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Zhang Y, Song B, Zhao X, Jin Z, Zhang J, Li L. Meta-analysis of experimental factors influencing single-pulse TMS effects on the early visual cortex. Front Neurosci 2024; 18:1351399. [PMID: 38894939 PMCID: PMC11185874 DOI: 10.3389/fnins.2024.1351399] [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: 12/07/2023] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
Background Single-pulse transcranial magnetic stimulation (spTMS) applied to the Early Visual Cortex (EVC) has demonstrated the ability to suppress the perception on visual targets, akin to the effect of visual masking. However, the reported spTMS suppression effects across various studies have displayed inconsistency. Objective We aim to test if the heterogeneity of the spTMS effects can be attributable to variations in experimental factors. Methods We conducted a meta-analysis using data collected from the PubMed and Web of Science databases spanning from 1995 to March 2024. The meta-analysis encompassed a total of 40 independent experiments drawn from 33 original articles. Results The findings unveiled an overall significant spTMS suppression effect on visual perception. Nevertheless, there existed substantial heterogeneity among the experiments. Univariate analysis elucidated that the spTMS effects could be significantly influenced by TMS intensity, visual angle of the stimulus, coil type, and TMS stimulators from different manufacturers. Reliable spTMS suppression effects were observed within the time windows of -80 to 0 ms and 50 to 150 ms. Multivariate linear regression analyses, which included SOA, TMS intensity, visual angle of the stimulus, and coil type, identified SOA as the key factor influencing the spTMS effects. Within the 50 to 150 ms time window, optimal SOAs were identified as 112 ms and 98 ms for objective and subjective performance, respectively. Collectively, multiple experimental factors accounted for 22.9% (r = 0.3353) and 39.9% (r = 0.3724) of the variance in objective and subjective performance, respectively. Comparing univariate and multivariate analyses, it was evident that experimental factors had different impacts on objective performance and subjective performance. Conclusion The present study provided quantitative recommendations for future experiments involving the spTMS effects on visual targets, offering guidance on how to configure experimental factors to achieve the optimal masking effect.
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Affiliation(s)
| | | | | | | | - Junjun Zhang
- MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, Center for Psychiatry and Psychology, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Ling Li
- MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, Center for Psychiatry and Psychology, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
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2
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Wang W, Zhou T, Chen L, Huang Y. A subcortical magnocellular pathway is responsible for the fast processing of topological properties of objects: A transcranial magnetic stimulation study. Hum Brain Mapp 2023; 44:1617-1628. [PMID: 36426867 PMCID: PMC9921224 DOI: 10.1002/hbm.26162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/16/2022] [Accepted: 11/11/2022] [Indexed: 11/26/2022] Open
Abstract
Rapid object recognition has survival significance. The extraction of topological properties (TP) is proposed as the starting point of object perception. Behavioral evidence shows that TP processing takes precedence over other geometric properties and can accelerate object recognition. However, the mechanism of the fast TP processing remains unclear. The magnocellular (M) pathway is well known as a fast route to convey "coarse" information, compared with the slow parvocellular (P) pathway. Here, we hypothesize that the fast processing of TP occurs in a subcortical M pathway. We applied single-pulse transcranial magnetic stimulation (TMS) over the primary visual cortex to temporarily disrupt cortical processing. Besides, stimuli were designed to preferentially engage M or P pathways (M- or P-biased conditions). We found that, when TMS disrupted cortical function at the early stages of stimulus processing, non-TP shape discrimination was strongly impaired in both M- and P-biased conditions, whereas TP discrimination was not affected in the M-biased condition, suggesting that early M processing of TP is independent of the visual cortex, but probably occurs in a subcortical M pathway. Using an unconscious priming paradigm, we further found that early M processing of TP can accelerate object recognition by speeding up the processing of other properties, e.g., orientation. Our findings suggest that the human visual system achieves efficient object recognition by rapidly processing TP in the subcortical M pathway.
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Affiliation(s)
- Wenbo Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China
| | - Tiangang Zhou
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China.,Hefei Comprehensive National Science Center, Institute of Artificial Intelligence, Hefei, China
| | - Lin Chen
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China.,Hefei Comprehensive National Science Center, Institute of Artificial Intelligence, Hefei, China
| | - Yan Huang
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences. University of Chinese Academy of Sciences, China, Shenzhen, China
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3
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The Role of Foveal Cortex in Discriminating Peripheral Stimuli: The Sketchpad Hypothesis. NEUROSCI 2022. [DOI: 10.3390/neurosci4010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Foveal (central) and peripheral vision are strongly interconnected to provide an integrated experience of the world around us. Recently, it has been suggested that there is a feedback mechanism that links foveal and peripheral vision. This peripheral-to-foveal feedback differs from other feedback mechanisms in that during visual processing a novel representation of a stimulus is formed in a different cortical region than that of the feedforward representation. The functional role of foveal feedback is not yet completely understood, but some evidence from neuroimaging studies suggests a link with peripheral shape processing. Behavioural and transcranial magnetic stimulation studies show impairment in peripheral shape discrimination when the foveal retinotopic cortex is disrupted post stimulus presentation. This review aims to link these findings to the visual sketchpad hypothesis. According to this hypothesis, foveal retinotopic cortex stores task-relevant information to aid identification of peripherally presented objects. We discuss how the characteristics of foveal feedback support this hypothesis and rule out other possible explanations. We also discuss the possibility that the foveal feedback may be independent of the sensory modality of the stimulation.
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Lega C, Cattaneo L, Costantini G. How to Test the Association Between Baseline Performance Level and the Modulatory Effects of Non-Invasive Brain Stimulation Techniques. Front Hum Neurosci 2022; 16:920558. [PMID: 35814951 PMCID: PMC9265211 DOI: 10.3389/fnhum.2022.920558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Abstract
Behavioral effects of non-invasive brain stimulation techniques (NIBS) can dramatically change as a function of different factors (e.g., stimulation intensity, timing of stimulation). In this framework, lately there has been a growing interest toward the importance of considering the inter-individual differences in baseline performance and how they are related with behavioral NIBS effects. However, assessing how baseline performance level is associated with behavioral effects of brain stimulation techniques raises up crucial methodological issues. How can we test whether the performance at baseline is predictive of the effects of NIBS, when NIBS effects themselves are estimated with reference to baseline performance? In this perspective article, we discuss the limitations connected to widely used strategies for the analysis of the association between baseline value and NIBS effects, and review solutions to properly address this type of question.
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Affiliation(s)
- Carlotta Lega
- Department of Psychology and Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy
- *Correspondence: Carlotta Lega
| | - Luigi Cattaneo
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
- Centre for Medical Sciences (CISMed), University of Trento, Trento, Italy
| | - Giulio Costantini
- Department of Psychology and Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy
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5
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Janssens SEW, Sack AT. Spontaneous Fluctuations in Oscillatory Brain State Cause Differences in Transcranial Magnetic Stimulation Effects Within and Between Individuals. Front Hum Neurosci 2021; 15:802244. [PMID: 34924982 PMCID: PMC8674306 DOI: 10.3389/fnhum.2021.802244] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 11/16/2021] [Indexed: 01/01/2023] Open
Abstract
Transcranial magnetic stimulation (TMS) can cause measurable effects on neural activity and behavioral performance in healthy volunteers. In addition, TMS is increasingly used in clinical practice for treating various neuropsychiatric disorders. Unfortunately, TMS-induced effects show large intra- and inter-subject variability, hindering its reliability, and efficacy. One possible source of this variability may be the spontaneous fluctuations of neuronal oscillations. We present recent studies using multimodal TMS including TMS-EMG (electromyography), TMS-tACS (transcranial alternating current stimulation), and concurrent TMS-EEG-fMRI (electroencephalography, functional magnetic resonance imaging), to evaluate how individual oscillatory brain state affects TMS signal propagation within targeted networks. We demonstrate how the spontaneous oscillatory state at the time of TMS influences both immediate and longer-lasting TMS effects. These findings indicate that at least part of the variability in TMS efficacy may be attributable to the current practice of ignoring (spontaneous) oscillatory fluctuations during TMS. Ignoring this state-dependent spread of activity may cause great individual variability which so far is poorly understood and has proven impossible to control. We therefore also compare two technical solutions to directly account for oscillatory state during TMS, namely, to use (a) tACS to externally control these oscillatory states and then apply TMS at the optimal (controlled) brain state, or (b) oscillatory state-triggered TMS (closed-loop TMS). The described multimodal TMS approaches are paramount for establishing more robust TMS effects, and to allow enhanced control over the individual outcome of TMS interventions aimed at modulating information flow in the brain to achieve desirable changes in cognition, mood, and behavior.
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Affiliation(s)
- Shanice E W Janssens
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.,Maastricht Brain Imaging Centre (MBIC), Maastricht, Netherlands
| | - Alexander T Sack
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.,Maastricht Brain Imaging Centre (MBIC), Maastricht, Netherlands.,Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Brain + Nerve Centre, Maastricht University Medical Centre+ (MUMC+), Maastricht, Netherlands.,Centre for Integrative Neuroscience (CIN), Maastricht University, Maastricht, Netherlands
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6
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Silvanto J, Cattaneo Z. Nonlinear interaction between stimulation intensity and initial brain state: Evidence for the facilitatory/suppressive range model of online TMS effects. Neurosci Lett 2020; 742:135538. [PMID: 33259928 DOI: 10.1016/j.neulet.2020.135538] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/17/2020] [Accepted: 11/24/2020] [Indexed: 11/16/2022]
Abstract
The effects of online Transcranial Magnetic Stimulation (TMS) can qualitatively vary as a function of brain state. For example, TMS intensities which normally impair performance can have a facilitatory effect if the targeted neuronal representations are in a suppressed state. These phenomena have been explained in terms of the existence of distinct facilitatory and suppressive ranges as a function of TMS intensity which are shifted by changes in neural excitability. We tested this model by applying TMS at a low (60 % of phosphene threshold) or high (120 % of phosphene threshold) intensity during a priming paradigm. Our results show that state-dependent TMS effects vary qualitatively as a function of TMS intensity. Whereas the application of TMS at 120 % of participants' phosphene threshold impaired performance on fully congruent trials (in effect, reducing the benefit of priming), TMS applied at a lower intensity (60 % of phosphene threshold), facilitated performance on congruent trials. These results demonstrate that behavioral effects of TMS reflect a nonlinear interaction between initial activation state and TMS intensity. They also provide support for the existence of facilitatory/suppressive ranges of TMS effects which shift when neural excitability changes.
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Affiliation(s)
- Juha Silvanto
- School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Stag Hill Guildford, GU2 7XH, UK.
| | - Zaira Cattaneo
- Department of Psychology, University of Milano-Bicocca, Milan, Italy; IRCCS Mondino Foundation, Pavia, Italy
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7
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Guo K, Calver L, Soornack Y, Bourke P. Valence-dependent Disruption in Processing of Facial Expressions of Emotion in Early Visual Cortex—A Transcranial Magnetic Stimulation Study. J Cogn Neurosci 2020; 32:906-916. [DOI: 10.1162/jocn_a_01520] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
Our visual inputs are often entangled with affective meanings in natural vision, implying the existence of extensive interaction between visual and emotional processing. However, little is known about the neural mechanism underlying such interaction. This exploratory transcranial magnetic stimulation (TMS) study examined the possible involvement of the early visual cortex (EVC, Area V1/V2/V3) in perceiving facial expressions of different emotional valences. Across three experiments, single-pulse TMS was delivered at different time windows (50–150 msec) after a brief 10-msec onset of face images, and participants reported the visibility and perceived emotional valence of faces. Interestingly, earlier TMS at ∼90 msec only reduced the face visibility irrespective of displayed expressions, but later TMS at ∼120 msec selectively disrupted the recognition of negative facial expressions, indicating the involvement of EVC in the processing of negative expressions at a later time window, possibly beyond the initial processing of fed-forward facial structure information. The observed TMS effect was further modulated by individuals' anxiety level. TMS at ∼110–120 msec disrupted the recognition of anger significantly more for those scoring relatively low in trait anxiety than the high scorers, suggesting that cognitive bias influences the processing of facial expressions in EVC. Taken together, it seems that EVC is involved in structural encoding of (at least) negative facial emotional valence, such as fear and anger, possibly under modulation from higher cortical areas.
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8
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Janssens SEW, Sack AT, Jessen S, de Graaf TA. Can processing of face trustworthiness bypass early visual cortex? A transcranial magnetic stimulation masking study. Neuropsychologia 2020; 137:107304. [PMID: 31838099 DOI: 10.1016/j.neuropsychologia.2019.107304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 12/02/2019] [Accepted: 12/10/2019] [Indexed: 12/18/2022]
Abstract
As a highly social species, we constantly evaluate human faces to decide whether we can trust someone. Previous studies suggest that face trustworthiness can be processed unconsciously, but the underlying neural pathways remain unclear. Specifically, the question remains whether processing of face trustworthiness relies on early visual cortex (EVC), required for conscious perception. If processing of trustworthiness can bypass EVC, then disrupting EVC should impair subjective (conscious) trustworthiness perception while leaving objective (forced-choice) trustworthiness judgment intact. We applied double-pulse transcranial magnetic stimulation (TMS) to right EVC, at different stimulus onset asynchronies (SOAs) from presentation of a face in either the left or right hemifield. Faces were slightly rotated clockwise or counterclockwise, and were either trustworthy or untrustworthy. On each trial, participants discriminated 1) trustworthiness, 2) stimulus rotation, and 3) reported subjective visibility of trustworthiness. At early SOAs and specifically in the left hemifield, performance on the rotation task was impaired by TMS. Crucially, though TMS also impaired subjective visibility of trustworthiness, no effects on trustworthiness discrimination were obtained. Thus, conscious perception of face trustworthiness (captured by subjective visibility ratings) relies on intact EVC, while objective forced-choice trustworthiness judgments may not. These results are consistent with the hypothesis that objective trustworthiness processing can bypass EVC. For basic visual features, extrastriate pathways are well-established; but face trustworthiness depends on a complex configuration of features. Its potential processing without EVC is therefore of particular interest, further highlighting its ecological relevance.
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Affiliation(s)
- Shanice E W Janssens
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience Maastricht University, Maastricht, the Netherlands; Maastricht Brain Imaging Centre (MBIC), Maastricht University, Maastricht, the Netherlands.
| | - Alexander T Sack
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience Maastricht University, Maastricht, the Netherlands; Maastricht Brain Imaging Centre (MBIC), Maastricht University, Maastricht, the Netherlands; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Brain+Nerve Centre, Maastricht University, Maastricht, the Netherlands; Center for Integrative Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Sarah Jessen
- Department of Neurology, University of Lübeck, Lübeck, Germany
| | - Tom A de Graaf
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience Maastricht University, Maastricht, the Netherlands; Maastricht Brain Imaging Centre (MBIC), Maastricht University, Maastricht, the Netherlands; Center for Integrative Neuroscience, Maastricht University, Maastricht, the Netherlands
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9
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Center EG, Knight R, Fabiani M, Gratton G, Beck DM. Examining the role of feedback in TMS-induced visual suppression: A cautionary tale. Conscious Cogn 2019; 75:102805. [DOI: 10.1016/j.concog.2019.102805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/04/2019] [Accepted: 08/10/2019] [Indexed: 11/25/2022]
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10
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Silvanto J, Cattaneo Z. Common framework for "virtual lesion" and state-dependent TMS: The facilitatory/suppressive range model of online TMS effects on behavior. Brain Cogn 2017; 119:32-38. [PMID: 28963993 PMCID: PMC5652969 DOI: 10.1016/j.bandc.2017.09.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/06/2017] [Accepted: 09/18/2017] [Indexed: 11/22/2022]
Abstract
Transcranial magnetic stimulation can either facilitate or impair behavior. Nature of behavioral effects depends on factors such as brain state and intensity. We present a common framework to account for these effects. There are distinct intensity ranges for facilitatory and suppressive effects of TMS. Changes in excitability shift these ranges and account for behavioral effects.
The behavioral effects of Transcranial Magnetic Stimulation (TMS) are often nonlinear; factors such as stimulation intensity and brain state can modulate the impact of TMS on observable behavior in qualitatively different manner. Here we propose a theoretical framework to account for these effects. In this model, there are distinct intensity ranges for facilitatory and suppressive effects of TMS – low intensities facilitate neural activity and behavior whereas high intensities induce suppression. The key feature of the model is that these ranges are shifted by changes in neural excitability: consequently, a TMS intensity, which normally induces suppression, can have a facilitatory effect if the stimulated neurons are being inhibited by ongoing task-related processes or preconditioning. For example, adaptation reduces excitability of adapted neurons; the outcome is that TMS intensities which inhibit non-adapted neurons induce a facilitation on adapted neural representations, leading to reversal of adaptation effects. In conventional “virtual lesion” paradigms, similar effects occur because neurons not involved in task-related processes are inhibited by the ongoing task. The resulting reduction in excitability can turn high intensity “inhibitory” TMS to low intensity “facilitatory” TMS for these neurons, and as task-related neuronal representations are in the inhibitory range, the outcome is a reduction in signal-to-noise ratio and behavioral impairment.
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Affiliation(s)
- Juha Silvanto
- University of Westminster, Faculty of Science and Technology, Department of Psychology, 115 New Cavendish Street, W1W 6UW London, UK.
| | - Zaira Cattaneo
- Department of Psychology, University of Milano-Bicocca, 20126 Milan, Italy; Brain Connectivity Center, National Neurological Institute C. Mondino, 27100 Pavia, Italy
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11
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Silvanto J, Bona S, Cattaneo Z. Initial activation state, stimulation intensity and timing of stimulation interact in producing behavioral effects of TMS. Neuroscience 2017; 363:134-141. [PMID: 28893648 PMCID: PMC5648046 DOI: 10.1016/j.neuroscience.2017.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 11/12/2022]
Abstract
TMS effects depend on various factors such as intensity, brain state and timing. We examined how these factors interact to give rise to behavioral effects. TMS was applied while participants performed a behavioral priming task. State dependency of TMS effect was found to interact with intensity and timing.
Behavioral effects of transcranial magnetic stimulation (TMS) have been shown to depend on various factors, such as neural activation state, stimulation intensity, and timing of stimulation. Here we examined whether these factors interact, by applying TMS at either sub- or suprathreshold intensity (relative to phosphene threshold, PT) and at different time points during a state-dependent TMS paradigm. The state manipulation involved a behavioral task in which a visual prime (color grating) was followed by a target stimulus which could be either congruent, incongruent or partially congruent with the color and orientation of the prime. In Experiment 1, single-pulse TMS was applied over the early visual cortex (V1/V2) or Vertex (baseline) at the onset of the target stimulus – timing often used in state-dependent TMS studies. With both subthreshold and suprathreshold stimulation, TMS facilitated the detection of incongruent stimuli while not significantly affecting other stimulus types. In Experiment 2, TMS was applied at 100 ms after target onset –a time window in which V1/V2 is responding to visual input. Only TMS applied at suprathreshold intensity facilitated the detection of incongruent stimuli, with no effect with subthreshold stimulation. The need for higher stimulation intensity is likely to reflect reduced susceptibility to TMS of neurons responding to visual stimulation. Furthermore, the finding that in Experiment 2 only suprathreshold TMS induced a behavioral facilitation on incongruent targets (whereas facilitations in the absence of priming have been reported with subthreshold TMS) indicates that priming, by reducing neural excitability to incongruent targets, shifts the facilitatory/inhibitory range of TMS effects.
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Affiliation(s)
- Juha Silvanto
- Department of Psychology, Faculty of Science and Technology, University of Westminster, 309 Regent Street, W1B 2HW London, UK.
| | - Silvia Bona
- Department of Psychology, University of Milano-Bicocca, 20126 Milan, Italy
| | - Zaira Cattaneo
- Department of Psychology, University of Milano-Bicocca, 20126 Milan, Italy; Brain Connectivity Center, National Neurological Institute C. Mondino, 27100 Pavia, Italy
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12
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de Graaf T, Duecker F, Stankevich Y, ten Oever S, Sack A. Seeing in the dark: Phosphene thresholds with eyes open versus closed in the absence of visual inputs. Brain Stimul 2017; 10:828-835. [DOI: 10.1016/j.brs.2017.04.127] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 02/24/2017] [Accepted: 04/23/2017] [Indexed: 01/13/2023] Open
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13
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Cambieri C, Iacovelli E, Gori MC, Onesti E, Ceccanti M, Frasca V, Inghilleri M. Effects of visual deprivation on primary motor cortex excitability: a study on healthy subjects based on repetitive transcranial magnetic stimulation. Exp Brain Res 2017; 235:2059-2067. [DOI: 10.1007/s00221-017-4945-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
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14
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Weldon KB, Rich AN, Woolgar A, Williams MA. Disruption of Foveal Space Impairs Discrimination of Peripheral Objects. Front Psychol 2016; 7:699. [PMID: 27242612 PMCID: PMC4862972 DOI: 10.3389/fpsyg.2016.00699] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/26/2016] [Indexed: 11/17/2022] Open
Abstract
Visual space is retinotopically mapped such that peripheral objects are processed in a cortical region outside the region that represents central vision. Despite this well-known fact, neuroimaging studies have found information about peripheral objects in the foveal confluence, the cortical region representing the fovea. Further, this information is behaviorally relevant: disrupting the foveal confluence using transcranial magnetic stimulation impairs discrimination of peripheral objects at time-points consistent with a disruption of feedback. If the foveal confluence receives feedback of information about peripheral objects to boost vision, there should be behavioral consequences of this phenomenon. Here, we tested the effect of foveal distractors at different stimulus onset asynchronies (SOAs) on discrimination of peripheral targets. Participants performed a discrimination task on target objects presented in the periphery while fixating centrally. A visual distractor presented at the fovea ~100 ms after presentation of the targets disrupted performance more than a central distractor presented at other SOAs. This was specific to a central distractor; a peripheral distractor at the same time point did not have the same effect. These results are consistent with the claim that foveal retinotopic cortex is recruited for extra-foveal perception. This study describes a new paradigm for investigating the nature of the foveal feedback phenomenon and demonstrates the importance of this feedback in peripheral vision.
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Affiliation(s)
- Kimberly B Weldon
- Perception in Action Research Centre, Department of Cognitive Science, Faculty of Human Sciences, Macquarie UniversitySydney, NSW, Australia; ARC Centre of Excellence in Cognition and its Disorders, Macquarie UniversitySydney, NSW, Australia
| | - Anina N Rich
- Perception in Action Research Centre, Department of Cognitive Science, Faculty of Human Sciences, Macquarie UniversitySydney, NSW, Australia; ARC Centre of Excellence in Cognition and its Disorders, Macquarie UniversitySydney, NSW, Australia
| | - Alexandra Woolgar
- Perception in Action Research Centre, Department of Cognitive Science, Faculty of Human Sciences, Macquarie UniversitySydney, NSW, Australia; ARC Centre of Excellence in Cognition and its Disorders, Macquarie UniversitySydney, NSW, Australia
| | - Mark A Williams
- Perception in Action Research Centre, Department of Cognitive Science, Faculty of Human Sciences, Macquarie UniversitySydney, NSW, Australia; ARC Centre of Excellence in Cognition and its Disorders, Macquarie UniversitySydney, NSW, Australia
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15
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Hartwigsen G, Bergmann TO, Herz DM, Angstmann S, Karabanov A, Raffin E, Thielscher A, Siebner HR. Modeling the effects of noninvasive transcranial brain stimulation at the biophysical, network, and cognitive level. PROGRESS IN BRAIN RESEARCH 2015; 222:261-87. [PMID: 26541384 DOI: 10.1016/bs.pbr.2015.06.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how these approaches advance the scientific potential of NTBS as an interventional tool in cognitive neuroscience. (i) Leveraging the anatomical information provided by structural imaging, the electric field distribution in the brain can be modeled and simulated. Biophysical modeling approaches generate testable predictions regarding the impact of interindividual variations in cortical anatomy on the injected electric fields or the influence of the orientation of current flow on the physiological stimulation effects. (ii) Functional brain mapping of the spatiotemporal neural dynamics during cognitive tasks can be used to construct causal network models. These models can identify spatiotemporal changes in effective connectivity during distinct cognitive states and allow for examining how effective connectivity is shaped by NTBS. (iii) Modeling the NTBS effects based on neuroimaging can be complemented by behavior-based cognitive models that exploit variations in task performance. For instance, NTBS-induced changes in response speed and accuracy can be explicitly modeled in a cognitive framework accounting for the speed-accuracy trade-off. This enables to dissociate between behavioral NTBS effects that emerge in the context of rapid automatic responses or in the context of slow deliberate responses. We argue that these complementary modeling approaches facilitate the use of NTBS as a means of dissecting the causal architecture of cognitive systems of the human brain.
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Affiliation(s)
- Gesa Hartwigsen
- Department of Psychology, Christian-Albrechts-University, Kiel, Germany.
| | - Til Ole Bergmann
- Department of Psychology, Christian-Albrechts-University, Kiel, Germany
| | - Damian Marc Herz
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Steffen Angstmann
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Anke Karabanov
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Estelle Raffin
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Grenoble Institute of Neuroscience, Research Centre U836 Inserm-UJF, Team 11 Brain Function & Neuromodulation, Grenoble, France
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Biomedical Engineering Section, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark.
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16
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de Graaf TA, Duecker F, Fernholz MHP, Sack AT. Spatially specific vs. unspecific disruption of visual orientation perception using chronometric pre-stimulus TMS. Front Behav Neurosci 2015; 9:5. [PMID: 25688194 PMCID: PMC4311643 DOI: 10.3389/fnbeh.2015.00005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 01/08/2015] [Indexed: 11/13/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) over occipital cortex can impair visual processing. Such "TMS masking" has repeatedly been shown at several stimulus onset asynchronies (SOAs), with TMS pulses generally applied after the onset of a visual stimulus. Following increased interest in the neuronal state-dependency of visual processing, we recently explored the efficacy of TMS at "negative SOAs", when no visual processing can yet occur. We could reveal pre-stimulus TMS disruption, with results moreover hinting at two separate mechanisms in occipital cortex biasing subsequent orientation perception. Here we extended this work, including a chronometric design to map the temporal dynamics of spatially specific and unspecific mechanisms of state-dependent visual processing, while moreover controlling for TMS-induced pupil covering. TMS pulses applied 60-40 ms prior to a visual stimulus decreased orientation processing independent of stimulus location, while a local suppressive effect was found for TMS applied 30-10 ms pre-stimulus. These results contribute to our understanding of spatiotemporal mechanisms in occipital cortex underlying the state-dependency of visual processing, providing a basis for future work to link pre-stimulus TMS suppression effects to other known visual biasing mechanisms.
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Affiliation(s)
- Tom A de Graaf
- Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Centre Maastricht, Netherlands
| | - Felix Duecker
- Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Centre Maastricht, Netherlands
| | - Martin H P Fernholz
- Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Centre Maastricht, Netherlands
| | - Alexander T Sack
- Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Centre Maastricht, Netherlands
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17
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Tapia E, Beck DM. Probing feedforward and feedback contributions to awareness with visual masking and transcranial magnetic stimulation. Front Psychol 2014; 5:1173. [PMID: 25374548 PMCID: PMC4204434 DOI: 10.3389/fpsyg.2014.01173] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 09/26/2014] [Indexed: 11/13/2022] Open
Abstract
A number of influential theories posit that visual awareness relies not only on the initial, stimulus-driven (i.e., feedforward) sweep of activation but also on recurrent feedback activity within and between brain regions. These theories of awareness draw heavily on data from masking paradigms in which visibility of one stimulus is reduced due to the presence of another stimulus. More recently transcranial magnetic stimulation (TMS) has been used to study the temporal dynamics of visual awareness. TMS over occipital cortex affects performance on visual tasks at distinct time points and in a manner that is comparable to visual masking. We draw parallels between these two methods and examine evidence for the neural mechanisms by which visual masking and TMS suppress stimulus visibility. Specifically, both methods have been proposed to affect feedforward as well as feedback signals when applied at distinct time windows relative to stimulus onset and as a result modify visual awareness. Most recent empirical evidence, moreover, suggests that while visual masking and TMS impact stimulus visibility comparably, the processes these methods affect may not be as similar as previously thought. In addition to reviewing both masking and TMS studies that examine feedforward and feedback processes in vision, we raise questions to guide future studies and further probe the necessary conditions for visual awareness.
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Affiliation(s)
- Evelina Tapia
- Beckman Institute, University of Illinois Urbana-Champaign Urbana, IL USA
| | - Diane M Beck
- Beckman Institute, University of Illinois Urbana-Champaign Urbana, IL USA ; Department of Psychology, University of Illinois Urbana-Champaign Urbana, IL, USA
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18
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Jacobs C, de Graaf TA, Sack AT. Two distinct neural mechanisms in early visual cortex determine subsequent visual processing. Cortex 2014; 59:1-11. [DOI: 10.1016/j.cortex.2014.06.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 02/26/2014] [Accepted: 06/19/2014] [Indexed: 10/25/2022]
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19
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de Graaf TA, Koivisto M, Jacobs C, Sack AT. The chronometry of visual perception: review of occipital TMS masking studies. Neurosci Biobehav Rev 2014; 45:295-304. [PMID: 25010557 DOI: 10.1016/j.neubiorev.2014.06.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 11/17/2022]
Abstract
Transcranial magnetic stimulation (TMS) continues to deliver on its promise as a research tool. In this review article we focus on the application of TMS to early visual cortex (V1, V2, V3) in studies of visual perception and visual awareness. Depending on the asynchrony between visual stimulus onset and TMS pulse (SOA), TMS can suppress visual perception, allowing one to track the time course of functional relevance (chronometry) of early visual cortex for vision. This procedure has revealed multiple masking effects ('dips'), some consistently (∼+100ms SOA) but others less so (∼-50ms, ∼-20ms, ∼+30ms, ∼+200ms SOA). We review the state of TMS masking research, focusing on the evidence for these multiple dips, the relevance of several experimental parameters to the obtained 'masking curve', and the use of multiple measures of visual processing (subjective measures of awareness, objective discrimination tasks, priming effects). Lastly, we consider possible future directions for this field. We conclude that while TMS masking has yielded many fundamental insights into the chronometry of visual perception already, much remains unknown. Not only are there several temporal windows when TMS pulses can induce visual suppression, even the well-established 'classical' masking effect (∼+100ms) may reflect more than one functional visual process.
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Affiliation(s)
- Tom A de Graaf
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200MD Maastricht, The Netherlands; Maastricht Brain Imaging Center, PO Box 616, 6200MD Maastricht, The Netherlands.
| | - Mika Koivisto
- Centre for Cognitive Neuroscience and Department of Psychology, University of Turku, FIN-20014 Turku, Finland
| | - Christianne Jacobs
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200MD Maastricht, The Netherlands; Maastricht Brain Imaging Center, PO Box 616, 6200MD Maastricht, The Netherlands; Department of Psychology, Faculty of Science and Technology, University of Westminster, 309 Regent Street, W1B 2HW London, United Kingdom
| | - Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200MD Maastricht, The Netherlands; Maastricht Brain Imaging Center, PO Box 616, 6200MD Maastricht, The Netherlands
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20
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Roebuck H, Bourke P, Guo K. Role of lateral and feedback connections in primary visual cortex in the processing of spatiotemporal regularity - a TMS study. Neuroscience 2014; 263:231-9. [PMID: 24462610 DOI: 10.1016/j.neuroscience.2014.01.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 01/08/2014] [Accepted: 01/08/2014] [Indexed: 11/19/2022]
Abstract
Our human visual system exploits spatiotemporal regularity to interpret incoming visual signals. With a dynamic stimulus sequence of four collinear bars (predictors) appearing consecutively toward the fovea, followed by a target bar with varying contrasts, we have previously found that this predictable spatiotemporal stimulus structure enhances target detection performance and its underlying neural process starts in the primary visual cortex (area V1). However, the relative contribution of V1 lateral and feedback connections in the processing of spatiotemporal regularity remains unclear. In this study we measured human contrast detection of a briefly presented foveal target that was embedded in a dynamic collinear predictor-target sequence. Transcranial magnetic stimulation (TMS) was used to selectively disrupt V1 horizontal and feedback connections in the processing of predictors. The coil was positioned over a cortical location corresponding to the location of the last predictor prior to target onset. Single-pulse TMS at an intensity of 10% below phosphene thresholdwas delivered at 20 or 90ms after the predictor onset. Our analysis revealed that the delivery of TMS at both time windows equally reduced, but did not abolish, the facilitation effect of the predictors on target detection. Furthermore, if the predictors' ordination was randomized to suppress V1 lateral connections, the TMS disruption was significantly more evident at 20ms than at 90-ms time window. We suggest that both lateral and feedback connections contribute to the encoding of spatiotemporal regularity in V1. These findings develop understanding of how our visual system exploits spatiotemporal regularity to facilitate the efficiency of visual perception.
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Affiliation(s)
- H Roebuck
- School of Psychology, University of Lincoln, Lincoln LN6 7TS, UK
| | - P Bourke
- School of Psychology, University of Lincoln, Lincoln LN6 7TS, UK
| | - K Guo
- School of Psychology, University of Lincoln, Lincoln LN6 7TS, UK.
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21
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Rassovsky Y, Lee J, Nori P, D Wu A, Iacoboni M, Breitmeyer BG, Hellemann G, Green MF. Assessing temporal processing of facial emotion perception with transcranial magnetic stimulation. Brain Behav 2013; 3:263-72. [PMID: 23785658 PMCID: PMC3683286 DOI: 10.1002/brb3.136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 02/13/2013] [Accepted: 02/23/2013] [Indexed: 11/30/2022] Open
Abstract
The ability to process facial expressions can be modified by altering the spatial frequency of the stimuli, an effect that has been attributed to differential properties of visual pathways that convey different types of information to distinct brain regions at different speeds. While this effect suggests a potential influence of spatial frequency on the processing speed of facial emotion, this hypothesis has not been examined directly. We addressed this question using a facial emotion identification task with photographs containing either high spatial frequency (HSF), low spatial frequency (LSF), or broadband spatial frequency (BSF). Temporal processing of emotion perception was manipulated by suppressing visual perception with a single-pulse transcranial magnetic stimulation (TMS), delivered to the visual cortex at six intervals prior to (forward masking) or following (backward masking) stimulus presentation. Participants performed best in the BSF, followed by LSF, and finally HSF condition. A spatial frequency by forward/backward masking interaction effect demonstrated reduced performance in the forward masking component in the BSF condition and a reversed performance pattern in the HSF condition, with no significant differences between forward and backward masking in the LSF condition. Results indicate that LSF information may play a greater role than HSF information in emotional processing, but may not be sufficient for fast conscious perception of emotion. As both LSF and HSF filtering reduced the speed of extracting emotional information from faces, it is possible that intact BSF faces have an inherent perceptual advantage and hence benefit from faster temporal processing.
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Affiliation(s)
- Yuri Rassovsky
- Department of Psychology and Gonda Multidisciplinary Brain Research Center, Bar-Ilan University Ramat-Gan, Israel ; Department of Psychiatry and Biobehavioral Sciences, UCLA Semel Institute for Neuroscience and Human Behavior Los Angeles, California
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22
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Emmanouil TA, Avigan P, Persuh M, Ro T. Saliency affects feedforward more than feedback processing in early visual cortex. Neuropsychologia 2013; 51:1497-503. [PMID: 23643729 DOI: 10.1016/j.neuropsychologia.2013.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 04/19/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022]
Abstract
Early visual cortex activity is influenced by both bottom-up and top-down factors. To investigate the influences of bottom-up (saliency) and top-down (task) factors on different stages of visual processing, we used transcranial magnetic stimulation (TMS) of areas V1/V2 to induce visual suppression at varying temporal intervals. Subjects were asked to detect and discriminate the color or the orientation of briefly-presented small lines that varied on color saliency based on color contrast with the surround. Regardless of task, color saliency modulated the magnitude of TMS-induced visual suppression, especially at earlier temporal processing intervals that reflect the feedforward stage of visual processing in V1/V2. In a second experiment we found that our color saliency effects were also influenced by an inherent advantage of the color red relative to other hues and that color discrimination difficulty did not affect visual suppression. These results support the notion that early visual processing is stimulus driven and that feedforward and feedback processing encode different types of information about visual scenes. They further suggest that certain hues can be prioritized over others within our visual systems by being more robustly represented during early temporal processing intervals.
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Affiliation(s)
- Tatiana Aloi Emmanouil
- Department of Psychology and Program in Cognitive Neuroscience, The City College and Graduate Center of the City University of New York, NY 10031, USA
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23
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van de Ven V, Sack AT. Transcranial magnetic stimulation of visual cortex in memory: Cortical state, interference and reactivation of visual content in memory. Behav Brain Res 2013; 236:67-77. [DOI: 10.1016/j.bbr.2012.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 08/01/2012] [Indexed: 12/27/2022]
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24
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Rahnev DA, Maniscalco B, Luber B, Lau H, Lisanby SH. Direct injection of noise to the visual cortex decreases accuracy but increases decision confidence. J Neurophysiol 2012; 107:1556-63. [DOI: 10.1152/jn.00985.2011] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The relationship between accuracy and confidence in psychophysical tasks traditionally has been assumed to be mainly positive, i.e., the two typically increase or decrease together. However, recent studies have reported examples of exceptions, where confidence and accuracy dissociate from each other. Explanations for such dissociations often involve dual-channel models, in which a cortical channel contributes to both accuracy and confidence, whereas a subcortical channel only contributes to accuracy. Here, we show that a single-channel model derived from signal detection theory (SDT) can also account for such dissociations. We applied transcranial magnetic stimulation (TMS) to the occipital cortex to disrupt the internal representation of a visual stimulus. The results showed that consistent with previous research, occipital TMS decreased accuracy. However, counterintuitively, it also led to an increase in confidence ratings. The data were predicted well by a single-channel SDT model, which posits that occipital TMS increased the variance of the internal stimulus distributions. A formal model comparison analysis that used information theoretic methods confirmed that this model was preferred over single-channel models, in which occipital TMS changed the signal strength or dual-channel models, which assume two different processing routes. Thus our results show that dissociations between accuracy and confidence can, at least in some cases, be accounted for by a single-channel model.
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Affiliation(s)
| | - Brian Maniscalco
- Columbia University, Department of Psychology, New York, New York
| | - Bruce Luber
- Duke University, Department of Psychiatry, Durham, North Carolina; and
| | - Hakwan Lau
- Columbia University, Department of Psychology, New York, New York
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, Netherlands
| | - Sarah H. Lisanby
- Duke University, Department of Psychiatry, Durham, North Carolina; and
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25
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Topographic contribution of early visual cortex to short-term memory consolidation: a transcranial magnetic stimulation study. J Neurosci 2012; 32:4-11. [PMID: 22219265 DOI: 10.1523/jneurosci.3261-11.2012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The neural correlates for retention of visual information in visual short-term memory are considered separate from those of sensory encoding. However, recent findings suggest that sensory areas may play a role also in short-term memory. We investigated the functional relevance, spatial specificity, and temporal characteristics of human early visual cortex in the consolidation of capacity-limited topographic visual memory using transcranial magnetic stimulation (TMS). Topographically specific TMS pulses were delivered over lateralized occipital cortex at 100, 200, or 400 ms into the retention phase of a modified change detection task with low or high memory loads. For the high but not the low memory load, we found decreased memory performance for memory trials in the visual field contralateral, but not ipsilateral to the side of TMS, when pulses were delivered at 200 ms into the retention interval. A behavioral version of the TMS experiment, in which a distractor stimulus (memory mask) replaced the TMS pulses, further corroborated these findings. Our findings suggest that retinotopic visual cortex contributes to the short-term consolidation of topographic visual memory during early stages of the retention of visual information. Further, TMS-induced interference decreased the strength (amplitude) of the memory representation, which most strongly affected the high memory load trials.
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26
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TMS effects on subjective and objective measures of vision: Stimulation intensity and pre- versus post-stimulus masking. Conscious Cogn 2011; 20:1244-55. [DOI: 10.1016/j.concog.2011.04.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 04/01/2011] [Accepted: 04/27/2011] [Indexed: 11/22/2022]
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27
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de Graaf TA, Goebel R, Sack AT. Feedforward and quick recurrent processes in early visual cortex revealed by TMS? Neuroimage 2011; 61:651-9. [PMID: 22032946 DOI: 10.1016/j.neuroimage.2011.10.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Revised: 09/01/2011] [Accepted: 10/07/2011] [Indexed: 12/21/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) can be applied to occipital cortex to abolish (conscious) perception of visual stimuli. TMS research has revealed several time windows of masking relative to visual stimulus onset, most consistently a time window around 100ms post-stimulus. However, the exact nature of visual processing in this 'classical' time window, e.g. whether it represents the feedforward processing of the visual information, or rather a feedback projection from higher visual areas, remains unclear. Here, we used TMS to mask in the same participants two types of stimuli of different complexities (orientation Gratings and Faces) over different time windows. Interestingly, the masking functions were not the same for both stimulus types. We found an earlier peak masking latency for orientation stimuli, and a slower recovery for Faces. In a second, follow-up experiment, we superimposed both types of stimuli to create one composite stimulus set. Depending on the instruction, participants could then perform orientation or face discrimination tasks on the exact same stimuli. In addition, for each participant, stimuli were calibrated to equate task difficulties. The peak masking latency was now identical for both tasks, but the masking function revealed again a slower recovery during the face discrimination task, suggesting top-down (recurrent) effects in the second half of the masking function. Hence, rather than this masking window reflecting either feedforward or feedback processing, the early part of what is traditionally considered one masking window may reflect feedforward processing, while the latter part may already reflect recurrent processing. These findings shed new light on recurrent models of vision and related theoretical accounts of visual awareness.
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Affiliation(s)
- Tom A de Graaf
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
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28
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29
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Jacobs C, Goebel R, Sack AT. Visual awareness suppression by pre-stimulus brain stimulation; a neural effect. Neuroimage 2011; 59:616-24. [PMID: 21840406 DOI: 10.1016/j.neuroimage.2011.07.090] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 07/27/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) has established the functional relevance of early visual cortex (EVC) for visual awareness with great temporal specificity non-invasively in conscious human volunteers. Many studies have found a suppressive effect when TMS was applied over EVC 80-100 ms after the onset of the visual stimulus (post-stimulus TMS time window). Yet, few studies found task performance to also suffer when TMS was applied even before visual stimulus presentation (pre-stimulus TMS time window). This pre-stimulus TMS effect, however, remains controversially debated and its origin had mainly been ascribed to TMS-induced eye-blinking artifacts. Here, we applied chronometric TMS over EVC during the execution of a visual discrimination task, covering an exhaustive range of visual stimulus-locked TMS time windows ranging from -80 pre-stimulus to 300 ms post-stimulus onset. Electrooculographical (EoG) recordings, sham TMS stimulation, and vertex TMS stimulation controlled for different types of non-neural TMS effects. Our findings clearly reveal TMS-induced masking effects for both pre- and post-stimulus time windows, and for both objective visual discrimination performance and subjective visibility. Importantly, all effects proved to be still present after post hoc removal of eye blink trials, suggesting a neural origin for the pre-stimulus TMS suppression effect on visual awareness. We speculate based on our data that TMS exerts its pre-stimulus effect via generation of a neural state which interacts with subsequent visual input.
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Affiliation(s)
- Christianne Jacobs
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands.
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30
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Elkin-Frankston S, Fried P, Rushmore RJ, Valero-Cabré A. From qualia to quantia: A system to document and quantify phosphene percepts elicited by non-invasive neurostimulation of the human occipital cortex. J Neurosci Methods 2011; 198:149-57. [DOI: 10.1016/j.jneumeth.2011.02.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 02/11/2011] [Accepted: 02/16/2011] [Indexed: 10/18/2022]
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31
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Abstract
We probed for improvement of visual sensitivity in human participants using transcranial magnetic stimulation (TMS). Stimulation of visual cortex can induce an illusory visual percept known as a phosphene. It is known that TMS, delivered at intensities above the threshold to induce phosphenes, impairs the detection of visual stimuli. We investigated how the detection of a simple visual stimulus is affected by TMS applied to visual cortex at or below the phosphene threshold. Participants performed the detection task while the contrast of the visual stimulus was varied from trial to trial according to an adaptive staircase procedure. Detection of the stimulus was enhanced when a single pulse of TMS was delivered to the contralateral visual cortex 100 or 120 ms after stimulus onset at intensities just below the phosphene threshold. No improvement in visual sensitivity was observed when TMS was applied to the visual cortex in the opposite hemisphere (ipsilateral to the visual stimulus). We conclude that TMS-induced neuronal activity can sum with stimulus-evoked activity to augment visual perception.
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32
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Bolognini N, Rossetti A, Maravita A, Miniussi C. Seeing touch in the somatosensory cortex: a TMS study of the visual perception of touch. Hum Brain Mapp 2011; 32:2104-14. [PMID: 21305659 DOI: 10.1002/hbm.21172] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 08/20/2010] [Accepted: 08/26/2010] [Indexed: 12/21/2022] Open
Abstract
Recent studies suggest the existence of a visuo-tactile mirror system, comprising the primary (SI) and secondary (SII) somatosensory cortices, which matches observed touch with felt touch. Here, repetitive transcranial magnetic stimulation (rTMS) was used to determine whether SI or SII play a functional role in the visual processing of tactile events. Healthy participants performed a visual discrimination task with tactile stimuli (a finger touching a hand) and a control task (a finger moving without touching). During both tasks, rTMS was applied over either SI or SII, and to the occipital cortex. rTMS over SI selectively reduced subject performance for interpreting whether a contralateral visual tactile stimulus contains a tactile event, whereas SII stimulation impaired visual processing regardless of the tactile component. These findings provide evidence for a multimodal sensory-motor system with mirror properties, where somatic and visual properties of action converge. SI, a cortical area traditionally viewed as modality-specific, is selectively implicated in the visual processing of touch. These results are in line with the existence of a sensory mirror system mediating the embodied simulation concept.
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Affiliation(s)
- Nadia Bolognini
- Department of Psychology, University of Milano-Bicocca, Milan, Italy.
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33
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de Graaf T, Sack A. Null results in TMS: From absence of evidence to evidence of absence. Neurosci Biobehav Rev 2011; 35:871-7. [DOI: 10.1016/j.neubiorev.2010.10.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 10/08/2010] [Accepted: 10/11/2010] [Indexed: 10/18/2022]
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34
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de Graaf TA, Herring J, Sack AT. A chronometric exploration of high-resolution 'sensitive TMS masking' effects on subjective and objective measures of vision. Exp Brain Res 2010; 209:19-27. [PMID: 21161191 PMCID: PMC3035793 DOI: 10.1007/s00221-010-2512-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 11/24/2010] [Indexed: 11/03/2022]
Abstract
Transcranial magnetic stimulation (TMS) can induce masking by interfering with ongoing neural activity in early visual cortex. Previous work has explored the chronometry of occipital involvement in vision by using single pulses of TMS with high temporal resolution. However, conventionally TMS intensities have been high and the only measure used to evaluate masking was objective in nature. Recent studies have begun to incorporate subjective measures of vision, alongside objective ones. The current study goes beyond previous work in two regards. First, we explored both objective vision (an orientation discrimination task) and subjective vision (a stimulus visibility rating on a four-point scale), across a wide range of time windows with high temporal resolution. Second, we used a very sensitive TMS-masking paradigm: stimulation was at relatively low TMS intensities, with a figure-8 coil, and the small stimulus was difficult to discriminate already at baseline level. We hypothesized that this should increase the effective temporal resolution of our paradigm. Perhaps for this reason, we are able to report a rather interesting masking curve. Within the classical-masking time window, previously reported to encompass broad SOAs anywhere between 60 and 120 ms, we report not one, but at least two dips in objective performance, with no masking in-between. The subjective measure of vision did not mirror this pattern. These preliminary data from our exploratory design suggest that, with sensitive TMS masking, we might be able to reveal visual processes in early visual cortex previously unreported.
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Affiliation(s)
- Tom A de Graaf
- Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
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35
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Unique contributions of brain stimulation to the study of consciousness: where neuroscience meets philosophy. CNS Spectr 2010; 15:154-6. [PMID: 20414164 DOI: 10.1017/s1092852900027425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
True progress in understanding how experience arises from the brain has been relatively slow when viewed from a historical perspective. Recently, several technologies to study and stimulate the brain have been applied to this field of inquiry. Such progress was made only 2,500 years after the ancient Greek philosopher Parmenides first adopted a technical procedure involving the application of formal logic instruments to explore the perception of experiences.At the phenomenological level, consciousness has been referred to as “what vanishes every night when we fall into dreamless sleep and reappears when we wake up or when we dream. It is also all we are and all we have: lose consciousness and, as far as you are concerned, your own self, and the entire world dissolves into nothingness”. According to the integrated information theory, consciousness is integrated information.The term “consciousness” therefore has two key senses: wakefulness and awareness. Wakefulness is a state of consciousness distinguished from coma or sleep. Having one's eyes open is generally an indication of wakefulness and we usually assume that anyone who is awake will also be aware. Awareness implies not merely being conscious but also being conscious of something. The broad definition of consciousness includes a large range of processes that we normally regard as unconscious (eg, blindsight or priming by neglected or masked stimuli).Both sleep and anesthesia are reversible states of eyes-closed unresponsiveness to environmental stimuli in which the individual lacks both wakefulness and awareness. In contrast to sleep, where sufficient stimulation will return the individual to wakefulness, even the most vigorous exogenous stimulation cannot produce awakening in a patient under an adequate level of general anesthesia.
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Ro T. What can TMS tell us about visual awareness? Cortex 2010; 46:110-3. [DOI: 10.1016/j.cortex.2009.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 10/15/2008] [Accepted: 10/23/2008] [Indexed: 10/21/2022]
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Chambers CD, Heinen K. TMS and the functional neuroanatomy of attention. Cortex 2010; 46:114-7. [DOI: 10.1016/j.cortex.2009.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 10/04/2008] [Accepted: 03/03/2009] [Indexed: 11/17/2022]
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Event-related brain potential correlates of visual awareness. Neurosci Biobehav Rev 2009; 34:922-34. [PMID: 20005249 DOI: 10.1016/j.neubiorev.2009.12.002] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 12/04/2009] [Indexed: 11/22/2022]
Abstract
Electrophysiological recordings during visual tasks can shed light on the temporal dynamics of the subjective experience of seeing, visual awareness. This paper reviews studies on electrophysiological correlates of visual awareness operationalized as the difference between event-related potentials (ERPs) in response to stimuli that enter awareness and stimuli that do not. There are three candidates for such a correlate: enhancement of P1 around 100 ms, enhancement of early posterior negativity around 200 ms (visual awareness negativity, VAN), and enhancement of late positivity (LP) in the P3 time window around 400 ms. Review of studies using different manipulations of awareness suggests that VAN is the correlate of visual awareness that most consistently emerges across different manipulations of visual awareness. VAN emerges also relatively independent of manipulations of nonspatial attention, but seems to be dependent on spatial attention. The results suggest that visual awareness emerges about 200 ms after the onset of visual stimulation as a consequence of the activation of posterior occipito-temporal and parietal networks.
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Bachmann T. Finding ERP-signatures of target awareness: puzzle persists because of experimental co-variation of the objective and subjective variables. Conscious Cogn 2009; 18:804-8; discussion 809-10. [PMID: 19328726 DOI: 10.1016/j.concog.2009.02.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 02/22/2009] [Accepted: 02/28/2009] [Indexed: 10/21/2022]
Abstract
Using masking techniques combined with electrophysiological recordings is a promising way to study neural correlates of visual awareness, as shown in recent studies. Here I comment on the following puzzling aspects typical for this endeavour that have made obstacles for a potentially even more impressive progress. First, the continuing practice of confounds between objective stimulus variables and subjective dependent measures. Second, complexity of timing the emergence of subjective conscious percept which is partly due to complex interactivity between target and mask. Third, the ambiguity of the concept of neural correlates of awareness.
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Affiliation(s)
- Talis Bachmann
- Institute of Psychology and Institute of Public Law, University of Tartu, Tartu and Tallinn, Estonia.
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Alterations in the contents of consciousness in partial epileptic seizures. Epilepsy Behav 2008; 13:366-71. [PMID: 18522873 DOI: 10.1016/j.yebeh.2008.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 04/15/2008] [Accepted: 04/18/2008] [Indexed: 11/20/2022]
Abstract
Epilepsy research suffers from a deficiency of systematic studies concerning the phenomenology of the contents of consciousness during seizures, partially because of the lack of suitable research methods. The Phenomenology of Consciousness Inventory (PCI), a standardized, valid, and reliable questionnaire, was used here to study which dimensions of the contents of consciousness are distorted during partial epileptic seizures compared with baseline. Further, the similarity of the altered pattern of subjective experiences across recurring seizures was also explored. Our results indicate that patients with epilepsy report alterations on most dimensions of the contents of consciousness in conjunction with seizures, but individual seizure experiences remain similar from one seizure to another. The PCI was found suitable for the assessment of subjective experiences during epileptic seizures and could be a valuable tool in providing new information about phenomenal consciousness in epilepsy in both the research and clinical settings.
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Marzi CA, Mancini F, Savazzi S. Interhemispheric transfer of phosphenes generated by occipital versus parietal transcranial magnetic stimulation. Exp Brain Res 2008; 192:431-41. [DOI: 10.1007/s00221-008-1496-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Accepted: 07/08/2008] [Indexed: 01/01/2023]
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Abstract
It is well known that electrical activation of striate cortex (area V1) can disrupt visual behavior. Based on this knowledge, we discovered that electrical microstimulation of V1 in macaque monkeys delays saccadic eye movements when made to visual targets located in the receptive field of the stimulated neurons. This review discusses the following issues. First, the parameters that affect the delay of saccades by microstimulation of V1 are reviewed. Second, the excitability properties of the V1 elements mediating the delay are discussed. Third, the properties that determine the size and shape of the region of visual space affected by stimulation of V1 are described. This region is called a delay field. Fourth, whether the delay effect is mainly due to a disruption of the visual signal transmitted through V1 or whether it is a disturbance of the motor signal transmitted between V1 and the brain stem saccade generator is investigated. Fifth, the properties of delay fields are used to estimate the number of elements activated directly by electrical microstimulation of macaque V1. Sixth, these properties are used to make inferences about the characteristics of visual percepts induced by such stimulation. Seventh, the disruptive effects of V1 stimulation in monkeys and humans are compared. Eighth, a cortical mechanism to account for the disruptive effects of V1 stimulation is proposed. Finally, these effects are related to normal vision.
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Affiliation(s)
- Edward J Tehovnik
- Dept. of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Bldg. 46-6041, Cambridge, MA 02139, USA.
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Fitzsimmons NA, Drake W, Hanson TL, Lebedev MA, Nicolelis MAL. Primate reaching cued by multichannel spatiotemporal cortical microstimulation. J Neurosci 2007; 27:5593-602. [PMID: 17522304 PMCID: PMC6672750 DOI: 10.1523/jneurosci.5297-06.2007] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Both humans and animals can discriminate signals delivered to sensory areas of their brains using electrical microstimulation. This opens the possibility of creating an artificial sensory channel that could be implemented in neuroprosthetic devices. Although microstimulation delivered through multiple implanted electrodes could be beneficial for this purpose, appropriate microstimulation protocols have not been developed. Here, we report a series of experiments in which owl monkeys performed reaching movements guided by spatiotemporal patterns of cortical microstimulation delivered to primary somatosensory cortex through chronically implanted multielectrode arrays. The monkeys learned to discriminate microstimulation patterns, and their ability to learn new patterns and new behavioral rules improved during several months of testing. Significantly, information was conveyed to the brain through the interplay of microstimulation patterns delivered to multiple electrodes and the temporal order in which these electrodes were stimulated. This suggests multichannel microstimulation as a viable means of sensorizing neural prostheses.
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Affiliation(s)
- N. A. Fitzsimmons
- Departments of Neurobiology
- Center for Neuroengineering, Duke University, Durham, North Carolina 27100
| | - W. Drake
- Departments of Neurobiology
- Center for Neuroengineering, Duke University, Durham, North Carolina 27100
| | - T. L. Hanson
- Departments of Neurobiology
- Center for Neuroengineering, Duke University, Durham, North Carolina 27100
| | - M. A. Lebedev
- Departments of Neurobiology
- Center for Neuroengineering, Duke University, Durham, North Carolina 27100
| | - M. A. L. Nicolelis
- Departments of Neurobiology
- Biomedical Engineering, and
- Psychological and Brain Sciences and
- Center for Neuroengineering, Duke University, Durham, North Carolina 27100
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