Slow waves emerge from the cortical network during states of functional disconnection (non-REM sleep, anesthesia) and anatomical disconnection (slices, deafferented cortex) as if it were its default activity . Such emergent activity and its spatiotemporal patterns reveal features about the underlying network. By using an observational approach of these emergent slow waves we have identified alterations in the cortical emergent patterns in transgenic models of neurological disease . Here, we present a perturbational approach where we probe the network by electrical stimulation using two different approaches: (1) By means of DC electric fields we explore the modulation of the emergent activity, (2) By means of electric pulses we measure the complexity of the cortical network’s responses. To this end we have adapted to cortical slices the perturbational complexity index (PCI) recently introduced in humans to quantify the information content of deterministic patterns evoked in the brain by transcranial magnetic stimulation . Our in vitro perturbational study reveals that the spontaneous intrinsic cortical bistability breaks-off complexity in the neural network. We also explore the mechanisms modulating network complexity under different brain states.