Ventromedial prefrontal cortex · Grey Matter

The ventromedial prefrontal cortex (vmPFC) is the lower, midline part of the prefrontal cortex that gives options a value and keeps emotion in proportion: it tells the rest of the brain how good or bad a choice is likely to feel, and it damps the amygdala when a threat turns out to be harmless.

Ventromedial prefrontal cortex. The ventromedial prefrontal cortex (vmPFC) is the lower, midline part of the prefrontal cortex that gives options a value and keeps emotion in proportion: it tells the rest of the brain how good or bad a choice is likely to feel, and it damps the amygdala when a threat turns out to be harmless.

It sits above the eye sockets and along the midline, overlapping the medial orbitofrontal cortex (roughly Brodmann areas 10, 11 and the subgenual area 25). It is densely and reciprocally connected with the amygdala, the hypothalamus, the ventral striatum of the basal ganglia and the hippocampus, which puts it between bodily states, rewards, memories and decisions.

It stores what has been learned about safety. After a fear has been extinguished (a sound that once predicted a shock no longer does), the vmPFC is what suppresses the amygdala's response, and failures of this route are studied in anxiety disorders.

Its damage leaves intellect intact and judgement broken. Patients with vmPFC lesions reason well about choices in the abstract and still decide badly in their own lives, especially where risk and social cost are involved; reconstructions of Phineas Gage's skull placed his injury in this orbital and medial territory (on both sides in a 1994 model, on the left only in later models built from CT scans of the skull).

It appears in the example circuits of frustration, deciding what to eat, music that moves you and holding back an outburst.

Questions: Which areas decide what you eat when you are hungry and a pastry is on offer? The hypothalamus supplies the need: it senses low energy through hormones and nutrients in the blood and makes food more wanted. The orbitofrontal and ventromedial prefrontal cortex give each option its current value, which depends on hunger (the same pastry is worth less after a meal), and the striatum adds the pull of habit and reward. When a long-term goal argues against the pastry, the dorsolateral prefrontal cortex is engaged in weighing health against taste, and how much it does so tracks how much self-control the choice shows. What did the iron bar through Phineas Gage's frontal lobe change, and how much of the story is true? In 1848 a tamping iron about a metre long shot through the left cheek and out of the top of the head of a railway foreman, destroying much of the left frontal lobe, mainly its orbital and medial prefrontal parts and the white matter beneath. He survived, and his doctor reported that the efficient, well-liked man had become impulsive and profane. The historian Malcolm Macmillan later showed that many dramatic details were added by authors who never met him, and that Gage seems to have recovered substantially, later working for years as a stagecoach driver in Chile. The case still stands as early evidence that frontal damage can change judgement and social behaviour while leaving movement, speech and memory intact. How does telling yourself it is only a film calm a frightened amygdala? The amygdala and the prefrontal cortex talk in both directions: the amygdala tells the cortex that something is dangerous, and the ventromedial prefrontal cortex, which projects back onto inhibitory cells of the amygdala, can turn its output down. Reappraisal (reinterpreting what is seen, such as a scene being fiction) recruits the lateral prefrontal cortex, which works through the ventromedial part to reduce the amygdala's response, and imaging shows amygdala activity falling as the reappraisal succeeds. The same loop runs the other way when a worrying thought feeds the alarm, which is why thinking can either calm or amplify an emotion.