Behavioural state differentially engages septohippocampal cholinergic and GABAergic neurons in R6/1 Huntington's disease mice

Huntington's disease (HD) is a neurodegenerative condition characterised by progressive motor, psychological and cognitive decline. R6/1 HD transgenic mice model the clinical hippocampal-dependent cognitive deficits observed in patients. Cholinergic and GABAergic septohippocampal projections play important roles in hippocampal-dependent cognition. The current study examined neuronal activity of cholinergic and GABAergic septohippocampal projections in response to arousal elicited during differing behavioural states. The different behavioural states examined were; home cage (controls), acute exploration of a novel enriched environment and either spontaneous wakefulness (dark phase) or spontaneous sleep (light phase). We employed triple-label immunohistochemistry using c-Fos as an indirect marker of neuron activation and parvalbumin and choline acetyltransferase (ChAT) to label GABAergic and cholinergic neurons in the basal forebrain, respectively. The Y-maze was used to assess short-term hippocampal-dependent memory independently during either the dark or light phase and revealed a memory deficit in R6/1 HD mice compared to wild types that was particularly prominent during the dark phase. Three-way ANOVA of basal forebrain cholinergic and GABAergic activity through co-expression of c-Fos revealed overt responses to differing behavioural states. Both genotypes increased cholinergic neuron activity in response to exploring a novel enriched environment and also an increase during the dark phase compared to the light phase. Novel enriched environment exploration caused a larger response of GABAergic neuron activity in R6/1 HD mice, which also failed to increase the activity of GABAergic neurons during the dark phase compared to the light phase as observed for wildtype mice. Basal levels of c-Fos-positive cells were greatly increased in the hippocampal granule cell layer of R6/1 HD mice during both circadian phases. The differential activation of septohippocampal cholinergic and GABAergic neurons in R6/1 HD mice in response to differing behavioural states may be associated with impaired hippocampal-dependent short-term memory.     

Treating disturbed emotional regulation in sexual offenders: The potential applications of mindful self-regulation and controlled breathing techniques

It has been noted that some offenders are characterized by problems in the appropriate regulation of emotional states. Deficits in emotional regulation are particularly pertinent in sexual offenders. Therefore, therapeutic programs should, in part, focus on the development of effective strategies for the control of emotional arousal. In this review, we will provide an outline of how anatomical structures including the amygdala and regions of the prefrontal cortex (PFC) are involved in the appropriate regulation of emotion. It is argued in this paper that the effective control of emotional states may be helped through the adoption of a group of meditational practices, known as mindfulness techniques, which have emerged from Buddhist philosophy. These techniques involve slow, deep breathing and have been shown to affect vagal modulation of the heart and the functioning of specific neural circuits which are critically involved in emotional regulation.     

Text messaging amongst New Zealand drivers: Prevalence and risk perception

Recent work suggests that text messaging impairs simulated and actual driving performance and that this impairment exceeds that of conversing on a cell phone while driving. Additionally, research has shown that text messaging is common in several countries, and despite drivers acknowledging the high risk involved in doing so, drivers continue to engage in this behaviour – regardless of legislation banning it. A nationwide online survey in New Zealand, of 1057 respondents, collected anonymous self-report data regarding the frequency of cell phone use (conversing and text messaging) while driving, beliefs concerning the safety of conversing or text messaging while driving. This article presents part of the results of that study – focusing on text messaging behaviour and risk perception regarding text messaging while driving. Over half of respondents surveyed reported sending or reading between 1 and 5 text messages while driving in a typical week. Despite this, 89% of participants agreed that text messaging while driving in general impairs driving performance. There were no gender differences between the number of text messages read and sent. Age was found to be an important indicator of participant’s willingness to engage in text messaging while driving, with younger drivers more likely to engage in this behaviour. The implications of these findings for future research and countermeasure development are discussed.     

Harm to Future Persons: Non-Identity Problems and Counterpart Solutions

Non-Identity arguments have a pervasive but sometimes counter-intuitive grip on certain key areas in ethics. As a result, there has been limited success in supporting the alternative view that our choices concerning future generations can be considered harmful on any sort of person-affecting principle. However, as the Non-Identity Problem relies overtly on certain metaphysical assumptions, plausible alternatives to these foundations can substantially undermine the Non-Identity argument itself. In this paper, I show how the pervasive force and nature of Non-Identity arguments rely upon a specific adoption of a theory of modality and identity and how adopting an alternative account of modality can be used to reject many conclusions formed through Non-Identity type arguments. By using Lewis’s counterpart-theoretic account to understand ways we might have been, I outline the basis of a modal account of harm that incorporates a person-affecting aspect. This, in turn, has significant implications for ethical decision-making in areas such as reproductive choice and the welfare of future generations.     

Finding MAPs using strongly equivalent high order recurrent symmetric connectionist networks

Belief revision is the problem of finding the most plausible explanation for an observed set of evidences. It has many applications in various scientific domains like natural language understanding, medical diagnosis and computational biology. Bayesian Networks (BN) is an important probabilistic graphical formalism widely used for belief revision tasks. In BN, belief revision can be achieved by finding the maximum a posteriori (MAP) assignment. Finding MAP is an NP-Hard problem. In previous work, we showed how to find the MAP assignment in BN using High Order Recurrent Neural Networks (HORN) through an intermediate representation of Cost-Based Abduction. This method eliminates the need to explicitly construct the energy function in two steps, objective and constraints. This paper builds on that previous work by providing the theoretical foundation and proving that the resultant HORN used to find MAP is strongly equivalent to the original BN it tries to solve.     

Rehearsal dynamics in elementary school children

Several studies on free recall suggest that processes responsible for recall are analogous to processes responsible for rehearsal. In children, the relationship between cumulative rehearsal and recall performance has been proven to be critical; however, the locus of the effect of rehearsal is not yet fully understood. To unfold the mechanisms that come into play in an overt rehearsal free recall task, we assessed rehearsal and recall sequences in children between 8 and 10 years of age. These sequences give information about the context in which items are repeated and rearranged throughout the list and subsequently recalled. Rehearsal sequences consisted mainly of items from neighboring list positions in their original temporal order. The same characteristics were true for recall sequences. Qualitatively, order effects during study and recall did not differ over age groups. However, in older children who were using cumulative rehearsal more intensively, successive rehearsal and recall of items in their original order was more pronounced. Therefore, we suggest that a main feature of item rehearsal with regard to facilitating recall is the strengthening of interitem associations based on the temporal order within a list and that this characteristic develops with age.     

In perfect harmony: synchronizing the self to activated social categories

The self-concept is one of the main organizing constructs in the behavioral sciences because it influences how people interpret their environment, the choices they make, whether and how they initiate action, and the pursuit of specific goals. Because belonging to social groups and feeling interconnected is critical to human survival, the authors propose that people spontaneously change their working self-concept so that they are more similar to salient social categories. Specifically, 4 studies investigated whether activating a variety of social categories (i.e., jocks, hippies, the overweight, Blacks, and Asians) increased associations between the self and the target category. Whereas Studies 1 and 2 focused on associations between stereotypic traits and the self, Studies 3 and 4 examined self-perceptions and self-categorizations, respectively. The results provide consistent evidence that following social category priming, people synchronized the self to the activated category. Furthermore, the findings indicate that factors that influence category activation, such as social goals, and factors that induce a focus on the interconnectedness of the self, such as an interdependent vs. independent self-construal, can impact this process. The implications of changes to the working self-concept for intergroup relations are discussed.     

An evaluation of the consequences of using short measures of the Big Five personality traits

Researchers often use very abbreviated (e.g., 1-item, 2-item) measures of personality traits due to their convenience and ease of use as well as the belief that such measures can adequately capture an individual's personality. Using data from 2 samples (N = 437 employees, N = 355 college students), we show that this practice, particularly the use of single-item measures, can lead researchers to substantially underestimate the role that personality traits play in influencing important behaviors and thereby overestimate the role played by new constructs. That is, the use of very short measures of personality may substantially increase both the Type 1 and Type 2 error rates. We argue that even slightly longer measures can substantially increase the validity of research findings without significant inconvenience to the researcher or research participants.     

IRTs of the ABCs: children's letter name acquisition

We examined the developmental sequence of letter name knowledge acquisition by children from 2 to five years of age. Data from 2 samples representing diverse regions, ethnicity, and socioeconomic backgrounds (ns = 1074 and 500) were analyzed using item response theory (IRT) and differential item functioning techniques. Results from factor analyses indicated that letter name knowledge represented a unidimensional skill; IRT results yielded significant differences between letters in both difficulty and discrimination. Results also indicated an approximate developmental sequence in letter name learning for the simplest and most challenging to learn letters--but with no clear sequence between these extremes. Findings also suggested that children were most likely to first learn their first initial. We discuss implications for assessment and instruction.