PSYCH 454 Lecture Notes - Lecture 22: Thalamic Reticular Nucleus, Intralaminar Nuclei Of Thalamus, List Of Thalamic Nuclei
24 May 2018
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Lect 22: Consciousness part 2
Neural Correlates of Consciousness (NCC)
●NCC: minimal neural mechanisms that are jointly sufficient for consciousness
○NCC can be experimentally tested
●“Minimal neural mechanisms” → whole brain gives rise to consciousness, but which
parts are essential?
○Don’t need every part of the brain to be conscious on a certain level
●NCC → large-scale integration of processing across multiple brain areas
○Ex: frontal cortex, parietal cortex (posterior cingulate gyrus), region around
boundary of temporal and parietal cortex (TPJ)
○intralaminar nucleus of thalamus → extensively connected with above cortical
structures
●Integration of NCC relies on neural synchronization
→ how we get information to
different brain areas + neurons
○When conscious, synchronized activity (at higher freq) between distributed
groups of cortical neurons
■Synchronized
: functions in excitability of different parts of brain
coordinate to allow info transfer effectively
●Which brain areas are unlikely to be involved in NCC?
○Cerebellum → argued it doesn't participate in conscious perception
■Relates to fact cerebellum = organized into local modules that interact
little
●Ex: Planar dendrites with little connections between them
■Compared with cerebral cortex, in which neurons are extensively
connected
Brainstem and Thalamic Areas → important for arousal
●Localized lesions of these areas bilaterally can produce loss of consciousness
○Medial septal nucleus
○Hypothalamus: arousal role; speech regulation
○Basal nucleus of Meynert
○Brainstem
■Includes multiple reticular formations → role in projects to thalamus,
cortex etc
○ILN (intralaminar nuclei of thalamus): cell bodies inside thalamus
○NRT (thalamic reticular nucleus): provides inhibitory input to other thalamic
nuclei to regulate info transmission across cortex
○MCS (mesencephalic reticular formation)
Document Summary
Ncc: minimal neural mechanisms that are jointly sufficient for consciousness. Minimal neural mechanisms whole brain gives rise to consciousness, but which. Don"t need every part of the brain to be conscious on a certain level. Ncc large-scale integration of processing across multiple brain areas. Ex: frontal cortex, parietal cortex (posterior cingulate gyrus), region around boundary of temporal and parietal cortex (tpj) Intralaminar nucleus of thalamus extensively connected with above cortical structures. Integration of ncc relies on neural synchronization how we get information to. When conscious, synchronized activity (at higher freq) between distributed different brain areas + neurons groups of cortical neurons. Synchronized : functions in excitability of different parts of brain coordinate to allow info transfer effectively. Cerebellum argued it doesn"t participate in conscious perception. Relates to fact cerebellum = organized into local modules that interact little. Ex: planar dendrites with little connections between them. Compared with cerebral cortex, in which neurons are extensively connected.
