Hippocampus
H.M. suffered from intractable epilepsy (epileptic seizures)
- an epileptic seizure means that a large collection of neurons in the brain discharge in abnormal synchrony--seizures can be focal that spread throughout cortex or generalized, and may involve loss of consciousness as well as contraction of groups of skeletal muscle
- intractable means that his epileptic seizures were resistant to treatment
to stop his epileptic seizures, heunderwent bilateral hippocampectomy--bilateral removal of his hippocampi
following surgery:
- GOOD NEWS: his epilepsy stopped
- BAD NEWS: while he could remember events early in his life, he could not remember events just prior to surgery (mild form of “retrograde amnesia”), and he was unable to form new memories (“anterograde amnesia:)