02771nas a2200253 4500008004100000022001400041245014300055210006900198260001200267300000800279490000600287520196800293653002202261653003202283653001502315653002102330653001802351100001702369700002402386700002102410700001902431700001902450856004802469 2014 eng d a1662-516100aECoG high gamma activity reveals distinct cortical representations of lyrics passages, harmonic and timbre-related changes in a rock song.0 aECoG high gamma activity reveals distinct cortical representatio c10/2014 a7980 v83 a

Listening to music moves our minds and moods, stirring interest in its neural underpinnings. A multitude of compositional features drives the appeal of natural music. How such original music, where a composer's opus is not manipulated for experimental purposes, engages a listener's brain has not been studied until recently. Here, we report an in-depth analysis of two electrocorticographic (ECoG) data sets obtained over the left hemisphere in ten patients during presentation of either a rock song or a read-out narrative. First, the time courses of five acoustic features (intensity, presence/absence of vocals with lyrics, spectral centroid, harmonic change, and pulse clarity) were extracted from the audio tracks and found to be correlated with each other to varying degrees. In a second step, we uncovered the specific impact of each musical feature on ECoG high-gamma power (70-170 Hz) by calculating partial correlations to remove the influence of the other four features. In the music condition, the onset and offset of vocal lyrics in ongoing instrumental music was consistently identified within the group as the dominant driver for ECoG high-gamma power changes over temporal auditory areas, while concurrently subject-individual activation spots were identified for sound intensity, timbral, and harmonic features. The distinct cortical activations to vocal speech-related content embedded in instrumental music directly demonstrate that song integrated in instrumental music represents a distinct dimension in complex music. In contrast, in the speech condition, the full sound envelope was reflected in the high gamma response rather than the onset or offset of the vocal lyrics. This demonstrates how the contributions of stimulus features that modulate the brain response differ across the two examples of a full-length natural stimulus, which suggests a context-dependent feature selection in the processing of complex auditory stimuli.

10aacoustic features10aelectrocorticography (ECoG)10ahigh gamma10amusic processing10anatural music1 aSturm, Irene1 aBlankertz, Benjamin1 aPotes, Cristhian1 aSchalk, Gerwin1 aCurio, Gabriel uhttp://www.ncbi.nlm.nih.gov/pubmed/2535279903446nas a2200253 4500008004100000245011700041210006900158260001200227300001100239490000700250520261100257653003402868653002402902653003202926653002802958653002202986653003403008100002103042700001903063700002003082700002303102700001903125856004803144 2014 eng d00aSpatial and temporal relationships of electrocorticographic alpha and gamma activity during auditory processing.0 aSpatial and temporal relationships of electrocorticographic alph c08/2014 a188-950 v973 aNeuroimaging approaches have implicated multiple brain sites in musical perception, including the posterior part of the superior temporal gyrus and adjacent perisylvian areas. However, the detailed spatial and temporal relationship of neural signals that support auditory processing is largely unknown. In this study, we applied a novel inter-subject analysis approach to electrophysiological signals recorded from the surface of the brain (electrocorticography (ECoG)) in ten human subjects. This approach allowed us to reliably identify those ECoG features that were related to the processing of a complex auditory stimulus (i.e., continuous piece of music) and to investigate their spatial, temporal, and causal relationships. Our results identified stimulus-related modulations in the alpha (8-12 Hz) and high gamma (70-110 Hz) bands at neuroanatomical locations implicated in auditory processing. Specifically, we identified stimulus-related ECoG modulations in the alpha band in areas adjacent to primary auditory cortex, which are known to receive afferent auditory projections from the thalamus (80 of a total of 15,107 tested sites). In contrast, we identified stimulus-related ECoG modulations in the high gamma band not only in areas close to primary auditory cortex but also in other perisylvian areas known to be involved in higher-order auditory processing, and in superior premotor cortex (412/15,107 sites). Across all implicated areas, modulations in the high gamma band preceded those in the alpha band by 280 ms, and activity in the high gamma band causally predicted alpha activity, but not vice versa (Granger causality, p<1e(-8)). Additionally, detailed analyses using Granger causality identified causal relationships of high gamma activity between distinct locations in early auditory pathways within superior temporal gyrus (STG) and posterior STG, between posterior STG and inferior frontal cortex, and between STG and premotor cortex. Evidence suggests that these relationships reflect direct cortico-cortical connections rather than common driving input from subcortical structures such as the thalamus. In summary, our inter-subject analyses defined the spatial and temporal relationships between music-related brain activity in the alpha and high gamma bands. They provide experimental evidence supporting current theories about the putative mechanisms of alpha and gamma activity, i.e., reflections of thalamo-cortical interactions and local cortical neural activity, respectively, and the results are also in agreement with existing functional models of auditory processing.10aalpha and high gamma activity10aauditory processing10aelectrocorticography (ECoG)10afunctional connectivity10agranger causality10athalamo-cortical interactions1 aPotes, Cristhian1 aBrunner, Peter1 aGunduz, Aysegul1 aKnight, Robert, T.1 aSchalk, Gerwin uhttp://www.ncbi.nlm.nih.gov/pubmed/2476893300622nas a2200157 4500008004100000245011100041210006900152100001600221700001600237700002100253700002100274700001900295700001400314700001300328856012300341 2013 eng d00acortiQ – Clinical Software for Electrocorticographic Real-Time Functional Mapping of the Eloquent Cortex0 acortiQ Clinical Software for Electrocorticographic RealTime Func1 aPrueckl, R.1 aKapeller, C1 aPotes, Cristhian1 aKorostenskaja, M1 aSchalk, Gerwin1 aLee, K.H.1 aGuger, C uhttps://neurotechcenter.org/publications/cortiq-%E2%80%93-clinical-software-electrocorticographic-real-time-functional01883nas a2200217 4500008004100000022001400041245011000055210006900165260001200234300001100246490000900257520120500266100002001471700002401491700002101515700002601536700001901562700001501581700002101596856004801617 2013 eng d a1557-170X00aCortiQ - clinical software for electrocorticographic real-time functional mapping of the eloquent cortex.0 aCortiQ clinical software for electrocorticographic realtime func c07/2013 a6365-80 v20133 aPlanning for epilepsy surgery depends substantially on the localization of brain cortical areas responsible for sensory, motor, or cognitive functions, clinically also known as eloquent cortex. In this paper, we present the novel software package 'cortiQ' that allows clinicians to localize eloquent cortex, thus providing a safe margin for surgical resection with a low incidence of neurological deficits. This software can be easily used in addition to traditional mapping procedures such as the electrical cortical stimulation (ECS) mapping. The software analyses task-related changes in gamma activity recorded from implanted subdural electrocorticography electrodes using extensions to previously published methods. In this manuscript, we describe the system's architecture and workflow required to obtain a map of the eloquent cortex. We validate the system by comparing our mapping results with those acquired using ECS mapping in two subjects. Our results indicate that cortiQ reliably identifies eloquent cortex much faster (several minutes compared to an hour or more) than ECS mapping. Next-neighbour analyses show that there are no false positives and an average of 1.24% false negatives.1 aPrueckl, Robert1 aKapeller, Christoph1 aPotes, Cristhian1 aKorostenskaja, Milena1 aSchalk, Gerwin1 aLee, Ki, H1 aGuger, Christoph uhttp://www.ncbi.nlm.nih.gov/pubmed/2411119703280nas a2200229 4500008004100000022001400041245012300055210006900178260001200247300001000259490000700269520254700276653002402823653003202847653002402879653002002903100002102923700002002944700001902964700001902983856004803002 2012 eng d a1095-957200aDynamics of electrocorticographic (ECoG) activity in human temporal and frontal cortical areas during music listening.0 aDynamics of electrocorticographic ECoG activity in human tempora c07/2012 a841-80 v613 a

Previous studies demonstrated that brain signals encode information about specific features of simple auditory stimuli or of general aspects of natural auditory stimuli. How brain signals represent the time course of specific features in natural auditory stimuli is not well understood. In this study, we show in eight human subjects that signals recorded from the surface of the brain (electrocorticography (ECoG)) encode information about the sound intensity of music. ECoG activity in the high gamma band recorded from the posterior part of the superior temporal gyrus as well as from an isolated area in the precentral gyrus was observed to be highly correlated with the sound intensity of music. These results not only confirm the role of auditory cortices in auditory processing but also point to an important role of premotor and motor cortices. They also encourage the use of ECoG activity to study more complex acoustic features of simple or natural auditory stimuli.

10aauditory processing10aelectrocorticography (ECoG)10ahigh gamma activity10asound intensity1 aPotes, Cristhian1 aGunduz, Aysegul1 aBrunner, Peter1 aSchalk, Gerwin uhttp://www.ncbi.nlm.nih.gov/pubmed/2253760000443nas a2200085 4500008004100000245011300041210006900154100002100223856011300244 2009 eng d00aAssessment of Human Muscle Fatigue from Surface EMG Signals Recorded during Isometric Voluntary Contractions0 aAssessment of Human Muscle Fatigue from Surface EMG Signals Reco1 aPotes, Cristhian uhttps://neurotechcenter.org/publications/assessment-human-muscle-fatigue-surface-emg-signals-recorded-during01792nas a2200181 4500008004100000245010300041210006900144260001200213490000700225520116700232100001901399700002101418700001501439700001801454700001701472700002101489856010001510 2009 eng d00aCompressive Sensing Reconstruction with Prior Information by Iteratively reweighted Least-Squares.0 aCompressive Sensing Reconstruction with Prior Information by Ite c03/20090 v573 aIteratively reweighted least-squares (IRLS) algorithms have been successfully used in compressive sensing to reconstruct sparse signals from incomplete linear measurements taken in nonsparse domains. The underlying optimization problem corresponds to finding the vector that solves the lp minimization while explaining the measurements, and IRLS allows to easily control the used value of p, with effect on the number of required measurements. In this paper, we propose a weighting strategy in the reconstruction method based on IRLS in order to add prior information on the support of the sparse domain. Our simulation results show that the use of prior knowledge about positions of at least some of the nonzero coefficients in the sparse domain leads to a reduction in the number of linear measurements required for unambiguous reconstruction. This reduction occurs for all values of p , so that a further reduction can be achieved by decreasing p and using prior information. The proposed weighting scheme also reduces the computational complexity with respect to the IRLS with no prior information, both in terms of number of iterations and computation time.1 aJ., Miosso, C.1 aR., von, Borries1 aM., Argaez1 aL., Velazquez1 aC., Quintero1 aPotes, Cristhian uhttp://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4799125&abstractAccess=no&userType=inst00488nas a2200121 4500008004100000245007100041210006900112100002100181700002100202700001900223700002300242856010100265 2008 eng d00aAssessment of Muscle Fatigue from TF Distributions of SEMG Signals0 aAssessment of Muscle Fatigue from TF Distributions of SEMG Signa1 aPotes, Cristhian1 aR., von, Borries1 aJ., Miosso, C.1 aH., Pierluissi, J. uhttps://neurotechcenter.org/publications/assessment-muscle-fatigue-tf-distributions-semg-signals00394nas a2200109 4500008004100000245004700041210004700088100002100135700001900156700002100175856008800196 2007 eng d00aCompressed Sensing Using Prior Information0 aCompressed Sensing Using Prior Information1 aR., von, Borries1 aJ., Miosso, C.1 aPotes, Cristhian uhttps://neurotechcenter.org/publications/compressed-sensing-using-prior-information00486nas a2200109 4500008004100000245009400041210006900135100002100204700001900225700002100244856011100265 2007 eng d00aDirectional Filter Banks for Wavelet Decomposition of Images Based on the Radon Transform0 aDirectional Filter Banks for Wavelet Decomposition of Images Bas1 aR., von, Borries1 aJ., Miosso, C.1 aPotes, Cristhian uhttps://neurotechcenter.org/publications/directional-filter-banks-wavelet-decomposition-images-based-radon