Brain Networks in Schizophrenia

Schizophrenia—a severe psychiatric condition characterized by hallucinations, delusions, loss of initiative and cognitive function—is hypothesized to result from abnormal anatomical neural connectivity and a consequent decoupling of the brain’s integrative thought processes. The rise of in vivo neuroimaging techniques has refueled the formulation of dysconnectivity hypotheses, linking schizophrenia to abnormal structural and functional connectivity in the brain at both microscopic and macroscopic levels. Over the past few years, advances in high-field structural and functional neuroimaging techniques have made it increasingly feasible to reconstruct comprehensive maps of the macroscopic neural wiring system of the human brain, know as the connectome. In parallel, advances in network science and graph theory have improved our ability to study the spatial and topological organizational layout of such neural connectivity maps in detail. Combined, the field of neural connectomics has created a novel platform that provides a deeper understanding of the overall organization of brain wiring, its relation to healthy brain function and human cognition, and conversely, how brain disorders such as schizophrenia arise from abnormal brain network wiring and dynamics. In this review we discuss recent findings of connectomic studies in schizophrenia that examine how the disorder relates to disruptions of brain connectivity.     

HIV voluntary counselling and testing among recently initiated and traditionally circumcised men in the Eastern Cape Province of South Africa

HIV voluntary counselling and testing (VCT) is a cornerstone of the national strategic plan for HIV/AIDS treatment, care and support in South Africa. However, research shows that the utilisation of VCT services is disappointingly low, particular among males. This article focuses on the factors associated with the intention to test for HIV-infection among recently initiated and traditionally circumcised men in the rural areas of Eastern Cape Province, South Africa. Individual face-to-face interviews were conducted among 1656 sexually active men. Logistic regression analyses were used to explore the association between intention to test for HIV and psychosocial factors. Overall, 35.1% of the participants reported ever having tested for HIV. Intention to test for HIV was positively associated with perceived probability of getting an STI, positive attitudes towards gender-based violence, received general teachings about being a responsible man and highest grade passed. These findings provide specific information that can be used in the development of a focused cultural sensitive STI/HIV prevention programme aimed to increase VCT uptake among sexually active young men, which can be integrated into initiation and health education practices.     

Self-control depletion and sleep duration: the mediating role of television viewing

Abstract

Objective: Sleep insufficiency has been related to self-control failure: people fail to go to bed in time and end up sleep deprived. The role of state self-control in predicting bedtime and sleep duration has not yet been investigated. Based on research claiming an overlap between depleted self-control resources and fatigue, self-control depletion may foster earlier bedtimes. Conversely, self-control depletion also increases the propensity to procrastinate bedtime by giving in to the immediate gratification of late night entertainment. This study therefore looked at procrastinatory television viewing and its intermediary role in the association between state self-control and bedtime. The implications for sleep duration are examined. Design: Firstyear students (N = 234) participated in an online survey. Using Day Reconstruction Method, they charted their activities and experiences during the preceding day and subsequent bedtime behavior. Results: Self-control depletion was directly related to earlier bedtimes, which we explained by its similarity to fatigue. This was associated with longer sleep duration. Self-control depletion was indirectly related to later bedtimes because it increased the propensity to procrastinate by watching television. This was associated with shorter sleep duration. Conclusion: This study exposes a dual pathway between self-control depletion and sleep duration, whereby procrastinatory television viewing may reduce sleep duration.     

From a single-level analysis to a multilevel analysis of single-case experimental designs

Multilevel modeling provides one approach to synthesizing single-case experimental design data. In this study, we present the multilevel model (the two-level and the three-level models) for summarizing single-case results over cases, over studies, or both. In addition to the basic multilevel models, we elaborate on several plausible alternative models. We apply the proposed models to real datasets and investigate to what extent the estimated treatment effect is dependent on the modeling specifications and the underlying assumptions. By considering a range of plausible models and assumptions, researchers can determine the degree to which the effect estimates and conclusions are sensitive to the specific assumptions made. If the same conclusions are reached across a range of plausible assumptions, confidence in the conclusions can be enhanced. We advise researchers not to focus on one model but conduct multiple plausible multilevel analyses and investigate whether the results depend on the modeling options.     

The Importance of Written Information Packages in Support of Case-Finding Within Families at Risk for Inherited High Cholesterol

Inherited High Cholesterol is treatable, but highly underdiagnosed. To detect undiagnosed blood relatives at a presymptomatic stage, in the Netherlands written information packages are available to facilitate family communication. To investigate the role of those packages in the detection of carriers, we conducted a qualitative evaluation (plus-minus method combined with semistructured interviews with index patients and relatives). Our data suggest that interviewees approved the family approach for finding carriers, although reluctantly. The packages aided family disclosure by reducing hesitation. However, index patients only informed first-degree relatives and generally communicated the risk only once. This may be due to the cultural context and a limited understanding of genetics. For relatives the packages served as a cue to action and as a legitimation to gain access to a diagnostic cholesterol test. Despite the value of these written materials, they should not be used as the only communication between index patient and relatives.     

Automatic negative evaluation of suffocation sensations in individuals with suffocation fear

The current study tested whether "suffocation sensations" (respiratory loads) are automatically evaluated in a negative way by people fearing these sensations. It was found that, after having been primed with a slight respiratory load, participants with high suffocation fear (n=15) reacted more quickly to suffocation words and more slowly to positive words than participants with low suffocation fear (n=21). However, the effect was present only in participants who had noticed the primes. The findings are relevant to the cognitive model of panic disorder because automatic negative appraisal of sensations may play a role in initiating a panic attack.     

The computational implementation of the landscape model: Modeling inferential processes and memory representations of text comprehension

The complexity of text comprehension demands a computational approach to describe the cognitive processes involved. In this article, we present the computational implementation of the landscape model of reading. This model captures both on-line comprehension processes during reading and the off-line memory representation after reading is completed, incorporating both memory-based and coherence-based mechanisms of comprehension. The overall architecture and specific parameters of the program are described, and a running example is provided. Several studies comparing computational and behavioral data indicate that the implemented model is able to account for cycle-by-cycle comprehension processes and memory for a variety of text types and reading situations.     

Media exposure, mood, and body image dissatisfaction: an experimental test of person versus product priming

In the current study, 138 college females were randomly assigned to four media exposure conditions based on the presence or absence of an attractive person (fashion model) and the presence or absence of an appearance-related product. Outcome measures consisted of visual analogue ratings of multiple body image and mood variables. The results revealed a significant main effect for person, indicating that the presence of a model increased levels of body dissatisfaction and negative mood. No product effect emerged and there was no significant interaction between person and product. These findings suggest that the appearance priming effect of media exposure on body dissatisfaction and mood is specific to a person stimulus, with no additional effect promoted by a generic appearance-relevant stimulus.     

Brief report: Teaching persons with moderate mental retardation to use printed instructions and time cues in a work context

Printed instructions and programable watches were used for helping two adults with moderate mental retardation perform variable tasks and follow a time schedule for task execution. The subjects, who could not read, were to match the words appearing in instruction notes to identical words superimposed on illustrative pictures (and collected in a vocabulary form). The pictures identified through this matching explained the meaning of the words being matched (i.e., indicated to the subjects which responses/tasks to perform). Self-recording was also used. The results showed that both subjects learned to use the printed instructions and the watches successfully. The subjects' performance remained positive over time. Procedural aspects and practical implications of the study are discussed.     

Locus of control and adjustment to cancer

The English form of the Cancer Locus of Control Scale was administered to an heterogeneous sample of 68 cancer patients. A principal components analysis confirmed the three subscales described in the original Dutch form, however, with five items excluded. Correlations with other measures indicated that high internal control over the course of the illness was associated with a tendency to adopt an attitude toward cancer of 'fighting spirit' whereas high internal control over the cause of the illness was associated with an 'anxious preoccupation' about cancer. No specific relationship was found between scale scores and either depression and anxiety or the tendency to be emotionally controlled. It was concluded that the scale provides a valid measure of perceptions of control of cancer patients and is a useful method of assessing these important psychological responses.