Understanding memory impairment with memory models and hierarchical Bayesian analysis

The study of human episodic memory is a topic that interests cognitive and mathematical psychologists as well as clinicians interested in the diagnosis and assessment of Alzheimer’s disease and related disorders (ADRD). In this paper, we use simple cognitive models for the recognition and recall tasks typically applied in clinical assessments of ADRD to study memory performance in ADRD patients. Our models make use of hierarchical Bayesian methods as a way to model individual differences in patient performance and to facilitate the modeling of performance changes that occur during multiple recall tasks. We show how the models are able to account for different aspects of patient performance, and also discuss some of the predictive capabilities of the model. We conclude with a discussion on the scope to improve on our results by discussing the link between memory theory in psychology and clinical practice.     

The Owl and the Ostrich: Reply to Sami Pihlström on Ethical Unthinkabilities and Philosophical Seriousness

Sami Pihlström argues in his “Ethical Unthinkabilities and Philosophical Seriousness” that there are some philosophical views that are so dangerous that we should not discuss them. He advances this argument with special reference to my (anti‐natalist) view that being brought into existence is always a serious harm. In response I argue: (a) that there are major flaws in his argument for the conclusion that we should not think about (purportedly) unthinkable views; and (b) that my views about the harm of coming into existence are in any event neither unthinkable nor dangerous.     

The Impact of Neighborhood Factors on the Well-Being of Survivors of Intimate Partner Violence Over Time

Intimate partner violence (IPV) is a pervasive social problem impacting the psychological well-being of millions of US women annually. The extant literature draws our attention to the devastating mental health effects of IPV, but largely overlooks how ecological factors may further explain survivors' well-being. This study examined how neighborhood disadvantage may contribute to survivors' compromised well-being, in addition to the abuse women experienced. Neighborhood disorder and fear of victimization significantly impacted survivors' well-being, over and above abuse. Although between-women effects of neighborhood disorder and fear were unrelated to change in women's depression or quality of life (QOL), significant within-woman effects were detected. Change in neighborhood disorder was negatively associated with change in QOL, and this relationship was fully mediated by fear. While no direct relationship between change in neighborhood disorder and depression was detected, an indirect effect through survivors' fear was revealed. Implications for future research and practice are discussed.     

Impaired finger dexterity in Parkinson's disease is associated with praxis function

A controversial concept suggests that impaired finger dexterity in Parkinson’s disease may be related to limb kinetic apraxia that is not explained by elemental motor deficits such as bradykinesia. To explore the nature of dexterous difficulties, the aim of the present study was to assess the relationship of finger dexterity with ideomotor praxis function and parkinsonian symptoms. Twenty-five patients with Parkinson’s disease participated in the study. Their left and right arms were tested independently. Testing was done in an OFF and ON state as defined by a modified version of the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). Finger dexterity was assessed by a coin rotation (CR) task and ideomotor praxis using a novel test of upper limb apraxia (TULIA), in which the patients were requested to imitate and pantomime 48 meaningless, as well as communicative and tool-related gestures. Coin rotation significantly correlated with TULIA irrespective of the motor state and arm involved, but not with the MDS-UPDRS. This association was significantly influenced by Hoehn and Yahr stage.The strong association of finger dexterity with praxis function but not the parkinsonian symptoms indicates that impaired finger dexterity in Parkinson’s disease may be indeed apraxic in nature, yet, predominantly in advanced stages of the disease when cortical pathology is expected to develop. The findings are discussed within a cognitive-motor model of praxis function.     

How emotional pictures influence visuospatial binding in short-term memory in ageing and Alzheimer’s disease?

The present study examines the prediction that emotion can facilitate short-term memory. Nevertheless, emotion also recruits attention to process information, thereby disrupting short-term memory when tasks involve high attentional resources. In this way, we aimed to determine whether there is a differential influence of emotional information on short-term memory in ageing and Alzheimer's disease (AD). Fourteen patients with mild AD, 14 healthy older participants (NC), and 14 younger adults (YA) performed two tasks. In the first task, involving visual short-term memory, participants were asked to remember a picture among four different pictures (negative or neutral) following a brief delay. The second task, a binding memory task, required the recognition by participants of a picture according to its spatial location. The attentional cost involved was higher than for the first task. The pattern of results showed that visual memory performance was better for negative stimuli than for neutral ones, irrespective of the group. In contrast, binding memory performance was essentially poorer for the location of negative pictures in the NC group, and for the location of both negative and neutral stimuli in the AD group, in comparison to the YA group. Taken together, these results show that emotion has beneficial effects on visual short-term memory in ageing and AD. In contrast, emotion does not improve their performances in the binding condition.     

Negative cognitive style and looming cognitive style synergistically predict stress generation

There is a growing body of evidence that suggests that cognitive vulnerabilities to depression or anxiety may lead individuals to generate negative interpersonal life events. However, there has been no study to date that examines the effects of co-occurring vulnerabilities to depression and anxiety. In a sample of 304 participants, we examined the potential interaction of co-occurring negative cognitive style, a vulnerability to depression and looming cognitive style, vulnerability to anxiety. Results indicate that co-occurring cognitive vulnerabilities synergistically predict higher levels of negative interpersonal life events six weeks later, even when controlling for initial levels of stressful life events and symptoms of depression and anxiety. Thus, co-occurring vulnerabilities may have stronger stress generating effects than would be expected from the additive effects of each vulnerability considered separately. This finding highlights the importance of examining cognitive vulnerabilities as interactive effects rather than as individual vulnerabilities.     

Vulnerability-specific stress generation: an examination of depressogenic cognitive vulnerability across multiple domains

Background and Objectives: Although there is supporting evidence for the stress generation hypothesis (i.e., the tendency for depression-prone individuals to experience more negative dependent events influenced by their behaviors and characteristics), additional research is required to advance current understanding of the specific types of dependent events relevant to this effect. The present study elaborated on the stress generation hypothesis, in which the content of negative dependent events experienced by individuals is contingent upon, and matches, the nature of their particular vulnerabilities. This extension was tested within the context of Cole's competency-based model of depression. Design: Participants (n = 185) were assessed at two time-points separated by a four-month interval. Methods: Self-perceived competence in academic, social, and appearance domains at the initial time-point were examined in relation to negative life events prospectively occurring over the four-month follow-up period, assessed using the “contextual threat” method. Results: Partial support was obtained for vulnerability-specific stress generation. Stress-generation specificity was found for self-perceived competence in appearance and academic domains, but not for self-perceived social competence. Conclusions: The current findings are consistent with the possibility of a more complex relation between self-perceived social competence and domain-congruent stress generation. Individuals may be more likely to experience negative dependent events in domains matching their specific vulnerabilities.     

Understanding the relationships between age,gender, and life satisfaction: the mediating role of stress and religiosity

Although hundreds of investigations have examined the relationship between age and life satisfaction, a recent review of these studies reveals that relatively little is known about the nature of this relationship, especially between genders and across cultures, and the mechanisms that link age to life satisfaction. Using a large-scale study in Malaysia, the present research explores the mediating effects of stress and religiosity that might be responsible for the empirical findings reported in previous studies. Contrary to previous findings based on US studies, this study finds that women are more satisfied with their lives than men in the early and later stages of life. Chronic stress and religiosity were found to partially mediate the relationship between age and life satisfaction, suggesting that these may be mechanisms that explain the findings of previous studies.