1
|
Hoyer RS, Tewarie PKB, Laureys S. Spatiotemporal dynamics of brain activity in cognition and consciousness: Comment on "Beyond task responsePre-stimulus activity modulates contents of consciousness" by Northoff, Zilio, and Zhang. Phys Life Rev 2024; 50:63-65. [PMID: 38964240 DOI: 10.1016/j.plrev.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2024] [Accepted: 06/18/2024] [Indexed: 07/06/2024]
Affiliation(s)
- Roxane S Hoyer
- Joint International Research Unit on Consciousness, CERVO Brain Research Centre, Laval University, Canada
| | - Prejaas K B Tewarie
- Joint International Research Unit on Consciousness, CERVO Brain Research Centre, Laval University, Canada; Sir Peter Mansfield Imaging Center, School of Physics, University of Nottingham, United Kingdom; Clinical Neurophysiology Group, University of Twente, Netherlands
| | - Steven Laureys
- Joint International Research Unit on Consciousness, CERVO Brain Research Centre, Laval University, Canada; GIGA Consciousness Research Unit and Coma Science Group, Liège University, Belgium; International Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| |
Collapse
|
2
|
Ladas AI, Gravalas T, Stoneham T, Frantzidis CA. Towards a hybrid approach to unveil the Chimaira of neurosciences: philosophy, aperiodic activity and the neural correlates of consciousness. Front Hum Neurosci 2023; 17:1245868. [PMID: 37900726 PMCID: PMC10603270 DOI: 10.3389/fnhum.2023.1245868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/02/2023] [Indexed: 10/31/2023] Open
Abstract
Contemporary theories of consciousness, although very efficient in postulating testable hypotheses, seem to either neglect its relational aspect or to have a profound difficulty in operationalizing this aspect in a measurable manner. We further argue that the analysis of periodic brain activity is inadequate to reveal consciousness's subjective facet. This creates an important epistemic gap in the quest for the neural correlates of consciousness. We suggest a possible solution to bridge this gap, by analysing aperiodic brain activity. We further argue for the imperative need to inform neuroscientific theories of consciousness with relevant philosophical endeavours, in an effort to define, and therefore operationalise, consciousness thoroughly.
Collapse
Affiliation(s)
- Aristea I. Ladas
- Department of Psychology, CITY College, University of York Europe Campus, Thessaloniki, Greece
| | - Triantafyllos Gravalas
- Department of Psychology, CITY College, University of York Europe Campus, Thessaloniki, Greece
| | - Tom Stoneham
- Department of Philosophy, University of York, York, United Kingdom
| | - Christos A. Frantzidis
- School of Computer Science, University of Lincoln, Lincoln, United Kingdom
- Laboratory of Medical Physics and Digital Innovation, Biomedical Engineering and Aerospace Neuroscience (BEAN), Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| |
Collapse
|
3
|
Pepper JL, Nuttall HE. Age-Related Changes to Multisensory Integration and Audiovisual Speech Perception. Brain Sci 2023; 13:1126. [PMID: 37626483 PMCID: PMC10452685 DOI: 10.3390/brainsci13081126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/20/2023] [Accepted: 07/22/2023] [Indexed: 08/27/2023] Open
Abstract
Multisensory integration is essential for the quick and accurate perception of our environment, particularly in everyday tasks like speech perception. Research has highlighted the importance of investigating bottom-up and top-down contributions to multisensory integration and how these change as a function of ageing. Specifically, perceptual factors like the temporal binding window and cognitive factors like attention and inhibition appear to be fundamental in the integration of visual and auditory information-integration that may become less efficient as we age. These factors have been linked to brain areas like the superior temporal sulcus, with neural oscillations in the alpha-band frequency also being implicated in multisensory processing. Age-related changes in multisensory integration may have significant consequences for the well-being of our increasingly ageing population, affecting their ability to communicate with others and safely move through their environment; it is crucial that the evidence surrounding this subject continues to be carefully investigated. This review will discuss research into age-related changes in the perceptual and cognitive mechanisms of multisensory integration and the impact that these changes have on speech perception and fall risk. The role of oscillatory alpha activity is of particular interest, as it may be key in the modulation of multisensory integration.
Collapse
Affiliation(s)
| | - Helen E. Nuttall
- Department of Psychology, Lancaster University, Bailrigg LA1 4YF, UK;
| |
Collapse
|
4
|
Dehaghani NS, Maess B, Khosrowabadi R, Lashgari R, Braeutigam S, Zarei M. Pre-stimulus Alpha Activity Modulates Face and Object Processing in the Intra-Parietal Sulcus, a MEG Study. Front Hum Neurosci 2022; 16:831781. [PMID: 35585993 PMCID: PMC9108229 DOI: 10.3389/fnhum.2022.831781] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 04/08/2022] [Indexed: 11/13/2022] Open
Abstract
Face perception is crucial in all social animals. Recent studies have shown that pre-stimulus oscillations of brain activity modulate the perceptual performance of face vs. non-face stimuli, specifically under challenging conditions. However, it is unclear if this effect also occurs during simple tasks, and if so in which brain regions. Here we used magnetoencephalography (MEG) and a 1-back task in which participants decided if the two sequentially presented stimuli were the same or not in each trial. The aim of the study was to explore the effect of pre-stimulus alpha oscillation on the perception of face (human and monkey) and non-face stimuli. Our results showed that pre-stimulus activity in the left occipital face area (OFA) modulated responses in the intra-parietal sulcus (IPS) at around 170 ms after the presentation of human face stimuli. This effect was also found after participants were shown images of motorcycles. In this case, the IPS was modulated by pre-stimulus activity in the right OFA and the right fusiform face area (FFA). We conclude that pre-stimulus modulation of post-stimulus response also occurs during simple tasks and is therefore independent of behavioral responses.
Collapse
Affiliation(s)
- Narjes Soltani Dehaghani
- Institute of Medical Science and Technology, Shahid Beheshti University, Tehran, Iran
- Institute for Cognitive and Brain Sciences, Shahid Beheshti University, Tehran, Iran
| | - Burkhard Maess
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Reza Khosrowabadi
- Institute for Cognitive and Brain Sciences, Shahid Beheshti University, Tehran, Iran
| | - Reza Lashgari
- Institute of Medical Science and Technology, Shahid Beheshti University, Tehran, Iran
| | - Sven Braeutigam
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Mojtaba Zarei
- Institute of Medical Science and Technology, Shahid Beheshti University, Tehran, Iran
- Department of Neurology, Odense University Hospital, and Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- *Correspondence: Mojtaba Zarei
| |
Collapse
|
5
|
Rassi E, Wutz A, Peatfield N, Wiesz N. Efficient Prestimulus Network Integration of Fusiform Face Area Biases Face Perception during Binocular Rivalry. J Cogn Neurosci 2022; 34:1001-1014. [PMID: 35258573 DOI: 10.1162/jocn_a_01843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Ongoing fluctuations in neural excitability and connectivity influence whether or not a stimulus is seen. Do they also influence which stimulus is seen? We recorded magnetoencephalography data while 21 human participants viewed face or house stimuli, either one at a time or under bistable conditions induced through binocular rivalry. Multivariate pattern analysis revealed common neural substrates for rivalrous versus nonrivalrous stimuli with an additional delay of ∼36 msec for the bistable stimulus, and poststimulus signals were source-localized to the fusiform face area. Before stimulus onset followed by a face versus house report, fusiform face area showed stronger connectivity to primary visual cortex and to the rest of the cortex in the alpha frequency range (8-13 Hz), but there were no differences in local oscillatory alpha power. The prestimulus connectivity metrics predicted the accuracy of poststimulus decoding and the delay associated with rivalry disambiguation suggesting that perceptual content is shaped by ongoing neural network states.
Collapse
Affiliation(s)
- Elie Rassi
- University of Salzburg.,Radboud University, Nijmegen, The Netherlands
| | - Andreas Wutz
- University of Salzburg.,Massachusetts Institute of Technology
| | | | - Nathan Wiesz
- University of Salzburg.,University of Trento, Rovereto, Italy.,Paracelsus Medical University, Salzburg, Austria
| |
Collapse
|
6
|
Moheimanian L, Paraskevopoulou SE, Adamek M, Schalk G, Brunner P. Modulation in cortical excitability disrupts information transfer in perceptual-level stimulus processing. Neuroimage 2021; 243:118498. [PMID: 34428572 DOI: 10.1016/j.neuroimage.2021.118498] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 07/15/2021] [Accepted: 08/20/2021] [Indexed: 10/20/2022] Open
Abstract
Despite significant interest in the neural underpinnings of behavioral variability, little light has been shed on the cortical mechanism underlying the failure to respond to perceptual-level stimuli. We hypothesized that cortical activity resulting from perceptual-level stimuli is sensitive to the moment-to-moment fluctuations in cortical excitability, and thus may not suffice to produce a behavioral response. We tested this hypothesis using electrocorticographic recordings to follow the propagation of cortical activity in six human subjects that responded to perceptual-level auditory stimuli. Here we show that for presentations that did not result in a behavioral response, the likelihood of cortical activity decreased from auditory cortex to motor cortex, and was related to reduced local cortical excitability. Cortical excitability was quantified using instantaneous voltage during a short window prior to cortical activity onset. Therefore, when humans are presented with an auditory stimulus close to perceptual-level threshold, moment-by-moment fluctuations in cortical excitability determine whether cortical responses to sensory stimulation successfully connect auditory input to a resultant behavioral response.
Collapse
Affiliation(s)
- Ladan Moheimanian
- National Center for Adaptive Neurotechnologies, Albany, NY, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA
| | | | - Markus Adamek
- National Center for Adaptive Neurotechnologies, Albany, NY, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Gerwin Schalk
- National Center for Adaptive Neurotechnologies, Albany, NY, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA
| | - Peter Brunner
- National Center for Adaptive Neurotechnologies, Albany, NY, USA; Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, USA; Department of Neurology, Albany Medical College, Albany, NY, USA; Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
7
|
Ruhnau P, Zaehle T. Transcranial Auricular Vagus Nerve Stimulation (taVNS) and Ear-EEG: Potential for Closed-Loop Portable Non-invasive Brain Stimulation. Front Hum Neurosci 2021; 15:699473. [PMID: 34194308 PMCID: PMC8236702 DOI: 10.3389/fnhum.2021.699473] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 05/21/2021] [Indexed: 11/17/2022] Open
Abstract
No matter how hard we concentrate, our attention fluctuates – a fact that greatly affects our success in completing a current task. Here, we review work from two methods that, in a closed-loop manner, have the potential to ameliorate these fluctuations. Ear-EEG can measure electric brain activity from areas in or around the ear, using small and thus portable hardware. It has been shown to capture the state of attention with high temporal resolution. Transcutaneous auricular vagus nerve stimulation (taVNS) comes with the same advantages (small and light) and critically current research suggests that it is possible to influence ongoing brain activity that has been linked to attention. Following the review of current work on ear-EEG and taVNS we suggest that a combination of the two methods in a closed-loop system could serve as a potential application to modulate attention.
Collapse
Affiliation(s)
- Philipp Ruhnau
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto von Guericke University, Magdeburg, Germany
| | - Tino Zaehle
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto von Guericke University, Magdeburg, Germany
| |
Collapse
|
8
|
Michail G, Toran Jenner L, Keil J. Prestimulus alpha power but not phase influences visual discrimination of long‐duration visual stimuli. Eur J Neurosci 2021; 55:3141-3153. [DOI: 10.1111/ejn.15169] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 02/10/2021] [Accepted: 02/28/2021] [Indexed: 11/27/2022]
Affiliation(s)
- Georgios Michail
- Department of Psychiatry and Psychotherapy Multisensory Integration Lab Charité ‐ Universitätsmedizin Berlin Berlin Germany
| | | | - Julian Keil
- Biological Psychology Christian‐Albrechts‐University Kiel Germany
| |
Collapse
|
9
|
Zazio A, Ruhnau P, Weisz N, Wutz A. Pre-stimulus alpha-band power and phase fluctuations originate from different neural sources and exert distinct impact on stimulus-evoked responses. Eur J Neurosci 2021; 55:3178-3190. [PMID: 33539589 DOI: 10.1111/ejn.15138] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/22/2021] [Accepted: 01/31/2021] [Indexed: 11/28/2022]
Abstract
Ongoing oscillatory neural activity before stimulus onset influences subsequent visual perception. Specifically, both the power and the phase of oscillations in the alpha-frequency band (9-13 Hz) have been reported to predict the detection of visual stimuli. Up to now, the functional mechanisms underlying pre-stimulus power and phase effects on upcoming visual percepts are debated. Here, we used magnetoencephalography recordings together with a near-threshold visual detection task to investigate the neural generators of pre-stimulus power and phase and their impact on subsequent visual-evoked responses. Pre-stimulus alpha-band power and phase opposition effects were found consistent with previous reports. Source localization suggested clearly distinct neural generators for these pre-stimulus effects: Power effects were mainly found in occipital-temporal regions, whereas phase effects also involved prefrontal areas. In order to be functionally relevant, the pre-stimulus correlates should influence post-stimulus processing. Using a trial-sorting approach, we observed that only pre-stimulus power modulated the Hits versus Misses difference in the evoked response, a well-established post-stimulus neural correlate of near-threshold perception, such that trials with stronger pre-stimulus power effect showed greater post-stimulus difference. By contrast, no influence of pre-stimulus phase effects were found. In sum, our study shows distinct generators for two pre-stimulus neural patterns predicting visual perception, and that only alpha power impacts the post-stimulus correlate of conscious access. This underlines the functional relevance of prestimulus alpha power on perceptual awareness, while questioning the role of alpha phase.
Collapse
Affiliation(s)
- Agnese Zazio
- Neurophysiology Lab, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Philipp Ruhnau
- Department of Neurology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.,Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto, Italy
| | - Nathan Weisz
- Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto, Italy.,Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Andreas Wutz
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| |
Collapse
|
10
|
Spontaneous Network Coupling Enables Efficient Task Performance without Local Task-Induced Activations. J Neurosci 2020; 40:9663-9675. [PMID: 33158966 DOI: 10.1523/jneurosci.1166-20.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/18/2020] [Accepted: 09/12/2020] [Indexed: 11/21/2022] Open
Abstract
Neurobehavioral studies in humans have long concentrated on changes in local activity levels during repetitive executions of a task. Spontaneous neural coupling within extended networks has latterly been found to also influence performance. Here, we intend to uncover the underlying mechanisms, the relative importance, and the interaction between spontaneous coupling and task-induced activations. To do so, we recorded two groups of healthy participants (male and female) during rest and while they performed either a visual perception or a motor sequence task. We demonstrate that, for both tasks, stronger activations during the task as well as greater network coupling through spontaneous α rhythms at rest predict performance. However, high performers present an absence of classical task-induced activations and, instead, stronger spontaneous network coupling. Activations were thus a compensation mechanism needed only in subjects with lower spontaneous network interactions. This challenges classical models of neural processing and calls for new strategies in attempts to train and enhance performance.SIGNIFICANCE STATEMENT Our findings challenge the widely accepted notion that task-induced activations are of paramount importance for behavior. This will have an important impact on interpretations of human neurobehavioral research. They further link the widely used techniques of quantifying network communication in the brain with classical neuroscience methods and demonstrate possible ways of how network communication influences human behavior. Traditional training methods attempt to enhance neural activations through task repetitions. Our findings suggest a more efficient neural target for learning: enhancing spontaneous neural interactions. This will be of major interest for a large variety of scientific fields with very broad applications in schools, work, and others.
Collapse
|
11
|
Zazio A, Schreiber M, Miniussi C, Bortoletto M. Modelling the effects of ongoing alpha activity on visual perception: The oscillation-based probability of response. Neurosci Biobehav Rev 2020; 112:242-253. [DOI: 10.1016/j.neubiorev.2020.01.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 01/14/2020] [Accepted: 01/30/2020] [Indexed: 11/16/2022]
|
12
|
Decoding across sensory modalities reveals common supramodal signatures of conscious perception. Proc Natl Acad Sci U S A 2020; 117:7437-7446. [PMID: 32184331 PMCID: PMC7132110 DOI: 10.1073/pnas.1912584117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
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.
Collapse
|
13
|
Fertonani A, Pirulli C, Bollini A, Miniussi C, Bortoletto M. Age-related changes in cortical connectivity influence the neuromodulatory effects of transcranial electrical stimulation. Neurobiol Aging 2019; 82:77-87. [DOI: 10.1016/j.neurobiolaging.2019.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/15/2019] [Accepted: 07/17/2019] [Indexed: 12/21/2022]
|
14
|
Rassi E, Wutz A, Müller-Voggel N, Weisz N. Prestimulus feedback connectivity biases the content of visual experiences. Proc Natl Acad Sci U S A 2019; 116:16056-16061. [PMID: 31332019 PMCID: PMC6689959 DOI: 10.1073/pnas.1817317116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Ongoing fluctuations in neural excitability and in networkwide activity patterns before stimulus onset have been proposed to underlie variability in near-threshold stimulus detection paradigms-that is, whether or not an object is perceived. Here, we investigated the impact of prestimulus neural fluctuations on the content of perception-that is, whether one or another object is perceived. We recorded neural activity with magnetoencephalography (MEG) before and while participants briefly viewed an ambiguous image, the Rubin face/vase illusion, and required them to report their perceived interpretation in each trial. Using multivariate pattern analysis, we showed robust decoding of the perceptual report during the poststimulus period. Applying source localization to the classifier weights suggested early recruitment of primary visual cortex (V1) and ∼160-ms recruitment of the category-sensitive fusiform face area (FFA). These poststimulus effects were accompanied by stronger oscillatory power in the gamma frequency band for face vs. vase reports. In prestimulus intervals, we found no differences in oscillatory power between face vs. vase reports in V1 or in FFA, indicating similar levels of neural excitability. Despite this, we found stronger connectivity between V1 and FFA before face reports for low-frequency oscillations. Specifically, the strength of prestimulus feedback connectivity (i.e., Granger causality) from FFA to V1 predicted not only the category of the upcoming percept but also the strength of poststimulus neural activity associated with the percept. Our work shows that prestimulus network states can help shape future processing in category-sensitive brain regions and in this way bias the content of visual experiences.
Collapse
Affiliation(s)
- Elie Rassi
- Centre for Cognitive Neuroscience, University of Salzburg, 5020 Salzburg, Austria;
| | - Andreas Wutz
- Centre for Cognitive Neuroscience, University of Salzburg, 5020 Salzburg, Austria
- The Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Nadia Müller-Voggel
- Center for Biomagnetismus, Department of Neurosurgery, University Hospital, 91054 Erlangen, Germany
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Trento, Italy
| | - Nathan Weisz
- Centre for Cognitive Neuroscience, University of Salzburg, 5020 Salzburg, Austria
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Trento, Italy
| |
Collapse
|
15
|
Fuscà M, Ruhnau P, Neuling T, Weisz N. Local Network-Level Integration Mediates Effects of Transcranial Alternating Current Stimulation. Brain Connect 2018; 8:212-219. [DOI: 10.1089/brain.2017.0564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Marco Fuscà
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
| | - Philipp Ruhnau
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany
| | - Toralf Neuling
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Nathan Weisz
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| |
Collapse
|
16
|
Spontaneous brain oscillations as neural fingerprints of working memory capacities: A resting-state MEG study. Cortex 2017; 97:109-124. [PMID: 29102813 DOI: 10.1016/j.cortex.2017.09.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 03/31/2017] [Accepted: 09/22/2017] [Indexed: 01/03/2023]
Abstract
Short-term storage and mental information manipulation capacities in the human brain are key to healthy cognition. These brain processes collectively known as working memory (WM) are associated with modulations of rhythmic brain activity across multiple brain areas and frequencies. Yet, it is not clear whether - and, if so, how-intrinsic resting-state neuronal oscillations are related to individual WM capacities, as measured by standard neuropsychological tests. We addressed this question by probing the correlation between resting-state brain activity, recorded with magnetoencephalography (MEG), and verbal and visuo-spatial WM indices obtained from the standardized Wechsler Adult Intelligence Scale (WAIS-IV) and the Wechsler Memory Scale (WMS-IV). To this end, 5-min eyes-open resting-state MEG data were acquired in 28 healthy participants. Source-reconstructed spectral power estimates were then computed in standard frequency bands and their correlation with neuropsychological indices across individuals was assessed using Pearson correlation and cluster-level statistics. We found statistically significant positive correlations between spectral amplitudes measured at rest and standardized scores on both verbal and visuo-spatial WM performance. The correlation clusters primarily involved key medial and dorsolateral components within the parietal and prefrontal regions. In addition, while the correlation in some clusters was frequency selective (e.g., alpha-band oscillations), other areas showed correlations with WM across a wide range of frequencies reflecting a broadband effect. These results provide the first evidence for a positive correlation between neuromagnetic signals measured at rest and WM performance separately assessed by standardized neuropsychological tests. Our results advance our understanding of the link between WM capacities and intrinsic oscillatory dynamics networks. They also suggest that individual differences in baseline spectral power might need to be taken into account when probing differences in brain responses during the execution of WM tasks.
Collapse
|
17
|
Juxtaposing the real-time unfolding of subjective experience and ERP neuromarker dynamics. Conscious Cogn 2017; 54:3-19. [DOI: 10.1016/j.concog.2017.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 01/08/2023]
|
18
|
Gonzalez-Castillo J, Bandettini PA. Task-based dynamic functional connectivity: Recent findings and open questions. Neuroimage 2017; 180:526-533. [PMID: 28780401 DOI: 10.1016/j.neuroimage.2017.08.006] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/17/2017] [Accepted: 08/01/2017] [Indexed: 02/08/2023] Open
Abstract
The temporal evolution of functional connectivity (FC) within the confines of individual scans is nowadays often explored with functional neuroimaging. This is particularly true for resting-state; yet, FC-dynamics have also been investigated as subjects engage on numerous tasks. It is these research efforts that constitute the core of this survey. First, empirical observations on how FC differs between task and rest-independent of temporal scale-are reviewed, as they underscore how, despite overall preservation of network topography, the brain's FC does reconfigure in systematic ways to accommodate task demands. Next, reports on the relationships between instantaneous FC and perception/performance in subsequent trials are discussed. Similarly, research where different aspects of task-concurrent FC-dynamics are explored or utilized to predict ongoing mental states are also examined. The manuscript finishes with an incomplete list of challenges that hopefully fuels future work in this vibrant area of neuroscientific research. Overall, this review concludes that task-concurrent FC-dynamics, when properly characterized, are relevant to behavior, and that their translational value holds considerable promise.
Collapse
Affiliation(s)
| | - Peter A Bandettini
- Section on Functional Imaging Methods, NIMH, NIH, Bethesda, MD, USA; Functional MRI Core, NIH, Bethesda, MD, USA
| |
Collapse
|
19
|
Gallotto S, Sack AT, Schuhmann T, de Graaf TA. Oscillatory Correlates of Visual Consciousness. Front Psychol 2017; 8:1147. [PMID: 28736543 PMCID: PMC5500655 DOI: 10.3389/fpsyg.2017.01147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 06/23/2017] [Indexed: 11/21/2022] Open
Abstract
Conscious experiences are linked to activity in our brain: the neural correlates of consciousness (NCC). Empirical research on these NCCs covers a wide range of brain activity signals, measures, and methodologies. In this paper, we focus on spontaneous brain oscillations; rhythmic fluctuations of neuronal (population) activity which can be characterized by a range of parameters, such as frequency, amplitude (power), and phase. We provide an overview of oscillatory measures that appear to correlate with conscious perception. We also discuss how increasingly sophisticated techniques allow us to study the causal role of oscillatory activity in conscious perception (i.e., ‘entrainment’). This review of oscillatory correlates of consciousness suggests that, for example, activity in the alpha-band (7–13 Hz) may index, or even causally support, conscious perception. But such results also showcase an increasingly acknowledged difficulty in NCC research; the challenge of separating neural activity necessary for conscious experience to arise (prerequisites) from neural activity underlying the conscious experience itself (substrates) or its results (consequences).
Collapse
Affiliation(s)
- Stefano Gallotto
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, Netherlands.,Maastricht Brain Imaging CentreMaastricht, Netherlands
| | - Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, Netherlands.,Maastricht Brain Imaging CentreMaastricht, Netherlands
| | - Teresa Schuhmann
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, Netherlands.,Maastricht Brain Imaging CentreMaastricht, Netherlands
| | - Tom A de Graaf
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, Netherlands.,Maastricht Brain Imaging CentreMaastricht, Netherlands
| |
Collapse
|
20
|
Matsuda T, Kitajo K, Yamaguchi Y, Komaki F. A point process modeling approach for investigating the effect of online brain activity on perceptual switching. Neuroimage 2017; 152:50-59. [PMID: 28242318 DOI: 10.1016/j.neuroimage.2017.02.068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 01/30/2017] [Accepted: 02/23/2017] [Indexed: 11/19/2022] Open
Abstract
When watching an ambiguous figure that allows for multiple interpretations, our interpretation spontaneously switches between the possible options. Such spontaneous switching is called perceptual switching and it is modulated by top-down selective attention. In this study, we propose a point process modeling approach for investigating the effects of online brain activity on perceptual switching, where we define online activity as continuous brain activity including spontaneous background and induced activities. Specifically, we modeled perceptual switching during Necker cube perception using electroencephalography (EEG) data. Our method is based on the framework of point process model, which is a statistical model of a series of events. We regard perceptual switching phenomenon as a stochastic process and construct its model in a data-driven manner. We develop a model called the online activity regression model, which enables to determine whether online brain activity has excitatory or inhibitory effects on perceptual switching. By fitting online activity regression models to experimental data and applying the likelihood ratio testing with correction for multiple comparisons, we explore the brain regions and frequency bands with significant effects on perceptual switching. The results demonstrate that the modulation of online occipital alpha activity mediates the suppression of perceptual switching to the non-attended interpretation. Thus, our method provides a dynamic description of the attentional process by naturally accounting for the entire time course of brain activity, which is difficult to resolve by focusing only on the brain activity around the time of perceptual switching.
Collapse
Affiliation(s)
- Takeru Matsuda
- Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan.
| | - Keiichi Kitajo
- RIKEN BSI-Toyota Collaboration Center, RIKEN Brain Science Institute, Wako, Saitama, Japan; RIKEN Brain Science Institute, Wako, Saitama, Japan
| | | | - Fumiyasu Komaki
- Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan; RIKEN Brain Science Institute, Wako, Saitama, Japan
| |
Collapse
|
21
|
Keil J, Senkowski D. Individual Alpha Frequency Relates to the Sound-Induced Flash Illusion. Multisens Res 2017; 30:565-578. [DOI: 10.1163/22134808-00002572] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 03/30/2017] [Indexed: 01/21/2023]
Abstract
Ongoing neural oscillations reflect fluctuations of cortical excitability. A growing body of research has underlined the role of neural oscillations for stimulus processing. Neural oscillations in the alpha band have gained special interest in electrophysiological research on perception. Recent studies proposed the idea that neural oscillations provide temporal windows in which sensory stimuli can be perceptually integrated. This also includes multisensory integration. In the current high-density EEG-study we examined the relationship between the individual alpha frequency (IAF) and cross-modal audiovisual integration in the sound-induced flash illusion (SIFI). In 26 human volunteers we found a negative correlation between the IAF and the SIFI illusion rate. Individuals with a lower IAF showed higher audiovisual illusions. Source analysis suggested an involvement of the visual cortex, especially the calcarine sulcus, for this relationship. Our findings corroborate the notion that the IAF affects the cross-modal integration of auditory on visual stimuli in the SIFI. We integrate our findings with recent observations on the relationship between audiovisual integration and neural oscillations and suggest a multifaceted influence of neural oscillations on multisensory processing.
Collapse
Affiliation(s)
- Julian Keil
- Department of Psychiatry and Psychotherapy, St. Hedwig Hospital, Charité — Universitätsmedizin Berlin, Grosse Hambuger Strasse 5-1, 10115 Berlin, Germany
| | - Daniel Senkowski
- Department of Psychiatry and Psychotherapy, St. Hedwig Hospital, Charité — Universitätsmedizin Berlin, Grosse Hambuger Strasse 5-1, 10115 Berlin, Germany
| |
Collapse
|
22
|
Weise A, Hartmann T, Schröger E, Weisz N, Ruhnau P. Cross-modal distractors modulate oscillatory alpha power: the neural basis of impaired task performance. Psychophysiology 2016; 53:1651-1659. [DOI: 10.1111/psyp.12733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 07/10/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Annekathrin Weise
- Rotman Research Institute, Baycrest Centre; Toronto ON Canada
- Cognitive and Biological Psychology; University of Leipzig; Leipzig Germany
| | - Thomas Hartmann
- CCNS and Division of Physiological Psychology; University of Salzburg; Salzburg Austria
| | - Erich Schröger
- Cognitive and Biological Psychology; University of Leipzig; Leipzig Germany
| | - Nathan Weisz
- CCNS and Division of Physiological Psychology; University of Salzburg; Salzburg Austria
| | - Philipp Ruhnau
- Max Planck Institute for Human Cognitive and Brain Sciences; Leipzig Germany
- Department of Neurology; Otto-von-Guericke University Magdeburg; Magdeburg Germany
| |
Collapse
|
23
|
Rutiku R, Tulver K, Aru J, Bachmann T. Visual masking with frontally applied pre-stimulus TMS and its subject-specific neural correlates. Brain Res 2016; 1642:136-145. [DOI: 10.1016/j.brainres.2016.03.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 02/12/2016] [Accepted: 03/24/2016] [Indexed: 11/28/2022]
|
24
|
Magazzini L, Ruhnau P, Weisz N. Alpha suppression and connectivity modulations in left temporal and parietal cortices index partial awareness of words. Neuroimage 2016; 133:279-287. [PMID: 27001501 PMCID: PMC4907686 DOI: 10.1016/j.neuroimage.2016.03.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/25/2016] [Accepted: 03/12/2016] [Indexed: 11/25/2022] Open
Abstract
The partial awareness hypothesis is a theoretical proposal that recently provided a reconciling solution to graded and dichotomous accounts of consciousness. It suggests that we can become conscious of distinct properties of an object independently, ranging from low-level features to complex forms of representation. We investigated this hypothesis using classic visual word masking adapted to a near-threshold paradigm. The masking intensity was adjusted to the individual perception threshold, at which individual alphabetical letters, but not words, could be perceived in approximately half of the trials. We confined perception to a pre-lexical stage of word processing that corresponded to a clear condition of partial awareness. At this level of representation, the stimulus properties began to emerge within consciousness, yet they did not escalate to full stimulus awareness. In other words, participants were able to perceive individual letters, while remaining unaware of the whole letter strings presented. Cortical activity measured with MEG was compared between physically identical trials that differed in perception (perceived, not perceived). We found that compared to no awareness, partial awareness of words was characterized by suppression of oscillatory alpha power in left temporal and parietal cortices. The analysis of functional connectivity with seeds based on the power effect in these two regions revealed sparse connections for the parietal seed, and strong connections between the temporal seed and other regions of the language network. We suggest that the engagement of language regions indexed by alpha power suppression is responsible for establishing and maintaining conscious representations of individual pre-lexical units. Near-threshold visual masking is used to characterize partial awareness of words. Partial awareness is indexed by left temporal and parietal alpha power suppression. Functional connectivity dissociates nodes in temporal and parietal cortices.
Collapse
Affiliation(s)
- Lorenzo Magazzini
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
| | - Philipp Ruhnau
- Centre for Cognitive Neuroscience, Paris Lodron Universität Salzburg, Salzburg, Austria; Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
| | - Nathan Weisz
- Centre for Cognitive Neuroscience, Paris Lodron Universität Salzburg, Salzburg, Austria; Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
| |
Collapse
|
25
|
Frey JN, Ruhnau P, Leske S, Siegel M, Braun C, Weisz N. The Tactile Window to Consciousness is Characterized by Frequency-Specific Integration and Segregation of the Primary Somatosensory Cortex. Sci Rep 2016; 6:20805. [PMID: 26864304 PMCID: PMC4749972 DOI: 10.1038/srep20805] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 01/11/2016] [Indexed: 02/08/2023] Open
Abstract
We recently proposed that besides levels of local cortical excitability, also distinct pre-stimulus network states (windows to consciousness) determine whether a near-threshold stimulus will be consciously perceived. In the present magnetoencephalography study, we scrutinised these pre-stimulus network states with a focus on the primary somatosensory cortex. For this purpose participants performed a simple near-threshold tactile detection task. Confirming previous studies, we found reduced alpha and beta power in the somatosensory region contralateral to stimulation prior to correct stimulus detection as compared to undetected stimuli, and stronger event-related responses following successful stimulus detection. As expected, using graph theoretical measures, we also observed modulated pre-stimulus network level integration. Specifically, the right primary somatosensory cortex contralateral to stimulation showed an increased integration in the theta band, and additionally, a decreased integration in the beta band. Overall, these results underline the importance of network states for enabling conscious perception. Moreover, they indicate that also a reduction of irrelevant functional connections contributes to the window to consciousness by tuning pre-stimulus pathways of information flow.
Collapse
Affiliation(s)
- Julia Natascha Frey
- CIMeC, University of Trento, via delle Regole, 101, 38123 Mattarello (TN), Italy.,Center for Cognitive Neuroscience, Paris-Lodron Universität Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| | - Philipp Ruhnau
- CIMeC, University of Trento, via delle Regole, 101, 38123 Mattarello (TN), Italy.,Center for Cognitive Neuroscience, Paris-Lodron Universität Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| | - Sabine Leske
- Department of Psychology, University of Konstanz, Universitätsstr. 10, 78464 Konstanz, Germany
| | - Markus Siegel
- Centre for Integrative Neuroscience &MEG Center, University of Tübingen, Otfried-Müller-Str. 47, 72076 Tübingen, Germany
| | - Christoph Braun
- CIMeC, University of Trento, via delle Regole, 101, 38123 Mattarello (TN), Italy.,Centre for Integrative Neuroscience &MEG Center, University of Tübingen, Otfried-Müller-Str. 47, 72076 Tübingen, Germany
| | - Nathan Weisz
- CIMeC, University of Trento, via delle Regole, 101, 38123 Mattarello (TN), Italy.,Center for Cognitive Neuroscience, Paris-Lodron Universität Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| |
Collapse
|
26
|
Zoefel B, VanRullen R. The Role of High-Level Processes for Oscillatory Phase Entrainment to Speech Sound. Front Hum Neurosci 2015; 9:651. [PMID: 26696863 PMCID: PMC4667100 DOI: 10.3389/fnhum.2015.00651] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/16/2015] [Indexed: 11/13/2022] Open
Abstract
Constantly bombarded with input, the brain has the need to filter out relevant information while ignoring the irrelevant rest. A powerful tool may be represented by neural oscillations which entrain their high-excitability phase to important input while their low-excitability phase attenuates irrelevant information. Indeed, the alignment between brain oscillations and speech improves intelligibility and helps dissociating speakers during a “cocktail party”. Although well-investigated, the contribution of low- and high-level processes to phase entrainment to speech sound has only recently begun to be understood. Here, we review those findings, and concentrate on three main results: (1) Phase entrainment to speech sound is modulated by attention or predictions, likely supported by top-down signals and indicating higher-level processes involved in the brain’s adjustment to speech. (2) As phase entrainment to speech can be observed without systematic fluctuations in sound amplitude or spectral content, it does not only reflect a passive steady-state “ringing” of the cochlea, but entails a higher-level process. (3) The role of intelligibility for phase entrainment is debated. Recent results suggest that intelligibility modulates the behavioral consequences of entrainment, rather than directly affecting the strength of entrainment in auditory regions. We conclude that phase entrainment to speech reflects a sophisticated mechanism: several high-level processes interact to optimally align neural oscillations with predicted events of high relevance, even when they are hidden in a continuous stream of background noise.
Collapse
Affiliation(s)
- Benedikt Zoefel
- Université Paul Sabatier Toulouse, France ; Centre de Recherche Cerveau et Cognition (CerCo), CNRS, UMR5549, Pavillon Baudot CHU Purpan Toulouse, France
| | - Rufin VanRullen
- Université Paul Sabatier Toulouse, France ; Centre de Recherche Cerveau et Cognition (CerCo), CNRS, UMR5549, Pavillon Baudot CHU Purpan Toulouse, France
| |
Collapse
|
27
|
Leske S, Ruhnau P, Frey J, Lithari C, Müller N, Hartmann T, Weisz N. Prestimulus Network Integration of Auditory Cortex Predisposes Near-Threshold Perception Independently of Local Excitability. Cereb Cortex 2015; 25:4898-907. [PMID: 26408799 PMCID: PMC4635927 DOI: 10.1093/cercor/bhv212] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
An ever-increasing number of studies are pointing to the importance of network properties of the brain for understanding behavior such as conscious perception. However, with regards to the influence of prestimulus brain states on perception, this network perspective has rarely been taken. Our recent framework predicts that brain regions crucial for a conscious percept are coupled prior to stimulus arrival, forming pre-established pathways of information flow and influencing perceptual awareness. Using magnetoencephalography (MEG) and graph theoretical measures, we investigated auditory conscious perception in a near-threshold (NT) task and found strong support for this framework. Relevant auditory regions showed an increased prestimulus interhemispheric connectivity. The left auditory cortex was characterized by a hub-like behavior and an enhanced integration into the brain functional network prior to perceptual awareness. Right auditory regions were decoupled from non-auditory regions, presumably forming an integrated information processing unit with the left auditory cortex. In addition, we show for the first time for the auditory modality that local excitability, measured by decreased alpha power in the auditory cortex, increases prior to conscious percepts. Importantly, we were able to show that connectivity states seem to be largely independent from local excitability states in the context of a NT paradigm.
Collapse
Affiliation(s)
- Sabine Leske
- Department of Psychology, University of Konstanz, 78457 Konstanz, Germany
| | - Philipp Ruhnau
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy
| | - Julia Frey
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy
| | - Chrysa Lithari
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy
| | - Nadia Müller
- Department of Neurology, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Thomas Hartmann
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy
| | - Nathan Weisz
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38123 Mattarello (TN), Italy
| |
Collapse
|
28
|
Elgoyhen AB, Langguth B, De Ridder D, Vanneste S. Tinnitus: perspectives from human neuroimaging. Nat Rev Neurosci 2015; 16:632-42. [DOI: 10.1038/nrn4003] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
29
|
Leonardelli E, Braun C, Weisz N, Lithari C, Occelli V, Zampini M. Prestimulus oscillatory alpha power and connectivity patterns predispose perceptual integration of an audio and a tactile stimulus. Hum Brain Mapp 2015; 36:3486-98. [PMID: 26109518 DOI: 10.1002/hbm.22857] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 11/06/2022] Open
Abstract
To efficiently perceive and respond to the external environment, our brain has to perceptually integrate or segregate stimuli of different modalities. The temporal relationship between the different sensory modalities is therefore essential for the formation of different multisensory percepts. In this magnetoencephalography study, we created a paradigm where an audio and a tactile stimulus were presented by an ambiguous temporal relationship so that perception of physically identical audiotactile stimuli could vary between integrated (emanating from the same source) and segregated. This bistable paradigm allowed us to compare identical bimodal stimuli that elicited different percepts, providing a possibility to directly infer multisensory interaction effects. Local differences in alpha power over bilateral inferior parietal lobules (IPLs) and superior parietal lobules (SPLs) preceded integrated versus segregated percepts of the two stimuli (audio and tactile). Furthermore, differences in long-range cortical functional connectivity seeded in rIPL (region of maximum difference) revealed differential patterns that predisposed integrated or segregated percepts encompassing secondary areas of all different modalities and prefrontal cortex. We showed that the prestimulus brain states predispose the perception of the audiotactile stimulus both in a global and a local manner. Our findings are in line with a recent consistent body of findings on the importance of prestimulus brain states for perception of an upcoming stimulus. This new perspective on how stimuli originating from different modalities are integrated suggests a non-modality specific network predisposing multisensory perception.
Collapse
Affiliation(s)
| | - Christoph Braun
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy.,MEG Center, University of Tübingen, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience(CIN), University of Tübingen, Tübingen, Germany
| | - Nathan Weisz
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
| | - Chrysa Lithari
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
| | | | | |
Collapse
|
30
|
Aru J, Bachmann T. Still wanted-the mechanisms of consciousness! Front Psychol 2015; 6:5. [PMID: 25653636 PMCID: PMC4300864 DOI: 10.3389/fpsyg.2015.00005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 01/04/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jaan Aru
- Faculty of Mathematics and Computer Science/Faculty of Law, University of Tartu Tartu, Estonia
| | | |
Collapse
|