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Matthias M Muller - One of the best experts on this subject based on the ideXlab platform.
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visual auditory and Tactile stimuli compete for early sensory processing capacities within but not between senses
NeuroImage, 2014Co-Authors: Emanuele Porcu, Christian Keitel, Matthias M MullerAbstract:We investigated whether unattended visual, auditory and Tactile stimuli compete for capacity-limited early sensory processing across senses. In three experiments, we probed competitive audio-visual, visuo-Tactile and audio-Tactile Stimulus interactions. To this end, continuous visual, auditory and Tactile Stimulus streams (‘reference’ stimuli) were frequency-tagged to elicit steady-state responses (SSRs). These electrophysiological oscillatory brain responses indexed ongoing Stimulus processing in corresponding senses. To induce competition, we introduced transient frequency-tagged stimuli in same and/or different senses (‘competitors’) during reference presentation. Participants performed a separate visual discrimination task at central fixation to control for attentional biases of sensory processing. A comparison of reference-driven SSR amplitudes between competitor-present and competitor-absent periods revealed reduced amplitudes when a competitor was presented in the same sensory modality as the reference. Reduced amplitudes indicated the competitor's suppressive influence on reference Stimulus processing. Crucially, no such suppression was found when a competitor was presented in a different than the reference modality. These results strongly suggest that early sensory competition is exclusively modality-specific and does not extend across senses. We discuss consequences of these findings for modeling the neural mechanisms underlying intermodal attention.
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sustained spatial attention to vibration is mediated in primary somatosensory cortex
NeuroImage, 2007Co-Authors: Clairemarie Giabbiconi, Nelson J Trujillobarreto, Thomas Gruber, Matthias M MullerAbstract:Focusing attention to a specific body location has been shown to improve processing of events presented at this body location. One important debate concerns the stage in the somatosensory pathway at which the neural response is modulated when one attends to a Tactile Stimulus. Previous studies focused on components of the somatosensory evoked potential to transient stimuli, and demonstrated an early cortical attentional modulation. The neural basis of sustained spatial Stimulus processing with continuous stimulation remains, however, largely unexplored. A way to approach this topic is to present vibrating stimuli with different frequencies for several seconds simultaneously to different body locations while subjects have to attend to the one or the other location. The amplitude of the somatosensory steady-state evoked potential (SSSEP) elicited by these vibrating stimuli increases with attention. On the basis of 128 electrode recordings, we investigated the topographical distribution and the underlying cortical sources by means of a VARETA approach of this attentional amplitude modulation of the SSSEP. Sustained spatial attention was found to be mediated in primary somatosensory cortex with no differences in SSSEP amplitude topographies between attended and unattended body locations. These result patterns were seen as evidence for a low-level sensory gain control mechanism in Tactile spatial attention.
Mark Hallett - One of the best experts on this subject based on the ideXlab platform.
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activation of the primary visual cortex by braille reading in blind subjects
Nature, 1996Co-Authors: Norihiro Sadato, Alvaro Pascualleone, Jordan Grafman, Vicente Ibanez, M P Deiber, George Dold, Mark HallettAbstract:PRIMARY visual cortex receives visual input from the eyes through the lateral geniculate nuclei, but is not known to receive input from other sensory modalities1. Its level of activity, both at rest and during auditory or Tactile tasks, is higher in blind subjects than in normal controls2, suggesting that it can subserve non-visual functions; however, a direct effect of non-visual tasks on activation has not been demonstrated2–4. To determine whether the visual cortex receives input from the somatosensory system5–8, we used positron emission tomography (PET) to measure activation during Tactile discrimination tasks in normal subjects and in Braille readers blinded in early life. Blind subjects showed activation of primary and secondary visual cortical areas during Tactile tasks, whereas normal controls showed deactiva-tion. A simple Tactile Stimulus that did not require discrimination produced no activation of visual areas in either group. Thus, in blind subjects, cortical areas normally reserved for vision may be activated by other sensory modalities.
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activation of the primary visual cortex by braille reading in blind subjects
Nature, 1996Co-Authors: Norihiro Sadato, Alvaro Pascualleone, Jordan Grafman, Vicente Ibanez, M P Deiber, George Dold, Mark HallettAbstract:PRIMARY visual cortex receives visual input from the eyes through the lateral geniculate nuclei, but is not known to receive input from other sensory modalities1. Its level of activity, both at rest and during auditory or Tactile tasks, is higher in blind subjects than in normal controls2, suggesting that it can subserve non-visual functions; however, a direct effect of non-visual tasks on activation has not been demonstrated2–4. To determine whether the visual cortex receives input from the somatosensory system5–8, we used positron emission tomography (PET) to measure activation during Tactile discrimination tasks in normal subjects and in Braille readers blinded in early life. Blind subjects showed activation of primary and secondary visual cortical areas during Tactile tasks, whereas normal controls showed deactiva-tion. A simple Tactile Stimulus that did not require discrimination produced no activation of visual areas in either group. Thus, in blind subjects, cortical areas normally reserved for vision may be activated by other sensory modalities.
Christopher I. Moore - One of the best experts on this subject based on the ideXlab platform.
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cued spatial attention drives functionally relevant modulation of the mu rhythm in primary somatosensory cortex
The Journal of Neuroscience, 2010Co-Authors: Stephanie R. Jones, Dominique L. Pritchett, Matti Hämäläinen, Catherine E Kerr, Christopher I. MooreAbstract:Cued spatial attention modulates functionally relevant alpha rhythms in visual cortices in humans. Here, we present evidence for analogous phenomena in primary somatosensory neocortex (SI). Using magnetoencephalography (MEG), we measured changes in the SI mu rhythm containing mu-alpha (7-14 Hz) and mu-beta (15-29 Hz) components. We found that cued attention impacted mu-alpha in the somatopically localized hand representation in SI, showing decreased power after attention was cued to the hand and increased power after attention was cued to the foot, with significant differences observed 500-1100 milliseconds (ms) post-cue. Mu-beta showed differences in a time window 800–850ms post-cue. The visual cue also drove an early evoked response beginning ~70ms post-cue with distinct peaks modulated with cued attention. Distinct components of the Tactile Stimulus-evoked response were also modulated with cued attention. Analysis of a second data set showed that, on a trial-by-trial basis, Tactile detection probabilities decreased linearly with pre-Stimulus mu-alpha and mu-beta power. These results support the growing consensus that cue-induced alpha modulation is a functionally relevant sensory gating mechanism deployed by attention. Further, while cued attention had a weaker effect on the allocation of mu-beta, oscillations in this band also predicted Tactile detection.
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cued spatial attention drives functionally relevant modulation of the mu rhythm in primary somatosensory cortex
The Journal of Neuroscience, 2010Co-Authors: Stephanie R. Jones, Dominique L. Pritchett, Matti Hämäläinen, Catherine E Kerr, Qian Wan, Christopher I. MooreAbstract:Cued spatial attention modulates functionally relevant alpha rhythms in visual cortices in humans. Here, we present evidence for analogous phenomena in primary somatosensory neocortex (SI). Using magnetoencephalography, we measured changes in the SI mu rhythm containing mu-alpha (7-14 Hz) and mu-beta (15-29 Hz) components. We found that cued attention impacted mu-alpha in the somatopically localized hand representation in SI, showing decreased power after attention was cued to the hand and increased power after attention was cued to the foot, with significant differences observed 500-1100 ms after cue. Mu-beta showed differences in a time window 800-850 ms after cue. The visual cue also drove an early evoked response beginning ∼70 ms after cue with distinct peaks modulated with cued attention. Distinct components of the Tactile Stimulus-evoked response were also modulated with cued attention. Analysis of a second dataset showed that, on a trial-by-trial basis, Tactile detection probabilities decreased linearly with preStimulus mu-alpha and mu-beta power. These results support the growing consensus that cue-induced alpha modulation is a functionally relevant sensory gating mechanism deployed by attention. Further, while cued attention had a weaker effect on the allocation of mu-beta, oscillations in this band also predicted Tactile detection.
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event related fmri of Tactile Stimulus detection
NeuroImage, 2001Co-Authors: Christopher I. Moore, Emilie Crosier, Gary Jasdzewski, Doug Greve, Bruce Fischl, Robert L Savoy, Andrew M Siegel, Dylan Stiles, Jolie Chang, Michael M MerzenichAbstract:Introduction A variety of studies have investigated the effect of vibroTactile frequency, amplitude, and probability of detection on single-unit activity in the primate cortex (e.g., Mountcastle et al., 1969). In this study, we examined the effect of these variables on activation across human cortical regions using event-related fMRI. The event-related fMR1 approach facilitated evaluation of the response to relatively brief stimuli (1-set duration), the derivation of hemodynamic gain functions, and the correlation of correct and incorrect psychophysical responses with the pattern and amplitude of cortical activity.
Peter J. Marshall - One of the best experts on this subject based on the ideXlab platform.
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Individual differences in anticipatory mu rhythm modulation are associated with executive function and processing speed
Cognitive Affective & Behavioral Neuroscience, 2020Co-Authors: Staci Meredith Weiss, Rebecca N. Laconi, Peter J. MarshallAbstract:There is increasing interest in the role of brain oscillations in the regulation and control of behavior. The current study examined the relations between specific cognitive abilities and changes in brain oscillatory activity during anticipation of, and in response to, Tactile stimulation of the hand. The oscillation of interest was the sensorimotor mu rhythm (8-14 Hz) at central electrode sites. The electroencephalogram (EEG) was recorded during a task in which a visuospatial cue directed adults (N = 40) that a Tactile Stimulus would be delivered to their left or right hand. Lateralized changes in mu power following Tactile stimulation were associated with reaction time to the Tactile Stimulus. The extent of a contralateral anticipatory reduction in mu power during the 500 ms before the Tactile Stimulus was associated with performance on a separate processing speed task. Changes in ipsilateral mu power during anticipation of the Tactile Stimulus were associated with performance on a flanker task and were marginally correlated with performance on a card sort task. Regression analyses further indicated the specificity of these relations to anticipatory changes in mu power. In summary, mu rhythm modulation during anticipation of Tactile stimulation to a specific bodily location was related to a broad measure of processing speed and to variability in the broader ability to regulate behavior in a goal-directed manner. Implications are discussed in terms of the foundational role of anticipatory attention in cognitive processes and the utility of selective attention to the body as an index of attentional control more broadly.
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Neural measures of anticipatory bodily attention in children: Relations with executive function
Elsevier, 2018Co-Authors: Staci Meredith Weiss, Andrew N. Meltzoff, Peter J. MarshallAbstract:The ability to selectively direct attention to a certain location or modality is a key neurocognitive skill. One important facet of selective attention is anticipation, a foundational biological construct that bridges basic perceptual processes and higher-order cognition. The current study focuses on the neural correlates of bodily anticipation in 6- to 8-year-old children using a task involving Tactile stimulation. Electroencephalographic (EEG) activity over sensorimotor cortex was measured after a visual cue directed children to monitor their right or left hand in anticipation of Tactile stimulation. Prior to delivery of the Tactile Stimulus, a regionally-specific desynchronization of the alpha-range mu rhythm occurred over central electrode sites (C3/C4) contralateral to the cue direction. The magnitude of anticipatory mu rhythm desynchronization was associated with children’s performance on two executive function tasks (Flanker and Card Sort). We suggest that anticipatory mu desynchronization has utility as a specific neural marker of attention focusing in young children, which in turn may be implicated in the development of executive function. Keywords: Child electroencephalogram, Mu rhythm, Tactile, Somatosensory, Executive function, Anticipation, Attentio
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exploring potential social influences on brain potentials during anticipation of Tactile stimulation
Brain Research, 2017Co-Authors: Guannan Shen, Joni N Saby, Ashley R Drew, Peter J. MarshallAbstract:Abstract This study explored interpersonal influences on electrophysiological responses during the anticipation of Tactile stimulation. It is well-known that broad, negative-going potentials are present in the event-related potential (ERP) between a forewarning cue and a Tactile Stimulus. It has also been shown that the alpha-range mu rhythm shows a lateralized desynchronization over central electrode sites during anticipation of Tactile stimulation of the hand. The current study used a Tactile discrimination task in which a visual cue signaled that an upcoming Stimulus would either be delivered 1500 ms later to the participant’s hand, to a task partner’s hand, or to neither person. For the condition in which participants anticipated the Tactile stimulation to their own hand, a negative potential (contingent negative variation, CNV) was observed in the ERP at central sites in the 1000 ms prior to the Tactile Stimulus. Significant mu rhythm desynchronization was also present in the same time window. The magnitudes of the ERPs and of the mu desynchronization were greater in the contralateral than in the ipsilateral hemisphere prior to right hand stimulation. Similar ERP and EEG changes were not present when the visual cue indicated that stimulation would be delivered to the task partner or to neither person. The absence of social influences during anticipation of Tactile stimulation, and the relationship between the two brain signatures of anticipatory attention (CNV and mu rhythm) are discussed.
Kevin Warwick - One of the best experts on this subject based on the ideXlab platform.
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sensory perception through an electro Tactile Stimulus array on the tongue
Systems Man and Cybernetics, 2013Co-Authors: A Jeffs, Kevin WarwickAbstract:This paper details an investigation into sensory substitution by means of direct electrical stimulation of the tongue for the purpose of information input to the human brain. In particular, a device has been constructed and a series of trials have been performed in order to demonstrate the efficacy and performance of an electro-Tactile array mounted onto the tongue surface for the purpose of sensory augmentation. Tests have shown that by using a low resolution array a computer-human feedback loop can be successfully implemented by humans in order to complete tasks such as object tracking, surface shape identification and shape recognition with no training or prior experience with the device. Comparisons of this technique have been made with visual alternatives and these show that the tongue based Tactile array can match such methods in convenience and accuracy in performing simple tasks.