title: Neural "ignition": enhanced activation linked to perceptual awareness in human ventral stream visual cortex.
abstract: Human recognition performance is characterized by abrupt changes in perceptual states. Understanding the neuronal dynamics underlying such transitions could provide important insights into mechanisms of recognition and perceptual awareness. Here we examined patients monitored for clinical purposes with multiple subdural electrodes. The patients participated in a backward masking experiment in which pictures of various object categories were presented briefly followed by a mask. We recorded ECoG from 445 electrodes placed in 11 patients. We found a striking increase in gamma power (30-70 Hz) and evoked responses specifically associated with successful recognition. The enhanced activation occurred 150-200 ms after stimulus onset and consistently outlasted the stimulus presentation. We propose that the gamma and evoked potential activations reflect a rapid increase in recurrent neuronal activity that plays a critical role in the emergence of a recognizable visual percept in conscious awareness.
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Lior
authors: L
authors: Fisch
authors: Eran
authors: E
authors: Privman
authors: Michal
authors: M
authors: Ramot
authors: Michal
authors: M
authors: Harel
authors: Yuval
authors: Y
authors: Nir
authors: Svetlana
authors: S
authors: Kipervasser
authors: Fani
authors: F
authors: Andelman
authors: Miri Y
authors: MY
authors: Neufeld
authors: Uri
authors: U
authors: Kramer
authors: Itzhak
authors: I
authors: Fried
authors: Rafael
authors: R
authors: Malach
mesh_terms: D000328:Adult; D001364:Awareness / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult