Memories & the Self

In one sense, we are our memories. If we had no long-term memory, we would be locked in a world of immediate sensory experience with no means by which to interpret our environment or determine our actions within it. Our learning, encoded in memory, determines our belief systems, influences our perceptions, and defines "the self." Cognition, learning, and memory are inexorably linked.

The case history of a patient, referred to as HM, became famous as illustrating the importance of long term memory to daily functioning. In 1953, neurosurgery was performed on HM, aged 27, to treat his epileptic seizures. After the surgery, HM could recall memories up to age 16 but could not form new memories. He could not remember where he lived, when he ate his last meal, who his caretakers were, or how old he was, nor could he recognize a recent photograph of himself. Fortunately, his memories up to age 16 afforded him some functioning in the daily world, but he was mentally bound to the immediate present.*

MRI During Seizure** Image Copyright © 2003, TZ Ramsøy

*Scoville, W.B. & Milner, B., "Loss of Recent Memory After Bilateral Hippocampal Lesions." (1957) Journal of Neurology, Neurosurgery, & Psychiatry 20:11-21 and Milner, B.et al, "Further Analysis of the Hippocampal Amnesic Syndrome." (1968) Neuropsychologia 6, 215–234.
** Graphic from Ramsoy, T.Z., "Consciousness Lost: The Lightning Storm of Seizures," Science & Consciousness Review, January 2003, No.2 .