Formal and Tacit Knowledge Are Located in Different Parts of the Brain

Brenda Milner turned 106 on July 15, 2024.

(p. D5) At 98, Dr. Milner is not letting up in a nearly 70-year career to clarify the function of many brain regions — frontal lobes, and temporal; vision centers and tactile; the left hemisphere and the right — usually by painstakingly testing people with brain lesions, often from surgery. Her prominence long ago transcended gender, and she is impatient with those who expect her to be a social activist. It’s science first with Dr. Milner, say close colleagues, in her lab and her life.

Perched recently on a chair in her small office, resplendent in a black satin dress and gold floral pin and banked by moldering towers of old files, she volleyed questions rather than answering them. “People think because I’m 98 years old I must be emerita,” she said. “Well, not at all. I’m still nosy, you know, curious.”

. . .

Dr. Milner changed the course of brain science for good as a newly minted Ph.D. in the 1950s by identifying the specific brain organ that is crucial to memory formation.

She did so by observing the behavior of a 29-year-old Connecticut man who had recently undergone an operation to relieve severe epileptic seizures. The operation was an experiment: On a hunch, the surgeon suctioned out two trenches of tissue from the man’s brain, one from each of his medial temporal lobes, located deep below the skull about level with the ears. The seizures subsided.

But the patient, an assembly line worker named Henry Molaison, was forever altered. He could no longer form new memories.

. . .

In a landmark 1957 paper Dr. Milner wrote with Mr. Molaison’s surgeon, she concluded that the medial temporal areas — including, importantly, an organ called the hippocampus — must be critical to memory formation. That finding, though slow to sink in, would upend the accepted teaching at the time, which held that no single area was critical to supporting memory.

Dr. Milner continued to work with Mr. Molaison and later showed that his motor memory was intact: He remembered how to perform certain physical drawing tests, even if he had no memory of learning them.

The finding, reported in 1962, demonstrated that there are at least two systems in the brain for processing memory: one that is explicit and handles names, faces and experiences; and another that is implicit and incorporates skills, like riding a bike or playing a guitar.

“I clearly remember to this day my excitement, sitting there with H. M. and watching this beautiful learning curve develop right there in front of me,” Dr. Milner said. “I knew very well I was witnessing something important.”

. . .

For Dr. Milner, after a lifetime exploring the brain, the motive for the work is personal as well as professional. “I live very close; it’s a 10-minute walk up the hill,” she said. “So it gives me a good reason to come in regularly.”

For the full story see:

Benedict Carey. “At 98, ‘Still Nosy’ About the Brain.” The New York Times (Tuesday, May 16, 2017 [sic]): D5.

(Note: ellipses added.)

(Note: the online version of the story has the date May 15, 2017 [sic], and has the title “Brenda Milner, Eminent Brain Scientist, Is ‘Still Nosy’ at 98.”)

The “landmark 1957 paper” mentioned above is:

Scoville, William Beecher, and Brenda Milner. “Loss of Recent Memory after Bilateral Hippocampal Lesions.” Journal of Neurology, Neurosurgery & Psychiatry 20, no. 1 (Feb. 1957): 11-21.

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