Postural leaning direction challenges the manifestation of tendon vibration responses at the ankle joint

In this study, we examined the interaction between central and peripheral proprioceptive afferent pathways by applying ankle tendon vibration during postural leaning in different directions. Twenty young participants stood for 60s over the midline of two adjacent force platforms in (a) neutral stance distributing Body Weight (BW) equally between the platforms, (b) forward leaning transferring 80% of BW to the front platform and (c) backward leaning transferring 80% of BW to the rear platform. Participants controlled the degree of leaning by receiving on-line visual feedback of BW distribution matched to a target line. Vibration (80 Hz, 1.5–1.8 mm) was applied over the Achilles or tibialis anterior tendon during the middle 20s of standing. This induced a postural shift towards the vibration side and an increase in the variability of the BW distribution that was greater in backward compared to forward leaning. EMG responses to tendon vibration were independent of the leaning direction. Antagonistic activity also increased in response to vibration, the amplitude of this increase however was direction dependent. These results favor the hypothesis about the central co-modulation of the vibration evoked proprioceptive inflow based on postural and visual feedback rather than muscle tension constraints.     

From early markers to neuro-developmental mechanisms of autism

A fast growing field, the study of infants at risk because of having an older sibling with autism (i.e. infant sibs) aims to identify the earliest signs of this disorder, which would allow for earlier diagnosis and intervention. More importantly, we argue, these studies offer the opportunity to validate existing neuro-developmental models of autism against experimental evidence. Although autism is mainly seen as a disorder of social interaction and communication, emerging early markers do not exclusively reflect impairments of the “social brain”. Evidence for atypical development of sensory and attentional systems highlight the need to move away from localized deficits to models suggesting brain-wide involvement in autism pathology. We discuss the implications infant sibs findings have for future work into the biology of autism and the development of interventions.     

ENTHEOGENS IN A RELIGIOUS CONTEXT: THE CASE OF THE SANTO DAIME RELIGIOUS TRADITION

This essay first draws upon the work of William James and others to propose a nonphysicalistic understanding of the relationship between the brain and consciousness in order to articulate a philosophical perspective that can understand entheogenic visionary/mystical experiences as something other than hallucinations. It then focuses on the Santo Daime tradition, a religious movement that began in Brazil in the early part of the twentieth century, to provide an example of the personal and social ramifications of taking an entheogen (ayahuasca) within a disciplined religious context. The essay claims that the Santo Daime is one example of a contemporary mystery school; gives a brief history of the development of this religion; discusses the key theological assumptions of this movement; investigates the important role played by visionary/mystical experiences within this religion; underscores the centrality of healing and spiritual transformation for members of this tradition; and ends with an examination of the crucial significance of spiritual discipline within this entheogenically based religion.     

When Fluency Signals Truth: Prior Successful Reliance on Fluency Moderates the Impact of Fluency on Truth Judgments

Repeated statements are more frequently judged to be true. One position relates this so‐called “truth effect” to metacognitive experiences of fluency, suggesting that repeated statements are more frequently judged to be true because they are processed more fluently. Although most prior research focused on why repetition influences truth judgments, considerably less is known about when fluency is used as information. The present research addresses this question and investigates whether reliance on fluency is moderated by learning experiences. Specifically, we focus on changes in the reliance on fluency over the course of time. A series of experiments reveals that fluency is more likely to be used in truth judgments when previous reliance on fluency has resulted in valid judgments, compared with when previous reliance on fluency was misleading. These findings suggest that reliance on fluency in judgments is a finely tuned process that takes prior experiences with fluency‐based judgments into account. Copyright © 2013 John Wiley & Sons, Ltd.     

Gut interpretations: how difficulties in emotion regulation may help explain the relation of visceral sensitivity with depression and anxiety among young adults with gastrointestinal symptoms

It is widely recognized that abdominal pain and discomfort are common problems in the United States and are often associated with negative quality of life. The prevalence of anxiety/depression elevations and disorders among persons with gastrointestinal disturbances (GI) is estimated to be at least two to three times the rate in the general population. Visceral sensitivity reflects anxiety about GI sensations and its accompanying contexts and often leads to worsening of sensations (e.g. bloating, upset stomach, diarrhea). Among individuals with GI symptoms, visceral sensitivity may be associated with interpreting common sensations as catastrophic which may be related to greater difficulties with emotion dysregulation (e.g. severe anxiety and depression). The current study evaluated the indirect association of visceral sensitivity via emotion dysregulation in relation to depression, anxious arousal, and social anxiety symptoms among 344 young adults with a current history of GI symptoms and problems. Results indicated an indirect effect of visceral sensitivity via emotion dysregulation. These findings provide novel empirical support for the association of visceral sensitivity with emotional distress symptoms among young adults with GI symptoms. Based on the results, targeting emotion dysregulation may be a promising health promotion tactic among young adults with GI symptoms and disorders.     

Women’s breast-feeding meanings in the context of mother-to-child transmission of HIV

This study explored infant feeding practice meanings of HIV-positive mothers. Informants were eight black South African mothers (age range 18–29 years) enrolled in a mother-to-child transmission (MTCT) prevention programme. In-depth interviews on factors that influence exclusive breast-feeding were conducted with the mothers. Thematic analysis of the data yielded meanings around practices of knowledge contestation with health care providers and family, work demands, and personal preferences. Moreover, successful breast-feeding by mothers with HIV status may depend on addressing contradictory messages by health workers on infant feeding and community and family pressure to mix-feed the infant children.