  Much evidence seems to suggest cortex operates near a critical point, yet a
single set of exponents defining its universality class has not been found. In
fact, when critical exponents are estimated from data, they widely differ
across species, individuals of the same species, and even over time, or
depending on stimulus. Interestingly, these exponents still approximately hold
to a dynamical scaling relation. Here we show that the theory of
quasicriticality, an organizing principle for brain dynamics, can account for
this paradoxical situation. As external stimuli drive the cortex,
quasicriticality predicts a departure from criticality along a Widom line with
exponents that decrease in absolute value, while still holding approximately to
a dynamical scaling relation. We use simulations and experimental data to
confirm these predictions and describe new ones that could be tested soon.
