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-The neural mechanisms of consciousness. Dendritic Integration Theory (DIT) associates consciousness with the subset of thick-tufted layer 5 pyramidal neurons (L5 TT ; right) that are burst-firing, which occurs when depolarisation of the cell body via basal dendrites (red) coincides temporally with descending cortical inputs to apical dendrites (orange), particularly in the presence of gating inputs from higher-order, matrix-type thalamus (blue). Worked example (left): when inputs hit the retina, they contain information content that will drive feed-forward basal activity in the
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Interactions with large language models have led to the suggestion that these models may be conscious. From the perspective of neuroscience, this position is difficult to defend. For one, the architecture of large language models is missing key features of the thalamocortical system that have been linked to conscious awareness in mammals. Secondly,...
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... by ongoing processing within the dense, re-entrant thalamocortical network that forms the core of our brains [6][7][8]10,19,[24][25][26]. One theory that builds on this consensus and perhaps best encapsulates the level of biological detail relevant for the discussion about consciousness in LLMs, is Dendritic Integration Theory (DIT; [6]; Fig. ...
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... neurons that hold a central position in both thalamocortical and corticocortical loops [6]. Unlike other theories of consciousness, DIT focusses on a key physiological characteristic of thick-tufted, deep (i.e., the bodies of these sit in layer 5 of the cerebral cortex; L5 TT ), pyramidal cells -namely, that L5 TT have two major compartments (Fig. 3, orange and red cylinders) that process categorically distinct types of information: the basal compartment (red) processes externally-grounded information whereas the apical compartment (orange) processes internally-generated information. At rest, these two compartments are separated from one another, allowing information to flow ...
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... that we process to support our conscious awareness. The portion of the world that is perceptually 'available' to an organism has been described as its "Umwelt" (from the German 'environment' [34]). For instance, human retinas respond to wavelengths of light ranging from ~380-740 nanometers, which we perceive as a spectrum from blue to red (Fig. 3). Without technological augmentation, we are not susceptible to light waves outside of this narrow band -in the infrared (>740 nm) or ultraviolet (<380 nm) bands. We have a similar Umwelt for the auditory (we can perceive tones between 20-20,000 Hz), somatosensory (we can differentiate stimulation up to 1 mm apart on some parts of our ...
