Spatial attention and interhemispheric visuomotor integration in the absence of the corpus callosum

In the lateralized simple reaction time (SRT) task with unimanual responses (Poffenberger paradigm), reaction times (RTs) are faster with ipsilateral (uncrossed) than with contralateral (crossed) response hand-target hemifield combinations. The difference between crossed and uncrossed responses (CUD) has typically been interpreted to reflect callosal transfer time. Indeed, acallosal subjects and split-brain subjects have longer CUDs than control subjects. However, a few recent studies have demonstrated that, contrary to classical findings, the CUD is also affected by non-anatomical factors. Here we show that the CUD is also affected by non-anatomical factors in patients with agenesis of the corpus callosum and complete commissurotomy where interhemispheric transfer must be subcallosal. We tested acallosal subject M.M. and split brain patient A.A. on a lateralized SRT task with their arms alternately uncrossed (natural arms position) or crossed (unnatural arms position) across blocks of trials. The results revealed a significant effect of arms crossing on the size and direction of the CUD as previously found in normal subjects [Mooshagian, E., Iacoboni, M., & Zaidel, E. (2008). The role of task history in simple reaction time to lateralized light flashes. Neuropsychologia, 46(2), 659-664]. This suggests that non-anatomical factors that modulate interhemispheric visuomotor integration may occur in absence of the corpus callosum. Anterior commissure and interhemispheric cortico-subcortical pathways are likely implicated in these effects.     

Emotional dysregulation in dysphoria: Support for emotion context insensitivity in response to performance-based feedback

The Emotion Context Insensitivity (ECI) hypothesis predicts that individuals experiencing a sad mood will show diminished reactivity to emotionally evocative stimuli and will not differentiate emotional responses across contexts. Previous work has primarily been limited to studying depressed individuals' emotional responses to film clips, images, and autobiographical memories. The current study builds upon this work by examining emotional reactivity of dysphoric (n = 47) and non-dysphoric (n = 54) individuals to positive and negative feedback about their performance on a task they were led to believe measured social intelligence. Overall, dysphoric individuals reported higher negative emotion and lower positive emotion than non-dysphoric individuals before, during, and after feedback. However, consistent with ECI, dysphoric individuals displayed attenuated emotional reactivity to negative feedback compared to controls. Further, dysphoric individuals' emotional response did not differ to positive and negative feedback, whereas the non-dysphoric group appropriately differentiated their emotional response across these contexts. Findings support the ECI hypothesis and broaden its scope to include emotional reactivity to self-relevant performance feedback.     

Family Composition, Parental Involvement and Young Children's Academic Achievement

This study examined whether first-, second-, and third-grade students' achievement in language and mathematics was affected by factors from both the family context, including family size, number of adult caregivers, and parents' educational level, and the type of school related activities practised by parents. Participants in the study were 333 students (grades 1-3) whose parents had completed and returned a questionnaire designed to measure parents' attitude toward school and the extent of their involvement in school related activities. Academic achievement was related to measures of family composition (family size, number of adult caregivers, and parents' educational level). After controlling for race and gender, parents' educational level was associated with the students' scores on achievement tests. Furthermore, students whose parents engaged in learning activities at home were more likely to obtain higher achievement (language) scores. The study lends support to current practices commonly found in early childhood programs for involving parents in their children's schooling.     

Phasic vs Sustained Fear in Rats and Humans: Role of the Extended Amygdala in Fear vs Anxiety

Data will be reviewed using the acoustic startle reflex in rats and humans based on our attempts to operationally define fear vs anxiety. Although the symptoms of fear and anxiety are very similar, they also differ. Fear is a generally adaptive state of apprehension that begins rapidly and dissipates quickly once the threat is removed (phasic fear). Anxiety is elicited by less specific and less predictable threats, or by those that are physically or psychologically more distant. Thus, anxiety is a more long-lasting state of apprehension (sustained fear). Rodent studies suggest that phasic fear is mediated by the amygdala, which sends outputs to the hypothalamus and brainstem to produce symptoms of fear. Sustained fear is also mediated by the amygdala, which releases corticotropin-releasing factor, a stress hormone that acts on receptors in the bed nucleus of the stria terminalis (BNST), a part of the so-called ‘extended amygdala.'' The amygdala and BNST send outputs to the same hypothalamic and brainstem targets to produce phasic and sustained fear, respectively. In rats, sustained fear is more sensitive to anxiolytic drugs. In humans, symptoms of clinical anxiety are better detected in sustained rather than phasic fear paradigms.     

Educated and At-Risk: How the Shortage of Available Partners Influences HIV Risk for College-Educated African-American Women

Background

African-Americans have the greatest gender-ratio imbalance compared to other racial groups in the United States. This has been associated with higher rates of concurrent sexual partnerships, increasing risk of HIV infection. College-educated African-American women are of particular interest as they are not often represented in studies on HIV prevention, while their dating and sexual negotiation patterns may differ from those of their lower-educated and lower-income counterparts more often the subject of study in HIV research among African-Americans.

The effect of speaking context on spectral- and cepstral-based acoustic features of normal voice

The effect of speaking context on four cepstral- and spectral-based acoustic measures was investigated in 20 participants with normal voice. Speakers produced three different continuous speaking tasks that varied in duration and phonemic content. Cepstral and spectral measures that can be validly derived from continuous speech were computed across the three speaking contexts. Cepstral peak prominence (CPP), low/high spectral ratio, and the standard deviation (SD) of the low/high spectral ratio did not significantly differ across speaking contexts, and correlations for the first two measures were strong among the three speaking tasks. The SD of the CPP showed significant task differences, and relationships between the speaking contexts were generally moderate. These findings suggest that in speakers with normal voice, the differing phonemic content across several frequently used speaking stimuli minimally impacted group means for three clinically relevant cepstral- and spectral-based acoustic measures.     

The neurobiology of the emotional adolescent: From the inside out

Adolescents are commonly portrayed as highly emotional, with their behaviors often hijacked by their emotions. Research on the neural substrates of adolescent affective behavior is beginning to paint a more nuanced picture of how neurodevelopmental changes in brain function influence affective behavior, and how these influences are modulated by external factors in the environment. Recent neurodevelopmental models suggest that the brain is designed to promote emotion regulation, learning, and affiliation across development, and that affective behavior reciprocally interacts with age-specific social demands and different social contexts. In this review, we discuss current findings on neurobiological mechanisms of adolescents’ affective behavior and highlight individual differences in and social-contextual influences on adolescents’ emotionality. Neurobiological mechanisms of affective processes related to anxiety and depression are also discussed as examples. As the field progresses, it will be critical to test new hypotheses generated from the foundational empirical and conceptual work and to focus on identifying more precisely how and when neural networks change in ways that promote or thwart adaptive affective behavior during adolescence.     

Social comparison,competition and teacher–student relationships in junior high school classrooms predicts bullying and victimization

This cross-sectional research examines how social comparison, competition and teacher–student relationships as classroom characteristics are associated with bullying and victimization among junior high school students in grades 7 and 8 in Canada. The study tests a conceptual model of youth outcomes that highlights the importance of modeling the effects of teaching practices as proximal structural conditions at the classroom level (N = 38) that affect bullying outcomes at the individual level (N = 687). Results of Hierarchal linear modeling (HLM) revealed significant classroom-level effects in that increased social comparison, competition and teacher–student relationships were related to bullying and victimization. An interaction for teacher–student relationships and gender also emerged. These findings may guide future intervention programs for junior high schools that focus on enhancing cooperation and pro-social behavior in classrooms. The findings could also inform programs that focus on building strong relationships between students and teachers to help prevent bullying and victimization, particularly among boys.     

Predictions interact with missing sensory evidence in semantic processing areas

Human brain function draws on predictive mechanisms that exploit higher‐level context during lower‐level perception. These mechanisms are particularly relevant for situations in which sensory information is compromised or incomplete, as for example in natural speech where speech segments may be omitted due to sluggish articulation. Here, we investigate which brain areas support the processing of incomplete words that were predictable from semantic context, compared with incomplete words that were unpredictable. During functional magnetic resonance imaging (fMRI), participants heard sentences that orthogonally varied in predictability (semantically predictable vs. unpredictable) and completeness (complete vs. incomplete, i.e. missing their final consonant cluster). The effects of predictability and completeness interacted in heteromodal semantic processing areas, including left angular gyrus and left precuneus, where activity did not differ between complete and incomplete words when they were predictable. The same regions showed stronger activity for incomplete than for complete words when they were unpredictable. The interaction pattern suggests that for highly predictable words, the speech signal does not need to be complete for neural processing in semantic processing areas. Hum Brain Mapp 37:704–716, 2016. © 2015 Wiley Periodicals, Inc.     

Achieving change in health care practice

This study evaluated a practice development programme consisting of nine projects together known as STEP (South Thames Evidence-Based Practice Project). The aim of STEP was to establish and assess evidence-based practice in nursing and other health care practice areas. Objectives of the independent evaluation were to identify and assess outcomes from the process of change and investigate the association between these intermediate outcomes and patient outcomes. Outcomes were measured before and after the changes were introduced. Data collection methods included interviews with the change agents and other stakeholders, and a questionnaire to staff in each centre. Patient outcome data were collected from each centre. The findings revealed 'dissemination' of information to staff and 'adherence' by staff to new practice guidelines to be important intermediate outcomes in the process of change. The need emerged for a supportive organizational culture and commitment, recognition of the importance of change and a credible change agent. There was some evidence of linearity in the process of change in that a logical route appeared from dissemination of information to staff through adherence to the change guidelines to improvement in patient outcome in six of the nine centres. Linearity was less apparent in the other three centres, where the process of change seemed more dynamic and chaotic. These three centres were affected more than the others by organizational barriers to change. Our conclusions support the view that the linear model of change can work in settings with high levels of certainty but complexity theory is more likely to underpin the process of change in organizations characterized by uncertainty.