The Brainstem

Todayneuro-biology provides increasing evidence of how our reason, although powerful, isn’t as constant as most social scientists assume. Now we know that inner brain areas related to homeostatic and basic physiological functions are more relevant and permanent for surviving and evolving, than external areas of the cortex related to cognitive faculties. 

Complex cognitive skills do enrich our mental life, but aren’t critical for regulating physiological functions that are basic for existingIn a sense, we can exist with a poorer mental life—for instance following a damage in our external cortex, but we can’t exist without the basic regulation of our heartbeat or the respiratory rhythm–for instance, following a damage in our Brainstem. 

In fact, as Antonio Damasio has already explained, the Brainstem potentially houses the origin of consciousnessthe complex mental representation of the “self” that we continuously experience in first person. Even slight damages in subareas of the Brainstem lead to comatose and vegetative states, and the permanent lack of consciousness. 

Since the Brainstem’s activity is related to basic physiological and homeostatic functions, its activity is permanent, allowing the continuum construct of the self. Although our external appearance changes during our lifetime, our internal organs and biological functions remain mostly unchanged; if our consciousness is therefore grounded on those constant biological functions, it will also remain mostly constant. 

While regulating basic physiological functions, the Brainstem sends conscious signals to our self through automatic emotions and, specifically, through the conscious feelings of those emotions. Emotions are therefore the initial process linking our physiological needssuch as eating or breathingand the conscious self; the last part of the process consists of the feelings of those emotions, in the form of enriched mental experiences of joy, beauty or sorrow, for instance. 

Emotions, as a reflection of our physiological needs and homeostatic functions, and feelings, as conscious experiences of those emotions, are permanent and preponderant in our life because they link our physiology with our conscious self through the Brainstem 

Acknowledging functions and dynamics of the Brainstem and its subareas is useful for understanding human nature, the one mostly driven by spontaneous, automatic and capricious emotions and feelingsDaniel Kahneman and other theoristsmainly a small fraction among psychologists and neuro-economists, have already called attention to biases and capricious and irrational behaviors, but in most social sciences such knowledge is still uncommon.  

Acknowledging the origin and influence of emotions in human behavior don’t imply abdicating to irrationality, but just using our momentary and powerful rationality to understand our consciousness, and critical part of the regular humans mostly driven by dynamics in the Brainstem.