Joachim Bellet, Marion Gay, A. Dwarakanath, B. Jarraya, Timo van Kerkoerle, S. Dehaene, T. Panagiotaropoulos
{"title":"Decoding rapidly presented visual stimuli from prefrontal ensembles without report nor post-perceptual processing","authors":"Joachim Bellet, Marion Gay, A. Dwarakanath, B. Jarraya, Timo van Kerkoerle, S. Dehaene, T. Panagiotaropoulos","doi":"10.1093/nc/niac005","DOIUrl":"https://doi.org/10.1093/nc/niac005","url":null,"abstract":"Abstract The role of the primate prefrontal cortex (PFC) in conscious perception is debated. The global neuronal workspace theory of consciousness predicts that PFC neurons should contain a detailed code of the current conscious contents. Previous research showed that PFC is indeed activated in paradigms of conscious visual perception, including no-report paradigms where no voluntary behavioral report of the percept is given, thus avoiding a conflation of signals related to visual consciousness with signals related to the report. Still, it has been argued that prefrontal modulation could reflect post-perceptual processes that may be present even in the absence of report, such as thinking about the perceived stimulus, therefore reflecting a consequence rather than a direct correlate of conscious experience. Here, we investigate these issues by recording neuronal ensemble activity from the macaque ventrolateral PFC during briefly presented visual stimuli, either in isolated trials in which stimuli were clearly perceived or in sequences of rapid serial visual presentation (RSVP) in which perception and post-perceptual processing were challenged. We report that the identity of each stimulus could be decoded from PFC population activity even in the RSVP condition. The first visual signals could be detected at 60 ms after stimulus onset and information was maximal at 150 ms. However, in the RSVP condition, 200 ms after the onset of a stimulus, the decoding accuracy quickly dropped to chance level and the next stimulus started to be decodable. Interestingly, decoding in the ventrolateral PFC was stronger compared to posterior parietal cortex for both isolated and RSVP stimuli. These results indicate that neuronal populations in the macaque PFC reliably encode visual stimuli even under conditions that have been shown to challenge conscious perception and/or substantially reduce the probability of post-perceptual processing in humans. We discuss whether the observed activation reflects conscious access, phenomenal consciousness, or merely a preconscious bottom-up wave.","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47051140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Niikawa, Katsunori Miyahara, H. Hamada, S. Nishida
{"title":"Functions of consciousness: conceptual clarification","authors":"T. Niikawa, Katsunori Miyahara, H. Hamada, S. Nishida","doi":"10.1093/nc/niac006","DOIUrl":"https://doi.org/10.1093/nc/niac006","url":null,"abstract":"Abstract There are many theories of the functions of consciousness. How these theories relate to each other, how we should assess them, and whether any integration of them is possible are all issues that remain unclear. To contribute to a solution, this paper offers a conceptual framework to clarify the theories of the functions of consciousness. This framework consists of three dimensions: (i) target, (ii) explanatory order, and (iii) necessity/sufficiency. The first dimension, target, clarifies each theory in terms of the kind of consciousness it targets. The second dimension, explanatory order, clarifies each theory in terms of how it conceives of the explanatory relation between consciousness and function. The third dimension, necessity/sufficiency, clarifies each theory in terms of the necessity/sufficiency relation posited between consciousness and function. We demonstrate the usefulness of this framework by applying it to some existing scientific and philosophical theories of the functions of consciousness.","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46464193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diane Derrien, Clémentine Garric, C. Sergent, S. Chokron
{"title":"The nature of blindsight: implications for current theories of consciousness","authors":"Diane Derrien, Clémentine Garric, C. Sergent, S. Chokron","doi":"10.1093/nc/niab043","DOIUrl":"https://doi.org/10.1093/nc/niab043","url":null,"abstract":"Abstract Blindsight regroups the different manifestations of preserved discriminatory visual capacities following the damage to the primary visual cortex. Blindsight types differentially impact objective and subjective perception, patients can report having no visual awareness whilst their behaviour suggests visual processing still occurs at some cortical level. This phenomenon hence presents a unique opportunity to study consciousness and perceptual consciousness, and for this reason, it has had an historical importance for the development of this field of research. From these studies, two main opposing models of the underlying mechanisms have been established: (a) blindsight is perception without consciousness or (b) blindsight is in fact degraded vision, two views that mirror more general theoretical options about whether unconscious cognition truly exists or whether it is only a degraded form of conscious processing. In this article, we want to re-examine this debate in the light of recent advances in the characterization of blindsight and associated phenomena. We first provide an in-depth definition of blindsight and its subtypes, mainly blindsight type I, blindsight type II and the more recently described blindsense. We emphasize the necessity of sensitive and robust methodology to uncover the dissociations between perception and awareness that can be observed in brain-damaged patients with visual field defects at different cognitive levels. We discuss these different profiles of dissociation in the light of both contending models. We propose that the different types of dissociations reveal a pattern of relationship between perception, awareness and metacognition that is actually richer than what is proposed by either of the existing models. Finally, we consider this in the framework of current theories of consciousness and touch on the implications the findings of blindsight have on these.","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45694966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Consciousness as a multidimensional phenomenon: implications for the assessment of disorders of consciousness.","authors":"Jasmine Walter","doi":"10.1093/nc/niab047","DOIUrl":"10.1093/nc/niab047","url":null,"abstract":"<p><p>Disorders of consciousness (DoCs) pose a significant clinical and ethical challenge because they allow for complex forms of conscious experience in patients where intentional behaviour and communication are highly limited or non-existent. There is a pressing need for brain-based assessments that can precisely and accurately characterize the conscious state of individual DoC patients. There has been an ongoing research effort to develop neural measures of consciousness. However, these measures are challenging to validate not only due to our lack of ground truth about consciousness in many DoC patients but also because there is an open ontological question about consciousness. There is a growing, well-supported view that consciousness is a multidimensional phenomenon that cannot be fully described in terms of the theoretical construct of hierarchical, easily ordered conscious levels. The multidimensional view of consciousness challenges the utility of levels-based neural measures in the context of DoC assessment. To examine how these measures may map onto consciousness as a multidimensional phenomenon, this article will investigate a range of studies where they have been applied in states other than DoC and where more is known about conscious experience. This comparative evidence suggests that measures of conscious level are more sensitive to some dimensions of consciousness than others and cannot be assumed to provide a straightforward hierarchical characterization of conscious states. Elevated levels of brain complexity, for example, are associated with conscious states characterized by a high degree of sensory richness and minimal attentional constraints, but are suboptimal for goal-directed behaviour and external responsiveness. Overall, this comparative analysis indicates that there are currently limitations to the use of these measures as tools to evaluate consciousness as a multidimensional phenomenon and that the relationship between these neural signatures and phenomenology requires closer scrutiny.</p>","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/e1/fc/niab047.PMC8716840.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39791463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Perceptual Awareness Scale-recent controversies and debates.","authors":"Morten Overgaard, Kristian Sandberg","doi":"10.1093/nc/niab044","DOIUrl":"10.1093/nc/niab044","url":null,"abstract":"<p><p>Accurate insight into subjective experience is crucial for the science of consciousness. The Perceptual Awareness Scale (PAS) was created in 2004 as a method for obtaining precise introspective reports for participants in research projects, and since then, the scale has become increasingly popular. This does not mean, of course, that no critiques have been voiced. Here, we briefly recapitulate our main thoughts on the intended PAS usage and the findings of the first decade, and we update this with the latest empirical and theoretical developments. We focus specifically on findings with relevance to whether consciousness is gradual or all-or-none phenomenon, to what should be considered conscious/unconscious, and to whether PAS is preferable to alternative measures of awareness. We respond in detail to some recent, selected articles.</p>","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/00/d6/niab044.PMC8672240.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39739490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Representational 'touch' and modulatory 'retouch'-two necessary neurobiological processes in thalamocortical interaction for conscious experience.","authors":"Talis Bachmann","doi":"10.1093/nc/niab045","DOIUrl":"10.1093/nc/niab045","url":null,"abstract":"<p><p>Theories of consciousness using neurobiological data or being influenced by these data have been focused either on states of consciousness or contents of consciousness. These theories have occasionally used evidence from psychophysical phenomena where conscious experience is a dependent experimental variable. However, systematic catalog of many such relevant phenomena has not been offered in terms of these theories. In the perceptual retouch theory of thalamocortical interaction, recently developed to become a blend with the dendritic integration theory, consciousness states and contents of consciousness are explained by the same mechanism. This general-purpose mechanism has modulation of the cortical layer-5 pyramidal neurons that represent contents of consciousness as its core. As a surplus, many experimental psychophysical phenomena of conscious perception can be explained by the workings of this mechanism. Historical origins and current views inherent in this theory are presented and reviewed.</p>","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/e9/57/niab045.PMC8672242.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39739493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Erratum to: Stage 1 registered report: metacognitive asymmetries in visual perception and Stage 2 registered report: metacognitive asymmetries in visual perception.","authors":"Matan Mazor, Rani Moran, Stephen M Fleming","doi":"10.1093/nc/niab046","DOIUrl":"https://doi.org/10.1093/nc/niab046","url":null,"abstract":"<p><p>[This corrects the article DOI: 10.1093/nc/niab005.][This corrects the article DOI: 10.1093/nc/niab025.].</p>","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667774/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39817818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Hermann, A. Sangaré, Esteban Munoz-Musat, Amina Ben Salah, P. Pérez, Mélanie Valente, F. Faugeras, Vadim Axelrod, S. Demeret, C. Marois, N. Pyatigorskaya, M. Habert, A. Kas, J. Sitt, B. Rohaut, L. Naccache
{"title":"Importance, limits and caveats of the use of “disorders of consciousness” to theorize consciousness","authors":"B. Hermann, A. Sangaré, Esteban Munoz-Musat, Amina Ben Salah, P. Pérez, Mélanie Valente, F. Faugeras, Vadim Axelrod, S. Demeret, C. Marois, N. Pyatigorskaya, M. Habert, A. Kas, J. Sitt, B. Rohaut, L. Naccache","doi":"10.1093/nc/niab048","DOIUrl":"https://doi.org/10.1093/nc/niab048","url":null,"abstract":"Abstract The clinical and fundamental exploration of patients suffering from disorders of consciousness (DoC) is commonly used by researchers both to test some of their key theoretical predictions and to serve as a unique source of empirical knowledge about possible dissociations between consciousness and cognitive and/or neural processes. For instance, the existence of states of vigilance free of any self-reportable subjective experience [e.g. “vegetative state (VS)” and “complex partial epileptic seizure”] originated from DoC and acted as a cornerstone for all theories by dissociating two concepts that were commonly equated and confused: vigilance and conscious state. In the present article, we first expose briefly the major achievements in the exploration and understanding of DoC. We then propose a synthetic taxonomy of DoC, and we finally highlight some current limits, caveats and questions that have to be addressed when using DoC to theorize consciousness. In particular, we show (i) that a purely behavioral approach of DoC is insufficient to characterize the conscious state of patients; (ii) that the comparison between patients in a minimally conscious state (MCS) and patients in a VS [also coined as unresponsive wakefulness syndrome (UWS)] does not correspond to a pure and minimal contrast between unconscious and conscious states and (iii) we emphasize, in the light of original resting-state positron emission tomography data, that behavioral MCS captures an important but misnamed clinical condition that rather corresponds to a cortically mediated state and that MCS does not necessarily imply the preservation of a conscious state.","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48964387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Alpha and theta oscillations are inversely related to progressive levels of meditation depth.","authors":"Sucharit Katyal, Philippe Goldin","doi":"10.1093/nc/niab042","DOIUrl":"https://doi.org/10.1093/nc/niab042","url":null,"abstract":"<p><p>Meditation training is proposed to enhance mental well-being by modulating neural activity, particularly alpha and theta brain oscillations, and autonomic activity. Although such enhancement also depends on the quality of meditation, little is known about how these neural and physiological changes relate to meditation quality. One model characterizes meditation quality as five increasing levels of 'depth': hindrances, relaxation, concentration, transpersonal qualities and nonduality. We investigated the neural oscillatory (theta, alpha, beta and gamma) and physiological (respiration rate, heart rate and heart rate variability) correlates of the self-reported meditation depth in long-term meditators (LTMs) and meditation-naïve controls (CTLs). To determine the neural and physiological correlates of meditation depth, we modelled the change in the slope of the relationship between self-reported experiential degree at each of the five depth levels and the multiple neural and physiological measures. CTLs reported experiencing more 'hindrances' than LTMs, while LTMs reported more 'transpersonal qualities' and 'nonduality' compared to CTLs, confirming the experiential manipulation of meditation depth. We found that in both groups, theta (4-6 Hz) and alpha (7-13 Hz) oscillations were related to meditation depth in a precisely opposite manner. The theta amplitude positively correlated with 'hindrances' and increasingly negatively correlated with increasing meditation depth levels. Alpha amplitude negatively correlated with 'hindrances' and increasingly positively with increasing depth levels. The increase in the inverse association between theta and meditation depth occurred over different scalp locations in the two groups-frontal midline in LTMs and frontal lateral in CTLs-possibly reflecting the downregulation of two different aspects of executive processing-monitoring and attention regulation, respectively-during deep meditation. These results suggest a functional dissociation of the two classical neural signatures of meditation training, namely, alpha and theta oscillations. Moreover, while essential for overcoming 'hindrances', executive neural processing appears to be downregulated during deeper meditation experiences.</p>","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2021-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8633885/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39776293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Measuring metacognitive performance: type 1 performance dependence and test-retest reliability.","authors":"Matthias Guggenmos","doi":"10.1093/nc/niab040","DOIUrl":"10.1093/nc/niab040","url":null,"abstract":"<p><p>Research on metacognition-thinking about thinking-has grown rapidly and fostered our understanding of human cognition in healthy individuals and clinical populations. Of central importance is the concept of metacognitive performance, which characterizes the capacity of an individual to estimate and report the accuracy of primary (type 1) cognitive processes or actions ensuing from these processes. Arguably one of the biggest challenges for measures of metacognitive performance is their dependency on objective type 1 performance, although more recent methods aim to address this issue. The present work scrutinizes the most popular metacognitive performance measures in terms of two critical characteristics: independence of type 1 performance and test-retest reliability. Analyses of data from the Confidence Database (total <i>N</i> = 6912) indicate that no current metacognitive performance measure is independent of type 1 performance. The shape of this dependency is largely reproduced by extending current models of metacognition with a source of metacognitive noise. Moreover, the reliability of metacognitive performance measures is highly sensitive to the combination of type 1 performance and trial number. Importantly, trial numbers frequently employed in metacognition research are too low to achieve an acceptable level of test-retest reliability. Among common task characteristics, simultaneous choice and confidence reports most strongly improved reliability. Finally, general recommendations about design choices and analytical remedies for studies investigating metacognitive performance are provided.</p>","PeriodicalId":52242,"journal":{"name":"Neuroscience of Consciousness","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8633424/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39687858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}