Reply: Replicability and impact of statistics in the detection of neural responses of consciousness

Naccache, Lionel; Sitt, Jacobo; J, King; Rohaut, Benjamin; Faugeras, Frédéric; Chennu, Srivas; Strauss, Mélanie; Valente, Mélanie; Engemann, Denis A.; Raimondo, Federico; Demertzi, Athena; Bekinschtein, Tristán A.; Dehaene, Stanislas

doi:10.1093/brain/aww060

Cited by 9 publications

(8 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, if the research community generally agrees on the need of statistics for ERPs interpretation, several concerns have been raised on the important variability of the methods across studies and there is still no gold standard. 66,67 As we were able to demonstrate the existence of an MMN at the group level, we could probe individual MMN amplitudes accordingly to the latency observed at the group level. This methodological approach was to some extent validated by the fact that the MMN amplitudes were correlated with the occurrence of awakening after discontinuation of sedation.…”

Section: Discussionmentioning

confidence: 99%

Mismatch negativity to predict subsequent awakening in deeply sedated critically ill patients

Azabou

Rohaut

Porcher

et al. 2018

British Journal of Anaesthesia

View full text Add to dashboard Cite

Background: Mismatch negativity (MMN) is the neurophysiological correlate of cognitive integration of novel stimuli. Although MMN is a well-established predictor of awakening in non-sedated comatose patients, its prognostic value in deeply sedated critically ill patients remains unknown. The aim of this prospective, observational pilot study was to investigate the prognostic value of MMN for subsequent awakening in deeply sedated critically ill patients. Methods: MMN was recorded in 43 deeply sedated critically ill patients on Day 3 of ICU admission using a classical 'oddball' paradigm that delivers rare deviant sounds in a train of frequent standard sounds. Individual visual analyses and a group level analysis of recordings were performed. MMN amplitudes were then analysed according to the neurological status (awake vs not awake) at Day 28. Results: Median (inter-quartile range) Richmond Assessment Sedation Scale (RASS) at the time of recording was À5 (range, from À5 to À4.5). Visual detection of MMN revealed a poor inter-rater agreement [kappa¼0.17, 95% confidence interval (0.07e0.26)]. On Day 28, 30 (70%) patients had regained consciousness while 13 (30%) had not. Quantitative group

show abstract

Section: Discussionmentioning

confidence: 99%

Mismatch negativity to predict subsequent awakening in deeply sedated critically ill patients

Azabou

Rohaut

Porcher

et al. 2018

British Journal of Anaesthesia

View full text Add to dashboard Cite

show abstract

“…I close this proposal by underlining the importance of considering these functional brain imaging tools with caution regarding the complex data analysis methods that are often used, and the statistical challenges they raise (see for instance the following studies and discussions: Boly et al , 2011 ; King et al , 2011 ; Cruse et al , 2013 ; Goldfine et al , 2013 ; Naccache et al , 2015 , 2016 ; Tzovara et al , 2015 a , b ; Gabriel et al , 2016 ). A set of basic principles have to be respected such as: standardization of methods across sites, high-replicability and high-sensitivity, as well as using a hierarchical approach (from low to high cognitive measures), and combining basic and complex data analysis methods on the same datasets ( Naccache et al , 2016 ).…”

Section: Proposalsmentioning

confidence: 99%

Minimally conscious state or cortically mediated state?

Naccache

2017

Brain

Self Cite

133

102

View full text Add to dashboard Cite

show abstract

“…Clinicians interpreting these complex analyses must be perfectly aware of the caveats and pitfalls related to the signal processing and the applied statistics they use. This fundamental issue has been specifically assessed for the "Local Global" paradigm (82,83). If the presence of a genuine global effect (in the late temporal window; >250 ms) is highly predictive of conscious processing (both high specificity and positive predictive value), and can be observed in almost 100% of conscious controls attending to the stimuli (25,27,29), its absence is more difficult to interpret in patients.…”

Section: Discussionmentioning

confidence: 99%

Disentangling conscious from unconscious cognitive processing with event-related EEG potentials

Rohaut¹,

Naccache

2017

Revue Neurologique

View full text Add to dashboard Cite

By looking for properties of consciousness, cognitive neuroscience studies have dramatically enlarged the scope of unconscious cognitive processing. This emerging knowledge inspired the development of new approaches allowing clinicians to probe and disentangle conscious from unconscious cognitive processes in non-communicating brain-injured patients both in terms of behaviour and brain activity. This information is extremely valuable in order to improve diagnosis and prognosis in such patients both at acute and chronic settings. Reciprocally, the growing observations coming from such patients suffering from disorders of consciousness provide valuable constraints to theoretical models of consciousness. In this review we chose to illustrate these recent developments by focusing on brain signals recorded with EEG at bedside in response to auditory stimuli. More precisely, we present the respective EEG markers of unconscious and conscious processing of two classes of auditory stimuli (sounds and words). We show that in both cases, conscious access to the corresponding representation (e.g.: auditory regularity and verbal semantic content) share a similar neural signature (P3b and P600/LPC) that can be distinguished from unconscious processing occurring during an earlier stage (MMN and N400). We propose a two-stage serial model of processing and discuss how unconscious and conscious signatures can be measured at bedside providing relevant informations for both diagnosis and prognosis of consciousness recovery. These two examples emphasize how fruitful can be the bidirectional approach exploring cognition in healthy subjects and in brain-damaged patients.

show abstract

Reply: Replicability and impact of statistics in the detection of neural responses of consciousness

Cited by 9 publications

References 21 publications

Mismatch negativity to predict subsequent awakening in deeply sedated critically ill patients

Mismatch negativity to predict subsequent awakening in deeply sedated critically ill patients

Minimally conscious state or cortically mediated state?

Disentangling conscious from unconscious cognitive processing with event-related EEG potentials

Contact Info

Product

Resources

About