[steve_adams_86]

This might be a dumb question, because I doubt the distances between neurons makes a meaningful distance… But could a small brain, dense with neurons like a crow, possibly lead to a difference in things like response to stimuli or “compute” speed so to speak?

[tlarkworthy]

The electrical signals in brain are chemical reactions, not conductivity like a metal wire. They are slow! Synaptic junctions are a huge number of indirect chemical cascades, not a direct electrical connection, they are even slower! So brain morphology and connectome has a massive impact on what can be computed. Human twitch responses are done by cerebellum, not cerebrum. It's faster, but you can't do philosophy with the cerebellum, only learn to ride a bike etc. This is the brain doing the best it for the circumstances.

[ganeshkrishnan]

>The electrical signals in brain are chemical reactions, not conductivity like a metal wire.

Nerve signals are both chemical reactions and electrical impulses like metal wire. Electrical impulses are sent along the fat layer by ions Potassium , Calcium, Sodium etc.

Twitch responses are actually done in spinal cord. The signals are short circuited all along the spine and return back to muscle without touching the brain ever.

[out_of_protocol]

Regarding compute speed - it checks out. Humans "think" via neo cortex, thin ouside layer of the brain. Poor locality, signals needs to travel a lot. Easy to expand though. Crow brain have everything tightly concentrated in the center - fast communication between neurons, hard to have more "thinking" thing later (therefore hard to evolve above what crows currently have)

[philsnow]

Not a dumb question at all; one of the hard constraints of cou design is signal propagation time. Even going at 1/3 the speed of light, when you only have on the order of a billionth of a second (clock frequencies in the GHz), a signal can’t get very far.

I haven’t heard of a clocking mechanism in brains, but signals propagate much slower and a walnut / crow brain is much larger than a cpu die.

[RaftPeople]

> I haven’t heard of a clocking mechanism in brains

Brain waves (partially). They aren't exactly like a cpu clock, but they do coordinate activity of cells in space and time.

There are different frequencies that are involved in different types of activity. Lower frequencies synchronize across larger areas (can be entire brain) and higher frequencies across smaller local areas.

There is coupling between different types of waves (i.e. slow wave phase coupled to fast waves amplitude) and some researchers (Miller) thinks the slow wave is managing memory access and the fast wave is managing cognition/computation (utilizing the retrieved memory).

[michaelhoney]

Actually I think that's pretty plausible. Signal speed in the brain is pretty slow - it would have to make some difference

[JKCalhoun]

And here I was wondering if there were heat issues in a crow brain.

[steve_adams_86]

Throw some thermal paste on those neurons and they do just fine