Talk:Neural basis of emotions
I believe this article needs references in the text; a list of "further reading" is at the bottom, but no references are cited in the body. In addition, some "See also" links to other Scholarpedia articles would be useful.
This article for Scholarpedia comes from a leading light in the field of emotional neuroscience: Professor Antonio Damasio has been central to highlighting the pervasive relevance of emotions to human cognition and social & emotional behaviour and remains a major influence on understanding the underlying neurology of affect. He is thus is an ideal author.
In the introduction, Prof Damasio defines emotions as evoked action programs and distinguish this from feelings; experiential representation of these programs. This model is sequential, with the actions preceding the feelings. Taking this stance has many advantages in dissecting the neural basis of emotion into processes that detect emotion competent stimuli, those that initiate and support action programs and those that represent the action programs which ultimately give rise to feelings. Advances in both theoretical and experimental understanding of emotions have benefitted from such an approach, as highlighted within the text. This pragmatic stance however raises some issues that are potentially at odds with other models of emotion which highlight the continuous coupling of experience with other emotional processes. Such issues arise at the borders of definition: If emotions are potentially dissociable from cognitive states and feelings they generate explicitly or implicitly then they can potentially occur without cognitive consequences. If emotional competence is defined by obligatory changes in bodily state, it may equally be defined as obligatory changes in mental state. Monistic approaches, as emphasized by the Prof Damasio in earlier work, may be the solution, such that neurally-mediated perceptual changes such as attentional shifts are incorporated within (and influence) action programs.
This question of defining emotions in terms of action programs may artificially separate types of feeling states into those that are evoked through the sequences of stimulus -triggered action programs and those that emerge in less stereotypical ways from more complex interplay of cognitions, internal state and environment (that are difficult to attribute to independent triggers). Such feelings (as central motivational representations) may act as emotionally competent stimuli in themselves, the resolution of which is a goal of action programs.
These issues have in fact been well covered in the writings of Prof Damasio, most recently in his book ‘Self comes to mind’. As a consequence the introduction to the Scholarpedia article is both provocative and authoritative, prompting the reader to consider whether alternatives to the ‘action program model’ stand up to fine scrutiny. The introduction frames the subsequent account of neural basis of emotions within the clear logic of experimental neuroscience.
The article address addresses separately the neural basis of emotions (as action programs) and the neural basis of feelings. Without becoming bogged down in defining types of emotional response patterns, the author illustrates the principles in action, highlighting the critical dependence of evolutionally important action programs on subcortical structures, principally the brainstem in particular though discussion of protective responses to threat. Less attention is made to the basis of social communicative responses (though mentioned in disgust), which Darwin highlighted as embellishments of these evolutionary responses (it is very appropriate that the Darwin book is referenced) or the role of cingulate cortex and striatal regions in generating affective responses presumably via dorsal brainstem relays. Positive emotions are mentioned indirectly in the context of compassion, yet appetitive behaviours and even sexual ‘action programs’ provides an evolutionarily relevant basis for discussion of neural basis for a range of lower-order positive emotions.
The account of the neural basis of (emotional) feelings grounds this in perceptual representation of the emotion / action program in viscero- and somato-sensory cortices with good evidence, much of which from the Damasio group. It is noted that such representations are influenced by Incorporating the representation of the emotionally competent stimulus as per Schachter and Singer model and the learning of emotional feelings is insightfully discussed in the context of individual differences. There is relatively little about the location subcortical representations of action programs. Moreover the distinction between the representation of the action program and representation of the (peripheral physiological) consequences (unfolding) of the program is perhaps rightly blurred though expectancy mediated through corollary discharges are perhaps integral to the salience affective experience.
In summary, the article provides a wonderful overview of emotional neuroscientific thinking in relation to emotion and its neural basis. The points raised in this review highlight the power of the article to provoke further thoughts around the topic many of which have to be resolved satisfactorily. Highlighting where there is controversy is perhaps the only suggested amendment. The article serves as a stimulus to affective neuroscientists and an authoritative perspective on the present state of knowledge.
Reviewer 2:
I have little to add to the excellent comments of the first reviewer. The article provides a clear and authoritative introduction to the neural basis of emotional and feeling states. The complex neo-Jamesian view is very clearly articulated, with pointers to the current state-of-the-art in the neuroscience of emotions. However, before the article is accepted I suggest the following minor changes:
i) References should be incorporated into the text (perhaps an editorial assistant could help with this)?
ii) The article might benefit from additional discussion of those emotions (and corresponding feeling states) largely dependent on limbic/sub-cortical mechanisms (i.e., more 'primitive' emotions) and those with greater involvement of cortical (especially orbitofrontal) cortices (e.g., the more social emotions).
iii) The reading list could be extended as well, perhaps to cover some of Damasio's own works such as his recent 'Self comes to mind'.
