The Believing Brain - Michael Shermer [71]
In the Charles Bonnett syndrome, we find an example of the foundation for the neural correlates of agenticity. “As Charles Bonnett wondered two hundred and fifty years ago,” Sacks concluded, “how is the theater of the mind generated by the machinery of the brain?”31 We now have a fairly sound understanding of the machinery, thereby rendering the theater of the mind an illusion. There is no theater, and no agent sitting inside the theater watching the world go by on the screen. Yet our intuitions tell us that there is. This is the foundation of agenticity in the brain that further reinforces belief-dependent realism.
Theory of Mind and Agenticity
There is another activity of the brain that I strongly suspect is involved in agenticity, and that is a process called theory of mind (ToM), or the fact that we are self-aware of our own beliefs, desires, and intentions, as well as aware that others have beliefs, desires, and intentions. A higher-order ToM allows you to realize that others’ intentions may be the same as or different from your own. This is sometimes called mind reading, or the process of inferring the intentions of others by projecting yourself into their minds and imagining how you would feel. A still higher-level ToM means that you understand that others also have a theory of mind, and that you know that they know that you know they have a theory of mind. As Jackie Gleason used to growl to Art Carney in the classic 1950s television series The Honeymooners, “Norton, you know that I know that you know that I know that.…” How does ToM mind reading actually operate in the brain?
In a review of the research on what brain scans have revealed about the location of such mind reading, Glasgow University neuroscientists Helen Gallagher and Christopher Frith concluded that there are three areas consistently activated whenever ToM is needed—the first in the cortex and the other two in the temporal lobes: the anterior paracingulate cortex, the superior temporal sulci, and the temporal poles bilaterally. The first two brain structures are involved in processing explicit behavioral information, such as the perception of intentional behavior on the part of other organisms: “that predator intends to eat me.” The temporal poles are essential for the retrieval of personal experiences from memory, such as “the last time I saw a predator it tried to eat me.” All three of these structures are necessary for ToM, and Gallagher and Frith go so far as to posit that the anterior paracingulate cortex (located just behind your forehead) is the seat of the theory of mind mechanism.32
Theory of mind is a high-road automatic system that kicks in for specified activities involving other people, particularly in social situations. It most likely evolved out of a number of preexisting neural networks used for related activities, such as the ability to distinguish between animate and inanimate objects, to hold the attention of another being or agent by following their eye gaze, the ability to distinguish the actions of self and others, and the ability to represent actions that are goal directed. All of these functions are basic to survival in any social mammal, and thus theory of mind is most likely an exaptation, an ex-adaptation (sometimes called a preadaptation) or a feature co-opted for a different purpose than the one for which it originally evolved. What might that have been for ToM? Probably imitation, anticipation, and empathy. Enter mirror neurons—specialized neurons that “mirror” the actions of others.
In the late 1980s and early 1990s, Italian neuroscientist Giacomo Rizzolatti and his colleagues at the University of Parma serendipitously discovered mirror neurons when they were recording the activity of single neurons in the ventral premotor cortex of macaque monkeys. Poking hair-thin electrodes into individual neurons allows neuroscientists to monitor the rate and pattern of single-cell activity, and in this case the action from the