Wednesday, January 28, 2009

Man who mistook his wife for a hat (2/2)

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Development Agnosia is body part’s forgetfulness of its natural role due to lack of use. A girl child suffering from this was so cared for that she didn’t use her hands since birth and had all things done for her. So while her hands remain sensitive to pain, temperature and pressure, they don’t perceive things. She can identify things when shown but not when touched, because connection of perception to memory images in brain is weak. In contrasting case, some person still continue to maintain body image of missing limb, feeling pain and pressure in it, even after knowing that it’s not there.

In a decease called Hemi-inattention, person loses completely the idea of “left” and his memory erases any notion of left in the world. He cannot understand left turn or left part and when asked to turn, goes in clockwise circles. When given a pie to eat, left half will remain uneaten and unnoticed unless plate is turned to bring it right side again.

Some patients suffering from Aphasia lose understanding of words and speech, while maintaining their ability to listen. Their brain cannot combine words and phrases to make and comprehend sentences. These patients often exhibit enhanced understanding of tone, candour, expression, gesture and posture and cannot be lied to. When speech is de-tone through computer software, they fail to understand anything. Opposite of Aphasia is Aprosodia where person loses understanding of tone, fluctuation, modulation, expression or gesture and can understand only words and grammar. Patient cannot identify from sound if person is happy or sad.

Patients suffering from Tourette’s Syndrome are always in state of agitation, excitement and enthusiasm beyond their control. While they are always happy, quick and witty, they lose ability to calm down and think without being impatient, impulsive, impromptu or loud. They often utter profanities without control and are required to be under drug to help them calm down.

As world is our perception in brain and brain is very powerful, it often records memories of past in very vivid detail. In strange case of Musical Epilepsy, a song or stream of songs from past play continuously in mind which only patient can hear. This can go on for years and may make life unlivable because patient cannot sleep and is unable to concentrate. In related case of Memory Seizure, brain repeatedly plays a past memory is extreme details, which patient even didn’t know he had.

While these deceases are very very rare, the mere existence highlights how little we know about ourselves. What we perceive is nothing but understanding in our brain and subconscious beyond our own control. Many a scientific experiments are confirming that decisions which we assume we take consciously are already taken in subconscious mind and can be detected by brain scanning. In future, all your feelings and desires can be satisfied by sitting under brain tempering device and you can experience diving in sea, enjoying the Hawaii or eating a cake by mere signals sent to appropriate parts of brain and for all practical purpose you would’ve done that thing. A unpopular view in Science is that Time doesn’t exist and all things takes place or have taken place at one instant and it’s our brain which orders things to make us perceive. The day will come when fiction and reality will merge to make both meaningless.

Breaking the Bias – Lessons from Bayesian Statistical Perspective

Equitable and fair institutions are the foundation of modern democracies. Bias, as referring to “inclination or prejudice against one perso...