Before revision:   In contrast to prior work, our results show that complexity differences can emerge at very short time scales and across broad regions of the fly brain without the need to saturate Markov order , thus heralding the macroscopic state of anaesthesia in a previously unforeseen manner .
After revision:  We then go on to show that, in addition to reducing complexity, anesthesia also modulates the informational structure between the forward- and reverse-time neural signals. Specifically, using three distinct notions of temporal asymmetry we show that anesthesia reduces temporal asymmetry on information-theoretic and information-geometric grounds. In contrast to prior work, our results show that complexity differences can emerge at very short time scales and across broad regions of the fly brain without the need to saturate Markov order , thus heralding the macroscopic state of anaesthesia in a previously unforeseen manner .