Behavioral lateralization is not

While dogs are increasingly researched in studiesmeasuring brain activity, theirpaw preference (analog of human handedness) has not yet been examinedin relation to electroencephalogram (EEG) spectrum asymmetry during sleep.We investigated the connection between behavioral asymmetry and sleepcharacteristics in family dogs for the first time, based on dogs’ behaviorallateralizations shown in different behavioral tests and dogs’ EEG characteristicsduring sleep. Corroborating previous results, we have found individually highlyvariable behavioral lateralization in dogs’ behavior depending on the task, andwithout population-level behavioral asymmetry in any of the tasks. However,dogs were more likely to show side preference in a two-way choice taskthan to use their paws laterally in different behavioral tasks. We foundno significant correlations between dogs’ behavioral lateralization and EEGspectrum asymmetry in the first sleep cycle’s non-rapid eye-movement sleep orthe first sleep cycle’s macrostructure, with many of our results being individuallysignificant. We suggest that these results may be related to dogs’ highly variableand inconsistent behavioral lateralization patterns that do not have a pervasivelocal sleep effect, but non-exclusively, our results might be suggestive ofunderlying connections between behavioral asymmetry and sleep that warrantfurther investigations on larger samples.