EEG oscillations at 600 Hz are macroscopic markers for cortical spike bursts.
The human electroencephalogram (EEG) is generated predominantly by synchronised cortical excitatory postsynaptic potentials oscillating at frequencies <100 Hz. Unusually, EEG responses to electrical nerve stimulation contain brief bursts of high-frequency (600 Hz) wavelets. Here we show, in awake monkeys, that a subset of primary somatosensory cortex single units consistently fires both bursts and single spikes phase-locked to EEG wavelets. Spike bursts were also evoked by tactile stimuli, proving that this is a natural response mode. EEG wavelets at 600 Hz may therefore permit non-invasive assessment of population spike timing in human cortex.
Baker
Stuart N
SN
Department of Anatomy, University of Cambridge, Cambridge CB2 3DY, UK. snb11@cam.ac.uk
Curio
Gabriel
G
Lemon
Roger N
RN
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography; D004576:Electromyography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D008253:Macaca mulatta; D008475:Median Nerve / Q000502:physiology; D010812:Physical Stimulation; D012867:Skin / Q000294:innervation