As with other brain functions, there is a lateral asymmetry in the Neural processing of emotions, given that the right hemisphere has a more important role, both in recognition and in emotional expression. However, the left hemisphere also participates in the control of emotional information.
- 1 Recognition of emotions
- 2 Emotional expression
- 3 Functional lateralization of the cortex: positive and negative emotions
Recognition of emotions
It seems that the right hemisphere has a greater capacity to detect visual differences in emotional facial and postural expressions, and also to be able to detect with a smaller error rate the emotional modulation of the voice or prosody:
In 1991, Bowers and his collaborators saw that patients with lesions in the right hemisphere had difficulty recognizing emotions expressed facially and manually. They also showed a serious deterioration when describing mental images of emotional expressions.
Neuroimaging studies have shown an increase in the activity of the right prefrontal cortex in the face of emotional recognition from the tone of the voice.
George et al. (1996), by means of a positron emission tomography, observed a frontal activation in both hemispheres before the emotional recognition from the meaning of language, but only saw an activation of the right prefrontal cortex when the recognition was given from of the tone of the voice.
The right hemisphere is more important than the left in the recognition and understanding of emotions
Patients with lesions in the suprasilvians, the posterior frontal and anterior parietal lobes of the right hemisphere have difficulty manifesting emotions through modulation of the tone of language.
Aprosodia is a disorder characterized by the tendency to speak monotonously, with the same pattern of language, but with a correct cognitive perception of feelings. Thus, a person with aprosodia who, in addition, has suffered the loss of a loved one, can express their emotional pain with the content of the language, but with a tone that would seem like genuine indifference.
Different studies, both in humans and in nonhuman primates, have found lateral asymmetries in the intensity of emotional expression. Thus, facial expressions manifest faster, more intensely and more completely, in the left facial musculature (which is controlled by the right hemisphere).
Lesions of the right hemisphere incapacitate subjects to express emotions through facial expressions and / or the modulation of the tone of the language.
Functional lateralization of the cortex: positive and negative emotions
Different neuroimaging studies support the hypothesis that The prefrontal cortex of the left hemisphere is related to positive emotions, while that of law would be with negative emotions.
Electrophysiological studies have shown that the activation of the left prefrontal cortex seems to inhibit negative emotions, and also the willingness of the subject to suffer negative emotional states.
Epidemiological analyzes have described that the incidence and severity of depressive symptoms is higher in patients with lesions of the left anterior hemisphere. Also, some clinical studies have shown that lesions of the right anterior hemisphere can generate excessive signs of positive emotions.
Different clinical and experimental studies have shown a much more important role of the right hemisphere in the processing of negative emotions and of the left hemisphere in positive ones.
Many patients who are not able to recognize emotions from facial and manual expressions, can do so from the tone of the voice, showing some functional independence between the two systems of emotional understanding.