Some neurophysiologic aspects of consciousness

Area of Science:

• Neuroscience
• Physiology
• Cognitive Science

Background:

• Consciousness has multiple definitions, but a core element, subjectivity (C), is common.
• Distinguishing subjectivity from the contents of consciousness is key.
• Cerebro-cortical lesions often impair consciousness contents, not subjectivity itself.

Purpose of the Study:

• To investigate the anatomical and physiological basis of consciousness.
• To identify the specific neuronal mechanisms underlying subjective awareness.
• To explore the role of the thalamic intralaminar nuclei (ILN) in consciousness.

Main Methods:

• Anatomico-physiologic approach to consciousness.
• Distinguishing between consciousness property (C) and its contents.
• Analyzing lesion effects on consciousness in different brain regions.
• Correlating neuronal mechanisms with attention-action coordination.

Main Results:

• The neuronal mechanism for subjectivity also functions as an attention-action coordinator.
• The thalamic intralaminar nuclei (ILN) possess the necessary connectivity for this role.
• Large lesions outside the ILN do not disturb C, but small bilateral ILN lesions cause immediate unresponsiveness.

Conclusions:

• The thalamic intralaminar nuclei (ILN) are critically involved in generating subjective awareness.
• Further research on ILN interactions with the cortex and lower centers is vital for understanding consciousness.
• This study provides strong anatomical, neurological, and physiological evidence for the ILN's role in consciousness.