Brain complexity: learning new tasks depends on dendrites (Introduction)

by David Turell , Friday, March 23, 2018, 18:22 (2437 days ago) @ David Turell

New research moves the memory development from synapse changes to dendrite controls:

https://www.sciencedaily.com/releases/2018/03/180323084818.htm

" In the new dendritic learning scenario (right) only two adjustable red valves are located in close proximity to the computational element, the neuron.

"The brain is a complex network containing billions of neurons, where each of these neurons communicates simultaneously with thousands of other via their synapses (links). However, the neuron actually collects its many synaptic incoming signals through several extremely long ramified "arms" only, called dendritic trees.

"In 1949 Donald Hebb's pioneering work suggested that learning occurs in the brain by modifying the strength of the synapses, whereas neurons function as the computational elements in the brain. This has remained the common assumption until today.

"Using new theoretical results and experiments on neuronal cultures, a group of scientists, led by Prof. Ido Kanter, of the Department of Physics and the Gonda (Goldschmied) Multidisciplinary Brain Research Center at Bar-Ilan University, has demonstrated that the central assumption for nearly 70 years that learning occurs only in the synapses is mistaken.

"In an article published today in the journal Scientific Reports, the researchers go against conventional wisdom to show that learning is actually done by several dendrites, similar to the slow learning mechanism currently attributed to the synapses.

"'The newly discovered process of learning in the dendrites occurs at a much faster rate than in the old scenario suggesting that learning occurs solely in the synapses. In this new dendritic learning process, there are a few adaptive parameters per neuron, in comparison to thousands of tiny and sensitive ones in the synaptic learning scenario," said Prof. Kanter,

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"Another important finding of the study is that weak synapses, previously assumed to be insignificant even though they comprise the majority of our brain, play an important role in the dynamics of our brain. They induce oscillations of the learning parameters rather than pushing them to unrealistic fixed extremes, as suggested in the current synaptic learning scenario."

Comment: This adds another level of complexity and precise control to the brain as it develops new knowledge. We must continue to recognize the material side of the equation in the relationship between brain and s/s/c. It shows how the s/s/c is obligated to specific interfaces.