Observations placeholder
Damasio, Professor Antonio - David and learning
Identifier
006058
Type of Spiritual Experience
None
Background
There are two important facts that can be drawn from this observation.
- That the herpes simplex virus can cause brain damage - this may not be a commonly known fact. The next is to do with learning.
- That the existence of a system of learning can be demonstrated by examining the case histories of people who have brain damage. If we think of certain parts of the brain as the hardware processors for this function, then brain damage to these areas results in the function being disabled.
The separation of executable function from database of facts was also demonstrated via David's case history.
Although unable to remember or learn any new face, or place, or word, or situation, he was able to learn new functions.
Professor Damasio found that patients like David could not only learn the task, but that they learnt it perfectly and their actual performance was in no way distinguishable from the performance of a normal person. So in some ways it was a little like learning the instructions in a program. They learnt the executable code.
The only difference between those with an inability to store data in the database of memory and a normal person is that the amnesic patients do not learn anything whatsoever about the place, the people, the apparatus and the instructions for the experiment. All that they learn, is to perform the task, and they need to be told, ever so gently, every time they confront the apparatus, what the task is all about. Then they do it, and do it better and better each time, with fewer errors and at faster speed.
Patients like David don’t remember what they thought about the difficulties they encountered in the first sessions, nor do they remember what they thought about how to correct the performance and hone the skill – because these are facts. They simply perform in a skilled manner as if the challenge is being encountered for the first time.
Equally fascinating is the fact that Professor Damasio was able to demonstrate that the acquired function - the skill - remained available long after it was acquired. For instance, David could still perform as well as normal controls two years after skill acquisition.
So the executable programs of life we accumulate in memory are separate from the database of facts in memory.
A description of the experience
Professor Antonio Damasio – The Feeling of What Happens
David’s memory was entirely normal until the day he was struck by encephalitis. In David’s case, this infectious disease of the brain was caused by a virus, the herpes simplex virus type 1. Most of us carry the virus, but only a vanishingly small number of us will ever have encephalitis caused by it. No one knows why the virus suddenly behaves aggressively in the unfortunate few.
David was forty six at the time he developed encephalitis. The disease caused major damage in selected regions of David’s brain, namely, in the left and right temporal lobes. Once the disease process was over, in a matter of weeks, it became clear that David was unable to learn any new facts. …
It made no difference whether he encountered a new person or a new landscape, whether he witnessed a new event or was given a new word to remember, he just would not retain any fact in memory. His memory was limited to a window of time of less than one minute. During that brief period his memory for new facts was normal.
If I were to introduce myself to him, leave the room and come back within say twenty seconds, to ask him who I was, he would promptly say my name and say that yes, he had just met me, that I had disappeared and had now returned. But if, instead, I were to return three minutes later, David would not have the faintest idea of who I was.