Psychologist reveals tale of man without memory

He was intelligent and witty, but the man science knew as HM could remember nothing beyond the past 30 seconds of his life. A new book recounts the story of the world’s most famous brain.

Before his death in 2009, only a handful of people knew Henry Molaison’s name. Yet hundreds of scientists had quizzed and tested him, while images of his brain had appeared in almost every psychological textbook. Without ever becoming aware of his influence, he had transformed an entire intellectual field.

Molaison, the subject of a new book entitled Permanent Present Tense, started experiencing epileptic fits aged ten. Over the next 17 years they became increasingly unbearable until, in his desperation, he turned to a doctor who suggested an ‘experimental operation’ could hold the cure.

Two holes were drilled into the patient’s skull using a tool constructed from car parts, and the doctor proceeded to remove an entire region of Molaison’s brain – the hippocampus. It was a crude procedure. But the psychological research current in 1953 suggested that it might work.

Amazingly, it did: Molaison never experienced a crippling seizure again. But something else had changed too. Although he was just as calm and intelligent as he had always been, he could recall almost nothing of the years before his operation. Even more seriously, he was unable to form any new memories at all.

For the remaining 54 years of his life, Molaison’s amnesia imprisoned him constantly in the present moment. Beyond the previous thirty seconds he could remember neither people, facts nor experiences from his past; only vague impressions and procedural memory remained.

Molaison’s damaged brain was a personal tragedy, but a scientific goldmine. ‘HM’ (his real name was kept secret until his death) was examined by scientists for thousands of hours.

The case of HM revolutionised our understanding of how memory works. Previously it had been thought that new synapses were constantly created in the brain, capturing a record of memory as though it were being captured on film reel. HM proved that each region of the brain was in fact highly specialised, with different parts of the brain responsible for each type of memory.

Now Suzanne Corkin, the neuroscientist who led his case, has published a detailed chronicle of his condition. It’s a fascinating story – but what of the man himself?

A life scientific

In one episode of Corkin’s book, she describes her ‘ecstasy’ after Molaison’s death at seeing his ‘precious brain’ removed to the safety of a metal bowl. She freely admits that her main interest in him was intellectual rather than humane – but given how the insights he has brought can help humanity, she believes that this attitude is justified.

That makes some people very uncomfortable. Scientists claimed this man’s brain for their own, some say, and stole from him countless hours of life, while his very condition prevented him from knowing it. Nobody should be made a sacrifice to science.

You Decide

  1. If a relative had a rare kind of brain damage, would you give psychologists permission to study them for the sake of medicine and science?
  2. If all of your memories were suddenly deleted, would you still be the same person as you had been before?


  1. Devise an experiment to test an aspect of memory, then try it out on a partner.
  2. Draw a simple diagram showing where the hippocampus is located in the brain.

Some People Say...

“You are your memories.”

What do you think?

Q & A

Amnesia sounds terrifying! Is it common?
It depends what you mean by ‘amnesia’: in its broadest sense, the term just means a loss of memory. It’s not that uncommon to forget a brief period because of psychological trauma or a head injury, but the kind of amnesia that HM suffered is very rare indeed.
If you don’t have your memories, are you even the same person as you were?
That’s a very interesting question. If a person is defined by their personality, then HM suggests that memory might not be that fundamental: he retained the same traits and enjoyed distinctive style of joke that his psychologists called ‘Henryisms’. But a lack of memory does impair how you perceive yourself – and that, perhaps, is at the heart of a person’s identity.

Word Watch

Epileptic fits
Brain malfunctions experienced by about one in every 100 people, with symptoms including loss of bodily control, pain, severe confusion and sometimes unconsciousness. Most people who suffer from epilepsy can manage it and live a largely normal life, but in occasional cases it results in sudden death.
Located in the middle of the brain, in an area called the medial temporal lobe and named after the Greek word for ‘seahorse’ because of its shape. The hippocampus is almost solely responsible for forming memories that we can consciously express. It also has an important role in forming future plans and ideas.
Procedural memory
Memory of an action or process. We use this to learn skills like swimming, driving, cooking or even solving maths equations. It’s often known as the ‘how to’ bit of our memory.

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