Psychology - Applied - Pre-Adult Brain Development

background

what is grey matter?

neurones and synapses that cover the white matter, processing information - involved in movement, memory, emotional regulation, sensory processing , personality and intelligence (higher brain functions)

how much of the adult brain is grey matter?

40%

what is white matter?

located at the deeper parts of the brain it acts as a communication network allowing information to be transmitted around the brain and body - affects learning - subcortical in cerebrum and cerebellum but surrounds grey matter of spinal cord,

what is a myelinated neurone?

neurones conduct nerve impulses and are covered in a myelin sheath that prevents the impulse from one interfering with another whilst also speeding up their conduction - the breaking off leads to Parkinson’s, MS, Alzheimer’s etc

what is the pre-frontal cortex responsible for?

initiating higher-level functioning, contains Broca’s area that controls language - decision-making, problem-solving, intelligence and emotional regulation - social skills/personality,

what is the limbic system responsible for?

structures such as the amygdala, hippocampus, thalamus, hypothalamus etc - processing and regulating emotions (+ responses), survival instincts, social bonding, memory consolidation, arousal and learning, risk-taking

what is the ventral striatum responsible for?

reward gratification drive, impulsivity

what is synaptic pruning?

removal of neurones and synapses that are unnecessary - between 2-10 yrs and at ~20 yrs,

how do motor and visual skills develop?

0-5 months - reach and grasp items,

12-17 months - throw objects, place objects in container, point at objects,

24-29 months - bend and pick up objects, go up stairs with 2 feet per step,

36-41 months - sort shapes, go up stairs with 1 foot per step,

5 years - draw a person with 6 or more body parts,

how does brain weight change during childhood?

grows in spurts - ages 2-4, 6-8, 10-12 and 14-16 - by 5-10% over each 2 year period,

at 2 yrs brain = 55% of adult weight, at 6 yrs = 90%,

in adolescence grey matter reaches peak and then synaptic pruning begins, pre-frontal cortex last area to mature,

what is the role of serotonin and dopamine on behaviour?

dopamine - coordination, movement, feelings of pleasure and reward, mood, sleep, learning, blood flow, urine output,

serotonin - sleep-wake cycle, mood, emotions, metabolism and appetite, cognition and concentration, hormonal activity, body temperature and blood clotting.

what affects risk-taking behaviour in adolescents?

limbic system develops before pre-frontal cortex,

maturation of ventral striatum earlier,

reduction in serotonin in cerebral spinal cord (stress) can lead to impulsivity,

higher dopamine triggers V.S.

Eshel et al (2007)?

adults and adolescents were asked to choose between low probability/high reward and the opposite,

adults who made riskier decision showed activation of pre-frontal cortex - rational choice,

adolescents showed decreased activation - less likely to be rationalised choice,