The role of body image and self‐perception in anorexia nervosa: the neuroimaging perspective

Anorexia nervosa is a severe psychiatric illness characterized by intense fear of gaining weight, relentless pursuit of thinness, deep concerns about food and a pervasive disturbance of body image. Functional magnetic resonance imaging tries to shed light on the neurobiological underpinnings of anorexia nervosa. This review aims to evaluate the empirical neuroimaging literature about self‐perception in anorexia nervosa. This narrative review summarizes a number of task‐based and resting‐state functional magnetic resonance imaging studies in anorexia nervosa about body image and self‐perception. The articles listed in references were searched using electronic databases (PubMed and Google Scholar) from 1990 to February 2016 using specific key words. All studies were reviewed with regard to their quality and eligibility for the review. Differences in brain activity were observed using body image perception and body size estimation tasks showing significant modifications in activity of specific brain areas (extrastriate body area, fusiform body area, inferior parietal lobule). Recent studies highlighted the role of emotions and self‐perception in anorexia nervosa and their neural substrate involving resting‐state networks and particularly frontal and posterior midline cortical structures within default mode network and insula. These findings open new horizons to understand the neural substrate of anorexia nervosa.     

Crossmodal object-based attention: auditory objects affect visual processing

According to the object-based view, visual attention can be deployed to "objects" or perceptual units, regardless of spatial locations. Recently, however, the notion of object has also been extended to the auditory domain, with some authors suggesting possible interactions between visual and auditory objects. Here we show that task-irrelevant auditory objects may affect the deployment of visual attention, providing evidence that crossmodal links can also occur at an object-based level. Hence, in addition to the well documented control of visual objects over what we hear, our findings demonstrate that, in some cases, auditory objects can affect visual processing.     

Democratic School Climate and Sense of Community in School: A Multilevel Analysis

This study examines individual- and school-level predictors of sense of community in school among adolescents. Hierarchical linear modeling was used to examine the relationships between individual (demographics, control and monitoring by parents, and perception of democratic school climate), class, and school characteristics (mean democratic school climate, demographics, activities, school size, public/private governance of the school, and facilities) and students' sense of community in the school. Data were analyzed using a three-level model based on 4,092 10- to 18-year-old students nested within 248 classes (across three grade levels: 6th, 8th, and 10th grade level, where the median age was 11, 13, and 15, respectively) in 134 schools in the Veneto region of northeast Italy. Individual and contextual measures of the perception of a democratic school climate, modeled at the individual, class, and school levels simultaneously, were each significant predictor of school sense of community. More parental monitoring and less parental control were also predictive at the individual level. School-level SES predicted between school variation in sense of community, controlling for individual student SES and other student and school-level predictors. School size, facilities (physical spaces resources), level of interaction of the school with the community, public, or private governance, and number of extracurricular activities offered were all nonsignificant. The study demonstrates significant variation in school sense of community at the student, class, and school levels and the important role played by democratic school practices, such as student participation in making rules and organizing events, freedom of expression, and the perceived fairness of rules and teachers, in determining this variable.     

Foreground–background segmentation and attention: A change blindness study

One of the most debated questions in visual attention research is what factors affect the deployment of attention in the visual scene? Segmentation processes are influential factors, providing candidate objects for further attentional selection, and the relevant literature has concentrated on how figure–ground segmentation mechanisms influence visual attention. However, another crucial process, namely foreground–background segmentation, seems to have been neglected. By using a change blindness paradigm, we explored whether attention is preferentially allocated to the foreground elements or to the background ones. The results indicated that unless attention was voluntarily deployed to the background, large changes in the color of its elements remained unnoticed. In contrast, minor changes in the foreground elements were promptly reported. Differences in change blindness between the two regions of the display indicate that attention is, by default, biased toward the foreground elements. This also supports the phenomenal observations made by Gestaltists, who demonstrated the greater salience of the foreground than the background.     

Stability of heartbeat interval distributions in chronic high altitude hypoxia.

Recent studies of nonlinear dynamics of the long-term variability of heart rate have identified nontrivial long-range correlations and scale-invariant power-law characteristics (l/f noise) that were remarkably consistent between individuals and were unrelated to external or environmental stimuli (Meyer et al., 1998a). The present analysis of complex nonstationary heartbeat patterns is based on the sequential application of the wavelet transform for elimination of local polynomial nonstationary behavior and an analytic signal approach by use of the Hilbert transform (Cumulative Variation Amplitude Analysis). The effects of chronic high altitude hypoxia on the distributions and scaling functions of cardiac intervals over 24 hr epochs and 4 hr day/nighttime subepochs were determined from serial heartbeat interval time series of digitized 24 hr ambulatory ECGs recorded in 9 healthy subjects (mean age 34 yrs) at sea level and during a sojourn at high altitude (5,050 m) for 34 days (Ev-K2-CNR Pyramid Laboratory, Sagarmatha National Park, Nepal). The results suggest that there exists a hidden, potentially universal, common structure in the heterogeneous time series. A common scaling function with a stable Gamma distribution defines the probability density of the amplitudes of the fluctuations in the heartbeat interval time series of individual subjects. The appropriately rescaled distributions of normal subjects at sea level demonstrated stable Gamma scaling consistent with a single scaled plot (data collapse). Longitudinal assessment of the rescaled distributions of the 24 hr recordings of individual subjects showed that the stability of the distributions was unaffected by the subject's exposure to a hypobaric (hypoxic) environment. The rescaled distributions of 4 hr subepochs showed similar scaling behavior with a stable Gamma distribution indicating that the common structure was unequivocally applicable to both day and night phases and, furthermore, did not undergo systematic changes in response to high altitude. In contrast, a single function stable over a wide range of time scales was not observed in patients with congestive heart failure or patients after cardiac transplantation. The functional form of the scaling in normal subjects would seem to be attributable to the underlying nonlinear dynamics of cardiac control. The results suggest that the observed Gamma scaling of the distributions in healthy subjects constitutes an intrinsic dynamical property of normal heart function that would not undergo early readjustment or late acclimatization to extrinsic environmental physiological stress, e.g., chronic hypoxia.     

Stability of heartbeat interval distributions in chronic high altitude hypoxia

Recent studies of nonlinear dynamics of the long-term variability of heart rate have identified nontrivial long-range correlations and scale-invariant power-law characteristics (1/f noise) that were remarkably consistent between individuals and were unrelated to external or environmental stimuli (Meyer et al., 1998a). The present analysis of complex nonstationary heartbeat patterns is based on the sequential application of the wavelet transform for elimination of local polynomial nonstationary behavior and an analytic signal approach by use of the Hilbert transform (Cumulative Variation Amplitude Analysis). The effects of chronic high altitude hypoxia on the distributions and scaling functions of cardiac intervals over 24 hr epochs and 4 hr day/nighttime subepochs were determined from serial heartbeat interval time series of digitized 24 hr ambulatory ECGs recorded in 9 healthy subjects (mean age 34 yrs) at sea level and during a sojourn at high altitude (5,050 m) for 34 days (Ev-K2-CNR Pyramid Laboratory, Sagarmatha National Park, Nepal). The results suggest that there exists a hidden, potentially universal, common structure in the heterogeneous time series. A common scaling function with a stable Gamma distribution defines the probability density of the amplitudes of the fluctuations in the heartbeat interval time series of individual subjects. The appropriately rescaled distributions of normal subjects at sea level demonstrated stable Gamma scaling consistent with a single scaled plot (data collapse). Longitudinal assessment of the rescaled distributions of the 24 hr recordings of individual subjects showed that the stability of the distributions was unaffected by the subject’s exposure to a hypobaric (hypoxic) environment. The rescaled distributions of 4 hr subepochs showed similar scaling behavior with a stable Gamma distribution indicating that the common structure was unequivocally applicable to both day and night phases and, furthermore, did not undergo systematic changes in response to high altitude. In contrast, a single function stable over a wide range of time scales was not observed in patients with congestive heart failure or patients after cardiac transplantation. The functional form of the scaling in normal subjects would seem to be attributable to the underlying nonlinear dynamics of cardiac control. The results suggest that the observed Gamma scaling of the distributions in healthy subjects constitutes an intrinsic dynamical property of normal heart function that would not undergo early readjustment or late acclimatization to extrinsic environmental physiological stress, e.g., chronic hypoxia.     

Ever since language and learning: afterthoughts on the Piaget-Chomsky debate

The central arguments and counter-arguments presented by several participants during the debate between Piaget and Chomsky at the Royaumont Abbey in October 1975 are here reconstructed in a particularly concise chronological and “logical” sequence. Once the essential points of this important exchange are thus clearly laid out, it is easy to witness that recent developments in generative grammar, as well as new data on language acquisition, especially in the acquisition of pronouns by the congenitally deaf child, corroborate the “language specificity” thesis defended by Chomsky. By the same token these data and these new theoretical refinements refute the Piagetian hypothesis that language is constructed upon abstractions from sensorimotor schemata. Moreover, in the light of modern evolutionary theory, Piaget's basic assumptions on the biological roots of cognition, l language and learning turn out to be unfounded. In hindsight, all this accrues to the validity of Fodor's seemingly “paradoxical” argument against “learning” as a transition from “less” powerful to “more” powerful conceptual systems.     

HIV infection and drug users: Setting up support groups

The emergence of Human Immunodeficiency Virus (HIV) infection has highlighted the need for the development of risk reduction strategies among drug users. A network of support and self help, whilst fully developed among gay men, has been slow to develop with drug users. Possible reasons for this are examined. Examples of this type of approach in Britain and other countries are reviewed. The positive aspects of encouraging the development of self help groups are discussed. The lesons learned from the first 6 months of a drug users support group are described.     

Cross-modal attentional deficits in processing tactile stimulation

In order to substantiate recent theorization on the possible links between the causes of the attentional blink and the psychological refractory period phenomena (e.g., Jolicoeur, 1999a), four experiments are reported in which two target stimuli, T₁ and T₂, were presented in different modalities at varying stimulus onset asynchronies (SOAs), with each stimulus being associated with a distinct task, Task₁ and Task₂. In Experiment 1, T₁ was a tone, and Task₁ was a speeded vocal response based on pitch. T₂ was a brief press applied to either of two distal fingerpads, and Task₂ was a speeded manual response based on tactile stimulus location. In Experiment 2, the same T₁ as that used in Experiment 1 was presented, and in Task₁ the subject either made a speeded vocal response based on pitch or ignored T₁. T₂ was a masked tactile stimulation, and Task₂ was an unspeeded manual discrimination of the tactile stimulation location. This Task₂ was maintained in Experiments 3 and 4. The auditory T₁ was replaced with a white digit embedded in a rapid serial visualization presentation of a stream of black letters, and in Task₁ the subject either made an unspeeded decision based on T₁ identity or ignored T₁. In all the experiments, the results showed an SOA-locked impairment in Task₂. As SOA was decreased, reaction times in the speeded Task₂ of Experiment 1 increased, and accuracy in the unspeeded Task₂ of Experiments 2–4 decreased. The SOA-locked impairment was almost eliminated when T₁ could be ignored or was absent. The results are discussed in terms of central processing limitations as the cause of such effects.