Early Experiments Discover Lateralization
Lateral dominance of the hypoglossal nerve conveying messages from the brain to the syrinx was first observed in the 1970s. This lateral dominance was determined in a breed of canary, the waterschlager canary, bred for its long and complex song, by lesioning the ipsilateral tracheosyringeal branch of the hypoglossal nerve, disabling either the left or right syrinx. The numbers of song elements in the birds’ repertoires were greatly attenuated when the left side was cut, but only modestly attenuated when the right side was disabled, indicating left syringeal dominance of song production in these canaries. Similar lateralized effects have been observed in other species such as the white-crowned sparrow (Zonotrichia leucophrys), the Java sparrow (Lonchura oryzivora) and the zebra finch (Taeniopygia guttata), which is right-side dominant. However, denervation in these birds does not entirely silence the affected syllables but creates qualitative changes in phonology and frequency.
Read more about this topic: Lateralization Of Bird Song
Famous quotes containing the words early, experiments and/or discover:
“I looked at my daughters, and my boyhood picture, and appreciated the gift of parenthood, at that moment, more than any other gift I have ever been given. For what person, except one’s own children, would want so deeply and sincerely to have shared your childhood? Who else would think your insignificant and petty life so precious in the living, so rich in its expressiveness, that it would be worth partaking of what you were, to understand what you are?”
—Gerald Early (20th century)
“Science is a dynamic undertaking directed to lowering the degree of the empiricism involved in solving problems; or, if you prefer, science is a process of fabricating a web of interconnected concepts and conceptual schemes arising from experiments and observations and fruitful of further experiments and observations.”
—James Conant (1893–1978)
“Women are considered deep—why? Because one can never discover any bottom to them. Women are not even shallow.”
—Friedrich Nietzsche (1844–1900)