Darwin discusses why different muscles are brought into action under different emotions and how particular animals have adapted for association with man.

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)

The precise relationship between the autonomic nervous system and emotion has been a topic of intense debate and research throughout the history of modern psychology. The present article considers some of the more influential theoretical frameworks that continue to drive contemporary research on the relationship between emotion and physiological processes. In particular, we highlight the multiple routes through which somatovisceral afference influences emotion and how this relates to the topic of emotion-specific patterns of autonomic nervous system activity.

In many evolutionary/functionalist theories, emotions organize the activity of the autonomic nervous system and other physiological systems. Two kinds of patterned activity are discussed: coherence, and specificity. For each kind of patterning, significant methodological obstacles are considered that need to be overcome before empirical studies can adequately test theories and resolve controversies. Finally, links that coherence and specificity have with health and well-being are considered.

The article considers patterns of reactivity in organ systems mediated by the autonomic nervous system as they relate to central neural circuits activated by affectively arousing cues. The relationship of these data to the concept of discrete emotion and their relevance for the autonomic feedback hypothesis are discussed. Research both with animal and human participants is considered and implications drawn for new directions in emotion science. It is suggested that the proposed brain-based view has a greater potential for scientific advance (...) than the traditional model that emphasizes specific states of mind as mediators or reflectors of visceral action. (shrink)

Among discrete emotions, basic emotions are the most elemental; most distinct; most continuous across species, time, and place; and most intimately related to survival-critical functions. For an emotion to be afforded basic emotion status it must meet criteria of: (a) distinctness (primarily in behavioral and physiological characteristics), (b) hard-wiredness (circuitry built into the nervous system), and (c) functionality (provides a generalized solution to a particular survival-relevant challenge or opportunity). A set of six emotions that most clearly meet these criteria (enjoyment, (...) anger, disgust, fear, surprise, sadness) and three additional emotions (relief/contentment, interest, love) for which the evidence is not yet quite as strong is described. Empirical approaches that are most and least useful for establishing basic-emotion status are discussed. Basic emotions are thought to have a central organizing mechanism and to have the capacity to influence behavior, thoughts, and other fundamental processes. (shrink)