Anatomic Magnetic Resonance Imaging of the Developing Child and Adolescent Brain and Effects of Genetic Variation

Magnetic resonance imaging studies have begun to map effects of genetic variation on trajectories of brain development. Longitudinal studies of children and adolescents demonstrate a general pattern of childhood peaks of gray matter followed by adolescent declines, functional and structural increases in connectivity and integrative processing, and a changing balance between limbic/subcortical and frontal lobe functions, which extends well into young adulthood. Twin studies have demonstrated that genetic factors are responsible for a significant amount of variation in pediatric brain morphometry. Longitudinal studies have shown specific genetic polymorphisms affect rates of cortical changes associated with maturation. Although over-interpretation and premature application of neuroimaging findings for diagnostic purposes remains a risk, converging data from multiple imaging modalities is beginning to elucidate the influences of genetic factors on brain development and implications of maturational changes for cognition, emotion, and behavior.     

Acute effects of alcohol on memory: Impact of emotional context and serial position

Although the amnestic effects of alcohol in humans are well known, its effects on emotional memory are unclear. In this study, using a randomized double-blind placebo-controlled design, we examine narrative emotional episodic memory in healthy human female volunteers (n = 32) who received either a single dose of alcohol (0.6 g/kg), or a placebo and then viewed neutral story elements presented in either a neutral or emotional context. Memory was tested for gist and detail of the neutral elements 3 days later in a surprise recognition test. Since alcohol modulates GABAergic neurotransmission and may exert its effects on emotion through the limbic system, we predicted that acute alcohol treatment would reduce the expected emotional memory-advantage for gist, leaving detail memory relatively unaffected. Furthermore, given previous findings showing that ‘primacy’ memory is enhanced by physiological arousal, we predicted that reduced arousal produced by alcohol would have the opposite effect and impair primacy memory relative to the middle or ‘recency’ sections of the narrative. Emotional arousal was expected to oppose this effect, so impaired primacy memory following alcohol was only expected in the neutral version of the narrative. Although there was a main effect of story phase (though not of story version), contrary to expectations, alcohol impaired primacy memory for emotionally encoded neutral material. The results suggest that under certain circumstances emotional context or physiological arousal make memories labile and susceptible to disruption through pharmacological manipulation during encoding.     

The modification of attentional bias to emotional information: A review of the techniques,mechanisms, and relevance to emotional disorders

A negative bias in the deployment of attention to emotional stimuli is commonly found in both anxiety and depression. Recent work has highlighted that such biases are causally related to emotional vulnerability, suggesting that interventions that ameliorate them may be therapeutic. Here, we review the evidence that attentional bias can be modified using both pharmacological and psychological interventions. We highlight the behavioral and neuroimaging studies that suggest that these interventions impact upon attention via alteration of distinct neural mechanisms. Specifically, pharmacological interventions appear to influence the initial deployment of attention via an effect on the amygdala-based stimulus appraisal system, whereas psychological interventions influence attention at later time points and may alter activity in the lateral prefrontal cortex. Finally, we suggest a conceptual framework that embraces both pharmacological and psychological approaches and consider the possible implications of this work for future research and treatment development.     

The Role of Occupational Characteristics and Occupational Imbalance in Explaining Well-being

One of the key factors for promoting well-being lies in balancing one’s daily life occupations and the nature of these occupations. Occupation refers to a group of everyday life goal-directed activities which may be associated to any life domain, not necessarily work, such as leisure, education, or self-care. Yet it is not clear what constitutes occupational imbalance, and its association to other factors has not been examined systematically. This study proposed and tested a theoretical model for specifying the structural relationships between occupational imbalance, occupational characteristics, personality and well-being. 288 working adults completed the following questionnaires: Inter-goal Relations Questionnaire (occupational imbalance), Personal Projects Analysis (occupational characteristics), the Big Five Inventory (personality traits) and the Satisfaction with Life Scale (well-being). Twenty-five models were tested using structural equation modeling. All the models fit the data well. Occupational characteristics, with the exception of stress, served as significant mediators between personality and well-being, yet occupational imbalance did not play a significant role across all models. Our findings provide substantial support for the importance of occupation to well-being, however occupational imbalance is still an elusive concept that requires further investigation theoretically and empirically.     

Rightward collisions and their association with pseudoneglect

Whereas right parietal damage can result in left hemineglect, the general population shows a subtle neglect of the right hemispace-known as pseudoneglect. A recent study has demonstrated that people collide to the right more often and attributed this bias to pseudoneglect. [Nicholls, M. E. R., Loftus, A., Meyer, K., & Mattingley, J.B. (2007). Things that go bump in the right: The effect of unimanual activity on rightward collisions. Neuropsychologia, 45, 1122-1126]. Nicholls examined the effect of unimanual activation by requiring participants to fire projectiles at a target whilst walking and found that the rightward bias was exaggerated or reversed when the left and right hands were active, respectively. However, the act of aiming at a target may have inadvertently biased walking trajectory to the right. The current study addressed this issue by requiring participants (n=149) to walk through a narrow doorway three times whilst entering text into a phone using the (a) left, (b) right or (c) both hands. Despite the fact that entering text into a phone should produce no rightward bias, participants bumped to the right more often. Unlike previous research, no effect of unimanual activation was observed. This lack of effect was attributed to the smaller hand movements for entering numbers compared to firing a toy gun. Finally, this study showed an association for the first time between biases in observable bumping and line bisection performance-suggesting that unilateral bumping is related to pseudoneglect.     

Maternal responsiveness to young children at three ages: longitudinal analysis of a multidimensional, modular, and specific parenting construct

Responsiveness defines the prompt, contingent, and appropriate reactions parents display to their children in the context of everyday exchanges. Maternal responsiveness occupies a theoretically central position in developmental science and possesses meaningful predictive validity over diverse domains of children's development, yet basic psychometric features of maternal responsiveness are still poorly understood. In this prospective longitudinal study, the authors examined structure, individual variation, and continuity of multiple dimensions of responsiveness in 40 mothers to their infants' activities at 10, 14, and 21 months during natural home-based play interactions. Both age-general and age-specific patterns emerged in maternal responding. The study's developmental results support the multidimensionality, modularity, and specificity of this central parenting construct.     

The relationship between stress and depression in first onsets versus recurrences: a meta-analytic review

S. M. Monroe and K. L. Harkness reviewed the empirical evidence supporting R. M. Post's kindling model, which suggests the 1st episode of depression is more likely to be preceded by major stressors than are subsequent episodes. Their review highlighted the diverse interpretations of Post's premise in the current literature and the changes in research methods that have contributed to this interpretive shift. The authors conducted a meta-analysis (N=13 studies) to test Post's premise that integrated early and recent research and examined potential moderators. A proportion difference effect size was used. Results indicated that 1st onsets of depression were more likely than recurrences to be preceded by severe life events, supporting Post's premise. The moderator analyses suggested that support may be most evident in patient samples and may vary according to age and gender, with less support for Post's premise evidenced in younger samples and in women. Although these results are preliminary, as the analysis included a small number of studies, they suggest that future research should further examine factors that influence the stress-depression relationship with successive recurrences.     

Cross-modal interactions in the experience of musical performances: physiological correlates

This experiment was conducted to investigate cross-modal interactions in the emotional experience of music listeners. Previous research showed that visual information present in a musical performance is rich in expressive content, and moderates the subjective emotional experience of a participant listening and/or observing musical stimuli [Vines, B. W., Krumhansl, C. L., Wanderley, M. M., & Levitin, D. J. (2006). Cross-modal interactions in the perception of musical performance. Cognition, 101, 80--113.]. The goal of this follow-up experiment was to replicate this cross-modal interaction by investigating the objective, physiological aspect of emotional response to music measuring electrodermal activity. The scaled average of electrodermal amplitude for visual-auditory presentation was found to be significantly higher than the sum of the reactions when the music was presented in visual only (VO) and auditory only (AO) conditions, suggesting the presence of an emergent property created by bimodal interaction. Functional data analysis revealed that electrodermal activity generally followed the same contour across modalities of presentation, except during rests (silent parts of the performance) when the visual information took on particular salience. Finally, electrodermal activity and subjective tension judgments were found to be most highly correlated in the audio-visual (AV) condition than in the unimodal conditions. The present study provides converging evidence for the importance of seeing musical performances, and preliminary evidence for the utility of electrodermal activity as an objective measure in studies of continuous music-elicited emotions.     

How do people apprehend large numerosities?

People discriminate remarkably well among large numerosities. These discriminations, however, need not entail numerical representation of the quantities being compared. This research evaluated the role of both non-numerical and numerical information in adult judgments of relative numerosity for large-numerosity spatial arrays. Results of Experiment 1 indicated that judgments of relative numerosity were affected by the amount of open space in the arrays being compared. Further, the accuracy of verbal estimates of the numerosities of the arrays made upon completion of the comparison task bore little relation to performance on that task. Experiment 2, however, showed that numerical estimates for individually presented arrays were affected in much the same way by open space within or around the edges of the array as were the comparative judgments examined in Experiment 1. The findings suggest that adults heuristically utilize non-numerical cues as well as numerical information in apprehending large numerosities.