Annika Ruppert


A Behavioral Study of Brain Lateralization in Frogs: Does a Right Ear Advantage Bias Phonotaxis?

The tendency for humans to characterize themselves as “right-brained” or “left-brained” emerges from the observation that the left and right hemispheres exhibit some specialization for different functions. Previous electrophysiological studies of frogs suggest they may also exhibit brain lateralization in the form of a right ear advantage (REA) for the sensory processing of conspecific advertisement calls. Because frogs must compare information from two ears to accurately localize sound sources, we hypothesized that a REA could lead to a directional bias in phonotaxis toward calling males. We tested this hypothesis by tracking the movements of females of Cope’s gray treefrog (Hyla chrysoscelis) in response to simulated calling males. While individual females tended to consistently travel to the left or right across repeated trials as they approached a source of calls, there was little evidence to indicate a directional bias at the population level. These results, while inconsistent with the hypothesis that a REA biases direction, highlight the existence of consistent individual differences in a directional bias in phonotaxis.

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