Department of Neuroscience, "C. Munari" Epilepsy Surgery Centre, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162 Milan, Italy.
2 papers in the library · 16 citations · publishing 2025
Conscious perception of simple touch depends on sustained neural activity in higher-order somatosensory regions, specifically the posterior perisylvian areas. Using human intracortical recordings, tonic responses in these regions showed all-or-nothing patterns at the sensory threshold, remained unchanged whether or not participants reported the stimulus, and most clearly distinguished perceived from non-perceived stimuli. These dynamics may serve as an organizational principle of somatosensory awareness.
After hemispherotomy surgery for epilepsy, which disconnects an entire brain hemisphere, the isolated cortex shows brainwave patterns typical of deep sleep or anesthesia, not wakefulness. In 10 pediatric patients, EEG recordings revealed prominent slow oscillations and a steeper spectral decay in the disconnected hemisphere, while the connected hemisphere maintained normal waking patterns. These sleep-like patterns persisted years after surgery, suggesting the isolated cortex likely lacks awareness.