Naïve and Robust: Class‐Conditional Independence in Human Classification Learning

Humans excel in categorization. Yet from a computational standpoint, learning a novel probabilistic classification task involves severe computational challenges. The present paper investigates one way to address these challenges: assuming class‐conditional independence of features. This feature independence assumption simplifies the inference problem, allows for informed inferences about novel feature combinations, and performs robustly across different statistical environments. We designed a new Bayesian classification learning model (the dependence‐independence structure and category learning model, DISC‐LM) that incorporates varying degrees of prior belief in class‐conditional independence, learns whether or not independence holds, and adapts its behavior accordingly. Theoretical results from two simulation studies demonstrate that classification behavior can appear to start simple, yet adapt effectively to unexpected task structures. Two experiments—designed using optimal experimental design principles—were conducted with human learners. Classification decisions of the majority of participants were best accounted for by a version of the model with very high initial prior belief in class‐conditional independence, before adapting to the true environmental structure. Class‐conditional independence may be a strong and useful default assumption in category learning tasks.     

Generalized Information Theory Meets Human Cognition: Introducing a Unified Framework to Model Uncertainty and Information Search

Searching for information is critical in many situations. In medicine, for instance, careful choice of a diagnostic test can help narrow down the range of plausible diseases that the patient might have. In a probabilistic framework, test selection is often modeled by assuming that people's goal is to reduce uncertainty about possible states of the world. In cognitive science, psychology, and medical decision making, Shannon entropy is the most prominent and most widely used model to formalize probabilistic uncertainty and the reduction thereof. However, a variety of alternative entropy metrics (Hartley, Quadratic, Tsallis, Rényi, and more) are popular in the social and the natural sciences, computer science, and philosophy of science. Particular entropy measures have been predominant in particular research areas, and it is often an open issue whether these divergences emerge from different theoretical and practical goals or are merely due to historical accident. Cutting across disciplinary boundaries, we show that several entropy and entropy reduction measures arise as special cases in a unified formalism, the Sharma–Mittal framework. Using mathematical results, computer simulations, and analyses of published behavioral data, we discuss four key questions: How do various entropy models relate to each other? What insights can be obtained by considering diverse entropy models within a unified framework? What is the psychological plausibility of different entropy models? What new questions and insights for research on human information acquisition follow? Our work provides several new pathways for theoretical and empirical research, reconciling apparently conflicting approaches and empirical findings within a comprehensive and unified information‐theoretic formalism.     

The Contribution of Sex to Quality of Life in Modern Societies

Sexual behavior is a core activity not only for our genes, but also for individual happiness. It is therefore important to assess how this aspect of life functions in industrialized nations. Adopting the idea that society should aim at maximizing happiness, the question is whether the present situation is optimal, or if we should strive toward cultural changes that may improve the impact of sex. Sex is associated with some of the strongest rewards the brain has to offer, and consequently should serve to improve quality of life. There are, however, numerous pitfalls in that sex easily elicits negative emotions. Certain aspects of sexuality may reflect what is referred to as a ‘disease of modernity’; that is, the present environment is causing an increase in the prevalence of sex-related misery. The text use both an evolutionary and a bioecological perspective to understand human behavior. Biological (nature) and ecological (environment or nurture) factors are considered in order to assess how to improve the impact of sex on quality of life.

     

Cognitive conflict in a syllable identification task causes transient activation of speech perception area

It has previously been shown that task performance and frontal cortical activation increase after cognitive conflict. This has been argued to support a model of attention where the level of conflict automatically adjusts the amount of cognitive control applied. Conceivably, conflict could also modulate lower-level processing pathways, which would be evident as trial-to-trial changes in domain specific activation. The present fMRI experiment used a syllable identification task where conflict is manipulated by presenting recently ignored syllables. Results showed that on trials following a high conflict trial, activation increased primarily in the planum temporale region of the left temporal cortex, an area believed to be involved in syllable discrimination. The experiment thus showed a transient, domain specific attention effect that was modulated on a trial-to-trial basis. We argue that this indicates a self-regulating system where increased levels of conflict directs resources in order to improve performance.     

The Development of Anxiety Disorders: Considering the Contributions of Attachment and Emotion Regulation

Anxiety disorders are among the most common psychiatric disorders in childhood. Nonetheless, theoretical knowledge of the development and maintenance of childhood anxiety disorders is still in its infancy. Recently, research has begun to investigate the influence of emotion regulation on anxiety disorders. Although a relation between anxiety disorders and emotion regulation difficulties has been demonstrated, little attention has been given to the question of why anxious individuals have difficulties regulating their emotions. The present review examines the evidence of the link between emotion regulation and anxiety. It also explores the unique contributions of attachment style and dysfunctional emotion regulation to the development of anxiety disorders.     

Threat-relevance impairs executive functions: negative impact on working memory and response inhibition

The effects of emotional stimulus content on attention are well-known. In contrast, the impact of emotional information on higher executive control functions is undetermined. To elucidate the role of negative emotion in cognitive control, 56 adult female participants performed a combined working memory and response inhibition task, with threat-relevant (spider and snake) and neutral (flower and mushroom) stimuli. Threat-relevant stimuli impaired performance, by causing prolonged response times to working memory items and increased response inhibition error rate relative to neutral stimuli. The impaired response inhibition was only evident when threat-relevant stimuli co-occurred with working memory matches, in line with a common resource pool view of executive functions and emotion processing. Individual differences in reported fear of spiders were associated with differences of inhibitory control, while fear of snakes was associated with impaired overall accuracy on working memory trials. The results are discussed in relation to the dual-competition framework for interaction between executive functions and emotion (Pessoa, 2009).     

Cuban health psychology: A priority is the primary health care system

Cuban health psychology has experienced a great expansion during the last 25 years, both in the number of psychologists and in range of activities in the field. Today, psychologists are integrated at all levels of the national health system, an achievement which is particularly interesting in that Cuba is a developing country. In a position isolated from trends in international psychology, Cuba has developed a role for psychologists within the field of health which is adapted to its situation as a poor and socialistic country. Priority is given to preventive and community-based psychology within primary health care facilities. Psychologists in primary health care serve a composite client-group, with high priority given to pregnant women and to children. The work of these psychologists covers a wide range of health problems—-physical as well as mental—and focuses upon individuals as bio-psycho-social units. Their responsibilities include health promotion, disease prevention, consultation and treatment, rehabilitation, research and education. This report is based on a 2½ month long field study in Cuba, where Cuban health psychology, particularly as it relates to primary health care, was explored.     

Darwinian Happiness: Can the Evolutionary Perspective on Well-Being Help us Improve Society?

The concept of Darwinian Happiness was coined to help people take advantage of knowledge on how evolution has shaped the brain; as processes within this organ are the main contributors to well-being. Fortuitously, the concept has implications that may prove beneficial for society: Compassionate behavior offers more in terms of Darwinian Happiness than malicious behavior; and the probability of obtaining sustainable development may be improved by pointing out that consumption beyond sustenance is not important for well-being. It is difficult to motivate people to act against their own best interests. Darwinian Happiness offers a concept that, to some extent, combines the interests of the individual with the interests of society.