Brain construction
Wiring and insulation
Brain is has a lot of many armed cells called neurons (grey matter). Using these arms (axons) they communicate with each other using electrical signals. Assisting this signaling but decreasing branching flexibility of grey matter, there exists an insulatory ‘myelin’ sheath around axons formed by fatty, cholesterol-built cells (white matter).
Plumbing
The brain is fed by a lot of capillaries. Brain consumes a huge fraction of oxygen obtained by breathing. Ruptured vessels lead to oxygen and food deprivation, and cells begin to die within a few minutes.
So it is sensitive to high blood pressure and concussions (considered elsewhere).
Protection
For protection from impact, there is the skull. For immunological protection, there is the famed blood-brain barrier.
Brain parts and regions
Connection to function
Different areas have cells focused on different functions. Ultimately, however, different firing patterns correspond to different computations.
Areas
It is roughly divided into two hemishperes. Corpus collussum is a bunch of wires incharge of inter-hemisphere communication.
Forebrain is associated with higher cognition.
Close to brain stem
Areas close to the brain stem (in the rear of the brain) are in-charge of behaviorally basic functions, such as vision, movement, and fundamental processing. This is the brain of our evolutionary ancestors.
Hippocampus
Hippocampus is a sort of memory directory, strongly associated with emotion. It is not where the memories themselves are stored, but where the ‘index’ to the memories are stored. Damage to hippocampus is associated with amnesia.
Development stages
Teenage
The teenage brain is in a great state of flux. Plus, different hormones begin to act during teenage years.
There is much synaptic pruning (removal of unused circuits), increase of myelin sheaths/ white matter (making circuits more efficient and less flexible). These changes move in a slow wave from the brain’s rear (in charge of basic functions) to its front (in charge of complicated thinking). Corpus collussum thickens. Stronger links also develop between the hippocampus and the forebrain.
Effect of these changes on behavior is considered elsewhere.
Learning
Chemicals along with firing patterns trigger changes in brain wiring.
Fire together, wire together
Acquisition of new skills and habits involves the growth, and the reinforcement, with insulation, of neural pathways activated together frequently: neurons which fire together wire together. This is in keeping with the associative nature of neurons in the brain. This is true irrespective of whether an instinctive skill (eg: tennis, predicting complex sequence of events) or conceptual knowledge is being learned.
Sequence prediction
The role of the Dopamine system is considered elsewhere.