Criticality in the Macaque cortex

The healthy brain is believed to operate near "Criticality", a transition phase between ordered and disordered states. This transition phase, known as the critical state, has remarkable properties that are highly beneficial for the brain. For example, it provides maximal sensitivity to perturbations, a large repertoire of dynamical states, and enhanced capacity to store, process, and transfer information. Here, we have investigated criticality in the awake macaque cortex using extracellular recordings from specific areas of the brain, such as the frontal pole and the dorsal premotor cortex (PMD) during different task-free epochs of the object-in-place paradigm. Using the maximum likeli- hood estimation (MLE) method and the KS test, we detected avalanches with true power-law distributions and obtained accurate critical exponents. The results revealed differences between regions during different epochs of the task. To measure proximity to criticality quantitatively, the DCC parameter, which is defined based on the scaling relation between critical exponents, has been used. The DCC indicated that the frontal pole area remained near the critical state regardless of the task epoch, whereas the PMD area deviated from criticality during Inter-Trial Intervals. However, in longer pauses between the task, such as white screen and resting sessions, both areas approached the critical state. In addition, the frontal pole area was closer to it and showed smaller variations in its distance during the resting-state epoch compared to the PMD area.