What H.M. Taught Us

Preferences, Beliefs and Equilibrium: What Have Experiments Taught Us?

Are memories just ripples in time?

Henry Molaison (1926–2008) suffered from severe epilepsy until 1953, when a surgeon undertook a drastic experimental intervention and removed parts of his brain, including both hippocampi. That operation cured the epilepsy, but it soon became clear that it also gave the patient a new, equally serious disability. The brain surgery blocked Molaison’s ability to form new memories and turned him in...

Visual cognition in amnesic H.M.: selective deficits on the What's-Wrong-Here and Hidden-Figure tasks.

Two experiments compared the visual cognition performance of amnesic H.M. and memory-normal controls matched for age, background, intelligence, and education. In Experiment 1 H.M. exhibited deficits relative to the controls in detecting "erroneous objects" in complex visual scenes--for example, a bird flying inside a fishbowl. In Experiment 2 H.M. exhibited deficits relative to the controls in ...

ALLHAT: what has it taught us so far?

Speech errors of amnesic H.M.: unlike everyday slips-of-the-tongue.

Three language production studies indicate that amnesic H.M. produces speech errors unlike everyday slips-of-the-tongue. Study 1 was a naturalistic task: H.M. and six controls closely matched for age, education, background and IQ described what makes captioned cartoons funny. Nine judges rated the descriptions blind to speaker identity and gave reliably more negative ratings for coherence, vagu...