Modelling mechanisms with causal cycles

Mechanistic philosophy of science views a large part of scientific activity as engaged in modelling mechanisms. While science textbooks tend to offer qualitative models of mechanisms, there is increasing demand for models from which one can draw quantitative predictions and explanations. Casini et al. (Theoria 26(1):5–33, 2011) put forward the Recursive Bayesian Networks (RBN) formalism as well suited to this end. The RBN formalism is an extension of the standard Bayesian net formalism, an extension that allows for modelling the hierarchical nature of mechanisms. Like the standard Bayesian net formalism, it models causal relationships using directed acyclic graphs. Given this appeal to acyclicity, causal cycles pose a prima facie problem for the RBN approach. This paper argues that the problem is a significant one given the ubiquity of causal cycles in mechanisms, but that the problem can be solved by combining two sorts of solution strategy in a judicious way.     

An investigation into the effects of meditation with children in a Catholic primary school

This article reports on some findings of a small research project that examined the role of meditation in enhancing the relational lives of children, in particular, their relationship with God. It begins by discussing the literature on relevant research studies that investigate different aspects of meditation. The research method in the project was a case study that involved one Catholic primary school in the Melbourne Archdiocese. Different data collecting strategies were utilised, and this article presents and discusses the analysis and findings from one data source – the analysis and interpretation of a drawing activity which was designed to follow one of the weekly meditation exercises that had been observed by the researchers. Finally, the implications of the findings for education and, in particular, religious education are presented.     

Electrophysiological evidence for greater attention to threat when cognitive control resources are depleted

In this study, we investigated the time course of attentional bias for threat-related (angry) facial expressions under conditions of high versus low cognitive (working memory) load. Event-related potential (ERP) and reaction time (RT) data were recorded while participants viewed pairs of faces (angry paired with neutral face) displayed for 500 ms and followed by a probe. Participants were required to respond to the probe while performing a concurrent task of holding in working memory a sequence of digits that were either in the same order (low memory load) or in a random mixed order (high memory load). The ERP results revealed that higher working memory load resulted in enhanced lateralized neural responses to threatening relative to neutral faces, consistent with greater initial orienting of attention to threatening faces (early N2pc: 180–252 ms) and enhanced maintenance of processing representations of threat (late N2pc, 252–320 ms; SPCN, 320–500 ms). The ERP indices showed significant positive relationships with each other, and also with the behavioral index of attentional bias to threat (reflected by faster RTs to probes replacing angry than neutral faces at 500 ms), although the latter index was not significantly influenced by memory load. Overall, the findings indicate that depletion of cognitive control resources, using a working memory manipulation, increases the capacity of task-irrelevant threat cues to capture and hold attention.     

Recall of 9/11/01 as an Indicator of Cognitive Functioning in the Elderly

The purpose of this study was to assess the relationship between the recall of a highly salient remote event, the terrorist attack in New York City on 9/11/01, and general cognitive functioning in the elderly. A heterogeneous group (n = 93) of persons ≥65 years of age (M = 76.5, SD = 6.4), from both community and hospital settings, were asked to describe as much as they could remember about the events of 9/11/01 in New York City. The number of correct factual details, affective or emotional responses, and incorrect details were recorded. Ten multiple choice questions were then administered to assess recognition of the 9/11 events (M = 9.1 items correct, SD = 1.2). The mini mental state exam (MMSE) was also administered (M = 26.3, SD = 3.4). Participants generated a mean of 4.8 (SD = 3) correct factual details about 9/11, 1.1 affective/emotional responses (SD = 1.1), and 0.22 incorrect recollections (SD = 0.46). Significant correlations (p &;lt; .01) were found between correct details recalled and the MMSE (0.42), education (0.37), and age (?0.31). A significant negative correlation (p &;lt; .01) was found between incorrect details recalled and MMSE scores (?0.38). Female participants generated significantly more affective responses than males (M = 1.3 vs. 0.51; p &;lt; .001) but recall of correct details was equivalent. The recall of 9/11 events, approximately 18 months after the incident, appears related to general mental status, education, and age. Responses to this question may be helpful in assessing the mental status of the elderly. In addition, now that objective memory data has been established, recall of this event by other samples of seniors can be monitored over time to determine the cognitive processes related to the storage and retrieval of this unique and tragic event.     

Health anxiety,anxiety sensitivity,and attentional biases for pictorial and linguistic health‐threat cues

The study investigated attentional biases for pictorial and linguistic health‐threat stimuli in high and low health anxious individuals, who were selected from the upper and lower quartile ranges of a normal sample using a screening measure of health anxiety. Attentional bias was assessed using a visual probe task which presented health‐threat and neutral pictures and words at two exposure durations, 500 ms and 1250 ms. The prediction that the high health anxious group would show a greater attentional bias for health‐threat cues than the low health anxious group was not supported despite the groups being well‐differentiated on a general measure of health anxiety, the Illness Attitudes Scale (IAS). Instead, the results indicated that individuals with high levels of anxiety sensitivity showed a significantly greater initial attentional bias for threat pictures compared with those with low anxiety sensitivity, as assessed by the Anxiety Sensitivity Index (ASI).     

Gender differences in smoking: A longitudinal study of beliefs predicting smoking in 11–15 year olds

This longitudinal study investigated differences in beliefs and perceived behavioural control between smokers and non-smokers in a large sample of adolescents. Positive and negative instrumental beliefs, normative beliefs, perceived behavioural control (PBC) and smoking status were assessed in the same participants at 11, 13 and 15 years of age. Prospective analyses among non-smokers revealed that for boys, negative instrumental beliefs in non-smokers at age 11 predicted smoking at age 15 years. For girls, normative beliefs and PBC in non-smokers at age 11 predicted smoking status at age 13; normative beliefs at age 11 predicted smoking at age 15; and positive instrumental beliefs and normative beliefs at age 13 predicted smoking status at age 15. Cross-sectional data revealed that smokers were significantly more likely than non-smokers to endorse positive instrumental beliefs, less likely to agree with negative instrumental belief items, more likely than non-smokers to perceive social pressure to smoke, and less likely to report control over smoking, and that female smokers reported less control over smoking and fewer negative instrumental beliefs than all other groups including male smokers at age 13. The need for belief-based preventative interventions that are age- and gender-relevant is discussed.