Not bad! But I stand by « random before (..) » as a better picture in the following sense: neurons don’t connect once to an address ending in 3. It connects several thousands of times to an address ending in 3. Some connexion are on the door, some on windows, some on the roof, one has been seen trying to connect to the dog, etc. Then it’s pruned, and the result looks not that far from a crystal. Or a convnet.
(there’s also long lasting silent synapses and a bit of neurogenesis, but that’s details for another time)
Yes, that’s fair. I think we’ve now described the situation well enough that I don’t think future readers of this thread will end up with a wrong impression.
To expand on Ilio’s point: the connection point on the “building” (recipient neuron’s dendrites) matters a lot because the location of of the synapse on the dendrites sets a floor and ceiling on the strength of the connection which cannot be exceeded by weight modifications due to temporal synchronicity.
Also, yes, there is neurogenesis ongoing throughout the lifespan. Never long range (e.g. cross country in our metaphor), only short range (within same metropolitan area). The long range connections are thus special in that they are irreplaceable.
Not bad! But I stand by « random before (..) » as a better picture in the following sense: neurons don’t connect once to an address ending in 3. It connects several thousands of times to an address ending in 3. Some connexion are on the door, some on windows, some on the roof, one has been seen trying to connect to the dog, etc. Then it’s pruned, and the result looks not that far from a crystal. Or a convnet.
(there’s also long lasting silent synapses and a bit of neurogenesis, but that’s details for another time)
For those interested in more details, I recommend this video:
Yes, that’s fair. I think we’ve now described the situation well enough that I don’t think future readers of this thread will end up with a wrong impression. To expand on Ilio’s point: the connection point on the “building” (recipient neuron’s dendrites) matters a lot because the location of of the synapse on the dendrites sets a floor and ceiling on the strength of the connection which cannot be exceeded by weight modifications due to temporal synchronicity. Also, yes, there is neurogenesis ongoing throughout the lifespan. Never long range (e.g. cross country in our metaphor), only short range (within same metropolitan area). The long range connections are thus special in that they are irreplaceable.