left and right

Left and Right .
Andre Willers
19 May 2011

Synopsis :
Ever wonder why nerves cross-over from the left-to-right and vice-versa in the neck ?
Because it doubled our fishy ancestor's chances of not being on the menu .
It also resulted in handedness .

Discussion :
It is called Mauthner-neurons .
See http://en.wikipedia.org/wiki/Mauthner_cell

Briefly , a single neuron-axon assembly transmits the signal of a startle on one side of the body to the muscles on the other side , causing them to contract with speeds of about 4 ms . A very fast getaway .
Without it (see below) , it is double that , about 9 ms .
http://www.biolbull.org/cgi/reprint/199/2/180.pdf

This is a huge competitive advantage .

We all duly have inherited crossed notochords . With the ancillary baggage of startle-reflexes .
Eg : snap your fingers next to someone's right ear and his head will jerk to the left long before any signals could be transmitted via standard ways . It even works on yourself (ie warning does not prevent the reflex: try it)

Handedness :
Fishballs (also known as bait-balls)
A survival strategy where many fish cluster together in a dense , rotating ball .
They actually rotate around a moving barycentre . The whole fish-ball has a distinct and delineated survival probability structure .
This is dependant on the rotation of the ocean gyre they find themselves in .
Even small differences over millions of years leads to a breaking of symmetry .
(Swimming with the current gives a small , but distinct advantage . So does slipstreams)
Startle responses (ie responding to schooling signals by neighbouring fishes) will be reinforced in an asymmetric fashion .
Pattern recognition for the out-facing eye-ear and predictive systems for the in-facing eye-ear .
We still sit with this legacy .
See "Sports" below .

Dimensions:
The fishball is sensitive to currents in a three-dimensional medium .
Hence , startle responses in the Mauthner-neurons have been evolved in 3 dimensions , especially moving between vertical dimensions .
This came in handy in moving onto the land , and we still have it .
(Click your fingers behind your neck , if you don't believe me . Your head will jerk backward .)

Predator behaviour :
Predators have learned to exploit this startle response .
A really nice piece of work is in SciAm Apr 2011 "Natural born killer" by KC Catania (p65)
A snake has evolved mouth-tentacles to detect and startle fish into optimum eating positions .
(Sounds like the Wall Street Journal .)

Dolphins use the same with rising or plunging bubble curtains .
(Any air bubble in water has to have a spin as it changes density levels in a planetary ocean . This confuses and startles a fish . They instinctively (Mauthner-literally) curve into the fish-ball .

Other examples abound .

Sports :
Training is the interesting bit .
Most human sports have a 3 dimensional element (height) .
This can be optimally trained by mimicking sparkling , rotating bubbles
You can directly train the Mauthner-neurons .
To get better than 4 milliseconds , I suggest precognition or FTL

This is fine for sports like tennis , soccer , etc .
But what about Golf ?

We train the same way , but invert it .
From the hole , fire sparkling , rotating bubbles at the player .
Virtual would be easiest . The player stands within a envelope of spinning bubbles . He only has to play into the available space . About 400 million years of evolution works for him , then .
Not allowable in competition , but fine in training .

Click Languages :
A click language decreases startlement .
Test it . Double-click with tongue , then immediately snap fingers behind neck .
Mauthner-neuron response is inhibited (synapse exhaustion initially , then learned response)

Sculpting Good-Muscle Memory :
Also used in rousing music .
Using the differential speeds of impulses in air (0.00343 cm/ms) vs impulse in salty water(body) (0.0156 cm/ms) . The ratio is 4.558 . In other words , sound clicks in air have to be less than 4.558 cm from the skin to have a training effect .

Loud music from many speakers :
The sound-pressure wave is so flat and discrete that skin sensors see it as less than 4.5 cm .Note the fine muscle delineation in rock stars .They did not start out that way .


Ear-buds :
An interesting way of programming human systems .
Below 4.558 cm the system sees signals as endogenous . Many defense systems allow it . End-sequences to musical pieces (as discussed before) on an earbud will trigger telomere sequences .

I really don't care any more .

Andre