phantom limbs

ok, the highly anticipated (as if) discussion of phantom limbs!

why do people still experience the sensation of having an intact limb even after they have been amputated? they certainly can't see it, but some do feel it moving. there're even some who suffer from pain attributed to the phantom limb. in Ramachandran's book, he described a patient who constantly felt the pain of fingernails digging hard into his phantom palm, and since he can't unclench a palm that wasn't there, the pain remained. there are more patients who experience sensations of this sort though the sensations themselves may differ.

these patients also commonly feel sensations on their phantom body parts when another existing part of the body is stimulated. why? because of this:

it turns out that our body parts are mapped onto corresponding parts of a strip of our brain called the somatosensory cortex in this manner. the parts that are drawn especially large are not due to the artist being funny but reflects an overrepresentation of that body part in the brain. so these areas are especially sensitive to touch.

it is possible that when a body part, for example, an arm, is removed, the brain stops receiving input from there and neurons from adjacent areas grow into the region vacated by the arm. Thus, if an arm is amputated, neurons from adjacent areas like the face and shoulder will grow into that space, so stimulation of the shoulder or the face elicits sensations on the phantom arm.

COOL HUH!

gosh, the book is really damn good la. plus it's not boring at all cos the author is damn funny. besides phantom limbs, it talks about other curious phenomena too, but i will not talk about them cos i'll recommend you all to read the book!

anyway, work on my lab report is much better today, if you're interested to know. a good night's sleep really does help solve problems. this is because, even though you have stopped thinking about the problem consciously, your subconscious is actually still working on it, and it might be better at uncovering some critical clue, maybe cos it's not interfered with by other stimuli. this results in the "Aha!" moment where the solution of the problem just sudden;y comes to us. so, sleep is really important, so make sure you get enough sleep.

ok, tata!