Some neurophysiologic aspects of consciousness.
An anatomico-physiologic approach to consciousness is facilitated by recognizing that the various meanings of consciousness have in common a crucial core C variously called subjectivity, awareness, consciousness-as-such, or consciousness per se. A sharp distinction is made between the property C and the contents of consciousness, partial loss of which is typical of cerebro-cortical lesions. The neuronal mechanism producing subjectivity also acts as an attention-action coordinator, hence must have specific connectivity requirements. These requirements are best met by the thalamic intralaminar nuclei (ILN). Whereas large lesions elsewhere leave C undisturbed, quite small bilateral lesions in ILN engender immediate unresponsiveness. This combination of anatomic and neurologic evidence is bolstered by a variety of physiologic evidence leading to the conclusion that further investigations of the ILN, and their interaction with lower centers as well as cerebral cortex, are most apt to yield a better understanding of consciousness.
Bogen
J E
JE
University of Southern California Los Angeles, USA.
D001288:Attention / Q000502:physiology; D003243:Consciousness / Q000502:physiology*; D004569:Electroencephalography; D006801:Humans; D009424:Nervous System Physiological Phenomena; D013787:Thalamic Nuclei / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology; D014836:Volition / Q000502:physiology