A perfectly matched layer (PML) absorbing material composed of a uniaxial anisotropic material is presented for the truncation of finite-difference time-domain (FDTD) lattices. It is shown that the uniaxial PML material formulation is mathematically equivalent to the perfectly matched layer method published by Berenger (see J. Computat. Phys., Oct. 1994). However, unlike Berenger's technique, the uniaxial PML absorbing medium presented in this paper is based on a Maxwellian formulation. Numerical examples demonstrate that the FDTD implementation of the uniaxial PML medium (...) is stable, equal in effectiveness as compared to Berenger's PML medium, while being more computationally efficient. (shrink)

Attention is automatically allocated to stimuli that are opposite in valence to the current motivational focus (Rothermund, 2003; Rothermund, Voss, & Wentura, 2008). We tested whether this incongruency effect is due to affective–motivational counter-regulation or to an increased salience of stimuli that mismatch with cognitively activated information. Affective processing biases were assessed with a search task in which participants had to detect the spatial position at which a positive or negative stimulus was presented. In the motivational condition, positive or negative (...) affective–motivational states were induced by performance feedback after each trial. In the cognitive activation condition, participants memorised the word “good” or “bad” during the search task. The affective incongruency effect was replicated in the motivational condition, whereas an affective congruency effect obtained in the cognitive activation condition. These findings support an explanation of affective incongruency effects in terms of automatic counter-regulation that is motivational in nature. (shrink)

In this article we outline the history, elements, and variations of functional accounts of emotions. Summarising diverse theories and observations, we propose that functional accounts of emotions: (1) address why humans have emotions; (2) define emotions as solutions to problems and opportunities related to physical and social survival; (3) treat emotions as systems of interrelated components; and (4) focus on the beneficial consequences of emotions. This conceptual approach to emotion is complemented by several empirical strategies, including the study of emotion (...) dysfunction, the effects of emotions on others, and the relations between emotions and personal and social outcomes. We conclude by considering how functional accounts of emotion vary, including in terms of their level of analysis, specificity, manner of organisation, and range of focus, and the implications functional accounts have for the study of emotion. (shrink)