scholarly journals Magnetoencephalographic Activity Related to Conscious Perception Is Stable within Individuals across Years but Not between Individuals

2014 ◽  
Vol 26 (4) ◽  
pp. 840-853 ◽  
Author(s):  
Kristian Sandberg ◽  
Gareth Robert Barnes ◽  
Geraint Rees ◽  
Morten Overgaard
Keyword(s):  
Individual Differences ◽  
Binocular Rivalry ◽  
Neural Activity ◽  
Time Window ◽  
Stimulus Presentation ◽  
Neural Correlates ◽  
Classification Algorithms ◽  
Conscious Perception ◽  
Large Drop ◽  
Decoding Accuracy

Studies indicate that conscious perception is related to changes in neural activity within a time window that varies between 130 and 320 msec after stimulus presentation, yet it is not known whether such neural correlates of conscious perception are stable across time. Here, we examined the generalization across time within individuals and across different individuals. We trained classification algorithms to decode conscious perception from neural activity recorded during binocular rivalry using magnetoencephalography (MEG). The classifiers were then used to predict the perception of the same participants during different recording sessions either days or years later as well as between different participants. No drop in decoding accuracy was observed when decoding across years compared with days, whereas a large drop in decoding accuracy was found for between-participant decoding. Furthermore, underlying percept-specific MEG signals remained stable in terms of latency, amplitude, and sources within participants across years, whereas differences were found in all of these domains between individuals. Our findings demonstrate that the neural correlates of conscious perception are stable across years for adults, but differ across individuals. Moreover, the study validates decoding based on MEG data as a method for further studies of correlations between individual differences in perceptual contents and between-participant decoding accuracies.

scholarly journals Early Visual Responses Predict Conscious Face Perception within and between Subjects during Binocular Rivalry

2013 ◽  
Vol 25 (6) ◽  
pp. 969-985 ◽  
Author(s):  
Kristian Sandberg ◽  
Bahador Bahrami ◽  
Ryota Kanai ◽  
Gareth Robert Barnes ◽  
Morten Overgaard ◽  
...  
Keyword(s):  
Face Perception ◽  
Binocular Rivalry ◽  
Neural Activity ◽  
Time Window ◽  
Conscious Experience ◽  
Time Range ◽  
Conscious Perception ◽  
Visual Responses ◽  
Physical Stimulation ◽  
Better Than

Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170–800 msec after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using multivariate classification on MEG data recorded when participants reported changes in conscious perception evoked by binocular rivalry between a face and a grating, we showed that only MEG signals in the 120–320 msec time range, peaking at the M170 around 180 msec and the P2m at around 260 msec, reliably predicted conscious experience. Conscious perception could not only be decoded significantly better than chance from the sensors that showed the largest average difference, as previous studies suggest, but also from patterns of activity across groups of occipital sensors that individually were unable to predict perception better than chance. In addition, source space analyses showed that sources in the early and late visual system predicted conscious perception more accurately than frontal and parietal sites, although conscious perception could also be decoded there. Finally, the patterns of neural activity associated with conscious face perception generalized from one participant to another around the times of maximum prediction accuracy. Our work thus demonstrates that the neural correlates of particular conscious contents (here, faces) are highly consistent in time and space within individuals and that these correlates are shared to some extent between individuals.

scholarly journals Can binocular rivalry reveal neural correlates of consciousness?

2014 ◽  
Vol 369 (1641) ◽  
pp. 20130211 ◽  
Author(s):  
Randolph Blake ◽  
Jan Brascamp ◽  
David J. Heeger
Keyword(s):  
Decision Making ◽  
Binocular Rivalry ◽  
Neural Activity ◽  
Neural Correlates ◽  
Causal Link ◽  
Neural Dynamics ◽  
Perceptual Decision Making ◽  
Neural Correlate ◽  
Neural Correlates Of Consciousness ◽  
Neural Correlate Of Consciousness

This essay critically examines the extent to which binocular rivalry can provide important clues about the neural correlates of conscious visual perception. Our ideas are presented within the framework of four questions about the use of rivalry for this purpose: (i) what constitutes an adequate comparison condition for gauging rivalry's impact on awareness, (ii) how can one distinguish abolished awareness from inattention, (iii) when one obtains unequivocal evidence for a causal link between a fluctuating measure of neural activity and fluctuating perceptual states during rivalry, will it generalize to other stimulus conditions and perceptual phenomena and (iv) does such evidence necessarily indicate that this neural activity constitutes a neural correlate of consciousness? While arriving at sceptical answers to these four questions, the essay nonetheless offers some ideas about how a more nuanced utilization of binocular rivalry may still provide fundamental insights about neural dynamics, and glimpses of at least some of the ingredients comprising neural correlates of consciousness, including those involved in perceptual decision-making.

Binocular rivalry and emotion: Implications for neural correlates of consciousness and emotional biases in conscious perception

Cortex ◽  
2019 ◽  
Vol 120 ◽  
pp. 539-555
Author(s):  
María Hernández-Lorca ◽  
Kristian Sandberg ◽  
Dominique Kessel ◽  
Uxía Fernández-Folgueiras ◽  
Morten Overgaard ◽  
...  
Keyword(s):  
Binocular Rivalry ◽  
Neural Correlates ◽  
Conscious Perception ◽  
Neural Correlates Of Consciousness

scholarly journals Decoding across sensory modalities reveals common supramodal signatures of conscious perception

2020 ◽  
Vol 117 (13) ◽  
pp. 7437-7446 ◽  
Author(s):  
Gaëtan Sanchez ◽  
Thomas Hartmann ◽  
Marco Fuscà ◽  
Gianpaolo Demarchi ◽  
Nathan Weisz
Keyword(s):  
Neural Activity ◽  
Activity Patterns ◽  
Neural Correlates ◽  
Brain Regions ◽  
Button Press ◽  
Visual Modality ◽  
Conscious Perception ◽  
Neural Processes ◽  
Sensory Modalities ◽  
Near Threshold

An increasing number of studies highlight common brain regions and processes in mediating conscious sensory experience. While most studies have been performed in the visual modality, it is implicitly assumed that similar processes are involved in other sensory modalities. However, the existence of supramodal neural processes related to conscious perception has not been convincingly shown so far. Here, we aim to directly address this issue by investigating whether neural correlates of conscious perception in one modality can predict conscious perception in a different modality. In two separate experiments, we presented participants with successive blocks of near-threshold tasks involving subjective reports of tactile, visual, or auditory stimuli during the same magnetoencephalography (MEG) acquisition. Using decoding analysis in the poststimulus period between sensory modalities, our first experiment uncovered supramodal spatiotemporal neural activity patterns predicting conscious perception of the feeble stimulation. Strikingly, these supramodal patterns included activity in primary sensory regions not directly relevant to the task (e.g., neural activity in visual cortex predicting conscious perception of auditory near-threshold stimulation). We carefully replicate our results in a control experiment that furthermore show that the relevant patterns are independent of the type of report (i.e., whether conscious perception was reported by pressing or withholding a button press). Using standard paradigms for probing neural correlates of conscious perception, our findings reveal a common signature of conscious access across sensory modalities and illustrate the temporally late and widespread broadcasting of neural representations, even into task-unrelated primary sensory processing regions.

scholarly journals Decoding across sensory modalities reveals common supramodal signatures of conscious perception

2017 ◽  
Author(s):  
Gaëtan Sanchez ◽  
Thomas Hartmann ◽  
Marco Fuscà ◽  
Gianpaolo Demarchi ◽  
Nathan Weisz
Keyword(s):  
Neural Activity ◽  
Activity Patterns ◽  
Neural Correlates ◽  
Brain Regions ◽  
Button Press ◽  
Visual Modality ◽  
Conscious Perception ◽  
Sensory Modalities ◽  
Spatio Temporal ◽  
Near Threshold

AbstractAn increasing number of studies highlight common brain regions and processes in mediating conscious sensory experience. While most studies have been performed in the visual modality, it is implicitly assumed that similar processes are involved in other sensory modalities. However, the existence of supramodal neural processes related to conscious perception has not been convincingly shown so far. Here, we aim to directly address this issue by investigating whether neural correlates of conscious perception in one modality can predict conscious perception in a different modality. In two separate experiments, we presented participants with successive blocks of near-threshold tasks involving tactile, visual or auditory stimuli during the same magnetoencephalography (MEG) acquisition. Using decoding analysis in the post-stimulus period between sensory modalities, our first experiment uncovered supramodal spatio-temporal neural activity patterns predicting conscious perception of the feeble stimulation. Strikingly, these supramodal patterns included activity in primary sensory regions not directly relevant to the task (e.g. neural activity in visual cortex predicting conscious perception of auditory near-threshold stimulation). We carefully replicate our results in a control experiment that furthermore show that the relevant patterns are independent of the type of report (i.e. whether conscious perception was reported by pressing or withholding a button-press). Using standard paradigms for probing neural correlates of conscious perception, our findings reveal a common signature of conscious access across sensory modalities and illustrate the temporally late and widespread broadcasting of neural representations, even into task-unrelated primary sensory processing regions.

scholarly journals Forward modelling reveals dynamics of neural orientation tuning to unconscious visual stimuli during binocular rivalry

2019 ◽  
Author(s):  
Matthew F. Tang ◽  
Ehsan Arabzadeh ◽  
Jason B. Mattingley
Keyword(s):  
Binocular Rivalry ◽  
Neural Activity ◽  
Visual Stimuli ◽  
Orientation Tuning ◽  
Conscious Perception ◽  
Forward Modelling ◽  
Neural Responses ◽  
Fine Grained ◽  
Eeg Data ◽  
Selective Information

AbstractWhen different visual stimuli are presented to the two eyes, they typically compete for access to conscious perception, a phenomenon known as binocular rivalry. Previous studies of binocular rivalry have shown that neural responses to consciously suppressed stimuli are markedly diminished in magnitude, though they may still be encoded to some extent. Here we employed multivariate forward modelling of human electroencephalography (EEG) data to quantify orientation-selective responses to visual gratings during binocular rivalry. We found robust orientation tuning to both conscious and unconscious gratings. This tuning was enhanced for the suppressed stimulus well before it was available for conscious report. The same pattern was evident in the overall magnitude of neural responses, and it emerged even earlier than the changes in neural tuning. Taken together, our findings suggest that rivalry suppression affects broadband, non-orientation selective aspects of neural activity before refining fine-grained feature-selective information.

scholarly journals Optokinetic nystagmus reflects perceptual directions in the onset binocular rivalry in Parkinson’s disease

2016 ◽  
Author(s):  
Mana Fujiwara ◽  
Catherine Ding ◽  
Lisandro Kaunitz ◽  
Julie C Stout ◽  
Dominic Thyagarajan ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Eye Movements ◽  
Binocular Rivalry ◽  
Optokinetic Nystagmus ◽  
Stimulus Presentation ◽  
Button Press ◽  
Motor Disorder ◽  
Conscious Perception ◽  
Inter Trial Interval

AbstractOptokinetic nystagmus (OKN), the reflexive eye movements evoked by a moving field, has recently gained interest among researchers as a useful tool to assess conscious perception. When conscious perception and stimulus are dissociated, such as in binocular rivalry —when dissimilar images are simultaneously presented to each eye and perception alternates between the two images over time — OKN correlates with perception rather than with the physical direction of the moving field. While this relationship is well established in healthy subjects it is yet unclear whether it also generalizes to clinical populations, for example, patients with Parkinson’s disease. Parkinson’s disease is a motor disorder, causing tremor, slow movements and rigidity. It may also be associated with oculomotor deficits, such as impaired saccades and smooth pursuit eye movements. Here, we employed short-duration, onset binocular rivalry (2 s trial of stimulus presentation followed by 1 s inter-trial interval) with moving grating stimuli to assess OKN in Parkinson’s disease patients (N=39) and controls (N=29) of a similar age. Each trial was either non-rivalrous (same stimuli presented to both eyes) or rivalrous, as in binocular rivalry. We analyzed OKN to discriminate direction of stimulus and perception on a trial-by-trial basis. OKN reflected conscious perceptions in both groups. Treatment with anti-Parkinson drugs and deep brain stimulation improved motor ability of patients assessed by a standard scale of Parkinson’s disease, but did not impact on OKN. Furthermore, OKN-based measures were robust and their latencies were shorter than manual button-based measures in all subjects, regardless of stimulus condition. Our findings suggest that OKN can be used as an indicator of conscious perception in binocular rivalry even in Parkinson’s disease patients in whom impaired manual dexterity may render button-press reports less reliable.

scholarly journals Decoding the contents of consciousness from prefrontal ensembles

2020 ◽  
Author(s):  
Vishal Kapoor ◽  
Abhilash Dwarakanath ◽  
Shervin Safavi ◽  
Joachim Werner ◽  
Michel Besserve ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Binocular Rivalry ◽  
Critical Role ◽  
Neural Correlates ◽  
Conscious Perception ◽  
Cognitive Variables ◽  
Ongoing Debate ◽  
Macaque Monkeys ◽  
Multistable Perception ◽  
Ensemble Activity

ABSTRACTMultiple theories attribute to the primate prefrontal cortex a critical role in conscious perception. However, opposing views caution that prefrontal activity could reflect other cognitive variables during paradigms investigating consciousness, such as decision-making, monitoring and motor reports. To resolve this ongoing debate, we recorded from prefrontal ensembles of macaque monkeys during a no-report paradigm of binocular rivalry that instigates internally driven transitions in conscious perception. We could decode the contents of consciousness from prefrontal ensemble activity during binocular rivalry with an accuracy similar to when these stimuli were presented without competition. Oculomotor signals, used to infer conscious content, were not the only source of these representations since visual input could be significantly decoded when eye movements were suppressed. Our results suggest that the collective dynamics of prefrontal cortex populations reflect internally generated changes in the content of consciousness during multistable perception.One sentence summaryNeural correlates of conscious perception can be detected and perceptual contents can be reliably decoded from the spiking activity of prefrontal populations.

scholarly journals Temporal Dynamics of Neural Activity at the Moment of Emergence of Conscious Percept

2012 ◽  
Vol 24 (10) ◽  
pp. 1983-1997 ◽  
Author(s):  
Yasuki Noguchi ◽  
Takemasa Yokoyama ◽  
Megumi Suzuki ◽  
Shinichi Kita ◽  
Ryusuke Kakigi
Keyword(s):  
Neural Activity ◽  
Temporal Dynamics ◽  
Rapid Change ◽  
Neural Correlates ◽  
Conscious Perception ◽  
Bottom Up ◽  
Neural Correlates Of Consciousness ◽  
Ventral Pathway ◽  
The Moment ◽  
The Brain

From which regions of the brain do conscious representations of visual stimuli emerge? This is an important but controversial issue in neuroscience because some studies have reported a major role of the higher visual regions of the ventral pathway in conscious perception, whereas others have found neural correlates of consciousness as early as in the primary visual areas and in the thalamus. One reason for this controversy has been the difficulty in focusing on neural activity at the moment when conscious percepts are generated in the brain, excluding any bottom–up responses (not directly related to consciousness) that are induced by stimuli. In this study, we address this issue with a new approach that can induce a rapid change in conscious perception with little influence from bottom–up responses. Our results reveal that the first consciousness-related activity emerges from the higher visual region of the ventral pathway. However, this activity is rapidly diffused to the entire brain, including the early visual cortex. These results thus integrate previous “higher” and “lower” views on the emergence of neural correlates of consciousness, providing a new perspective for the temporal dynamics of consciousness.

scholarly journals Conscious perception and perceptual echoes: a binocular rivalry study

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Canhuang Luo ◽  
Rufin VanRullen ◽  
Andrea Alamia
Keyword(s):  
Binocular Rivalry ◽  
Visual Information ◽  
Visual Stimulation ◽  
Brain Regions ◽  
Travelling Wave ◽  
Alpha Power ◽  
Conscious Perception ◽  
Impulse Response Functions ◽  
Band Frequency ◽  
Underlying Mechanisms

Abstract Alpha rhythms (∼10Hz) in the human brain are classically associated with idling activities, being predominantly observed during quiet restfulness with closed eyes. However, recent studies demonstrated that alpha (∼10Hz) rhythms can directly relate to visual stimulation, resulting in oscillations, which can last for as long as one second. This alpha reverberation, dubbed perceptual echoes (PE), suggests that the visual system actively samples and processes visual information within the alpha-band frequency. Although PE have been linked to various visual functions, their underlying mechanisms and functional role are not completely understood. In this study, we investigated the relationship between conscious perception and the generation and the amplitude of PE. Specifically, we displayed two coloured Gabor patches with different orientations on opposite sides of the screen, and using a set of dichoptic mirrors, we induced a binocular rivalry between the two stimuli. We asked participants to continuously report which one of two Gabor patches they consciously perceived, while recording their EEG signals. Importantly, the luminance of each patch fluctuated randomly over time, generating random sequences from which we estimated two impulse-response functions (IRFs) reflecting the PE generated by the perceived (dominant) and non-perceived (suppressed) stimulus, respectively. We found that the alpha power of the PE generated by the consciously perceived stimulus was comparable with that of the PE generated during monocular vision (control condition) and higher than the PE induced by the suppressed stimulus. Moreover, confirming previous findings, we found that all PEs propagated as a travelling wave from posterior to frontal brain regions, irrespective of conscious perception. All in all our results demonstrate a correlation between conscious perception and PE, suggesting that the synchronization of neural activity plays an important role in visual sampling and conscious perception.

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