Sunday, April 9, 2017

'The brain as a computer' - II

With the invention of the electronic computer, it became the norm to think of the brain as a similar information processing device. A computer is just a metaphor for the functioning of the brain and like all metaphors, it should not be carried too far. Here is a post that tells the differences between a brain and a computer. Thinking of the brain as a cognitive computer ignores emotions which do not function independently of the body.

In Geek Nation, Sunny Joseph, who works on the truth machine,  tells Angela Saini, 'Experiences can't be planted in the mind by police officers or lawyers...information will be stored in the brain only if we undergo an experience.' This sort of thought comes if we think of the brain as a computer and memory is like the hard-disk, which is erroneous. Memory is a self-justifying historian that resorts to confabulation, distortion and plain forgetting to preserve our core self-images. (Slate had an 8 part series on memory manipulation.) Angela Saini writes:
But I am skeptical. Not only is every human brain different, but criminals in particular are more likely to have aberrant mental states. Psychopaths and pathological killers, for example, often show signs of brain damage. Memories also change and fade over time.
It is estimated that a piece of the brain the size of a grain of sand would contain one hundred thousand neurons, two million axons and one billion synapses, all communicating with each other. It has been calculated that the number of possible brain states - the number of permutations and combinations of activity that are theoretically possible — exceeds the number of elementary particles in the universe.

V.S. Ramachandran, one of leading lights of brain research, said that we began researching the brain 300 years ago and he sometimes feels that we are still at the same place. In Phantoms in the Brain, he writes, 'The Cambridge physiologist Horace Barlow recently pointed out at a scientific meeting that we have spent five decades studying the cerebral cortex in excruciating detail, but we still don't have the foggiest idea of how it works or what it does.'

Granted that the book was written a couple of decades ago but it is improbable that in this time we have learnt everything about how the brain does what it does. And here were people who were confident of determining a person's guilt based on a few electrical signals from the brain. What is scary is that they have the ear of the authorities.

In the second book of The Shiva Trilogy by Amish Tripathi, he mentions Lord Ram's law - No innocent person should be punished and no criminal should escape This situation is like the concept of a frictionless surface - an idealization that does not exist in practice. In practice, two types of errors are possible - type 1 error or false positive (an innocent person is found to be guilty) and type 2 error or false negative (allowing a person who is actually guilty to escape).

You cannot eliminate both types of errors simultaneously. If you try to reduce the number of false positives, the number of false negatives will increase and vice versa. A British judge once said that it is better to let ten guilty persons escape than to let one innocent person suffer. This principle is broadly accepted by all humane societies. Reliance on the truth machine risks creating a horror society where it is considered ok to let innocents suffer so long as all the guilty are caught.

Beware of simple solutions to complex problems. As Nassim Nicholas Taleb says about the difference between a cat and a washing machine: living systems are complex; man-made objects are merely complicated. We seem to be bombarded with the idea that it is easy to do many things - pop a pill and your memory will improve by leaps and bounds, read a particular book and you can speak English fluently in a month, can identify criminals easily by some electrical signals from the brain.

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