Book T of C
Chap T of C
This is the 2007 version. Click here for the 2017 chapter 04 table of contents.
Sensitivity to magnetic fields is found in many species (Hsu & Li, 1994). Pigeons, for example, have a tiny amount of natural magnetite (magnetic rock) in a crucial place in their brains, enabling them to orient their flight according to the magnetic fields of the earth. Similarly, salamanders have magnetic sensitivity they use to find their way around a maze when other cues are removed. When pigeons or salamanders are fitted with little caps containing magnets, they lose their navigating ability. This proves it is magnetism that guides them.
Why are pigeons able to detect magnetic fields? What was Baker's research? What happened when other researchers tried to replicate it?
Humans also have tiny amounts of magnetite in their brains. Do humans have a magnetic sense? For a time it seemed so. A British researcher named Baker (1980) reported in Science that blindfolded subjects released 6 to 52 km away from home were able to point toward home with greater-than-expected accuracy. The subjects became less accurate when wearing magnets on their heads, as would be expected if they had genuine magnetic sensitivity.
Gould and Able (1981) were intrigued by these results and attempted to replicate them with a sample of 40 Princeton undergraduates and 19 students from the State University of New York at Albany. Baker visited and helped them replicate his original study. They were disappointed. "Despite the apparent simplicity of Baker's various methods and the consistency of his results, we could not repeat the phenomenon either at Albany or Princeton."
What is evidence that human brains respond to magnetism? What does a researcher (Kirschvink) suspect?
Kerr (1993) reported that patients with electrodes implanted deep in their brains for exploration of seizure-prone areas before surgery showed a distinct response to weak magnetic fields. We know nerve cell activity generates weak magnetic fields; that is the basis of the brain scanning technology called MEG (magnetoencephalography). Whether magnetic sensitivity in humans has any significance or functional importance has not yet been determined. The magnetite is there, the neural response is there, but no researcher has yet documented a human behavioral response to magnetism.
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Copyright © 2007-2011 Russ Dewey