We have discovered an unexpected correlation between the operational temperature of the brain and cognitive abilities across a wide variety of animal species. This correlation is extracted from available data in the literature of the temperature range Δ T at which an animal's brain can operate and its encephalization quotient EQ, which can be used as a proxy for cognitive ability. In particular, we found a power-law dependence between Δ T and EQ. These data support the theory that the brain behaves as a critical system where temperature is one of the critical parameters, tuning the performance of the neural network.
Keywords: Criticality; brain; encephalization quotient; power law; temperature.