Undernutrition during the brain growth period of the rat significantly delays the development of processes mediating Pavlovian trace conditioning

Pavlovian trace conditioning procedures allow one to assess the ability of animals to associate events that are temporally separated because the conditioned stimulus terminates prior to the occurrence of the unconditioned stimulus. We report that undernutrition during Postnatal Days 2-18 significantly delays the development of trace conditioning to a visual stimulus. Previously undernourished 20-day-old rats conditioned when no temporal interval separated the termination of the CS and US onset (0-s trace interval). However, it was not until the undernourished pups were 30 days old that they conditioned when the trace interval was 10 or 30 s. In contrast, control pups only 20 days old were able to condition when a 10-s trace interval separated the CS and US events, and 25-day-old control pups conditioned when the interval was either 10 or 30 s. These results suggest that undernutrition delays the development of processes that enable the rat to sustain a representation of a visual CS during the trace interval.     

Deriving Training Strategies for Spatial Knowledge Acquisition From Behavioral,Cognitive, and Neural Foundations

While much has been made of the potential uses for virtual environment (VE) technologies as training aids, there are few guidelines and strategies to inform system development from the user’s perspective. Assumptions are that a human factors-based evaluation will ensure optimal performance, transferring training from virtual to real worlds; however, there are complex, yet unexplored, issues surrounding system optimization and employment. A comprehensive investigation into the foundations of training, traversing levels of performance analysis, from overt behavioral responses to the less explicit neuronal patterns, is proposed from which optimal training strategies can be inferred and system development guidelines deduced.     

Social Discounting and Externalizing Behavior Problems in Boys

Social discounting refers to the fact that most people assign more value to the welfare of close affiliates than they do to the welfare of distant affiliates—they discount the latter compared to the former. We report the first study to apply a social discounting paradigm to boys. We were particularly interested in investigating the relations between social discounting, age, and externalizing behavior problems (antisocial behavior). Results showed that (1) preadolescent boys were more likely than adolescent boys to show atypical response patterns in allocating rewards to affiliates; (2) task behavior was well represented as social discounting once boys with atypical response patterns were deleted from the sample, and (3) boys functioning in the clinical range on indices of externalizing behavior problems demonstrated steeper social discounting compared to controls. We conclude that social discounting as a measure of perceived social closeness is feasible for use in adolescent samples. Social discounting may operate similarly to other forms of discounting in impulsive individuals. Copyright © 2011 John Wiley & Sons, Ltd.     

Cancer and the development of will

People with cancer, who live better or longer than expected or who recover completely despite a poor medical prognosis, usually go through a profound change and self-development. This paper is an attempt to describe and understand the nature of this transformation by examining how initially unexamined conceptions of oneself, life, illness, etc., become manifest and get developed. One feature of this process is that people leave the present-day medical conception, which is based on the notion of ‘victim’ of and ‘battle’ against illness, and discover that they have other resources for dealing with life and illness. It will be argued that at the centre of this transformation lies the discovery and development of the ‘will’, which is closely associated with the willingness to examine one's conceptions of oneself, health, illness and life.     

DHPG activation of group 1 mGluRs in BLA enhances fear conditioning

Group 1 metabotropic glutamate receptors are known to play an important role in both synaptic plasticity and memory. We show that activating these receptors prior to fear conditioning by infusing the group 1 mGluR agonist, (R.S.)-3,5-dihydroxyphenylglycine (DHPG), into the basolateral region of the amygdala (BLA) of adult Sprague–Dawley rats enhances freezing normally supported by a weak footshock. This effect of DHPG was blocked when it was co-infused with either the general group 1 mGluR1 antagonist, (R,S)-1-aminoindan-1,5 dicarboxylic acid (AIDA), or with the selective mGluR5 antagonist, 2-methyl-6-(phenylethynyl)-pyridine (MPEP). These results support previous findings by Rodrigues and colleagues that mGluR5s in the lateral region of the amygdala make an import contribution to fear conditioning. More importantly, they support the general ideas embedded in the concept of metaplasticity, as per Abraham, and the synaptic-tagging hypothesis per Frey and Morris—that the processes that specify the content of experience can be experimentally separated from those needed to acquire the memory.The last decade has seen an increased appreciation of the view that the plasticity state of neurons—their ability to be modified by experience—is not fixed. Instead, the effect of experience depends on the physiological or biochemical state of the neurons or synapses that receive and store information contained in the experience, and this state is variable. This perspective is captured by the concept called “metaplasticity” (Abraham and Bear 1996; Abraham and Tate 1997; Abraham 2008), which recognizes that prior events can change the general plasticity or modifiability of neurons and synapses that will potentially store information contained in a subsequent target experience. This idea is also embedded in the synaptic-tagging hypothesis (Frey and Morris 1997, 1998) that will be described in some detail in the Discussion section. This view is important because it recognizes that the processes that specify the content of experience can be experimentally separated from those that are needed to store the memory for the experience.As reviewed by Abraham (2008), the range of prior events that can potentially determine a neuron''s state of plasticity is quite large and can be mediated by their effects on many components of the machinery that supports changes in synaptic strength. They include modification in NMDA-receptor function, AMPA-receptor trafficking, neuronal excitability, and epigenetic modifications.One way that the potential for plasticity can be altered is by activation of group 1 metabotropic glutamate receptors (mGluR1s and mGlur5s) (Abraham 2008). A number of reports based on the in vitro long-term potentiation (LTP) methodology suggest that activating this class of receptors prior to the delivery of a relatively weak inducing stimulus can transform a normally short-lasting form of LTP into a more persistent form (Cohen and Abraham 1996; Cohen et al. 1998; Raymond et al. 2000). For example, an infusion of (R.S.)-3,5-dihydroxyphenylglycine (DHPG), a group 1 mGluR agonist, into the bathing medium 30 min prior to the delivery of a weak inducing stimulus can significantly enhance the persistence of the resulting LTP, while having no effect on the baseline response (Cohen et al. 1998; Raymond et al. 2000). This effect of DHPG, however, is blocked (Raymond et al. 2000) when its administration is accompanied by an infusion of the group 1 mGluR antagonist, (R,S)-1-aminoindan-1,5 dicarboxylic acid (AIDA).Group 1 mGluRs also have been implicated in fear conditioning. For example, Rodrigues et al. (2002) reported that one subtype, mGluR5, is localized in dendrites and spines in neurons in the lateral nucleus of the amygdala, and fear conditioning can be significantly impaired if the mGluR5 antagonist, 2-methyl-6-(phenylethynyl)-pyridine (MPEP), is infused into the lateral nucleus prior to conditioning.These findings, from the studies of synaptic plasticity and fear conditioning, provide the empirical basis for the hypothesis that motivates the experiments reported here—that the plasticity potential of neurons in the amygdala that support fear conditioning can be increased by activating group 1 mGluRs prior to the conditioning experience.To evaluate this idea, we followed a strategy similar to that used to study the role of mGluRs in LTP (Cohen and Abraham 1996; Cohen et al. 1998; Raymond et al. 2000). In these in vitro LTP experiments, a relatively weak inducing stimulus was used to generate a short-lasting LTP. Infusing the group 1 agonist DHPG prior to the delivery of the inducing stimulus transformed this short-lasting LTP into a more persistent form. Their results suggest that the activation of group 1 mGluR1 receptors independently initiates processes that make an important contribution to long-lasting LTP. To apply this strategy to fear conditioning, we used a very low level of shock—one that by itself produced an almost undetectable level of conditioned fear (as measured by freezing, the innate defensive response of rodents). We then determined if the activation of group 1 mGluRs prior to the conditioning experience would transform this outcome and produce a stronger level of freezing. DPHG was infused into the basolateral region of the amygdala (BLA) to activate the mGluRs.     

Autonomy,culture, and well-being: The benefits of inclusive autonomy

In an attempt to understand cultural variation in motivation, we distinguished between the type of motivation (ranging from controlled to autonomous, as conventionally measured) and the subject of motivation (“I” vs. “my family and I”), creating measures of individual and inclusive academic motivation. Support was found for three hypotheses. First, Chinese Canadian and Singaporean students felt less relative autonomy than European Canadian students, on both the inclusive and individual measures. Second, individual relative autonomy was associated with psychological well-being (WB) for European Canadians and Chinese Canadians (Study 1), and Singaporeans (Study 2). Third, inclusive relative autonomy was associated with psychological well-being for Chinese Canadians and Singaporeans, but not European Canadians. Exploratory analyses are also presented, and implications for the theory and measurement of autonomy are discussed.     

Older spouses' perceptions of partners' chronic arthritis pain: implications for spousal responses, support provision, and caregiving experiences

This study of older patients with osteoarthritis and their spouses examined concordance between patients' and spouses' reports of patients' pain severity and the association of concordance with support and caregiving outcomes. Patients and spouses independently viewed videotapes of the patient performing simulated household tasks and provided ratings of patients' pain. Spousal overestimation of patients' pain was the most common type of nonconcordance. Spouses who were accurate in their perceptions of their partner's level of pain during a log-carrying task responded less negatively and provided emotional support that was more satisfying to patients. In addition, spouses who were accurate in their perceptions of their partner's pain during the log-carrying task reported less stress from providing support and assistance. Future research that uses such observational methods may be highly useful for understanding the effects of chronic illness on older couples.     

Narcissism and depression: MMPI-2 evidence for the continuum hypothesis in clinical samples

According to one hypothesis, self-report measures of narcissism help describe a psychological continuum related to self-esteem. Most of the previous support for this idea appeared in studies of undergraduates responding to the Narcissistic Personality Inventory (NPI; Raskin & Hall, 1981) along with other self-report instruments. In this project, results consistent with the continuum hypothesis were obtained when Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) narcissism scales were correlated with depression in adults receiving treatment for alcoholism. Essentially identical outcomes emerged in a second sample of state psychiatric hospital patients. A third study upheld the hypothesis when narcissism scales were correlated with clinical assessments rather than self-reports of depression. None of these findings were easily explained in terms of alternative interpretations of self-reported narcissism, and these data demonstrate that empirical support for the continuum hypothesis was not limited to the NPI, undergraduates, or self-report measures.