What drives us to take action associated with pain or to express ourselves even at the risk of being condemned ? Neurobiologists at Emory University in Atlanta have discovered two areas of the cortex whose neuronal activity is linked to decision-making – primarily in the ventromedial prefrontal cortex (vmPFC). Using functional MRI, Emory University in Atlanta (USA) showed that the vmPFC clearly assessed the known risks, while the nerve cells of the second zone of the cortex were related to the assessment of unknown risks, the daily Nezavisimaya Gazeta wonders Thursday. The results of this topographic study of the brain have been published in the scientific journal PNAS. In the conclusion of their article entitled "Cortical Networks of Subjective Evaluation of Expectations and Behavior Related to Achieving Efforts to Achieve a Goal," the authors write that vmPFC neurons encode the expected reward before obtaining all of the information. This confirms the correctness of the famous proverb "the eyes are afraid, but the hands act".
The feeling of satisfaction that comes with getting a reward is generated by nerve cells with a dopamine protein receptor on their envelopes that form an adjoining nucleus. Dopamine is a derivative of the amino acid tyrosine. Another amino acid, glutamine, is one of the major generators of excitation in the brain.
To discover the link between amygdala cell activity and serotonin autoreceptors modulating the activity of its own neurons, the authors of an article for the journal Neuroimage used functional MRI and tomography by positron emission (PET). During a study, faces with different emotional expressions were presented to 31 volunteers and, for reference, simple geometric figures. PET has determined the impact of serotonin on the autoreceptors of amygdala cells.
Using electrodes introduced into the amygdala, physiologists discovered unimodal and multimodal cells that were selectively excited by different expressions of the human face. Neuroimaging revealed the triggering of amygdala cells in response not only to the menacing and sad faces, which was expected, but also happy – which was a surprise. As has been confirmed the role of serotonin neurons of the dorsal nucleus in the treatment of the spectrum of negative and positive images and their impact on the feeling of satisfaction and emotional behavior.
To validate this conclusion, British and American researchers have shown that women respond not only to men's long legs, but also to their facial expression, but indirectly. In the article "Partner choice is copied to common social learning", the experts indicate that women found male faces more attractive if they were rated better by their friends or other women. Thus, the participants in the experiment found themselves under social influence even in a process, at first glance, as intimate and personal as the choice of partner.
The opinions expressed in this content are the sole responsibility of the author of the article taken from Russian media and translated in its entirety into French.