The ventromedial prefrontal cortex (vmPFC) is a part of the prefrontal cortex in the mammalian brain. The ventral medial prefrontal is located in the frontal lobe at the bottom of the cerebral hemispheres and is implicated in the processing of risk and fear, as it is critical in the regulation of amygdala activity in humans. It also plays a role in the inhibition of emotional responses, and in the process of decision-making and self-control. It is also involved in the cognitive evaluation of morality.
The vmPFC is connected to and receives input from the ventral tegmental area, amygdala, the temporal lobe, the olfactory system, and the dorsomedial thalamus. It, in turn, sends signals to many different brain regions including; The temporal lobe, amygdala, the lateral hypothalamus, the hippocampal formation, the cingulate cortex, and certain other regions of the prefrontal cortex. This huge network of connections affords the vmPFC the ability to receive and monitor large amounts of sensory data and to affect and influence a plethora of other brain regions, particularly the amygdala.
Patients with bilateral lesions of the vmPFC develop severe impairments in personal and social decision-making even though most of their intellectual ability is preserved. For instance, they have difficulties in choosing between options with uncertain outcomes, whether the uncertainty is in the form of a risk or of an ambiguity. After their lesion, these patients have an impaired capacity to learn from their mistakes, making the same decisions again and again even though they lead to negative consequences. These patients choose alternatives that give immediate rewards, but seem to be blind to the future consequences of their actions. However, the underlying mechanisms of this behavior are not yet fully understood.
Emotions and an understanding of social norms are used to provide reasoning of the moral nature on our behaviors, beliefs, and the people around us. The vmPFC works as the neural basis in allowing emotion to influence moral judgement. In functional imaging studies, increased activity in the vmPFC is associated with thinking of these personal moral situations, while making harmless decisions does not. Patients with vmPFC lesions made the same decision in impersonal and personal dilemmas. Dysfunction of the vmPFC causes failure in using correct moral emotion, which explains why these patients showed less emotional responses when facing these dilemmas.
The vmPFC plays an important role in regulating and inhibiting our response to emotions. VmPFC seems to use our emotional reactions to model our behavior and control emotional reactions in certain social situations. The inputs of the vmPFC provide it with information from the environment and the plans of the frontal lobe, and its outputs allow the vmPFC to control different physiological responses and behaviors. The role of the vmPFC is especially highlighted in people with damage to this region. A damaged vmPFC causes impairments of behavioral control and decision making, consequences which are rooted in emotional dysregulation.
The first and most famous case of someone with defects to this region was Phineas Gage, a railroad construction foreman who had his vmPFC bilaterally destroyed in an accident in 1848. Before his accident, Gage was described as “serious, industrious and energetic. Afterward he became childish, irresponsible, and thoughtless of others.” Another patient with vmPFC damage wasted away his life savings on foolish investments and failed to make appropriate decisions in his personal life. In patients with vmPFC damage, evidence shows that there is a correlation between emotional disregulation and dysfunction in real world competencies.