Research Topics
| Walter J FreemanSummaryAffiliation: University of California Country: USA Publications
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Detail Information
Publications
Definitions of state variables and state space for brain-computer interface : Part 2. Extraction and classification of feature vectorsWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, 94720 3206, USA
Cogn Neurodyn 1:85-96. 2007..The aim of the review is to enable researchers to conceive and identify goal-oriented states in brain activity for use as commands, in order to relegate the details of execution to adaptive control devices outside the brain...
Ndn, volume transmission, and self-organization in brain dynamicsWalter J Freeman
Department of Molecular and Cell Biology, Donner 101, University of California at Berkeley, 94720 3206, USA
J Integr Neurosci 4:407-21. 2005..These systems instantiate volume transmission by nonsynaptic diffusion transmission, in concert with the self-organization of the textured neural activity that supports cognition...
Combining fMRI with EEG and MEG in order to relate patterns of brain activity to cognitionWalter J Freeman
Department of Molecular and Cell Biology, University of California MC 3206, Berkeley CA 94720 USA
Int J Psychophysiol 73:43-52. 2009..Here the requisite patterns are predicted to be large-scale spatial amplitude modulation (AM) of synchronized neuronal signals in the beta and gamma ranges that are coordinated but not correlated with fMRI intensities...
Deep analysis of perception through dynamic structures that emerge in cortical activity from self-regulated noiseWalter J Freeman
Department of Molecular and Cell Biology, University of California MC 3206, Berkeley, CA, 94720, USA
Cogn Neurodyn 3:105-16. 2009..The beats in dynamic theory are deemed essential for perception, by gating beta and gamma bursts at theta rates through enhancement of the cortical signal-to-noise ratio in exceptionally deep down spikes called null spikes...
The place of 'codes' in nonlinear neurodynamicsWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 3206, USA
Prog Brain Res 165:447-62. 2007..Here I review the central neural mechanisms of olfaction as a paradigm for use of codes to explain how brains create cortical activities that mediate sensation, perception, comprehension, prediction, decision, and action or inaction...
Brain neural activity patterns yielding numbers are operators, not representationsWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720 3206, USA
Behav Brain Sci 32:336-7; discussion 356-73. 2009..We postulate that specialized operators produce symbolic representations existing only outside of brains...
Perception of time and causation through the kinesthesia of intentional actionWalter J Freeman
University of California, Berkeley, CA 94720 3206, USA
Integr Psychol Behav Sci 42:137-43. 2008....
Simulating cortical background activity at rest with filtered noiseWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, CA 94720 3206, USA
J Integr Neurosci 7:337-44. 2008..We estimate a threshold in null spike minimal amplitudes below which perceptual frames having gamma oscillations may recur at theta rates...
Understanding perception through neural "codes"Walter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
IEEE Trans Biomed Eng 58:1884-90. 2011..My aim is to describe the main properties of the macroscopic code and the grand challenge it poses: how do very large patterns of textured synchronized oscillations form in cortex so quickly?..
Simulated power spectral density (PSD) of background electrocorticogram (ECoG)Walter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, 94720 3206, USA
Cogn Neurodyn 3:97-103. 2009..We conclude that the resting ECoG truly is low-dimensional noise, and that the resting state is an optimal starting point for defining and measuring both artifactual and physiological structures emergent in the activated ECoG...
Definitions of state variables and state space for brain-computer interface : Part 1. Multiple hierarchical levels of brain functionWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, 94720 3206, USA
Cogn Neurodyn 1:3-14. 2007....
Vortices in brain activity: their mechanism and significance for perceptionWalter J Freeman
Department of Molecular and Cell Biology, Donner 101, University of California, Berkeley CA 94720 3206, United States
Neural Netw 22:491-501. 2009....
Aperiodic phase re-setting in scalp EEG of beta-gamma oscillations by state transitions at alpha-theta ratesWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, California 94720 3200, USA
Hum Brain Mapp 19:248-72. 2003..Cortex functions by serial changes in state. The Hilbert transform of EEG from high-density arrays can visualize these state transitions with high temporal and spatial resolution and should be useful in relating EEG to cognition...
Metastability, instability, and state transition in neocortexWalter J Freeman
University of California at Berkeley, Berkeley, CA 94720, USA
Neural Netw 18:497-504. 2005..A model based on the intentional action-perception cycle is proposed to complement the information processing model...
A cinematographic hypothesis of cortical dynamics in perceptionWalter J Freeman
Department of Molecular and Cell Biology, LSA 142 University of California, Berkeley, 94720 3200, USA
Int J Psychophysiol 60:149-61. 2006..The size, texture, timing, and duration of the AM patterns support the hypothesis that these frames may provide the basis for multisensory percepts (Gestalts)...
Origin, structure, and role of background EEG activity. Part 3. Neural frame classificationWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, 94720-3200, USA
Clin Neurophysiol 116:1118-29. 2005..SIGNIFICANCE: The size, texture and duration of these AM patterns indicate that spatial patterns of human beta frames may be accessible with high-density scalp arrays for correlation with phenomenological reports by human subjects...
A pseudo-equilibrium thermodynamic model of information processing in nonlinear brain dynamicsWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720 3206, USA
Neural Netw 21:257-65. 2008....
Fine spatiotemporal structure of phase in human intracranial EEGWalter J Freeman
Department of Molecular and Cell Biology University of California at Berkeley, Berkeley, CA 94720 3206, USA
Clin Neurophysiol 117:1228-43. 2006..To transfer to the clinic for humans the technology and theory for high-resolution EEG analysis that have been developed in the laboratory with animals...
The wave packet: an action potential for the 21st centuryWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 3200, USA
J Integr Neurosci 2:3-30. 2003..The prediction is made for clinical testing that wave packets are precursor to states of awareness. They are not by themselves accessible to experience, as may be the macroscopic states initiated by global state transitions...
Origin, structure, and role of background EEG activity. Part 2. Analytic phaseWalter J Freeman
Department of Molecular and Cell Biology, LSA 142, University of California, Berkeley, CA 94720 3200, USA
Clin Neurophysiol 115:2089-107. 2004..To explain spontaneous EEG through measurements of spatiotemporal patterns of phase among beta-gamma oscillations...
A field-theoretic approach to understanding scale-free neocortical dynamicsWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720 3206, USA
Biol Cybern 92:350-9. 2005..Self-organized local domains precede formation of global domains that supervene and contribute global modulations to local domains. This mechanism is proposed to explain Gestalt formation in perception...
Origin, structure, and role of background EEG activity. Part 4: Neural frame simulationWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Donner 101, MC 3206, Berkeley, CA 94720 3206, USA
Clin Neurophysiol 117:572-89. 2006....
Origin, structure, and role of background EEG activity. Part 1. Analytic amplitudeWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, LSA 142, Berkeley CA 94720 3200, USA
Clin Neurophysiol 115:2077-88. 2004..To explain the neural mechanisms of spontaneous EEG by measuring the spatiotemporal patterns of synchrony among beta-gamma oscillations during perception...
Evidence from human scalp electroencephalograms of global chaotic itinerancyWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA
Chaos 13:1067-77. 2003..The jumps appear to be subcritical bifurcations. They reflect the aperiodic evolution of brain states through sequences of attractors that on access support the experience of remembering...
Neurodynamic models of brain in psychiatryWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 3200, USA
Neuropsychopharmacology 28:S54-63. 2003..Lack of recognition and understanding may cause failure to use brief windows of opportunity to instill long-term relief of psychic pain by restructuring intentionality in distressed patients...
Spatial spectra of scalp EEG and EMG from awake humansWalter J Freeman
Division of Neurobiology, Department of Molecular and Cell Biology, University of California, LSA 142, MC 3200, Berkeley, CA 94720, USA
Clin Neurophysiol 114:1053-68. 2003..Evaluate spectral scaling properties of scalp electroencephalogram (EEG) and electromyogram (EMG), optimal spacing of electrodes, and strategies for mitigating EMG...
The emergence of mind and emotion in the evolution of neocortexWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
Riv Psichiatr 46:281-7. 2011..Here in this dynamics are to be sought the keys to understanding and treating the disorders that uniquely plague the human mind...
Indirect biological measures of consciousness from field studies of brains as dynamical systemsWalter J Freeman
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720 3206, USA
Neural Netw 20:1021-31. 2007..The results of dynamical analysis are discussed in terms serving to distinguish between the neural point processes dictated by the neuron doctrine vs. continuously variable neural fields generated by neural masses in cortex...
Fine temporal resolution of analytic phase reveals episodic synchronization by state transitions in gamma EEGsWalter J Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 3200, USA
J Neurophysiol 87:937-45. 2002..Further support for this inference will require improvements in methods for temporal resolution of the times of onset of spatial patterns of phase modulation...
Phase transitions in the neuropercolation model of neural populations with mixed local and non-local interactionsRobert Kozma
Department of Mathematical Sciences, University of Memphis, Memphis, TN 38152, USA
Biol Cybern 92:367-79. 2005..Finally, we propose a potential interpretation of ontogenetic development of the neuropil maintaining a dynamical state at the edge of criticality...
Basic principles of the KIV model and its application to the navigation problemRobert Kozma
Division of Computer Science, The University of Memphis, Memphis, TN 38152, USA
J Integr Neurosci 2:125-45. 2003..We demonstrate the learning and navigation principles using the Evolving Multi-module Mobile Agent (EMMA) in 2D software environment...
Analysis of evoked and emergent patterns of stimulus-related auditory cortical activityFrank W Ohl
Leibniz Institut für Neurobiologie, Magdeburg, Germany
Rev Neurosci 14:35-42. 2003..The results indicate the coexistence in the same neuronal tissue of a topographic mapping principle for the evoked activity and a holographic mapping principle for the emergent activity...
