Do dogs rescue their owners from a stressful situation? A behavioral and physiological assessment

Animal Cognition - Rescue behavior is considered a type of pro-social response, defined as a voluntary action directed to benefit another individual who is in a stressful or dangerous situation. In...     

Why and how to use virtual reality to study human social interaction: The challenges of exploring a new research landscape

As virtual reality (VR) technology and systems become more commercially available and accessible, more and more psychologists are starting to integrate VR as part of their methods. This approach offers major advantages in experimental control, reproducibility, and ecological validity, but also has limitations and hidden pitfalls which may distract the novice user. This study aimed to guide the psychologist into the novel world of VR, reviewing available instrumentation and mapping the landscape of possible systems. We use examples of state-of-the-art research to describe challenges which research is now solving, including embodiment, uncanny valley, simulation sickness, presence, ethics, and experimental design. Finally, we propose that the biggest challenge for the field would be to build a fully interactive virtual human who can pass a VR Turing test – and that this could only be achieved if psychologists, VR technologists, and AI researchers work together.     

Virtual reality and the new psychophysics

Virtual reality (VR) promises methodological rigour with the extra benefit of allowing us to study the context-dependent behaviour of individuals in their natural environment. Pan and Hamilton (2018, Br. J. Psychol.) provide a useful overview of methodological recommendations for using VR. Here, we highlight some other aspects of the use of VR. Our first argument is that VR can be useful by virtue of its differences from the normal perceptual environment. That is, by virtue of its relative non-realism and poverty of its perceptual elements, it can actually offer increased clarity with respect to the features of interest for the researcher. Our second argument is that VR exerts its measurable influence more by eliciting an acceptance of the virtual world (i.e., ‘suspension of disbelief’) rather than by eliciting a true belief of the realism of the VR environment. We conclude by providing a novel suggestion for combining neuroimaging methods with embodied VR that relies on the suspension of disbelief.     

Virtual reality: A new track in psychological research

One major challenge of social interaction research is to achieve high experimental control over social interactions to allow for rigorous scientific reasoning. Virtual reality (VR) promises this level of control. Pan and Hamilton guide us with a detailed review on existing and future possibilities and challenges of using VR for social interaction research. Here, we extend the discussion to methodological and practical implications when using VR.     

Thought-shape fusion in anorexia nervosa: an experimental investigation

Cognitive biases and cognitive distortions have been implicated as important factors in the development and maintenance of many disorders. The concept of thought-shape fusion (TSF) in eating disorders was developed by Shafran, Teachman, Kerry, and Rachman (British Journal of Clinical Psychology 38 (1999) 167) as a variant of thought-action fusion, described by Shafran, Thordarson and Rachman (Journal of Anxiety Disorders 10 (1996) 379). TSF occurs when thinking about eating certain types of food increases a person's estimate of their shape and/or weight, elicits a perception of moral wrongdoing, and/or makes the person feel fat. Shafran et al. (1999) examined both the psychometric and experimental properties of TSF in an undergraduate sample. This paper reports an extension of this work to a clinical group (N=20) of patients with anorexia nervosa. After completing a set of relevant questionnaires, participants were asked to think about a food which they considered extremely fattening. They were then asked to write out the sentence, "I am eating--.", inserting the name of the fattening food in the blank. After being asked to rate their anxiety, guilt, feelings about their weight, morality, etc., participants were given the opportunity to neutralize their statement in any way they chose. The majority of the participants neutralized in ways consistent with the findings of Shafran et al. (1999). The results are discussed in terms of cognitive-behavioural formulations of eating disorders, and of the influence of cognitive biases and cognitive distortions on the processing of information relevant to food, weight and shape in anorexia nervosa.     

Classical Non-Associative Lambek Calculus

We introduce non-associative linear logic, which may be seen as the classical version of the non-associative Lambek calculus. We define its sequent calculus, its theory of proof-nets, for which we give a correctness criterion and a sequentialization theorem, and we show proof search in it is polynomial.     

Satisfiability Testing for Boolean Formulas Using Δ-trees

The tree-based data structure of -tree for propositional formulas is introduced in an improved and optimised form. The -trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal form A at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem.