When the brain of a child changes over time due to age, experience and learning, the mind follows how can it be a separate entity? From that developing, maturing, organic tissue?
When certain parts of the brain are damaged or diseased, the mind, cognition, personality, memories change in very specific ways, in relation to that injury or disease.
For example, Huntington’s Chorea is genetic, a terrible disease with high chance of a diseased parent passing it on to a child.
Loss of mental ability, speech, cognition, muscle control over time eventually leading to dementia and a raft of other complications. Life expectancy is shorter if early onset.
The defective gene has a high number of repeated base pairs in a certain region giving rise the defective protein if above a threshold.
So, one can say with some certainty that a baby with zero symptoms, outwardly normal but with the defective gene, that child’s mind will change with some predictability to a certain state in a certain time frame.
Early and late onset also have some predictability with predictable results.
So, the mind is not only inextricably linked to the brain, which is organic nothing more, but also the genes that build that brain.
Genes of course are also purely organic, comprising of bases pairs arranged in a particular combination and number.