Functional and connectivity changes during working memory in Huntington’s disease: 18 month longitudinal data from the IMAGE-HD study

Background

This study aimed to characterize, for the first time, 18 month longitudinal changes in both functional activation and functional connectivity during working memory in premanifest Huntington’s disease (pre-HD) and symptomatic HD (symp-HD).

Methods

Functional magnetic resonance imaging (fMRI) was used to investigate longitudinal changes in neuronal activity during working memory performance via an N-BACK task (0-BACK and 1-BACK) in 27 pre-HD, 17 symp-HD, and 23 control participants. Whole-brain analysis of activation and region-of-interest analysis of functional connectivity was applied to longitudinal fMRI data collected at baseline and 18 months follow-up.

Results

Compared with controls, the pre-HD group showed significantly increased activation longitudinally during 1-BACK versus 0-BACK in the lateral and medial prefrontal, anterior cingulate, primary motor, and temporal areas cortically, and caudate and putamen subcortically. Pre-HD far from onset, compared with controls, showed further longitudinal increases in the right and left dorsolateral prefrontal cortex (DLPFC). Longitudinal increased activation in anterior cingulate and medial primary motor areas were associated with disease burden in the pre-HD group. Moreover, in pre-HD increased activation over time in primary motor and putamen regions were associated with average response time during 1-BACK performance. During 1-BACK, functional connectivity between the right DLPFC and posterior parietal, anterior cingulate, and caudate was significantly reduced over 18 months only in the pre-HD group.

Conclusions

Longitudinal reductions in connectivity over 18 months may represent an early signature of cortico-cortical and cortico-striatal functional disconnectivity in pre-HD, whereas the concomitant increased cortical and subcortical activation may reflect a compensatory response to the demands for cognitive resources required during task performance. Our findings demonstrate that functional imaging modalities have the potential to serve as sensitive methods for the assessment of cortical and subcortical responses to future treatment measures.     

Regulation of brain activity in the fusiform face and parahippocampal place areas in 7–11-year-old children

Developmental studies have demonstrated that cognitive processes such as attention, suppression of interference and memory develop throughout childhood and adolescence. However, little is currently known about the development of top-down control mechanisms and their influence on cognitive performance. In the present study, we used functional magnetic resonance imaging to investigate modulation of activity in the ventral visual cortex in healthy 7–11-year-old children and young adults. The participants performed tasks that required attention to either face (Fs task) or scene (Sf task) images while trying to ignore distracting scene or face images, respectively. A face-selective area in the fusiform gyrus (fusiform face area, FFA) and an area responding preferentially to scene images in the parahippocampal gyrus (parahippocampal place area, PPA) were defined using functional localizers. Children responded slower and less accurately in the tasks than adults. In children, the right FFA was less selective to face images and regulation of activity between the Fs and Sf tasks was weaker compared to adults. In the PPA, selectivity to scenes and regulation of activity, there according to the task demands were comparable between children and adults. During the tasks, children activated prefrontal cortical areas including the middle (MFG) and superior (SFG) frontal gyrus more than adults. Functional connectivity between the right FFA and left MFG was stronger in adults than children in the Fs task. Children, on the other hand, had stronger functional connectivity than adults in the Sf task between the right FFA and right PPA and between right MFG and medial SFG. There were no group differences in the functional connectivity between the PPA and the prefrontal cortex (PFC). Together the results suggest that, in 7–11-year-old children, the FFA is still immature, whereas the selectivity to scenes and regulation of activity in the PPA is comparable to adults. The results also indicated functional immaturity of the PFC in children compared to adults and weaker connectivity between the PFC and the rFFA, explaining the weaker regulation of activity in the rFFA between the Fs and Sf tasks.     

Adherence to pharmacological treatment of non-malignant chronic pain: The role of illness perceptions and medication beliefs

The objective was to identify the degree to which illness perceptions and medication beliefs explain variations in reported adherence to medication prescribed for the treatment of non-malignant chronic pain and to test the applicability of an extended version of the self-regulatory model to the chronic pain population. A cross-sectional design included 217 clinic patients completing validated questionnaires assessing their illness perceptions, medication beliefs and reported adherence to medication. Perceptions of illness (pain) as chronic, uncontrollable and unremitting were associated with greater adherence, fewer medication concerns and a belief that treatment was necessary. Structural equation modelling supports an extended SRM for chronic pain. It suggests that patients holding perceptions of serious consequences of pain and high emotion levels have more concerns about medication and are less adherent. Perceptions of serious illness consequences are also associated with stronger beliefs about the necessity of medicines and greater adherence. Beliefs about illness and medication are associated with adherence to treatment in chronic pain and this can be explained by an extended SRM. Results are preliminary and require replication. Further studies should explore the role that emotion has on coping strategies in chronic pain. Interventions should focus on altering unhelpful beliefs that reduce adherence.     

Are smokers interested in genetic testing for smoking addiction? A socio-cognitive approach

Genetic advances have made genetically tailored smoking cessation treatments possible. In this study, we examined whether smokers are interested in undergoing a genetic test to identify their genetic susceptibility to nicotine addiction. In addition, we aimed to identify socio-cognitive determinants of smokers’ intention to undergo genetic testing. Following the protection motivation theory (PMT), we assessed the following constructs using an online survey among 587 smokers: threat appraisal (i.e. susceptibility and severity), fear, coping appraisal (i.e. response efficacy and self-efficacy), response costs and intention. In addition, knowledge, social norms and information-seeking behaviour were measured. Mean intention rates were 2.57 on a 5-point scale. Intention was significantly associated with threat appraisal and coping appraisal, as predicted by the PMT. Fear of the outcome was negatively associated with the intention to undergo genetic testing, but response costs, knowledge and social influence were not. Intention to undergo genetic testing in turn was positively related to seeking information about genetic testing and genetically tailored smoking cessation treatments. Smokers seem ambivalent or ‘on the fence’ with regard to undergoing a genetic test for smoking addiction. Socio-cognitive concepts such as susceptibility, severity, response efficacy and self-efficacy may be used to inform or educate smokers about the value of genetically tailored smoking cessation treatments.     

Narrowing the Creativity Gap: The Moderating Effects of Perceived Support for Creativity

This article examines the role of 3 types of perceived support for creativity in moderating the relation between creative self-efficacy and self-perceived creativity. The findings suggest significant interaction effects for perceived work-group support and supervisor support, but not for perceived organizational support. This study is among the first to (a) examine the importance of perceived support for creativity in unlocking creative potential and increasing creativity in organizations and (b) use interaction terms in structural equation modeling (SEM) to investigate moderator effects in an applied research setting. These results imply that organizational interventions focused on training supervisors and work-group members to support creativity in the workplace may be more effective than broader and less focused interventions at the organizational level.     

A Computationally More Efficient and More Accurate Stepwise Approach for Correcting for Sampling Error and Measurement Error

Over the last decade or two, multilevel structural equation modeling (ML-SEM) has become a prominent modeling approach in the social sciences because it allows researchers to correct for sampling and measurement errors and thus to estimate the effects of Level 2 (L2) constructs without bias. Because the latent variable modeling software Mplus uses maximum likelihood (ML) by default, many researchers in the social sciences have applied ML to obtain estimates of L2 regression coefficients. However, one drawback of ML is that covariance matrices of the predictor variables at L2 tend to be degenerate, and thus, estimates of L2 regression coefficients tend to be rather inaccurate when sample sizes are small. In this article, I show how an approach for stabilizing covariance matrices at L2 can be used to obtain more accurate estimates of L2 regression coefficients. A simulation study is conducted to compare the proposed approach with ML, and I illustrate its application with an example from organizational research.     

Models for the Detection of Deviations from the Expected Processing Strategy in Completing the Items of Cognitive Measures

This paper presents confirmatory factor models with fixed factor loadings that enable the identification of deviations from the expected processing strategy. The instructions usually define the expected processing strategy to a considerable degree. Simplification is a deviation from instructions that is likely to occur in complex cognitive measures. Since simplification impairs the validity of the measure, its identification is important. Models representing simplicity and instruction-based processing strategies were considered in investigating the data of 345 participants obtained by a working memory measure in order to find out whether and how the use of these strategies influences model-data fit. As expected, the consideration of simplicity strategies improved the model-data fit achieved for the instruction-based strategy.     

The Appeal of Personal Selling as a Career: A Decade Later

While students' attitudes and perceptions toward personal selling as a career have been discussed at length, the literature reflects remarkably little effort to understand students' preferences for sales careers. The authors synthesize extant knowledge on the subject and extend the knowledge base by conducting a time-series replication of an earlier study and by examining the relative importance of marketing-related career characteristics. Managerial implications of this research are discussed.     

Alcohol-specific parenting,adolescent alcohol use and the mediating effect of adolescent alcohol-related cognitions

Objectives : Previous research indicated that alcohol-specific parenting is an important precursor of adolescent alcohol use, but failed to define the underlying mechanism. Based on social cognitive theory, alcohol-related cognitions such as alcohol refusal self-efficacy and alcohol-related expectancies were hypothesised to mediate this link.

Design : A cross-sectional survey included 1349 mothers and their sixth grade (11–12?years old) adolescent offspring. Structural equation modelling was employed to test the association between alcohol-specific parenting and adolescent alcohol use, mediated by adolescent alcohol-related cognitions.

Main outcome measures : Adolescent alcohol use, drinking refusal self-efficacy and alcohol expectancies.

Results : The associations between frequency of communication, maternal alcohol use and adolescent alcohol use were mediated by negative alcohol-related expectancies. The associations between quality of communication, rules and disclosure and adolescent alcohol use were mediated by self-efficacy.

Conclusions : The present study provides a first indication that the underlying mechanism of the association between the most important alcohol-specific parenting practices and adolescent alcohol use can be contributed to the mediating effect of alcohol-refusal self-efficacy.