Specialized Brain Hemispheres Provide More Efficiency

Magpies favor one brain hemisphere depending on how they intend to approach a threat

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If you are trying to predict a magpie’s next move, just look into its eyes. A June 15 study in Brain Research Bulletin found that when these birds view a potential predator, they use either their left or right eye, depending on whether they intend to run away or move closer. These findings reveal clues about how the brain segregates information between its hemispheres.

Neuroscientist Lesley Rogers and her colleagues at the University of New England in Australia observed wild Australian magpies (Gymnorhina tibicen) in the presence of a stuffed monitor lizard. Rogers found that before fleeing, birds would fixate on the “predator” with their left eye—which sends nearly all its input to the right side of the brain. But if they were about to approach the lizard for further investigation, they would inspect it with their right eye, thus using the left hemisphere.

Recent studies in humans suggest that the right hemisphere processes information that is novel and potentially threatening, whereas the left hemisphere carries out more methodical analyses. According to Rogers, the allocation of different functions to different hemispheres allows the brain to function more efficiently. “Historically, this [specialization] was thought to explain man’s higher cognitive abilities,” she says. “But we’ve shown that even in animals with comparatively simple brains, it affects everyday behaviors in the natural environment.”


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Note: This article was originally printed with the title, "Left or Right, Fight or Flight".

SA Mind Vol 19 Issue 5This article was published with the title “Left or Right, Fight or Flight” in SA Mind Vol. 19 No. 5 (), p. 11
doi:10.1038/scientificamericanmind1008-11a

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