CENTER FOR RESEARCH IN
COGNITION & NEUROSCIENCES/ConnexConnex

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.