Proust Was a Neuroscientist

by Jonah Lehrer

Like Descartes, phrenologists looked for the soul solely in the head, desperate to reduce the mind to its cranial causes.

the human being is an irreducible whole. Body and soul are emulsified into each other.

his honest refusal to be anything but himself,

“People used to say to me, ‘Walt, you are doing miracles for those fellows in the hospitals.’ I wasn’t. I was … doing miracles for myself.”

our matter was entangled with our spirit. When you cut the flesh, you also cut the soul.

He has no limbs left: they have all been cut off. Dedlow describes himself as a “use-less torso, more like some strange larval creature than anything of human shape.”

But even though Dedlow is now limbless, he still feels all of his limbs. His body has become a ghost, and yet it feels as real as ever.

to lose any part must lessen this sense of his own existence.”

“There is a presence in what is missing.” That presence is our own.

He thought that people should stop thinking of scientific theories as mirrors of nature, what he called “the copy version of truth.” Instead, they should see its facts as tools, which “help us get into a satisfactory relation with experience.”

He loved questions more than answers, the uncertainty of faith more than the conviction of reason. He wanted to call the universe the pluriverse.

science cannot define feeling without also taking consciousness — what the feeling is about — into account.

Because the mind is divorced from the flesh, the patient lives in a cocoon of numbness — numb even to his or her own tragedy.

feelings generated by the body are an essential element of rational thought.

(As Nietzsche put it, “There is more reason in your body than in your best wisdom.”)

nerves singing with minor voltages.)

The soul's urge to feel

The unconscious feelings generated by the body preceded the conscious decision. The hand led the mind.

“the spirit receives from the body just as much as it gives to the body.”

“these feelings of our duty about either truth or error are in any case only expressions of our passional life … Objective evidence and certitude are doubtless very fine ideals to play with, but where on this moonlit and dream-visited planet are they found?”

“reason is, and ought to be, the slave of the passions”

If reality is governed by mechanical causes, then is life just a fancy machine? Are we nothing but chemicals and instincts, adrift in an indifferent universe? Is free will just an elaborate illusion?

Eliot’s art argued that the mind was “not cut in marble.” She believed that the most essential element of human nature was its malleability, the way each of us can “will ourselves to change.” No matter how many mechanisms science uncovered, our freedom would remain.

the sky described by astronomers was consistently inconsistent. Laplace, trusting the order of the heavens over the eye of man, believed this irregularity resulted from human error.

The fault was not in the stars, but in ourselves.

William Thomson

The universe, he declared, was destined for chaos.

human freedom is innate, for we are the equation without a set answer. We solve ourselves.*

Because evolution has no purpose or plan — it is merely the sum of its accumulated mistakes — our biology remains impenetrable.

“If we had a keen vision and feeling of all ordinary human life,” she warns us in Middlemarch, “it would be like hearing the grass grow and the squirrel’s heart beat, and we should die of that roar which lies on the other side of silence.

at some point in our distant past, primates had traded the ability to give birth to new neurons for the ability to modify the connections between our old neurons.

“Take nature away and all your insight is in a biological vacuum.”

The mind is never beyond redemption, for no environment can extinguish neurogenesis. As long as we are alive, important parts of the brain are dividing. The brain is not marble, it is clay, and our clay never hardens.

to be alive is to be ceaselessly beginning.

Since we each start every day with a slightly new brain, neurogenesis ensures that we are never done with our changes. In the constant turmoil of our cells — in the irrepressible plasticity of our brains — we find our freedom.

the human brain does not develop in accordance with a strict genetic program that specifies its design.

For example, many readers find the ending of Middlemarch, in which Dorothea elopes with Will, to be a traditional happy ending, in which marriage triumphs over evil. However, some readers — such as Virginia Woolf — see Dorothea’s inability to live alone as a turn of plot “more melancholy than tragedy.” The same book manages to inspire two completely different conclusions. But there is no right interpretation. Everyone is free to find his or her own meaning in the novel. Our genome works the same way. Life imitates art.

retrotransposons

troublemaking scraps of DNA insert themselves into almost 80 percent of our brain cells, arbitrarily altering their genetic program. At first, Gage was befuddled by this data. The brain seemed intentionally destructive, bent on dismantling its own precise instructions. But then Gage had an epiphany. He realized that all these genetic interruptions created a population of perfectly unique minds, since each brain reacted to retrotransposons in its own way. In other words, chaos creates individuality.

umami, the Japanese word for “delicious.” Umami is what you taste when you eat everything from steak to soy sauce. It’s what makes stock more than dirty water and deglazing the essential process of French cooking. To be precise, umami is actually the taste of L-glutamate (C5H9NO4), the dominant amino acid in the composition of life.

(“The impression is for the writer what experimentation is for the scientist”),

The laws of science were fine for inert matter, Bergson said, for discerning the relationships between atoms and cells, but us? We had a consciousness, a memory, a being.

“Testing the Proustian Hypothesis” — that our senses of smell and taste are uniquely sentimental. This is because smell and taste are the only senses that connect directly to the hippocampus, the center of the brain’s long-term memory. Their mark is indelible. All our other senses (sight, touch, and hearing) are first processed by the thalamus, the source of language and the front door to consciousness. As a result, these senses are much less efficient at summoning up our past.

What Joseph Conrad said about maps is also true of the brain: the most interesting places are the empty spaces, for they are what will change.

A memory is only as real as the last time you remembered

it. The more you remember something, the less accurate the memory becomes.

It reveals memory as a ceaseless process, not a repository of inert information. It shows us that every time we remember anything, the neuronal structure of the memory is delicately transformed, a process called reconsolidation.