Wistar rats show episodic-like memory for unique experiences

Human episodic memory refers to the recollection of an unique past experience in terms of its details, its locale, and temporal occurrence. Episodic memory, even in principle, has been difficult to demonstrate in non-verbal mammals. Previously, we provided evidence that mice are able to form an integrated memory for "what," "where," and "when" aspects of single experiences by combining different versions of the novelty-preference paradigm, i.e., object recognition memory, the memory for locations in which objects were explored, and the temporal order memory for objects presented at distinct time points. In the present series of experiments we evaluated whether this paradigm, with minor modifications, also works with rats. We found that rats spent more time exploring an "old familiar" object relative to a "recent familiar" object, suggesting that they recognized objects previously explored during separate trials and remembered their order of presentation. Concurrently, the rats responded differentially to spatial object displacement dependent on whether an "old familiar" or "recent familiar" object was shifted to a location, where it was not encountered previously. These results provide strong evidence that the rats established an integrated memory for "what," "where," and "when." We also found that acute stress impaired the animal's performance in the episodic-like memory task, which, however, could be partially reversed by the N-Methyl-D-aspartate-receptors agonist D-cycloserine.     

Multiple Memory Processes Following Training That a Food Is Inedible in Aplysia

In many organisms, memory after training can be separated into a number of processes. We now report that separable memory processes are also initiated by a training procedure affecting Aplysia feeding behavior, a model system for examining the neural mechanisms underlying the regulation of a complex behavior. Four distinct memory process were identified: (1) a very short-term memory that declines within 15 min, (2) a short-term memory that persists for 0.5–1.0 hr, (3) an intermediate-term memory, observed 4 hr after training, and (4) a long-term memory that is seen only after a 12- to 24-hr delay. The four memory processes can be distinguished by the different training procedures that are required to elicit them. A single 5-min training session is sufficient to elicit the very short-term memory. However, a longer training session that continues until the animal stops responding to food is needed to elicit short-term memory. Intermediate-term memory is observed only after a spaced training procedure (three 5-min training sessions separated by 30-min intervals). A single 5-min training session that does not cause either short-term or intermediate-term memory is sufficient to induce long-term memory, indicating that short- and long-term memory are independent, parallel processes. Short- and long-term memory can also be separated by the effects of a post-training experience. Long-term, but not short-term, memory can be attenuated by cooling animals immediately after training. Cooling before the training does not affect either the training or the subsequent short- or long-term memory.     

The importance of conduct problems and depressive symptoms in predicting adolescent substance use

The current study assessed the relative importance of conduct problems and depressive symptoms, measured at two ages (11 and 15), for predicting substance use at age 15 in an unselected birth cohort of New Zealand adolescents. Among males, when the relative predictive utility of both conduct problems and depressive symptoms was assessed, only pre-adolescent depressive symptoms were found to predict multiple drug use 4 years later. No predictive relation was found between early symptomatology and later substance use among females. The strongest association between predictors and substance use emerged between age 15 multiple drug use and concurrent conduct problems for both males and females. Finally, both conduct problems and depressive symptoms at age 15 were also found to be associated with concurrent self-medication among females.This work was supported by USPHS grants MH-43746 and MH-45070 from the Antisocial and Violent Behavior Branch of the National Institute of Mental Health to Terrie Moffitt. Bill Henry was funded by a Fulbright Travel Award. The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council and Health Research Council of New Zealand. Appreciation is expressed to the interviewers who collected the data, and to the young New Zealanders who were members of the sample.     

The Composite Nature of Epistemic Justification

According to many, to have epistemic justification to believe P is just for it to be epistemically permissible to believe P. Others think it is for believing P to be epistemically good. Yet others think it has to do with being epistemically blameless in believing P. All such views of justification encounter problems. Here, a new view of justification is proposed according to which justification is a kind of composite normative status. The result is a view of justification that offers hope of solving some longstanding epistemological problems.     

Interactions between serotonin transporter gene haplotypes and quality of mothers' parenting predict the development of children's noncompliance

The LPR and STin2 polymorphisms of the serotonin transporter gene (SLC6A4) were combined into haplotypes that, together with quality of maternal parenting, were used to predict initial levels and linear change in children's (N = 138) noncompliance and aggression from age 18-54 months. Quality of mothers' parenting behavior was observed when children were 18 months old, and nonparental caregivers' reports of noncompliance and aggression were collected annually from 18 to 54 months of age. Quality of early parenting was negatively related to the slope of noncompliance only for children with the LPR-S/STin2-10 haplotype and to 18-month noncompliance only for children with haplotypes that did not include LPR-S. The findings support the notion that SLC6A4 haplotypes index differential susceptibility to variability in parenting quality, with certain haplotypes showing greater reactivity to both supportive and unsupportive environments. These different genetic backgrounds likely reflect an evolutionary response to variation in the parenting environment.     

Social-evaluative versus self-evaluative appearance concerns in Body Dysmorphic Disorder

Body Dysmorphic Disorder (BDD) is characterised by significant preoccupation and distress relating to an imagined or slight defect in appearance. Individuals with BDD frequently report marked concerns relating to perceived negative evaluation of their appearance by others, but research specifically investigating such concerns remains limited. This study investigated the extent and nature of appearance-related social-evaluative and self-evaluative concerns in individuals with BDD and healthy controls. BDD participants, in comparison to controls, reported high levels of importance and anxiety associated with perceptions of others' views of their appearance, in addition to their own view. No differences were observed in the level of importance and anxiety associated with their self-view in comparison to others' views. These findings support existing evidence indicating that appearance-related social-evaluative concerns are a central feature of BDD. Cognitive-behavioural treatment implications are discussed.     

Age-related differences in actual and perceived levels of physical activity in adolescent girls

Age-related differences in actual and perceived physical activity were investigated in a sample of adolescent girls, also considering the relationship between physical activity and motor abilities. Self-reported physical activity was measured in 11-year-old (n=66) and 13-year-old (n=52) girls by means of the physical activity questionnaire-children form, and actual levels of activity were assessed by means of the Lifecorder uniaxial accelerometer. The Sit-and-Reach Test was employed to estimate flexibility, while lower limb strength was measured by squat jump and counter-movement jump tests. Weight and height were measured, and sex-specific age-related body mass index cutoff points were used to identify overweight and obesity. Findings showed a drop in objective vigorous physical activity in older girls, which was also reflected in the physical activity questionnaire. Contrary to expectations, no association was found between motor abilities and measured physical activity. Results highlight the need to understand the reasons why girls progressively reduce their involvement in physical activity as they get older, so as to plan interventions aimed at preventing this decline.     

Physical activity and determinants of sedentary behavior in Brazilian adolescents from an underdeveloped region

The purpose of the study was to analyze the physical activity and the determinants of sedentary behavior in 1,268 Brazilian adolescents (638 girls, 630 boys) between the ages of 15 and 18 years, randomly selected from a relatively underdeveloped region. Data were collected from a community-based survey in the city of Jo?o Pessoa, Paraiba, Brazil. Information related to physical activity was derived on the short version of the International Physical Activity Questionnaire. The prevalence of sedentary behavior was 28.2% for girls and 19.1% for boys, whilst 28.9% of the girls and 36.7% of the boys showed high physical activity. The sedentary behavior varied by sociodemographic and environmental determinants studied. Parents' education, socioeconomic status, school's characteristics, transport to school, paid work, smoking, alcohol use, and BMI scores were significantly related to sedentary behavior for boys and girls.     

Attachment insecurity and strategies for regulation: when emotion triggers attention

Attachment-related strategies are thought to be critical for regulation and processing of emotional information. This study examined biases in selective attention to emotional stimuli as a function of insecure attachment. Participants searched for a single target image preceded by to-be-ignored distracters depicting emotional images varying in valence and arousal. Results revealed that, in general, negative distracters affected accuracy levels, and that the anxious attached participants showed a clear interference of the emotional distracters. In contrast, the avoidant group evinced a higher control on such interference. In addition, arousal ratings to distracter images indicated superior emotional activation only for anxious attached participants. Consistent with the evolutionary-based attachment theory threat-related stimuli prompted priority attentional responses. Present findings are in line with evidence showing the deployment of distinct strategies in insecurely attached individuals for the regulation of attention to emotional information.