Neural detection of complex sound sequences or of statistical regularities in the absence of consciousness?

Naccache, Lionel; J, King; Sitt, Jacobo; Engemann, Denis A.; Karoui, Imen; Rohaut, Benjamin; Faugeras, Frédéric; Chennu, Srivas; Strauss, Mélanie; Bekinschtein, Tristán A.; Dehaene, Stanislas

doi:10.1093/brain/awv190

Cited by 19 publications

(14 citation statements)

References 17 publications

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“…In line with these results an improvement in auditory deviance detection positively correlated with functional and cognitive performance levels at awakening in coma survivors . To what extent deviance detection capacity in comatose patients persists as a function of stimulus complexity and stimulus modality is currently a focus of an intense research activity …”

Section: Introductionmentioning

confidence: 57%

Somatosensory and auditory deviance detection for outcome prediction during postanoxic coma

Pfeiffer

Nguissi

Chytiris

et al. 2018

Ann Clin Transl Neurol

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ObjectiveProminent research in patients with disorders of consciousness investigated the electrophysiological correlates of auditory deviance detection as a marker of consciousness recovery. Here, we extend previous studies by investigating whether somatosensory deviance detection provides an added value for outcome prediction in postanoxic comatose patients.MethodsElectroencephalography responses to frequent and rare stimuli were obtained from 66 patients on the first and second day after coma onset.ResultsMultivariate decoding analysis revealed an above chance‐level auditory discrimination in 25 patients on the first day and in 31 patients on the second day. Tactile discrimination was significant in 16 patients on the first day and in 23 patients on the second day. Single‐day sensory discrimination was unrelated to patients’ outcome in both modalities. However, improvement of auditory discrimination from first to the second day was predictive of good outcome with a positive predictive power (PPV) of 0.73 (CI = 0.52–0.88). Analyses considering the improvement of tactile, auditory and tactile, or either auditory or tactile discrimination showed no significant prediction of good outcome (PPVs = 0.58–0.68).InterpretationOur results show that in the acute phase of coma deviance detection is largely preserved for both auditory and tactile modalities. However, we found no evidence for an added value of somatosensory to auditory deviance detection function for coma‐outcome prediction.

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Section: Introductionmentioning

confidence: 57%

Somatosensory and auditory deviance detection for outcome prediction during postanoxic coma

Pfeiffer

Nguissi

Chytiris

et al. 2018

Ann Clin Transl Neurol

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“…Note however that in a recent study, Tzovara et al used a multivariate decoding algorithm (and not the usual ERP method), and reported evidence for preserved processing of the global regularity in some post-cardiac arrest comatose patients (68). While this result may challenge the general value of the 'global effect' signature to probe consciousness, several important points suggest that this decoding performance was driven by an unconscious early processing (within the MMN window) we previously published (69), and not by the late and sustained (P3b) event that we proposed as the possible signature of conscious access (70). Note that such an effect is inherent to a statistical regularity difference between the physical identity of global standard (GS) and global deviant (GD) trials that modulates the early and unconscious MMN-window response.…”

Section: Probing Conscious Access To External Stimulimentioning

confidence: 72%

“…A strong finding supporting this view stems from tests of generalization of the decoding algorithm: when half of trials (LS or LD) are used to train a decoder to distinguish global standard from global deviant trials, and that this decoder is then tested on the second half of trials (LS or LD), the decoding performance in the early time window drops considerably, whereas the decoding performance of the late time windows remains unchanged. Therefore, the early and unconscious decoding effect seems specific to statistical regularities of the physical stimuli, whereas the late P3b effect seems to reflect a genuine abstract processing of global violations, and the updating of a rule representation in conscious working memory (70).…”

Section: Probing Conscious Access To External Stimulimentioning

confidence: 91%

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

Rohaut¹,

Naccache

2017

Revue Neurologique

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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.

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“…) , (10) where (µ i , Σ i ) i=1,2 are the mean and variance computed from each class C 1 and C 2 from S n . We used the fraction π = ns ns+n d =, for the number of survival n s and deceased patients n d .…”

Section: Gaussian Estimatormentioning

confidence: 99%

“…Indeed, a considerable amount of information is lost by considering only these averages and calls for a different statistical approach for the diagnosis of the patient brain condition. Several complementary methods have been developed to quantify the predictive value of the MMN for comatose patients: some are based on t-test in time (100-200 ms) to check the presence of a detectable peak of the mismatch negativity, others are based on wavelet transform, multivariate, cross-correlation and probabilistic methods [4,5,6,7,8,9,10,11]. Finally, we still missing a consensus about the quality of the existing features [12,2,13] to predict the outcome of post-anoxic coma.…”

Section: Introductionmentioning

confidence: 99%

Predictive analysis of patient recovery from cardiac-respiratory arrest

Floyrac¹,

Doumergue²,

Kubis

et al. 2019

Preprint

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The severity of neuronal damages in comatose patients following anoxic brain injury can be probed by evoked auditory responses. However, it remains challenging to predict the return to full consciousness of post-anoxic coma of hospitalized patients. We presented here a method to predict the return to consciousness based on the analysis of periodic responses to auditory stimulations, recorded from surface cranial electrodes. The input data are event-related potentials (ERPs), recorded non-invasively with electro-encephalography (EEG). We extracted several novel features from the time series responses in a window of few hundreds of milliseconds from deviant and non-deviant auditory stimulations. We use these features to construct two-dimensional statistical maps, that show two separated clusters for recovered (conscience) and deceased patients, leading to a high classification success as tested by a cross-validation procedure. Finally, using Gaussian, K-neighborhood and SVM classifiers, we construct probabilistic maps to predict the outcome of post-anoxic coma. To conclude, statistics of deviant and non-deviant responses considered separately provide complementary and confirmatory predictions for the outcome of anoxic coma.

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Neural detection of complex sound sequences or of statistical regularities in the absence of consciousness?

Cited by 19 publications

References 17 publications

Somatosensory and auditory deviance detection for outcome prediction during postanoxic coma

Somatosensory and auditory deviance detection for outcome prediction during postanoxic coma

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

Predictive analysis of patient recovery from cardiac-respiratory arrest

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