Anyone have any ideas on what the Claustrum is doing?

The basic summary, for those unfamiliar, is that it’s a part of the brain with similar cell types to the cortex, but appears to only have one layer. It’s highly connected to every part of the cortex, as well as the thalamus and basal ganglia. There are even special cells in L6 that project specifically to the claustrum.

While not very well-studied or well-understood (it’s rather thin and hard to get at, so measuring activity is difficult), but is believed to play a significant role in conscious thought and attention. It’s sometimes also compared to an Orchestra Conductor, in that it’s believed to coordinate all parts of the cortex. Interfering with the claustrum can easily make a patient go unconscious.

Any ideas how this may play into HTM theory? I have a feeling it may play a role in the Thousand Brains Model, perhaps as a supplement to voting mechanisms, but I’m not certain.


There are corticoclaustral cells in L5 too. In V1, 85% are in L6, but only 30% elsewhere [1]. I don’t know whether those L5 cells only project there though.

I think it’s probably involved in attention. Its small size seems to fit a role less concerned with information contained in the sensory input. Its cells can have sensory selectivity though [2].

A role of the claustrum in auditory scene analysis by reflecting sensory change
Claustral cells did not have selectivity for the sound, but were able to distinguish a target sound in a noisy background. Their responses seem to be to a change in the auditory scene. They propose that the claustrum is for detecting novel or salient things.

[1] Abstract of Morphology and laminar distribution of cortico-claustral neurons in different areas of the rabbit cerebral cortex
[2] What is the function of the claustrum?


For HTM theory, I am not sure, but in Humans, this 1/2 of 1% of brain is probably originally an agent for integrating afferent and efferent events - somatosensory integration and feedback; but potentially it is also an agent for neuro-plasticity since it connects with many regions, and can sustain memory traffic even when some areas are damaged, and that traffic can spill into new parts of the brain. the deep embedding could suggest survival after external structures have been compromised.

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This little guy seems to be really important

That’s interesting, but seems like just a single case study. Are there more studies to collaborate that the claustrum is the “on / off switch”?

I’ve seen that brought up a few times. From my understanding, stimulation of the claustrum is known to cause patients to lose consciousness.

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In this other study [1] wasn’t the case. The video is referring to [2]. (There’s a lot of contradictory papers regarding the claustrum)

[1] S. Bickel and J. Parvizi, “Electrical stimulation of the human claustrum,” Epilepsy Behav. , vol. 97, pp. 296–303, Aug. 2019.

[2] M. Z. Koubeissi, F. Bartolomei, A. Beltagy, and F. Picard, “Electrical stimulation of a small brain area reversibly disrupts consciousness,” Epilepsy Behav. , vol. 37, pp. 32–35, 2014.


Crick & Koch:

Within the context of the neurobiological theories of consciousness mentioned in the introduction, the highly networked nature of the claustrum raises the question of whether it acts as a sort of ‘Cartesian theatre’. This is a metaphor, introduced and ridiculed by the philosopher Dennett (1991), for the fictitious centre where the mind and brain meet, where ‘it all comes together’ and consciousness occurs.

We think that a more appropriate analogy for the claustrum is that of a conductor coordinating a group of players in the orchestra, the various cortical regions. Without the conductor, the players can still play but they fall increasingly out of synchrony with each other. The result is a cacophony of sounds.

Looking like the Claustrum may be the crossbar switch.

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