Induction and HIV-Associated Neurocognitive Disorders

Antiretroviral medication has improved HIV-related prognosis. Yet HIV-associated neurocognitive disorders (HAND) have substantially increased, leading to decreased quality of life, increased illness severity and mortality. In the research literature, executive dysfunction (e.g. planning difficulties and cognitive inflexibility) has been identified as prominent in HAND, but there has been little analysis of the componential and qualitative aspects underpinning these deficits. Targeted and theory-driven neurorehabilition for HAND is limited due to the lack of this type of detailed information. This study aimed to explore whether induction, a key aspect of executive function, is impaired in HAND, and if so, the underpinning processes causing impairment. Thirteen participants with HAND and thirteen HIV-negative participants were matched for gender, age, education and reading ability. The HAND population were assessed for current functioning, and compared to the control group on verbal and non-verbal tests of induction. Qualitative analysis was used to derive a componential scoring system for the Brixton Spatial Anticipation Test (non-verbal measure of induction) to qualitatively and quantitatively characterise performance in the HAND group compared to the non-clinical sample. Results suggest that induction is impaired in HAND. However, initial rule detection appears spared. Processes such as slowed information processing, and lapses in attention and working memory affected induction across the HAND group. Other deficits appeared idiosyncratically: accordingly, no single profile of impairment was identified. This study showed that taking simple measures of executive function at face value does not provide an accurate description of individual performance in HAND. The results are interpreted in the context of a need for componential analyses of neuropsychological tests, generally in research and when interpreting scores in practic

A facial expression for anxiety.

Anxiety and fear are often confounded in discussions of human emotions. However, studies of rodent defensive reactions under naturalistic conditions suggest anxiety is functionally distinct from fear. Unambiguous threats, such as predators, elicit flight from rodents (if an escape-route is available), whereas ambiguous threats (e.g., the odor of a predator) elicit risk assessment behavior, which is associated with anxiety as it is preferentially modulated by anti-anxiety drugs. However, without human evidence, it would be premature to assume that rodent-based psychological models are valid for humans. We tested the human validity of the risk assessment explanation for anxiety by presenting 8 volunteers with emotive scenarios and asking them to pose facial expressions. Photographs and videos of these expressions were shown to 40 participants who matched them to the scenarios and labeled each expression. Scenarios describing ambiguous threats were preferentially matched to the facial expression posed in response to the same scenario type. This expression consisted of two plausible environmental-scanning behaviors (eye darts and head swivels) and was labeled as anxiety, not fear. The facial expression elicited by unambiguous threat scenarios was labeled as fear. The emotion labels generated were then presented to another 18 participants who matched them back to photographs of the facial expressions. This back-matching of labels to faces also linked anxiety to the environmental-scanning face rather than fear face. Results therefore suggest that anxiety produces a distinct facial expression and that it has adaptive value in situations that are ambiguously threatening, supporting a functional, risk-assessing explanation for human anxiet

Social validity of randomised controlled trials in health services research and intellectual disabilities: a qualitative exploration of stakeholder views

<p>Abstract</p> <p>Background</p> <p>Randomised controlled trials (RCTs) are the gold standard of evidence-based practice in medicine but they have had limited influence in the field of intellectual disabilities. Previous literature suggests that participants and professionals have limited tolerance for this type of research methodology. However, it is not known how well service users, carers and other health professionals understand and accept the need for RCTs, and why it is important for individuals with intellectual disabilities to be included in this kind of research.</p> <p>Methods</p> <p>We examined individual perceptions of RCTs in 51 participants (18 carers, 6 service users and 27 professionals) using semi-structured interviews. A framework approach was adopted in the analysis of data.</p> <p>Results</p> <p>We found that participants had concerns about capacity and resource allocation but held positive views towards this type of research methodology. Understanding of the principles behind RCTs was poor amongst service users and a minority of carers, but mediated by previous exposure to research for professionals.</p> <p>Conclusions</p> <p>The social validity of RCTs in intellectual disabilities may be compromised by lack of understanding of the design and the on-going concerns about obtaining informed consent especially in incapacitated adults. However, the overall finding that the need for this form of research was seen in a positive light suggests that there is a turning point in the perceptions of stakeholders working in intellectual disabilities services. We recommend that researchers include on-going education on RCT design during trials, tailoring it to all stakeholders with emphasis on strong service user and care involvement. This could be a pivotal element in improving acceptability of, and recruitment to RCTs.</p