scholarly journals Measuring graded changes in consciousness through multi-target filling-in

2018 ◽  
Author(s):  
Matthew J Davidson ◽  
Irene Graafsma ◽  
Naotsugu Tsuchiya ◽  
Jeroen van Boxtel
Keyword(s):  
Neural Activity ◽  
Second Harmonic ◽  
Visual Display ◽  
Neural Correlates ◽  
Background Information ◽  
Button Press ◽  
List Type ◽  
Subjective Report ◽  
Neural Correlates Of Consciousness ◽  
Visual Background

AbstractPerceptual filling-in (PFI) occurs when a physically-present visual target disappears from conscious perception, with its location filled in by the surrounding visual background. Compared to other visual illusions, these perceptual changes are crisp and simple, and can occur for multiple spatially-separated targets simultaneously. Contrasting neural activity during the presence or absence of PFI may complement other multistable phenomena to reveal the neural correlates of consciousness (NCC). We presented four peripheral targets over a background dynamically updating at 20 Hz. While participants reported on target disappearances/reappearances via button press/release, we tracked neural activity entrained by the background during PFI using steady-state visually evoked potentials (SSVEPs) recorded in the electroencephalogram. We found background SSVEPs closely correlated with subjective report, and increased with an increasing amount of PFI. Unexpectedly, we found that as the number of filled-in targets increased, the duration of target disappearances also increased, suggesting facilitatory interactions exist between targets in separate visual quadrants. We also found distinct spatiotemporal correlates for the background SSVEP harmonics. Prior to genuine PFI, the response at the second harmonic (40 Hz) increased before the first (20 Hz), which we tentatively link to an attentional effect. There was no difference between harmonics for physically removed stimuli. These results demonstrate that PFI can be used to study multi-object perceptual suppression when frequency-tagging the background of a visual display, and because there are distinct neural correlates for endogenously and exogenously induced changes in consciousness, that it is ideally suited to study the NCC.HighlightsPerceptual filling-in (PFI) has distinct advantages for investigating the neural correlates of consciousness.Participants can accurately report graded changes in consciousness using four simultaneous buttons.Frequency-tagging of visual background information tracks changes in visual perception.Spatiotemporal EEG responses differentiate PFI from phenomenally matched physical disappearances.

scholarly journals A multiple-response frequency-tagging paradigm measures graded changes in consciousness during perceptual filling-in

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Matthew J Davidson ◽  
Irene L Graafsma ◽  
Naotsugu Tsuchiya ◽  
Jeroen van Boxtel
Keyword(s):  
Neural Activity ◽  
Second Harmonic ◽  
Visual Display ◽  
Neural Correlates ◽  
Button Press ◽  
Subjective Report ◽  
Visual Background ◽  
Attentional Effect ◽  
Perceptual Changes ◽  
Induced Changes

Abstract Perceptual filling-in (PFI) occurs when a physically present visual target disappears from conscious perception, with its location filled-in by the surrounding visual background. These perceptual changes are complete, near instantaneous, and can occur for multiple separate locations simultaneously. Here, we show that contrasting neural activity during the presence or absence of multi-target PFI can complement other findings from multistable phenomena to reveal the neural correlates of consciousness (NCC). We presented four peripheral targets over a background dynamically updating at 20 Hz. While participants reported on target disappearances/reappearances via button press/release, we tracked neural activity entrained by the background during PFI using steady-state visually evoked potentials (SSVEPs) recorded in the electroencephalogram. We found background SSVEPs closely correlated with subjective report, and increased with an increasing amount of PFI. Unexpectedly, we found that as the number of filled-in targets increased, the duration of target disappearances also increased, suggesting that facilitatory interactions exist between targets in separate visual quadrants. We also found distinct spatiotemporal correlates for the background SSVEP harmonics. Prior to genuine PFI, the response at the second harmonic (40 Hz) increased before the first (20 Hz), which we tentatively link to an attentional effect, while no such difference between harmonics was observed for physically removed stimuli. These results demonstrate that PFI can be used to study multi-object perceptual suppression when frequency-tagging the background of a visual display, and because there are distinct neural correlates for endogenously and exogenously induced changes in consciousness, that it is ideally suited to study the NCC.

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.

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 Neural correlates of consciousness are not pictorial representations

2001 ◽  
Vol 24 (5) ◽  
pp. 999-1000 ◽  
Author(s):  
Geraint Rees ◽  
Chris Frith
Keyword(s):  
Neural Activity ◽  
Empirical Data ◽  
Neural Correlates ◽  
Neural Correlates Of Consciousness ◽  
Visual Consciousness ◽  
One To One ◽  
Pictorial Representations ◽  
The Brain

O'Regan & Noë (O&N) are pessimistic about the prospects for discovering the neural correlates of consciousness. They argue that there can be no one-to-one correspondence between awareness and patterns of neural activity in the brain, so a project attempting to identify the neural correlates of consciousness is doomed to failure. We believe that this degree of pessimism may be overstated; recent empirical data show some convergence in describing consistent patterns of neural activity associated with visual consciousness.

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 Ask and You Shall Receive: A closer look on unsolved consciousness issue

2021 ◽  
Author(s):  
Ali Motavalli ◽  
◽  
Javad Mahmoudi ◽  
Alireza Majdi ◽  
Saeed Sadigh-Eteghad ◽  
...  
Keyword(s):  
Middle Ages ◽  
Brain Function ◽  
Neural Correlates ◽  
Higher Order ◽  
Narrative Review ◽  
Historical Aspects ◽  
Neural Correlates Of Consciousness ◽  
States Of Consciousness ◽  
Mind And Body ◽  
The Brain

Although there are numerous views about the concept of consciousness, no consensus exists regarding the meaning. However, with the aid of the latest neuroscientific developments, the misleading obstacles related to consciousness have been removed. Over the last few decades, neuroscientific efforts in determining the function of the brain and merging these findings with philosophical theories, have brought a more comprehensive perception of the notion of consciousness. In addition to metaphysical/ontological views of consciousness e.g., higher-order theories, reflexive theories, and representationalist theories, there are some brain directed topics in this matter which include but not are limited to neural correlates of consciousness (NCC), brain loop connectivity, and lateralization. This narrative review sheds light on cultural and historical aspects of consciousness in old and middle ages and introduces some of the prominent philosophical discussions related to mind and body. Also, it illustrates the correlation of brain function with states of consciousness with a focus on the roles of function and connectivity.

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