Cognitive dynamics of sleep and sedation transitions
The main goals of this line of research is to characterise the behaviour and neurodynamics of the transitions from awake to asleep and from awake to sedated (and back) by means of auditory decision-making tasks. To this end we employed behavioural measures, high-density electroencephalography (EEG), EEG combined with functional magnetic resonance (EEG-fMRI), and intracranial recordings (local field potentials in epileptic patients). Varying several parameters in these tasks has allowed us to start to understand the changes of attentional resources, working memory and decision-making abilities during these transitions.
The characterization of such integrative processes using the same paradigms during sleep and anaesthesia transitions helps us understand the differences and commonalities between being conscious, semi-conscious and unconscious states. In short, as we fall asleep we seem to be able to take some decisions deeper into sleep but others fragment early on, we continue to take semantic decisions even during sleep, difficult decisions shift from perceptual to central integration processes when drowsy, we have less efficient decision-making with sedation but auditory processes only follow drug concentration, and sedation modulates the information between perceptual and attention processes.
The transition is a powerful model to understand the fragmentation of cognitive process, thus revealing its mechanisms.