Cognitive Neuroscience of Emotion is a patchy collection of seventeen articles on the neuropsychology of emotion. It comprises some interesting and original papers on recent empirical research, summaries of the work of prestigious authors, and some quite maverick opinions. Though the editors stress the importance of a cognitive framework in understanding the emotions, the majority of articles undermine their position.

The field of ‘cognitive neuroscience’ is portrayed in the introduction as an neurological strain of top-down cognitive psychology, in which cognitive models are prior to detailed neural mechanisms; neuroscience simply helps to identify the brain regions responsible for cognitive functions. Most of the contributors, however, would prefer a bottom-up approach to understanding mental function, inspired by the micro-architecture of the brain.

The editors proffer a partisan argument for placing emotion in a cognitivist framework, misconstruing or misusing some authors (Picard, Griffiths, Damasio) in the process. They arrange the articles into four groups or sections, and there is often a mismatch between the group theme and the content of the articles within them.

The Role of Cognition in Emotion

The first section, addressing the main theme, includes articles by the renowned neuroscientist Antonio Damasio, and the mainstream cognitivists Clore & Ortony, whose work contrasts with the neuroscientific project. Damasio presents a brief (11-page) and very general summary of his position in The Feeling of What Happens (1999). He defines emotions as "specific and consistent collections of physiological responses", and distinguishes them sharply from the cognitions that induce them. Like LeDoux, he argues that emotion and cognition are conceptually distinct functions implemented in different neural architectures which (normally) interact in an intimate way. Despite this, the editorial cites him in support of the view that emotion and cognition are essentially homogenous phenomena.

Clore & Ortony put up a lengthy (32-page) defense of the cognitivist position. In "Cognition in Emotion: Always, Sometimes or Never?", they argue emotions always include evaluative appraisals by definition, and hence cognition is a central part of the emotion concept. They dispute the relevance of neuroscientific findings to these conceptual issues, and their criticisms trivialize neuroscientific contributions to psychology. They meet the challenge of implicit or unconscious processing of emotional responses, by both denying that these constitute emotions, and widening the definition of cognition to include non-symbolic and non-conscious information processing.

The main opposition to the cognitivist view is found later in the book. The article by LeDoux, who has fought this battle many times, is buried deep in section 2. "Cognitive-Emotional Interactions: Listen to the Brain" adduces weighty conceptual and empirical evidence for a clear cognition/emotion distinction. In a detailed account of the structure and function of the amygdala, he explains how it interacts with and complements higher cognition in neocortical regions. LeDoux thinks that the physiological and behavioral responses orchestrated by the amygdala and other subcortical structures constitute emotion proper, and he distinguishes them from "cognitive computations" which occur in the neocortex.

At the end of the day, the claim that emotions are cognitive is a matter of definition. On a wide interpretation of "cognitive", it’s a mere platitude; on a narrow interpretation, it depends on whether you pin the term "emotion" on the physiological and behavioral responses, or the complex processing that (sometimes) precedes them. These semantic issues cannot be settled empirically, as two decades of this ongoing dispute testify.

The functions of the amygdala

This section deals with a range of brain regions (e.g. the amygdala, hippocampus, hypothalamus, anterior cingulate, prefrontal cortex) and is both detailed and rewarding. Some previous knowledge of gross neuroanatomy is presupposed.

Kolb & Taylor investigate the relationship between emotion and the processing of facial expression, concluding that the frontal lobe is largely responsible for the recognition of facial expression, categorizing emotions in others and generating emotional behavior. Although the authors don’t mention it, this analysis corresponds well with the suggested neural basis for the psychosomatic personality disorder known as alexithymia, which may result from poor communication between the frontal lobe and the more primitive limbic areas.

De Gelder discusses the emotional perception of vocal tone and facial expression. Arguing in favor of a modular view, she concludes "a significant part of emotional processes bypasses our subjective access to and our accountability for what we experience". This general point has important implications for the theoretical underpinnings of cognitive therapies.

The next five chapters-by Aggleton & Young, LeDoux, Emery & Amaral, Tranel, and Dolan & Morris-investigate the role of the amygdala in emotion processing. Relying heavily on animal research as well as human studies, these authors are in close agreement that the amygdala processes the emotional significance of external, internal and cognitive stimuli, particularly in the case of fear. Each stresses the intimate interaction with the prefrontal cortex, noting that the prefrontal-amygdala pathway allows the amygdala to trigger appropriate emotional reactions in response to highly processed cognition.

The conscious experience of emotion

It is puzzling that the first three chapters in this section avoid the topic almost entirely. The first, by Bradley & Lang, is a behavioral theory of emotion with no role for consciousness; the next, by Weiskrantz, is a theory of consciousness based on blindsight and the anatomy of visual structures. Minimal attempts are made to relate them to the question of how and where emotional experience is generated. The following chapter, by Ohman et al., deals with unconscious emotion, and is consistent with the theories in group 2. Damasio’s chapter in fact deals much more directly with the topic, but it is placed a different section.

Heilman takes a vaguely cognitive approach, arguing that the frontal lobes are required for processing emotional meaning, essential to genuine emotion, and suggests this is where experience occurs. He analyses three dimensions of emotion: valence, arousal and motor activation, lateralizing negative valence to the right hemisphere, and positive valence to the left. He asserts a psycho-physical correlation between certain dimensions of experience and discrimination, but provides no theory of consciousness per se.

Lane’s contribution is philosophically sophisticated, comprehensive and empirically sound. His layered model of emotional responses provides a mature solution to the cognition/emotion debate, integrating both non-cognitive and cognitive emotions. His PET research implicates the anterior cingulate cortex in the conscious awareness of emotion, and relates it to the philosophical distinction between phenomenal and reflective consciousness. This is a fascinating, if tentative, neuroscientific exploration of a difficult philosophical issue.

Emotion Regulation and Disregulation

The fourth section, on the regulation of emotional experience, overlaps considerably with group 2. Short offerings from Davidson alone and in collaboration with associates, notably two of the editorial team, are perhaps closest in spirit to the ‘cognitive neuroscience’ project envisaged in the introduction. They survey physiological and PET-scan evidence for the substrates of positive and negative valence, and approach and withdrawal, constructs which are important to cognitive analyses, and infer the roles of a range of cortical structures. The empirical findings seem quite secure, but no alternative accounts are included in this group.

Summary

Overall, this book contains some interesting studies and theoretical perspectives which provide insight into the advances and controversies in the neuropsychology of emotion; yet it is organized poorly and exhibits strong editorial prejudice, which is largely unrepresentative of the field. It may be of limited interest to therapists or a general readership, but it offers thought-provoking material for ongoing academic research.

Categories: General, Philosophical