Proprioceptive evoked gamma oscillations

A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure of precision of evoked oscillations. The window of interest was 25-75 Hz and 0-200 ms. ITPC maxima were determined by visual inspection and these results were compared to results of multi-way factor analyses. The predicted 40 Hz activity was observed 60 ms after stimulus onset in the parietal region contralateral to stimulus side and additionally an unexpected 20 Hz activity was observed slightly lateralized in the frontal central region. The gamma phase locking may be a manifestation of early somatosensory feature integration. The analyses suggest that the high frequency activity consists of two distinct underlying oscillatory processes, in need of further investigation.

[1]  P M Rossini,et al.  Bit-mapped somatosensory evoked potentials and muscular reflex responses in man: comparative analysis in different experimental protocols. , 1990, Electroencephalography and clinical neurophysiology.

[2]  Lars Kai Hansen,et al.  Decomposing the time-frequency representation of EEG using non-negative matrix and multi-way factorization , 2006 .

[3]  Riitta Hari,et al.  Task-Dependent Modulations of Cortical Oscillatory Activity in Human Subjects during a Bimanual Precision Grip Task , 2003, NeuroImage.

[4]  Andrew C. N. Chen,et al.  Perception of pain coincides with the spatial expansion of electroencephalographic dynamics in human subjects , 2001, Neuroscience Letters.

[5]  J. Desmedt,et al.  Transient phase-locking of 40 Hz electrical oscillations in prefrontal and parietal human cortex reflects the process of conscious somatic perception , 1994, Neuroscience Letters.

[6]  S Makeig,et al.  Blind separation of auditory event-related brain responses into independent components. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[7]  Febo Cincotti,et al.  Human brain oscillatory activity phase‐locked to painful electrical stimulations: A multi‐channel EEG study , 2002, Human brain mapping.

[8]  S Makeig,et al.  Functionally independent components of early event-related potentials in a visual spatial attention task. , 1999, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[9]  P. Roland,et al.  A quantitative analysis of sensations of tension and of kinaesthesia in man. Evidence for a peripherally originating muscular sense and for a sense of effort. , 1977, Brain : a journal of neurology.

[10]  Ralf Hemmingsen,et al.  Proprioceptive evoked potentials in man: cerebral responses to changing weight loads on the hand , 2000, Neuroscience Letters.

[11]  R. Lesser,et al.  Functional mapping of human sensorimotor cortex with electrocorticographic spectral analysis. II. Event-related synchronization in the gamma band. , 1998, Brain : a journal of neurology.

[12]  Arnaud Delorme,et al.  EEGLAB: an open source toolbox for analysis of single-trial EEG dynamics including independent component analysis , 2004, Journal of Neuroscience Methods.

[13]  Sidse M. Arnfred,et al.  Proprioceptive event related potentials: gating and task effects , 2005, Clinical Neurophysiology.

[14]  Riitta Hari,et al.  Reproducibility of cortex–muscle coherence , 2005, NeuroImage.

[15]  G. Pfurtscheller,et al.  Event-related dynamics of cortical rhythms: frequency-specific features and functional correlates. , 2001, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[16]  Lars Kai Hansen,et al.  ERPWAVELAB A toolbox for multi-channel analysis of time–frequency transformed event related potentials , 2007, Journal of Neuroscience Methods.

[17]  Claudio Babiloni,et al.  Gamma synchronization in human primary somatosensory cortex as revealed by somatosensory evoked neuromagnetic fields , 2003, Brain Research.

[18]  A. Engel,et al.  Cognitive functions of gamma-band activity: memory match and utilization , 2004, Trends in Cognitive Sciences.

[19]  V. De Pascalis,et al.  Pain perception, obstructive imagery and phase-ordered gamma oscillations. , 2005, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[20]  Lars Kai Hansen,et al.  Parallel Factor Analysis as an exploratory tool for wavelet transformed event-related EEG , 2006, NeuroImage.

[21]  William Gaetz,et al.  Localization of sensorimotor cortical rhythms induced by tactile stimulation using spatially filtered MEG , 2006, NeuroImage.

[22]  Vilfredo De Pascalis,et al.  Perception and modulation of pain in waking and hypnosis: functional significance of phase-ordered gamma oscillations , 2004, Pain.