A role for ERK MAP kinase in physiologic temporal integration in hippocampal area CA1

Recent studies demonstrate a requirement for the Extracellular signal Regulated Kinase (ERK) mitogen-activated protein kinase (MAPK) cascade in both the induction of long-lasting forms of hippocampal synaptic plasticity and in hippocampus-dependent associative and spatial learning. In the present studies, we investigated mechanisms by which ERK might contribute to synaptic plasticity at Schaffer collateral synapses in hippocampal slices. We found that long-term potentiation (LTP) induced with a pair of 100-Hz tetani does not require ERK activation in mice whereas it does in rats. However, in mice, inhibition of ERK activation blocked LTP induced by two LTP induction paradigms that mimicked the endogenous θ rhythm. In an additional series of studies, we found that mice specifically deficient in the ERK1 isoform of MAPK showed no impairments in tests of hippocampal physiology. To investigate ERK-dependent mechanisms operating during LTP-inducing stimulation paradigms, we monitored spike production in the cell body layer of the hippocampus during the period of θ-like LTP-inducing stimulation. θ-burst stimulation (TBS) produced a significant amount of postsynaptic spiking, and the likelihood of spike production increased progressively over the course of the three trains of TBS independent of any apparent increase in Excitatory Post-Synaptic Potential (EPSP) magnitude. Inhibition of ERK activation dampened this TBS-associated increase in spiking. These data indicate that, for specific patterns of stimulation, ERK may function in the regulation of neuronal excitability in hippocampal area CA1. Overall, our data indicate that the progressive increase in spiking observed during TBS represents a form of physiologic temporal integration that is dependent on ERK MAPK activity.     

A cross-linguistic data bank for oral picture naming in Dutch, English, German, French, Italian, Russian, Spanish, and Swedish (PEDOI)

The well established effect of word frequency on adult's picture naming performance is now called into question. This is particularly true for variables which are correlated with frequency, as is the case of age of word acquisition. Since the work of [Carrol and White, 1973] there is growing agreement among researchers to confer an important role in lexical access to this variable. Indeed, it has been shown ( [Hodgson and Ellis, 1998]) that for normal English-speaking adults only the variables 'age-of-acquisition' and 'name agreement' are independent predictors of naming success among the various variables considered. However, when brain-damaged subjects with and without degenerative pathologies are studied, word frequency and word length as well as concept familiarity all give significant effects ( [Hirsh and Funnell, 1995]; [Lambon Ralph et al., 1998]; [Nickels and Howard, 1995]). Finally, it has been suggested that the production of specific error types may be related to such variables. According to [Nickels and Howard, 1994] the production of semantic errors is specifically affected by 'imageability' and in the recent study by [Kremin et al., 2001] 'age of acquisition' predicts (frank) word finding difficulties.     

One size does not fit all: Exploring how the five-factor model facets predict disordered eating behaviours among adolescent and young adult males and females

There is a wealth of research that has highlighted the relationship between personality and eating disorders. It has been suggested that understanding how subclinical disordered eating behaviours are uniquely associated with personality can help to improve the conceptualization of individuals with eating disorders. This study aimed to explore how the facets of the Five-Factor Model (FFM) predicted restrictive eating, binge eating, purging, chewing and spitting, excessive exercising and muscle building among males and females. An online survey assessing disordered eating behaviours, FFM and general psychopathology was completed by 394 females and 167 males aged between 16 and 30 years. Simultaneous equations path models were systematically generated for each disordered eating behaviour to identify how the FFM facets, body dissatisfaction and age predicted behaviour. The results indicated that each of the six disordered behaviours were predicted by a unique pattern of thinking, feeling and behaving. Considerable differences between males and females were found for each path model, suggesting differences between males and females in the personality traits that drive disordered eating behaviours. It was concluded that it is important to take personality into account when treating males and females who engage in disordered eating behaviours.     

Psychological Variables as Predictors of Perceived Ethnic Discrimination Among Minority and Immigrant Adolescents1

The occurrence of discrimination in the real world is difficult to determine objectively, as it is defined in part by intentions. The perception of discrimination may therefore be influenced by one's interpretation of the intentions of others. In order to examine psychological characteristics that influence the perception of ethnic discrimination, 164 Armenian, Mexican American, and Vietnamese adolescents completed measures of perceived discrimination (PD), self-esteem, mastery, depression/anxiety, intergroup competence, and ethnic identity, as well as demographic variables. A path analysis showed that higher depression/anxiety scores and lower intergroup competence predicted more PD; depression/anxiety and intergroup competence were in turn predicted by self-esteem and mastery, respectively. Birthplace and socioeconomic status had an indirect effect on PD, via intergroup competence. The results suggest the importance of psychological variables in the perception of discrimination.     

Individuation of Actions from Continuous Motion

Three studies explored how infants parse a stream of motion into distinct actions. Results show that infants (a) can perceptually discriminate different actions performed by a puppet and (b) can individuate and enumerate heterogeneous sequences of such actions (e.g., jump-fall-jump) when the actions are separated by brief motionless pauses, but (c) are not able to individuate such actions when embedded within a continuous stream of motion. Combined with previous research showing that infants can individuate homogeneous actions from an ongoing stream of motion, these findings suggest that infants can use repeating patterns of motion in the perceptual input to define action boundaries. Results have implications as well for infants' conceptual structure for actions.     

Breast cancer representations in Canadian news media: a critical discourse analysis of meanings and the implications for identity

Despite the importance of critical media work, much is to be learned about breast cancer representations within media discourses and the implications for women’s identity construction. Building on research from Australia from a discursive perspective, this article used an eclectic approach to critical discourse analysis to explore the cultural construction of breast cancer in 25 detailed stories within Canada’s two national newspapers, The Globe and Mail and the National Post. Ten images accompanying stories and 17 advertisements/public service announcements were also analyzed to contextualize discourses and subject positions/identities within the stories. Analysis of this media affords the unique opportunity to explore taken for granted assumptions and prevailing meanings about breast cancer and the implications for subjectivity. Two primary discourses were identified: a discourse of biomedicine and a discourse of healthism. Subject positions identified included “breast cancer survivor,” “the good consumer,” and the “medical expert.” The psychological, social, political, and health promotion implications are discussed.     

Moving Beyond the Gym: Exploring Life Skill Transfer Within a Female Physical Activity-Based Life Skills Program

Physical activity programs are viable contexts to foster life skills. Researchers contend that programs must be structured to deliberately teach life skills and teach how such skills can be transferred. The purpose of this study is to understand female youths’ perceptions of life skills transfer from participation in a physical activity-based life skills program. Interviews were conducted with eight youth. Results indicated that youth learned intrapersonal (i.e., emotional regulation, focus, goal setting), interpersonal (i.e., respect, responsibility, social skills), and physical activity skills and applied these skills in other life domains. Leaders’ practical strategies used to explicitly teach transferable skills are discussed.     

Emotional disturbances and their interaction with neuropsychological deficits

The interaction and relationships between neuropsychological tests (which are principally oriented to intellectual and cognitive abilities) and tests of personality and emotional status are complex, but nevertheless important in the clinical assessment of brain-damaged persons. Are indications of emotional disturbances to be expected as a direct consequence of brain damage? If so, how can the indications of emotional disturbances be differentiated from results obtained with psychiatrically disturbed (non-brain-damaged) subjects? Some authors have presumed that emotional disturbances, such as depression, acute anxiety, etc., in their own right cause impaired performances on neuropsychological tests, whereas other authors have proposed that brain damage predisposes the individual to demonstrate evidence of emotional disturbances. If emotional disturbances cause impairment on neuropsychological tests, why is it that so many emotionally disturbed persons without brain damage tend to perform normally on neuropsychological tests? This review of relevant publications considers (1) different general approaches to these questions and their implications for neuropsychology, (2) evidence of differential sensitivity to brain damage of neuropsychological and emotional instruments, (3) the sensitivity and specificity of self-assessments and complaints of head-injured subjects, (4) MMPI findings among head-injured subjects and in interaction with neuropsychological measurements, and (5) principles and guidelines that may be of value in clinical application of findings reported in the literature.     

An investigation of overlap in children's speech

The simultaneous speech of six 4-year-old girls was investigated within three-party conversation. The data reveal two major types of overlap, one providing instances of turn completion projections and the other reflecting tension for the turn at speaking. The data are discussed in terms of the Sacks, Schegloff, and Jefferson (1974) model of conversational interaction.