Lifespan changes

Children learn various things easier than adults:

• 1. VISUO-MOTOR skills e.g. sports, instruments. If you don't start ice skating or playing the piano as a child, you will never become good enough to be professional
• 2. LANGUAGE - 2nd language learned after 8 years old will never be as fully mastered as your mother tongue.
• Feral children --> If you grow up without any language whatsoever, you may never fully acquire a language (can't speak due to abandonment and never had the chance to learn due to lack of ability to speak)

Things children can't master at all: All elements of cognitive control

• a) Complex, abstract concepts e.g. international law, analystical philosophy
• b) Self-control - healthy toddler cannot sit still for any length of time
• c) Time perception e.g. are we there yet? Minutes seem like hours, days seem like months
• d) Planning - consequences, delaying instant gratification in favour of greater, later pleasure

Ageing (associated with loss of structures): Loss of muscle mass, bone density e.t.c.

• Cortex and subcortical structures atrophy, death of neurons
• Loss of synaptic connections, decreased mental flexibility (less able to adapt)
• Decrease in mental capacity, forgetfulness, learning skills/habits is more difficult

To minimise cognitive decline in old age... 1. Grow up in environment that is interesting, varied and stimulating to learn a lot.  2. Practice various different skills (physical, social and cognitive). 3. Remain physically and mentally active throughout your life.

• Human ageing: Decline is less severe for people with high levels of education. More active, better stimulated brain has mor synaptic connections and can better afford to lose some. Decline is less severe for people who remain physically and mentally active.
• Environmental influence on cortical neurons: Rats reared in enriched environent had better developed cortical neurons. Also had more/larger dendritic branches, longer acons with more collaterals, more visible, thicker cortex

Critical period - begins when critical structures are in place and ends when required structural changes are no longer possible.

• More elaborate structural changes = more restricted critical period. Some learning doesn't have a crticial period. Some developments are extremely long lasting.

Frontal lobes = Last part of nervous system to mature

Phineas Gage: Damage to frontal lobes. Behavioural effects:

• Limited impact on motor, perceptual/intellectual skills. Personality change - later recovery
• Recovery of social skills and cognitive control. Frontal lobes crticually involved in cognitive control. Frontal lobes are not fully developed in children.

Stroke (brain injury) = neuron death due to lack of oxygen & glucose, because of a blocked blood vessel. Significant recovery is possible.

Cortical reorganisation after loss of input:

• Amputation of limb -> cortical area that represents this part of the body no longer receives input from it.
• Corresponding synaptic connections stay silent and wither away.
• This is done to make room for axons from nearby active areas (synaptic takeover).

Phantom sensation = from stimulation of body parts with adjacent cortical representation. Substantial reorganisation of cortex is possible even in adulthood.