Permanent Present Tense: The Unforgettable Life of the Amnesic Patient, H. M.
Format: PDF / Kindle (mobi) / ePub
But Henry’s tragedy would prove a gift to humanity. As renowned neuroscientist Suzanne Corkin explains in Permanent Present Tense, she and her colleagues brought to light the sharp contrast between Henry’s crippling memory impairment and his preserved intellect. This new insight that the capacity for remembering is housed in a specific brain area revolutionized the science of memory. The case of Henry—known only by his initials H. M. until his death in 2008—stands as one of the most consequential and widely referenced in the spiraling field of neuroscience. Corkin and her collaborators worked closely with Henry for nearly fifty years, and in Permanent Present Tense she tells the incredible story of the life and legacy of this intelligent, quiet, and remarkably good-humored man. Henry never remembered Corkin from one meeting to the next and had only a dim conception of the importance of the work they were doing together, yet he was consistently happy to see her and always willing to participate in her research. His case afforded untold advances in the study of memory, including the discovery that even profound amnesia spares some kinds of learning, and that different memory processes are localized to separate circuits in the human brain. Henry taught us that learning can occur without conscious awareness, that short-term and long-term memory are distinct capacities, and that the effects of aging-related disease are detectable in an already damaged brain.
Undergirded by rich details about the functions of the human brain, Permanent Present Tense pulls back the curtain on the man whose misfortune propelled a half-century of exciting research. With great clarity, sensitivity, and grace, Corkin brings readers to the cutting edge of neuroscience in this deeply felt elegy for her patient and friend.
puzzles, a frequent topic of conversation. Then I asked, “How long have you had trouble remembering things?” “That, I don’t know myself. I can’t tell you because I don’t remember.” “Well, do you think it’s days or weeks? Months? Years?” “Well, see, I can’t put it in exactly on a day, week, or month, or year basis.” “But do you think it’s been more than a year that you’ve had this problem?” “I think it’s about that. One year or more. Because I believe I had an—this is just a thought that I’m
processes independent of language. This finding of impaired word-completion priming with novel words, but robust perceptual identification priming with the same words, told us that different mechanisms sustain each kind of priming—one disrupted in Henry and the other still functioning.22 Henry’s differing results for these two nondeclarative-memory tasks—conceptual priming and perceptual priming—were important because they highlighted the fact that the two procedures activated brain circuits at
Neuropsychologia 3 (1965): 339–51, available online at web.mit.edu/bnl/pdf/Corkin_1965.pdf (accessed November 2012). Chapter Four: Thirty Seconds 1. D. O. Hebb, The Organization of Behavior: A Neuropsychological Theory (New York: Wiley, 1949). 2. S. R. Cajal, “La Fine Structure des Centres Nerveux,” Proceedings of the Royal Society of London 55 (1894): 444–68. 3. C. J. Shatz, “The Developing Brain,” Scientific American 267 (1992): 60–67; available online at
electrodes next to place cells in the rats’ hippocampus to record their activity. Each recording session had three phases—sleep, maze running, and sleep. The researchers predicted that during the second sleep period, neuronal firing in the hippocampus would resemble that in the cortex, and, in addition, the pattern of activity would correspond to that during maze running. The results verified their predictions. During sleep, the patterns of neuronal firing when the rat was in the maze were
would have been active while he was looking at them. But after he left the scanner, he would not remember them, because he lacked the necessary areas in his medial temporal lobe to form these new memories.15 The MIT researcher’s pivotal discovery inspired a team of scientists at Vanderbilt University to conduct further functional MRI studies, showing how the brain maps other kinds of expertise. They found that extensive knowledge of birds or cars also recruited the face-selective area in the