Neural Correlates of Emotion

The Neural Correlates of Emotion

Gyrus (Gyri) – Ridge(s)

Sulcus (Sulci) – Groove(s)

Emotions are real physically as much as psychologically. How does the brain produce or process emotion? One may want to turn to academic, or scholarly, articles for an answer. {As an aside, in choosing sources, the rule stands that the more recent the work – the better; unless, of course, it’s a classic. Most place the time limit around 10-20 years.}

To get back on track, the present [very!] short essay briefly discusses neural correlates of emotion. Cerebral mapping, enabling localization of function, can discover these clusters. However, the brain is very active, so the baseline activity must be deducted from the activation during exposure to particular stimuli. The mechanism is called the subtraction method. For the purpose of establishing cerebral correlates of human emotion, the most common stimulus type used is facial expressions. Popular neuroimaging techniques include [PET, CAT, MRI and fMRI]*. Other methods supplying neuroscientific insight include electrophysiology, lesion studies and TMS.

Promise. Persons often develop emotional attachment to their pets, and even to their stuffed toys. Peachy Pink (that’s the full name of the cutie above). Image: Copyright © Elena

Ina contemporary contribution to science, Vytal and Hamann (2010) combine tworesearch methods to compose their work: a literature review and a statisticaltechnique (meta-analysis). The authors explore basic emotion theory (fear,anger, sadness, happiness, and disgust) and corresponding consistent findingsof reliable neural correlates. Nonetheless, some doubt remains in thecommunity.

Intheir meta-analysis, Kober and Wager (2010) insist that the amygdala,[usually regarded as fundamental in feeling, and reacting to, fear] is notcritical for the experience of emotion, but for its perception. The authorsmaintain that the subcortical structure gets involved when visual stimuli mayconvey consequential information through emotional display.

Liet al. (2010) confirm that the parahippocampal gyrus/amygdala becomes activatedbilaterally during emotion perception. In their publication, the fusiform gyrus(known for facial recognition) is also active because subjects are trying toprocess facial expressions of affective states. Further, the relationshipextends to the area, together with the right superior frontal gyrus andlentiform nucleus. According to their meta-analytic review of a compilation ofneuroimaging studies, patients with schizophrenia appear to have difficultywith the task. The researchers suggest that perhaps this structural dysfunctioncauses the impaired affect understanding associated with the illness.

Ona final note, all three sources mentioned agree to at times disagree. Thus, inassessing limitations of scientific reports, one must realize that findings areseldom perfectly consistent. Still, validity, replicability andgeneralizability of effects are conditions for a theory to be supported andaccepted.

Traditional artists often reproach contemporary graphic designers the (arguable!) inability of computers to convey human emotion. Image: Megan (Elena)

*Some ABBREVIATIONS commonly used in the field:

ALE– Activation Likelihood Estimation

CAT– Computerized Axial Tomography

CIM–Contrast Indicator Map

CM– Contrast Map

FDR– False Discovery Rate

(f)MRI– (functional) Magnetic Resonance Imaging

FWER– FamilyWise Error Rate

FWHM– Full-Width Half-Maximum

(M)KDA– (Multilevel) Kernel Density Analysis

PET– Positron Emission Tomography

TMS– Transcranial Magnetic Stimulation

References:

•     Kober, H. & Wager, T. D. (2010). WIREs Cognitive Science, 1 (March/April): 293-300.
•     Li, H., Chan, R. C. K., 5, McAlonan, G. M. & Gong, QY. (2010). Facial emotion processing in schizophrenia: A meta-analysis of functional neuroimaging data. Schizophrenia Bulletin, 36 (5): 1029-39.
•     Vytal, K. and S. Hamann, S. (2010). Neuroimaging support for discrete neural correlates of basic emotions: A voxel-based meta-analysis. Journal of Cognitive Neuroscience, 22 (12): 2864-85.