Highlights

The Highlights

Read Deliverable D1.1: Consciousness: models, metrics & intervention in the electric brain

Check Luminous project on Research gate

Main findings of the second year of the Luminous project

  • Kolmogorov theory of consciousness is now published!
  • We validated the NMM software for producing wake-sleep cycle data through the adaptation of cortico-cortical and thalamo-cortical
  • New interregional communication mechanisms have been incorporated in the NMM: communication through coherence and gating by inhibition.
  • We found higher Lempel-Ziv complexity values on wakefulness compared to propofol anaesthesia in the resting-state EEG of healthy controls.
  • We proposed a multisite-tCS protocol for CLIS patients to increase vigilance and enhance communication performance through BCI.
  • We found that DOC (Disorders of Consciousness) networks are characterised by poor global information processing (network integration) and relatively larger local information processing (network segregation) compared to networks of healthy controls.
  • We implemented a closed-loop tCS protocol for patients with Disorders of Consciousness.
  • We designed a protocol where rTMS pulses induce alpha activity and tACS entrain it to induce lucid dreaming states.
  • We simplified the famous PCI (Perturbation Complexity Index) computation and started working with SEP (Somatosensory Evoked Potentials) as an alternative to TMS-induced PCI.

 

Main findings of the first year of the Luminous project

The first review meeting has been successfully carried out and here we present our main findings:
  • We modelled the E-field distribution of a patient in Minimally Conscious State (MCS) and a healthy control and we showed that there are differences due to the lesions of the patient, highlighting the need to create personalized models for brain stimulation.
  • We created strategies for tCS targeting networks for MCS and LIS (Locked-In Syndrome) patients, and designed a closed-loop system for stimulating high or low vigilance levels.
  • In a multisite tDCS (transcranial direct currect stimulation) and EEG (electroencephalography) study we demonstrated significant behavioural changes in TBI (Traumatic Brain Injury) In the same study, we estimated complexity from EEG signals under two experimental conditions (multisite tDCS stimulation and placebo), showing that complexity decreases with DOC (Disorders Of Consciousness) right after tDCS stimulation.
  • We showed that it’s feasible to titrate anaesthesia to achieve and maintain SWAS in an individual patient using real-time EEG feedback, and that changes in the thalamo-cortical connectivity at SWAS indicate true perception loss.
  • We trained a NIRS SVM (Near Infrared Spectroscopy Support Vector Machine) classifier on LIS patients in a BCI (Brain-Computer Interface) setting with a priori known true and false sentences and obtained classification accuracy of around 70%. Our next goal is to improve vigilance and BCI performance by stimulating with tCS/EEG.
  • We revealed a global mismatch component as early as 150 ms and latest difference at 500 ms, in a MMN (MisMatch Negativity) local-global paradigm study of healthy adults. Our goal is to extend this to fetuses.
  • We found MMN observed during wakefulness and REM sleep nut not in N1, N2, and N3 sleep.
  • We worked on EEG-based measures of consciousness using a non-invasive perturbational approach in a longitudinal multi-modal evaluation of DOC patients. These measures include the neuronal bistability and the perturbational complexity index. We distinguished between conscious and unconscious state with 100% specificity and sensitivity. We also carried out animal studies and human healthy subjects studies during wakefulness and NREM sleep, as well as TMS (Transcranial Magnetic Stimulation) applied to the primary motor cortex, and showed that the EEG-response to TMS of hand-M1 is larger and accompanied by a late event-related desynchronization.