaking at 150-200 ms) being more dominant. On the other hand, words elicited a strong late MMN, peaking at about 400-450 ms after stimulus onset. The MMN wave form was significantly weaker for pseudowords than for words. The late MMN wave, especially for word differences, was found to reflect summating MMN generators and memory trace formation on gestalt bases. Results suggest that the auditory processing, even nonattended, is highly associated with the cognitive meaning of the stimuli.     

The Penn Psychoanalytic Treatment Collection: a set of complete and recorded psychoanalyses as a research resource

From a set of seventeen complete and tape-recorded psychoanalyses, a sample of findings is presented: (a) the level of agreement of two clinical judges on the psychological health of these patients is adequate for the late sessions, but not for the early sessions; (b) the amount of change during psychoanalysis appears to be similar to that in the Menninger Foundation Psychotherapy Research Project; (c) psychiatric severity measures from the early sessions can yield a significant level of prediction of the later benefits from psychoanalysis. Finally, further research uses of this collection of psychoanalyses are suggested.     

Eye movements during visual mental imagery

It has long been debated whether eye movements play a functional role in visual mental imagery. A recent paper by Laeng and Teodorescu presents new evidence that eye movements are stored as a spatial index that is used to arrange the component parts correctly when mental images are generated.     

A Note on Hahn's Philosophy of Logic

Hans Hahn, mathematician, philosopher and co-founder of the Vienna Circle, attempted to reconcile the validity and applicability of both logic and mathematics with a strict empiricism. This article begins with a review of this attempt, focusing on his view of the relation of language to logic and his answer to the question of why we need logic. I then turn to some recent work by Stephen Yablo in an attempt to show that Yablo's fictionalism, and in particular his use of metaphor, can shed light on Hahn's philosophy of logic.     

The effects of two methods of training and sequencing on structuring and relationship skills of family therapists

Abstract

This study was an attempt to evaluate two methods of training family therapists (n = 26). Specifically, this research evaluated the relative effectiveness of observation-feedback (OF) and skill-based (SB) training methods, as well as OF-SB and SB-OF sequences of training on the acquisition of structuring and relationship skills. The only significant finding was that the OF-SB sequence resulted in significant gains in the acquisition of relationship skills. Implications are discussed for the training of family therapists.     

(Post)Enlightened Science

The Tragedy of Technology, by Stephen Hill, London: Pluto Press, 1988, 294 pages, hb £27.50, pb £8.95.     

Understanding Autism Implications for Psychoanalysis

Several lines of evidence inform current psychoanalytic thinking about infantile autism. Although early psychoanalytic interest in autism centered around the notion that experience might play a role in pathogenesis a large body of data suggest this is not the case; rather the condition appears to be the result of genetic and other neurobiological factors. Studies of children with autism do, however, suggest basic problems in capacities for object relations and other aspects of ego development which must be understood in the context of autistic social dysfunction. The study of normally developing infants raises considerable questions about the validity of notions such as a normal autistic phase; rather than for the normally developing child interest in the social world appears to be an innate capacity and one which has considerable importance for our understanding of the nature of early ego development and capacities for self-object differentiation.