Interpreting cross-sectional data on stages of change

Abstract

The vast majority of studies investigating stage theories of health behaviour such as the transtheoretical model have used a cross-sectional research design. Participants are classified into stages and compared on theoretically relevant variables. This paper discusses the proper interpretation of cross-sectional data on stages of change. Linear patterns are not consistent with the stage model assumption that different causal factors are important at different stages but discontinuity patterns (patterns that do not show consistent increments or decrements across stages) can be diagnostic of a stage model. Researchers who use cross-sectional designs should specify predictions concerning the patterns to be expected under a stage model and under possible rival models, and interpret their data accordingly. Wherever possible, they should conduct prospective longitudinal and experimental studies which enable stronger inferences to be drawn.     

Predictors of interest in direct-to-consumer genetic testing

Direct-to-consumer (DTC) genetic testing is an increasingly available option among individuals searching for information about their health risk factors and ancestry. This study is one of the first to examine predictors of interest in DTC genetic testing. Participants read one of the three types of information about DTC genetic testing (positive only, negative only or both) and reported perceptions of and intentions to pursue testing. The information which people read, their perceptions of the benefits of testing, their perceptions of the barriers to testing and anticipated regret predicted intentions to undergo testing. Interestingly, people who read both positive and negative information did not differ from people who read only negative information in their intentions to pursue testing. We discuss the implications of these findings for predicting interest in this relatively new type of genetic testing and for designing interventions to encourage (or discourage) testing.     

Illness perceptions and distress in women at increased risk of breast cancer

Variation in the levels of distress in women at increased risk of breast cancer has been reported, yet there is limited understanding of the factors that are associated with heightened distress in this population. This study took a theoretical approach using Leventhal's Self Regulatory Model (SRM) to understand variation in distress levels. The study examined the associations between perceptions of breast cancer and distress in women at increased risk of breast cancer, and a comparison sample with no experience of the disease in their social environment. Questionnaire data from 117 women at increased risk of breast cancer and 100 comparison women were analysed. Women at increased risk of breast cancer showed comparable levels of general distress but significantly higher levels of cancer specific distress than the comparison group. There were few differences in illness perceptions between the samples, although a number of cognitive perceptions of breast cancer were related to both general and cancer specific distress in the increased risk sample, but not in the comparison sample. The results suggest that the SRM provides a useful framework to explore the psychological response to genetic risk. Further research is required in this population to examine illness perceptions in more detail, validate quantitative measures of illness perceptions, and examine interactions between risk perception and the SRM constructs.     

Recall initiation strategies must be controlled in training studies that use immediate free recall tasks to measure the components of working memory capacity across time

There has been great interest in using working memory (WM) training regimens as an alternative treatment for ADHD, but it has recently been concluded that existing training regimens may not be optimally designed because they target the primary memory component but not the secondary component of WM capacity. This conclusion requires the ability to accurately measure changes in primary and secondary memory abilities over time. The immediate free recall task has been used in previous studies to measure these changes; however, one concern with these tasks is that the recall order required on training exercises may influence the recall strategy used during free recall, which may in turn influence the relative number of items recalled from primary and secondary memory. To address this issue, previous training studies have explicitly controlled recall strategy before and after training. However, the necessity of controlling for recall strategies has not been explicitly tested. The present study investigated the effects of forward-serial-order training on free recall performance under conditions in which recall strategy was not controlled using a sample of adolescents with ADHD. Unlike when recall order was controlled, the main findings showed selective improvement of the secondary memory component (as opposed to the primary memory component) when recall order was uncontrolled. This finding advances our understanding of WM training by highlighting the importance of controlling for recall strategies when free recall tasks are used to measure changes in the primary and secondary components of WM across time.     

A phase-field model for deformation twinning

We propose a phase-field model for modeling microstructure evolution during deformation twinning. The order parameters are proportional to the shear strains defined in terms of twin plane orientations and twinning directions. Using a face-centered cubic Al as an example, the deformation energy as a function of shear strain is obtained using first-principle calculations. The gradient energy coefficients are fitted to the twin boundary energies along the twinning planes and to the dislocation core energies along the directions that are perpendicular to the twinning planes. The elastic strain energy of a twinned structure is included using the Khachaturyan's elastic theory. We simulated the twinning process and microstructure evolution under a number of fixed deformations and predicted the twinning plane orientations and microstructures.     

Addressing Urgent Community Mental Health Needs in Rwanda: Culturally Sensitive Training Interventions

Rwandan leaders in the health and educational sectors have begun to discuss the necessity for establishing culturally appropriate community-based mental health counselling services in Rwanda, especially trauma counselling. The need for a community psychology approach is anchored in the lingering effects of the genocide and the continuing post-traumatic stress symptoms suffered by many in the population. Capacity building in an effort like this would require the design of multi-level counselling curricula that are sensitive to the social structures within Rwandan culture. These curricular endeavours call for the development of a National Counselling Centre to serve as a structural mechanism for organizing community-based counselling initiatives. We consider the community health services needs in Rwanda here, along with associated challenges and strategies for effective mental health services in a country with a recent history of genocide. A community psychology approach to mental health would benefit Rwandan society by making trauma counselling and recovery services available and accessible to citizens throughout the country.     

Autobiographical Memory Specificity in Patients with Tinnitus Versus Patients with Depression and Normal Controls

Several studies show that patients with depression and post-traumatic stress disorder respond with fewer specific autobiographical memories in a cued memory task (i.e. the autobiographical memory test; AMT) compared to healthy controls. One previous study found this phenomenon among tinnitus patients as well (Andersson, Ingerholt, & Jansson, 2003). The aim of this study was to replicate the previous study with an additional control group of depressed patients and memory errors as measured with the AMT as an additional outcome. We included 20 normal hearing tinnitus patients, 20 healthy controls and 20 persons diagnosed with clinical depression. The AMT was administered together with self-report measures of depression, anxiety and tinnitus distress. Both the tinnitus and depression groups differed from the healthy control group in that they reported fewer specific autobiographical memories. There were, however, differences between the tinnitus and depression groups in terms of the errors made on the AMT. The depression group had more overgeneral memories than the normal control group, whereas the tinnitus group did not differ from the control group on this memory error. The tinnitus group had more semantic associations and non-memories than the other two groups, suggesting that executive functioning may play a role for the tinnitus group when completing the AMT. Clinical and theoretical implications of the findings are discussed.     

Replication and Extension of a Hierarchical Model of Social Anxiety and Depression: Fear of Positive Evaluation as a Key Unique Factor in Social Anxiety

Wang, Hsu, Chiu, and Liang (2012, Journal of Anxiety Disorders, 26, 215–224) recently proposed a hierarchical model of social interaction anxiety and depression to account for both the commonalities and distinctions between these conditions. In the present paper, this model was extended to more broadly encompass the symptoms of social anxiety disorder, and replicated in a large unselected, undergraduate sample (n = 585). Structural equation modeling (SEM) and hierarchical regression analyses were employed. Negative affect and positive affect were conceptualized as general factors shared by social anxiety and depression; fear of negative evaluation (FNE) and disqualification of positive social outcomes were operationalized as specific factors, and fear of positive evaluation (FPE) was operationalized as a factor unique to social anxiety. This extended hierarchical model explicates structural relationships among these factors, in which the higher-level, general factors (i.e., high negative affect and low positive affect) represent vulnerability markers of both social anxiety and depression, and the lower-level factors (i.e., FNE, disqualification of positive social outcomes, and FPE) are the dimensions of specific cognitive features. Results from SEM and hierarchical regression analyses converged in support of the extended model. FPE is further supported as a key symptom that differentiates social anxiety from depression.     

孤独症群体的孤岛能力

孤岛能力是个体在一般能力普遍落后的情况下某一个或几个领域表现出来的与其整体能力极不匹配的超常能力。令人惊讶的是,人类近一半的孤岛能力产自于孤独症谱系障碍。本文系统回顾了孤独症孤岛能力的特征、传统的各种心理学解释和当前最有力的认知神经科学发现:脑病理性优势假说和孤独症特质假说。在此基础上,本文认为脑优势中心的转移和混乱的大脑连接可能是孤岛能力产生的前提,而特定技能的遗传和后天的反复练习则是孤岛能力得以强化和巩固的重要因素。     

胼胝体调节大脑两半球相互作用的机制

胼胝体是哺乳动物脑内最大的白质结构,不仅可以在大脑两半球间传递信息,也能调节半球间的相互作用,“抑制模型”和“兴奋模型”是当前解释胼胝体调节机制的主要模型.前者假设,胼胝体对半球间的信息传递起抑制作用,表现为优势半球的功能增强,非优势半球的活动抑制,因而可以提高半球加工的独立性和功能不对称性;后者则认为,胼胝体对半球间信息传递起促进作用,导致两半球同时性活动,并增强其功能连接性,因而可以降低半球的功能不对称性,有利于半球间的信息共享与功能整合.近期的研究显示,胼胝体并不是一个结构与功能的单一体,而是包含了在空间与时间上既分离又互动的多通道信息加工复合体.抑制与兴奋信息可以通过胼胝体的不同空间通道以不同的速度在半球间进行传递,并受到任务计算类型与复杂性的调节,因此,胼胝体的抑制与兴奋的协同可以调节两半球的动态相互作用.