An attractor network in the hippocampus: theory and neurophysiology

A quantitative computational theory of the operation of the CA3 system as an attractor or autoassociation network is described. Based on the proposal that CA3-CA3 autoassociative networks are important for episodic or event memory in which space is a component (place in rodents and spatial view in primates), it has been shown behaviorally that the CA3 supports spatial rapid one-trial learning and learning of arbitrary associations and pattern completion where space is a component. Consistent with the theory, single neurons in the primate CA3 respond to combinations of spatial view and object, and spatial view and reward. Furthermore, single CA3 neurons reflect the recall of a place from an object in a one-trial object-place event memory task. CA3 neurons also reflect in their firing a memory of spatial view that is retained and updated by idiothetic information to implement path integration when the spatial view is obscured. Based on the computational proposal that the dentate gyrus produces sparse representations by competitive learning and via the mossy fiber pathway forces new representations on the CA3 during learning (encoding), it has been shown behaviorally that the dentate gyrus supports spatial pattern separation during learning, and that the mossy fiber system to CA3 connections are involved in learning but not in recall. The perforant path input to CA3 is quantitatively appropriate to provide the cue for recall in CA3. The concept that the CA1 recodes information from CA3 and sets up associatively learned back-projections to neocortex to allow subsequent retrieval of information to neocortex provides a quantitative account of the large number of hippocampo-neocortical back-projections.     

Normality and impairment following profound early institutional deprivation: a longitudinal follow-up into early adolescence

Longitudinal analyses on normal versus impaired functioning across 7 domains were conducted in children who had experienced profound institutional deprivation up to the age of 42 months and were adopted from Romania into U.K. families. Comparisons were made with noninstitutionalized children adopted from Romania and with nondeprived within-U.K. adoptees placed before the age of 6 months. Specifically, the validity of the assessment, the degree of continuity and change in levels of functioning from 6 to 11 years, and the factors in the pre- and postadoption environment accounting for heterogeneity in outcome were examined. Pervasive impairment was significantly raised in children experiencing institutional deprivation for > or =6 months of life, with a minority within this group showing no impairment. There was no additional significant effect of duration of deprivation beyond the 6-month cutoff, and few other predictors explained outcome. The pattern of normality/impairment was mainly established by 6 years of age, with considerable continuity at the individual level between 6 and 11 years. The findings are discussed in terms of the possibility of a sensitive period for development.     

Neuropsychology Behind the Plate

Abstract

In baseball, plate umpires are asked to make difficult perceptual judgments on a consistent basis. This chapter addresses some neuro-psychological issues faced by umpires as they call balls and strikes, and whether it is ethical to ask fallible humans to referee sporting events when faced with technology that exposes “blown” calls.     

Linkages between violence-associated attitudes and psychological,physical, and sexual dating abuse perpetration and victimization among male and female adolescents

Attitudes about violence and sex in dating relationships were related to psychological, physical, and sexual teen dating abuse perpetration and victimization. Data from Wave 4 of the national, randomly selected, Growing up with Media cohort (n = 876 adolescents aged 14-19 years), collected in 2011, were analyzed. Dating youth perceived more peer pressure to have sex and were more accepting of sex in brief or nonmarital relationships than pre-dating youth. Boys had higher levels of rape-supportive attitudes than girls. Among dating youth, the relative odds of involvement in teen dating abuse as a perpetrator or a victim were generally associated with greater acceptance of relationship violence, perceived peer pressure to have sex, and acceptance of sex in brief and/or nonmarital relationships. Rape-supportive attitudes were not significantly associated with any type of teen dating abuse involvement. Programs aimed at preventing dating abuse might benefit from targeting attitudes associated with sexual activity as well as relationship violence.     

Association between substance use disorders and self- and other-directed aggression: An integrated model approach

Our study's objective is to determine whether substance use disorders’ association with aggression differs according to the type of substance and/or the form of aggression, within the same population. We used data from the National Survey on Drug Use and Health across 2008–2014, with a pooled sample of 270,227 adult respondents. We used regression models to estimate the odds ratios for those having alcohol and/or drug use disorder(s) perpetrating (a) each form of aggression compared with no aggression and (b) other-directed compared with self-directed aggression. Alcohol use disorder alone and drug use disorder(s) alone were both associated with significantly increased odds of committing self-directed, other-directed, and combined aggression. Individuals with drug use disorder(s) alone were more likely to commit other-directed than self-directed aggression (adjusted odds ratio = 1.46, 95% CI = 1.04–2.05). Individuals with alcohol use disorder alone were not likely to commit one over the other (adjusted odds ratio = 1.20, 95% CI = 0.90–1.61). In conclusion, the integrated model of aggression based on the stress–diathesis model is a relevant framework to study risk factors for aggression. Further research is needed to identify longitudinal predictors of directionality of aggression.     

Choice,Conditioned Reinforcement,and the Prius Effect

Psychologists have long been intrigued with the rationales that underlie our decisions. Similarly, the concept of conditioned reinforcement has a venerable history, particularly in accounting for behavior not obviously maintained by primary reinforcers. The studies of choice and of conditioned reinforcement have often developed in lockstep. Many contemporary approaches to these fundamental topics share an emphasis on context and on relative value. We trace the evolution of thinking about the potency of conditioned reinforcers from stimuli that were thought to acquire their value from pairings with more fundamental reinforcers to stimuli that acquire their value by being differentially correlated with these more fundamental reinforcers. We discuss some seminal experiments (including several that have been underappreciated) and some ongoing data, all of which have propelled us to the conclusion that the strength of conditioned reinforcers is determined by their signaling a relative improvement in the organism''s relation to reinforcement.