Now showing items 1-20 of 28

    • Avalanche Analysis from Multielectrode Ensemble Recordings in Cat, Monkey, and Human Cerebral Cortex during Wakefulness and Sleep 

      Dehghani, Nima; Hatsopoulos, Nicholas G.; Haga, Zach D.; Parker, Rebecca A.; Greger, Bradley; Halgren, Eric; Cash, Sydney S.; Destexhe, Alain (Frontiers Research Foundation, 2012)
      Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical ...
    • A Biologically Constrained, Mathematical Model of Cortical Wave Propagation Preceding Seizure Termination 

      González-Ramírez, Laura R.; Ahmed, Omar J.; Cash, Sydney S.; Wayne, C. Eugene; Kramer, Mark A. (Public Library of Science, 2015)
      Epilepsy—the condition of recurrent, unprovoked seizures—manifests in brain voltage activity with characteristic spatiotemporal patterns. These patterns include stereotyped semi-rhythmic activity produced by aggregate ...
    • Cellular and neurochemical basis of sleep stages in the thalamocortical network 

      Krishnan, Giri P; Chauvette, Sylvain; Shamie, Isaac; Soltani, Sara; Timofeev, Igor; Cash, Sydney S; Halgren, Eric; Bazhenov, Maxim (eLife Sciences Publications, Ltd, 2016)
      The link between the combined action of neuromodulators in the brain and global brain states remains a mystery. In this study, using biophysically realistic models of the thalamocortical network, we identified the critical ...
    • Comparative Power Spectral Analysis of Simultaneous Elecroencephalographic and Magnetoencephalographic Recordings in Humans Suggests Non-Resistive Extracellular Media 

      Dehghani, Nima; Bédard, Claude; Cash, Sydney S.; Halgren, Eric; Destexhe, Alain (Springer Verlag, 2010)
      The resistive or non-resistive nature of the extracellular space in the brain is still debated, and is an important issue for correctly modeling extracellular potentials. Here, we first show theoretically that if the medium ...
    • Distribution, Amplitude, Incidence, Co-Occurrence, and Propagation of Human K-Complexes in Focal Transcortical Recordings1,2,3 

      Mak-McCully, Rachel A.; Rosen, Burke Q.; Rolland, Matthieu; Régis, Jean; Bartolomei, Fabrice; Rey, Marc; Chauvel, Patrick; Cash, Sydney S.; Halgren, Eric (Society for Neuroscience, 2015)
      Abstract K-complexes (KCs) are thought to play a key role in sleep homeostasis and memory consolidation; however, their generation and propagation remain unclear. The commonly held view from scalp EEG findings is that KCs ...
    • Divergent cortical generators of MEG and EEG during human sleep spindles suggested by distributed source modeling 

      Dehghani, Nima; Hagler, Donald J.; Huang, Mingxiong; Dale, Anders M.; Halgren, Eric; Valdes-Sosa, Pedro Antonio; Cash, Sydney S.; Chen, Chih C. (Public Library of Science, 2010)
      Background: Sleep spindles are ∼1-second bursts of 10–15 Hz activity, occurring during normal stage 2 sleep. In animals, sleep spindles can be synchronous across multiple cortical and thalamic locations, suggesting a ...
    • Dynamic Balance of Excitation and Inhibition in Human and Monkey Neocortex 

      Dehghani, Nima; Peyrache, Adrien; Telenczuk, Bartosz; Le Van Quyen, Michel; Halgren, Eric; Cash, Sydney S.; Hatsopoulos, Nicholas G.; Destexhe, Alain (Nature Publishing Group, 2016)
      Balance of excitation and inhibition is a fundamental feature of in vivo network activity and is important for its computations. However, its presence in the neocortex of higher mammals is not well established. We investigated ...
    • EEG functional connectivity is partially predicted by underlying white matter connectivity 

      Chu, Catherine Jean; Tanaka, Naoaki; Diaz, J.; Edlow, Brian Lewis; Wu, Ona; Hamalainen, Matti S.; Stufflebeam, Steven Marshall; Cash, Sydney S.; Kramer, M.A. (Elsevier BV, 2015)
      Over the past decade, networks have become a leading model to illustrate both the anatomical relationships (structural networks) and the coupling of dynamic physiology (functional networks) linking separate brain regions. ...
    • Emergence of Stable Functional Networks in Long-Term Human Electroencephalography 

      Chu, Catherine Jean; Kramer, Mark R.; Pathmanathan, Jay Sriram; Bianchi, Matt Travis; Westover, Michael Brandon; Wizon, L.; Cash, Sydney S. (Society for Neuroscience, 2012)
      Functional connectivity networks have become a central focus in neuroscience because they reveal key higher-dimensional features of normal and abnormal nervous system physiology. Functional networks reflect activity-based ...
    • Extracting Spatiotemporal Word and Semantic Representations from Multiscale Neurophysiological Recordings in Humans 

      Chan, Alexander Mark (2012-09-13)
      With the recent advent of neuroimaging techniques, the majority of the research studying the neural basis of language processing has focused on the localization of various lexical and semantic functions. Unfortunately, ...
    • Finding synchrony in the desynchronized EEG: the history and interpretation of gamma rhythms 

      Ahmed, Omar J.; Cash, Sydney S. (Frontiers Media S.A., 2013)
      Neocortical gamma (30–80 Hz) rhythms correlate with attention, movement and perception and are often disrupted in neurological and psychiatric disorders. Gamma primarily occurs during alert brain states characterized by ...
    • Human seizures self-terminate across spatial scales via a critical transition 

      Kramer, M. A.; Truccolo, W.; Eden, U. T.; Lepage, K. Q.; Hochberg, Leigh Robert; Eskandar, Emad; Madsen, Joseph Russell; Lee, Jong Woo; Maheshwari, A.; Halgren, E.; Chu, Catherine Jean; Cash, Sydney S. (Proceedings of the National Academy of Sciences, 2012)
      Why seizures spontaneously terminate remains an unanswered fundamental question of epileptology. Here we present evidence that seizures self-terminate via a discontinuous critical transition or bifurcation. We show that ...
    • Local cortical dynamics of burst suppression in the anaesthetized brain 

      Lewis, Laura D.; Ching, ShiNung; Weiner, Veronica S.; Peterfreund, Robert A.; Eskandar, Emad N.; Cash, Sydney S.; Brown, Emery N.; Purdon, Patrick L. (Oxford University Press, 2013)
      Burst suppression is an electroencephalogram pattern that consists of a quasi-periodic alternation between isoelectric ‘suppressions’ lasting seconds or minutes, and high-voltage ‘bursts’. It is characteristic of a profoundly ...
    • Local field potentials primarily reflect inhibitory neuron activity in human and monkey cortex 

      Teleńczuk, Bartosz; Dehghani, Nima; Le Van Quyen, Michel; Cash, Sydney S.; Halgren, Eric; Hatsopoulos, Nicholas G.; Destexhe, Alain (Nature Publishing Group, 2017)
      The local field potential (LFP) is generated by large populations of neurons, but unitary contribution of spiking neurons to LFP is not well characterised. We investigated this contribution in multi-electrode array recordings ...
    • The maturation of cortical sleep rhythms and networks over early development 

      Chu, Catherine Jean; Leahy, J.; Pathmanathan, Jay Sriram; Kramer, M.A.; Cash, Sydney S. (Elsevier BV, 2014)
      Objective: Although neuronal activity drives all aspects of cortical development, how human brain rhythms spontaneously mature remains an active area of research. We sought to systematically evaluate the emergence of human ...
    • Network Analysis: Applications for the Developing Brain 

      Chu, Catherine Jean; Kramer, M. A.; Bianchi, Matt Travis; Caviness, Verne Strudwick; Cash, Sydney S. (SAGE Publications, 2011)
      Development of the human brain follows a complex trajectory of age-specific anatomical and physiological changes. The application of network analysis provides an illuminating perspective on the dynamic interregional and ...
    • Neural Correlates of Auditory Perceptual Awareness and Release from Informational Masking Recorded Directly from Human Cortex: A Case Study 

      Cash, Sydney S.; School, Harvard; Department of Medicine (Frontiers Media, 2016)
      In complex acoustic environments, even salient supra-threshold sounds sometimes go unperceived, a phenomenon known as informational masking. The neural basis of informational masking (and its release) has not been well ...
    • Obstructive Sleep Apnea Alters Sleep Stage Transition Dynamics 

      Bianchi, Matt Travis; Cash, Sydney S.; Mietus, Joseph; Peng, Chung-Kang; Thomas, Robert Joseph (Public Library of Science (PLoS), 2010)
      Introduction: Enhanced characterization of sleep architecture, compared with routine polysomnographic metrics such as stage percentages and sleep efficiency, may improve the predictive phenotyping of fragmented sleep. One ...
    • Optogenetic Delay of Status Epilepticus Onset in an In Vivo Rodent Epilepsy Model 

      Sukhotinsky, Inna; Chan, Alexander M.; Ahmed, Omar Jamil; Rao, Vikram Ramnath; Gradinaru, Viviana; Ramakrishnan, Charu; Deisseroth, Karl; Majewska, Ania K.; Cash, Sydney S. (Public Library of Science, 2013)
      Epilepsy is a devastating disease, currently treated with medications, surgery or electrical stimulation. None of these approaches is totally effective and our ability to control seizures remains limited and complicated ...
    • The probability of seizures during EEG monitoring in critically ill adults 

      Westover, Michael Brandon; Shafi, Mouhsin; Bianchi, Matt Travis; Moura, Lidia M.V.R.; O’Rourke, Deirdre; Rosenthal, Eric Scott; Chu, Catherine Jean; Donovan, Samantha; Hoch, Daniel B.; Kilbride, Ronan D.; Cole, Andrew James; Cash, Sydney S. (Elsevier BV, 2015)
      Objective: To characterize the risk for seizures over time in relation to EEG findings in hospitalized adults undergoing continuous EEG monitoring (cEEG). Methods: Retrospective analysis of cEEG data and medical records ...