1. Can germs survive on a bar of soap?

Yes, when you wash your hands, you transfer a thin film of bacteria, skin flakes and oils to the bar of soap. A 2006 study of 32 dental clinics found bacteria growing on the soap in all of them- after all standard soap doesn’t kill bacteria, it just dislodges them. A 1988 study found that washing your hands with a dirty bar of soap doesn’t transfer any of the germs onto your hands- but then the study was conducted by a US soap manufacturer.

2. Why does it feel good to scratch?

Studies using Functional Magnetic Resonance imaging (fRMI) have shown that scratching causes patterns of brain activity that are associated with pleasure and reward. This effect is strongest when you do the scratching yourself and when you are actually scratching an itch, rather than just an arbitrary patch of skin. But contrary to what you might expect or might have read elsewhere, there is no clear evidence that this pleasure comes from a release of endorphins- it happens purely in your brain and spine. This mechanism may have evolved to encourage us to dislodge skin parasites. All the evidence suggests that it is very ancient response- because all vertebrates scratch themselves- even fish.

3. Is our sense of self an illusion?

If an illusion is something that deceives us, yes most of us feel that we are more than just a body with a brain: we are someone who lives inside our bodies and controls them. Yet this cannot be true. The brain is a massively parallel system with no central place where a self could receive information or issue commands. Different regions make decisions, inhibit impulses, organize movements and control emotions, and these all operate at once without a central controller, some of them so quickly that we become aware that what has been decided only after the action is completed. Yet, we still say ‘I decided to do this’ or ‘I wanted to do that’. Our sense of a ‘Unitary Self’ that has consciousness and free will may or may not be useful- but it is certainly an illusion.

Source: Knowledge…..a Science magazine by Times of India

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