Edelman's theory of neural Darwinism
Chapter 5 endnote 18, from Lisa Feldman Barrett.
Some context is:
[Ch 5 note 18] ...some instances of concepts are more effective in a particular context to achieve a particular goal. Their competition in your brain is like Darwin’s theory of natural selection but carried out in milliseconds; the most suitable instances outlive all rivals to fit your goal in the moment. [...] These ideas are similar, although not identical, to those found in Edelman 1987.
[Ch 6 note 16] Your control network assists in efficiently constructing and selecting among the candidate instances so your brain can pick a winner. It helps neurons to participate in certain constructions rather than others, and keeps some concept instances alive while suppressing others. The result is akin to natural selection, in which the instances most suitable to the current environment survive to shape your perception and action.
Darwin proposed that variations among individuals in a species (population thinking) allows for natural selection during the course of evolution. Edelman’s theory of neural Darwinism also relies on variation and selection. He hypothesized that there are many brain patterns that implement a single thought, feeling, perception or action. That is, there are degenerate patterns. The brain contains a set of mechanisms that select the neural pattern amongst the many that are possible in any given instant.
Edelman focused on three types of selection:
- Developmental selection
- Through the course of development, some patterns become more likely than do others
- Experiential selection
- Because of lived experience, some patterns become more likely and others become less likely
- Reentrant selection
- In a given moment, some patterns emerge over others as different neural groups synchronize with one another
Using his own language and concepts, Edelman proposed that experiential selection was tied to value systems in the brain—the system of neuromodulators that help to establish and maintain allostasis and regulate the processing of prediction error, such as opioids, dopamine, etc. In fact, these systems are important to all three types of selection.
Notes on the Notes
- Edelman, Gerald M. 1987. Neural Darwinism: The Theory of Neuronal Group Selection. New York: Basic.
- For an accessible discussion, see Edelman, Gerald. M., & Giulio Tononi. 2000. A Universe of Consciousness. New York: Basic.