if the problems are the same, it (evolution) often finds the same solution"
- Richard Dawkins, The Blind Watchmaker
Neural Darwinism, also known as the theory of neuronal group selection, is a theory that proposes that the development and organisation of the brain is similar to the process of biological evolution. According to this theory, the brain is composed of a large number of neural networks that compete with each other for resources and survival, much like biological organisms competing for resources in their environment.
The main similarity between Neural Darwinism and evolution is that they both involve a process of variation, selection, and adaptation. In biological evolution, organisms with advantageous traits are more likely to survive and reproduce, passing those traits on to their offspring. Similarly, in Neural Darwinism, neural networks that are better able to compete for resources and perform necessary functions are more likely to be preserved and strengthened, while weaker or less effective networks are pruned away.
The core claims of Neural Darwinism:
- Neuronal groups, or populations of neurons that are functionally connected, compete with one another for resources and influence within the brain. Neuronal groups that are better adapted to a particular task or context are more likely to survive and thrive, while those that are less well-adapted are more likely to be eliminated or suppressed. The process of selection and adaptation occurs through a combination of genetic factors and experience-dependent modifications to neural connections. The brain is able to generate highly specific and adaptive responses to a wide range of stimuli through the dynamic interactions of neuronal populations.
- Spatiotemporal coordination of the neural activity underlying these selectional events is achieved mainly by a process of reentry. Reentry is the synchronous entrainment of reciprocally connected neuronal groups within sensorimotor maps into ensembles of coherent global activity.
- Neural Darwinism proposes that the brain uses degenerate coding, which means that multiple neural populations can respond to the same stimulus, allowing for redundancy and flexibility in neural processing.
- The initial population of groups is known as the primary repertoire and developed during prenatal development.
- The connections which are modified during development are between neuronal groups, rather than between specific cells.
- The primary repertoire and selection is responsible for the creation of a secondary repertoire which will be involved in the subsequent behavior of the organism.
- The operation of selection in Neural Darwinism is manifested through the selective stabilisation of neural connections that are relevant to the task at hand. Connections that are not relevant or are redundant are eliminated through a process of competitive interaction, while connections that are relevant are strengthened and stabilised.
- The relationship of external events to specific operations of selection in Neural Darwinism is that external events provide the stimuli and experiences that drive the selective stabilisation process. The brain is constantly adapting and modifying its neural connections based on the environmental stimuli and experiences that it encounters. Therefore, the specific operations of selection are driven by the external events that the brain is exposed to.
ND has little to say about how cognitive processes such as decision-making, problem-solving, and other executive functions exactly occur but it provides plausible basis for future developments. It has been mostly accepted (except for the fact that it lacks “units of evolution”, replicators capable of hereditary variation. I personally do not endorse this criticism and will address it in Narrative Theory section) and became a part of fruitful direction of research.