Thursday, January 15, 2009

Answers to questions you never thought you'd ask #3

How come you can hypnotise a chicken?

Many of you who grew up with chickens (I mean chickens as pets/egg factories of course; I am not suggesting that anyone here was raised by actual chickens...) will be familiar with the interesting phenomenon of hen hypnosis, by which one may reduce a flapping fowl to a quiescent and glassy-eyed Gallus gallus. I have heard of varying techiniques, including holding them upside-down, tucking a head under their wing, or- my personal favourite- placing them on the ground and drawing a chalk line from the beak (it has a certain mystical flair!). But how come this works?

For the record, I am not advocating anyone lining up large numbers of hypnotised chickens, but the technique could actually be useful if you wanted to easily administer medication to the feet. Do chickens get foot mites anyone?

Anyway, in search of a quick and easy answer, I consulted our resident psychologist, and we came up with a number of half-baked theories, including
1. The possibility that the technique somehow activates the circuitry that would normally cause the bird to fall asleep (plausible, since birds do sleep with their heads under their wings)
2. the bird's brain is like a very simple computer (you know, like the ones you used in primary school that ran on MS-DOS and had green font on a black screen), so simple in fact that the unusual input proves too much for the simple circuitry and the system, with no programmed response to this stimulus, crashes. (Also plausible, since you would not expect chickens to often encounter chalk lines too often in nature).
3. The 'hypnotic state' is actually a manifestation of tonic immobility, ie a defence response to a perceived predator (would a chicken hanging upside-down from a fox's mouth have a greater chance of survival by playing dead?).

The webbernet also had a number of far-out theories, my favourite being that the chicken "sees the line and visualises itself at both ends of the line simultaneously" or some such.

I also had a look for some papers (I have to admit, a very cursory look, since at this juncture I am probably better off researching things that are actually related to my thesis), and found one by some Russian researchers about hypnotising rabbits (incidentally, this is done by placing the animal in the prone position and gently pressing on the upper thoracic and sacral vertebrae). They found a difference between electrical activity between the left and right hemispheres of the brain, coupled with a general cooling. This is also a feature of human hypnosis.

So, if chicken hypnosis does indeed occur by the same mechanism as rabbit hypnosis, the reason that your mesmerised rooster is out for the count is that you have somehow managed to get it to cool its brain slightly and reduce the electrical activity in its right brain hemisphere. Aren't you clever?!

1 comment:

  1. You can induce a vagal response in reptiles by pressing on their eyes and then they lie still. Useful for positioning for xrays. Mind you I've never tried it and you might want to think twice if it is, say, a venemous snake or a crocodile.