Originally posted on July 19, 2019
Here is an excerpt:
Clinical neuroscientists and neurologists have identified the brain networks responsible for this sense of free will. There seems to be two: the network governing the desire to act, and the network governing the feeling of responsibility for acting. Brain-damaged patients show that these can come apart—you can have one without the other.
Lacking essentially all motivation to move or speak has a name: akinetic mutism. The researchers, lead by neurologists Michael Fox, of Harvard Medical School, and Ryan Darby, of Vanderbilt University, analyzed 28 cases of this condition, not all of them involving damage in the same departments. “We found that brain lesions that disrupt volition occur in many different locations, but fall within a single brain network, defined by connectivity to the anterior cingulate,” which has links to both the “emotional” limbic system and the “cognitive” prefrontal cortex, the researchers wrote. Feeling like you’re moving under the direction of outside forces has a name, too: alien limb syndrome. The researchers analyzed 50 cases of this condition, which again involved brain damage in different spots. “Lesions that disrupt agency also occur in many different locations, but fall within a separate network, defined by connectivity to the precuneus,” which is involved, among other things, in the experience of agency.
The results may not map onto “free will” as we understand it ethically—the ability to choose between right and wrong. “It remains unknown whether the network of brain regions we identify as related to free will for movements is the same as those important for moral decision-making, as prior studies have suggested important differences,” the researchers wrote. For instance, in a 2017 study, he and Darby analyzed many cases of brain lesions in various regions predisposing people to criminal behavior, and found that “these lesions all fall within a unique functionally connected brain network involved in moral decision making.”
The info is here.