How You Are Who You Are--in the Brain
Who you are is like riding a bicycle
Posted August 16, 2010
So far as I know the only neuroscientists who have addressed this question are neuropsychologist Jim Grigsby and his associates at the University of Colorado.
Grigsby and David Stevens (2000) and Grigsby and Hartlaub (1994) provide evidence that one can think of character (or personality or identity) as habits procedurally learned. The brain has several distinct memory systems, among them, declarative memory for facts about the world; episodic memory for facts about one's own experiences; emotional learning (conditioning); and procedural memory.
Procedural memory is a system that embodies, in particular, motor skills, but Grigsby and his co-workers also include perceptual abilities, cognitive skills (like reading or understanding music), and relations to other humans. I would say that procedural memory also includes our defenses and adaptations, our ways of relating inner and outer reality, in short, our styles.
Unlike declarative or episodic memory, procedural memory is non-verbal. We cannot put into words the way we walk or swim. Because, for motor memory, many systems must acquire permanent changes in the strength of their synaptic connections, procedural memory must be widely dispersed in the brain and even in the body. Neurologist Oliver Sacks concluded about brain-damaged patients: "One's self, one's style, one's persona exists as such, in its infinitely complex being; that it is not a question of this system or that, but of a total organization which must be described as a self" (1974, 239n).
Grigsby and Stevens therefore argue that character "results from the activation of neural networks that have been assembled as a consequence of procedural learning within the context of a specific temperament" (2000, 311). On this theory, infants acquire character as an array of procedural or conditioned memories (or habits) through their relations with early caregivers. These relationships establish, say Grigsby and Stevens, basic neurophysiological regulation, and later in life, we individuals use these same procedurally learned processes to regulate behavior. In that way each of us manifests character. "The genesis of character remains obscure not because of repression but because it is in the nature of procedural memories that they are unconscious, have no content, and are completely dissociable from declarative memory" (Grigsby and Stevens 2000, 321). We cannot say how we came to be the people we are.
As for developing this kind of persistent and pervasive identity, the prefrontal cortex is slow to myelinate. Memory in the first few years of life consists only of non-verbal procedural memory and memory traces. Classical conditioning also operates. Personality or character is thus more influenced by procedural learning (repetition) and conditioning than by semantic knowledge of the world or even episodic memory of experiences, the two kinds of memory we can put into words (Grigsby and Stevens 2000, 91-95).
Acquiring a procedural memory, such as learning to swim or to touch type, requires many, many repetitions. And such skills survive even with Alzheimer's. Procedural memories involve both slow learning and long retention. There is a kind of "inertial quality" to procedural memory and hence to personality. This means that identity as observed from outside will remain stable over time in the face of crises or even dementia.
Oliver Sacks wrote, commenting on an exhibit of Willem de Kooning's late works, painted when the artist's mind was deteriorating: "Style is the deepest part of one's being, and may be preserved, almost to the last, in a dementia" (1990). In another example, he pointed to letters Henry James wrote in a delirium that show signs of the delirium but also James' distinctive prose style (Sacks, 1974, 239n.) In suggesting "style" or a "total organization," then, Sacks could well be describing as a system of procedural memories what I have been calling identity or style of being.
Grigsby and Stevens also define "character" much as I define identity, as
those habitual behaviors that give people their own distinctive styles of being in the world. The foundations of character are acquired early in life but undergo change over time in association with experience and neurocognitive development. Nonetheless, certain predispositions (e.g., arrogance or obsequiousness) tend to remain fairly stable despite changes in the precise details of how they may be manifested across development.
They sum up, "The automatic, unconscious, repeated performance of routine behaviors is the essence of character" (2000, 310).
We have distinct styles of talking, walking, writing, and so on, but we can think of them as constituting together a persistent, pervasive style of being--call it an identity. Others can
Our brains embody this style of being as procedural memories widely diffused in our brains. But procedural memories are nonverbal. We cannot say how we are who we are. Not without years on the couch. Or perhaps by the use of mathematics, specifically, chaos theory, as I'll discuss in my third post on this topic.
Items I've referred to:
Grigsby, Jim, and G. Hartlaub, `Procedural Learning and the Development and Stability of Character', <em>Perceptual and Motor Skills</em> 79 (1994), 355-70.
Grigsby, Jim, and David Stevens, <em>Neurodynamics of Personality</em> (New York, 2000).
Sacks, Oliver, <em>Awakenings</em> (New York, 1974).
Sacks, Oliver, `Letters: Alzheimer's and Creativity', <em>Art and Antiques</em>, January 1990.