Aged rats are impaired on an attentional set-shifting task sensitive to medial frontal cortex damage in young rats

Normal aging is associated with disruption of neural systems that subserve different aspects of cognitive function, particularly in the hippocampus and frontal cortex. Abnormalities in hippocampal function have been well investigated in rodent models of aging, but studies of frontal cortex function in aged rodents are few. We tested young (4–5 mo old) and aged (27–28 mo old) male Long-Evans rats on an attentional set-shifting task modified slightly from previous publication. After training on two problems in which the reward was consistently associated with the same stimulus dimension, and a reversal of one problem, a new problem was presented in which the reward was consistently associated with the previously irrelevant stimulus dimension (extradimensional shift [EDS]). Aged rats as a group were significantly impaired on the EDS, although some individual aged rats performed as well as young rats on this phase. In addition, some aged rats were impaired on the reversal, although a group effect did not reach significance in this phase. Impairment in neither reversal nor EDS was associated with impairments in spatial learning in the Morris water maze. Young rats with neurotoxic lesions of medial frontal cortex are also selectively impaired on the EDS. These results indicate that normal aging in rats is associated with impaired medial frontal cortex function. Furthermore, age-related declines in frontal cortex function are independent of those in hippocampal function. These results provide a possible basis for correlating age-related changes in neurobiological markers in frontal cortex with cognitive decline.     

The Roots of Love and Commitment in Childhood

Drawing from her clinical work with children and own childhood reflections, Dr. Lawrence underscores that the earliest sense of a true self is for the infant an experience of a self as worthy of love. This self-image becomes internalized as the infant looks into the mirror of the not too conflicted caregiver. She stresses that love which only can exist in relationship, is a social experience, does organize social experience, outstanding among these being commitments—commitments that bind a person to a course of action and connection. Dr. Lawrence interfaces psychoanalytic wisdom with spiritual references as she describes her work with children and families.     

Context specificity of conditioning and latent inhibition: Evidence for a dissociation of latent inhibition and associative interference

Conditioning may generalize from one context to another when latent inhibition (the effect on subsequent conditioning of prior unreinforced exposure to the stimulus) does not. Experiment 1 studied conditioned approach and licking by rats to a stimulus paired with the delivery of water and confirmed that latent inhibition could be abolished by a change of context, while prior aversive conditioning to the stimulus, produced by pairing it with mild shock, interfered with the acquisition of conditioned approach and licking regardless of this change of context. Thus even when conditioning and latent inhibition were measured in the same way, the former generalized across contexts, and the latter did not. Experiment 2 showed that the effects not only of unreinforced exposure to a stimulus but also of presentation of the stimulus uncorrelated with the delivery of water were confined to the context in which they occurred. Thus the generalization of conditioning from one context to another and the failure of latent inhibition to generalize cannot be attributed to the occurrence of rein-forcers during conditioning and their absence in latent inhibition. This conclusion was confirmed in Experiment 3, where animals received both aversive conditioning trials and unreinforced presentations of other stimuli in the treatment phase of the experiment, but were then conditioned to one of these stimuli paired with water. Once again, the effects of aversive conditioning transferred perfectly from one context to another, while those of unreinforced presentations did not. Latent inhibition, these results suggest, is not easily explained by supposing that animals associate an unreinforced stimulus with zero consequences and have to unlearn this association when the stimulus is then paired with a reinforcer.     

Primary school children rate children with autism negatively on looks,speech and speech content

Adults and adolescents form negative first impressions of ASD adults and children. We examined the first impression ratings of primary school children (6–9 years) of their ASD peers. 146 school children rated either silent videos, speech or transcribe speech from 14 actors (7 ASD, 7 TD). The ASD actors were rated more negatively than the typically developing actors on all three stimulus types. Children with ASD are likely to be judged more negatively than their peers at the very start of their formal education. Contrary to previous research, for primary school children, the content of the speech was judged as negatively as the delivery of the speech.     

about the authors

After tobacco and alcohol, marijuana is the most frequently used and abused substance. Its use is particularly prevalent among young adults, aged 18 to 25. This study examines the role strain plays in chronic (as opposed to recreational) marijuana use. Three theoretical perspectives are included in this analysis: General Strain Theory, Social Learning, and Self Control. Data from the 2001 National Household Survey of Drug Abuse are used to determine the relative effects of peers (social learning), strain (general strain theory), and favorable attitudes toward risk-taking (self control). Data is divided into subsamples on the basis of gender. Logistic Regression analysis suggests that males are more likely to be chronic users, and that psychological strain, social learning, and low self control are significant factors associated with chronic use. Furthermore, strain has a stronger effect on chronic use for minority group members, as does a propensity to risky behavior. Social learning has a stronger effect on nonminority group members. All factors have a stronger significant effect on female chronic marijuana use than on male marijuana use (except for the demographic variable education). Policy implications and suggestions for future research are also included.     

Underlying Mechanisms Explaining the Link between Differentiation and Romantic Relationship Outcomes

Abstract

Differentiation of self has been associated with positive relationship outcomes, but little has been done to analyze the underlying mechanisms that promote these outcomes for highly differentiated people. Longitudinal data were collected from a sample of university students (N?=?162) and clinically relevant direct and indirect effects between I-position and emotional reactivity, anxious attachment, relationship efficacy, and relationship satisfaction and conflict hostility were analyzed using path analysis. In general, anxious attachment and relationship efficacy mediated the association between differentiation of self and conflict hostility. Clients may benefit from therapists assessing differentiation and attachment, facilitating conversations that contribute to increasing differentiation and attachment, and using both of these constructs as mechanisms to enhance relationships in young adults.     

Thanks to 2010 Reviewers

Abstract

The electronic conductivity, diffusion coefficient and the self-energy in the vicinity of the energy gap of amorphous Si at T=0K have been computed as a function of energy for a fully bonded model of Si. We have used the equation-of-motion method in κ-space to show, for the first time, the probable position and existence of mobility edges. The conductivity rises rapidly away from the mobility edges to take values typical of those found in liquid metals. The behaviour of the self-energy indicates that a resonance phenomenon is responsible for the formation of a gap.     

Determining technology: myopia and dystopia

Throughout its brief history the philosophy of technology has been largely concerned with the debate over the nature of technology. Typically, technology has been viewed as being essentially another term for applied science, the practical application of scientific theory to the material world. In recent years philosophers and cultural critics have characterised technology in a far more problematic fashion, as an authoritarian power with the ability to bring about far-reaching cultural, political and ecological effects. Proponents of the former view are often termed instrumentalists and those of the latter technological determinists. The debate between them revolves around the question of the fact/value distinction, namely whether technology can be deemed to be value-neutral. I argue that employing a phenomenological approach to technology grants us a fresh perspective on the instrumentalism-determinism debate. It enables us to recast the instrumentalist/determinist debate as a debate between technological idealism and materialism, and to ground the instrumentalist and determinist positions in different experiential relations to technology. It also gives us a better grasp of the function of the different critiques of technology, with idealists concerned primarily with the misapplication of technology as a form of knowledge, and materialists with the existential implications of concrete technological relations.     

Motivational Influences in Persons Found Not Criminally Responsible on Account of Mental Disorder: A Review of Legislation and Research

This paper provides a review of the legislative reforms and case law that have impacted the defense of Not Criminally Responsible on Account of Mental Disorder (NCRMD) in Canada over the past three decades. As in other jurisdictions internationally, we observe that legislative reforms of procedural, as opposed to substantive, aspects of the NCRMD defense have impacted the manner in which NCRMD criteria are applied in common practice. More people are being declared NCRMD in recent years, and there is greater heterogeneity in the offending and psychiatric profiles of these individuals, suggesting that NCRMD criteria are being applied more liberally over time. In light of the substantial growth of the forensic mental health system over the past two decades, witnessed both in Canada and abroad, we propose that the study of motivational influences underlying the offending behaviors of persons with serious mental illness (SMI) is necessary to begin disentangling symptom‐based offending from violent and antisocial behaviors that may have other motives. This, in turn, can help to determine legal issues, better define the nature of each person's offending and treatment needs, and provide a more fine‐grained analysis of the drivers behind the growth experienced by the forensic system. Copyright © 2013 John Wiley & Sons, Ltd.