Learning and Human Brain Development

• see also:
  • Brain Development
  • Cognitive Impairment
  • Evolution of the human brain
  • Evolution of human sexuality
  • Human behaviour
  • Motivation
  • Personality

Learned behaviour patterns:

• the brain can be likened to a computer which has an enormous memory bank of learned behavioural patterns or routines which in computers are analogous to individual programs stored on the hard drive.
• when there is a particular stimulus which may be conscious or subconsciously via associated emotional states, this learned behavioural pattern is set running.
• often such learned patters are useful for complex tasks such as when playing a musical instrument or driving a car is made automatic.
• severe stresses can embed such patterns deeply and result in post-traumatic stress syndrome where similar stimuli as occurred at the initial stress evoke highly emotive memories and a stress response.
• unless we have insight into this we may not be able to control it or at least modulate it or turn it off, which may lead to a vicious cycle of escalating occasions of maladaptive behaviour.
• if we allow such undesirable patterns to run unrestrained, they become further embedded in our memory processes (in a similar way that frequently run computer programs become listed in the Start Menu on the computer and made even more accessible). Worse still, the more often the program is run, each time it may develop new associations and so when these new associated situations occur later, they again trigger the behavioural pattern leading to obsessive-compulsive behavioural patterns or anger management problems.
• this particular occurs in long term relationships, where similar circumstances repeatedly arise creating similar stimuli which if one allows it to, will activate a certain behaviour pattern such as learned helplessness or defensive anger with verbal abuse rather than a more constructive solution of discussion and resolution would be more appropriate. Nevertheless, all too frequently, these "lazy" learned behaviours can dominate interpersonal relationships with resultant game playing & loss of true intimacy, respect  and love for each other.  

• critical periods for learning:
  • hearing required for learning speech at 2-4yrs age
  • exposure to substantial music instrumental playing required for perfect pitch at age 4-8yrs
  • children born with cataracts which are removed as adults can fixate figures, scan them & follow moving figures but cannot identify by sight alone objects very familiar from touch & cannot tell which stick is longer or discern a triangle from a square without counting its sides
  • without light stimulation of the retina, the visual cortex begins to atrophy
  • absence or minimal sensory stimulation results in lack of the normal avoidance response to painful stimuli
• stages in development:
  • motor development
  • cognitive development
    • sensorimotor
      • birth - 2 years
    • preoperational
      • 2-7yrs
      • uses language & can represent objects by images and words
      • still egocentric
      • classifies objects by single salient features
      • begins to use numbers & develop conservation concepts
    • concrete operational
      • 7-12yrs
      • becomes capable of logical thought
      • achieves conservation concepts in this order: numbers (age 6); mass (age 7); weight (age 9)
      • can classify objects, order them in series along a dimension (eg. weight) & understand relational terms
    • formal operational
      • 12 yrs and up
      • can think in abstract terms, follow logical propositions & reason by hypothesis
      • becomes concerned with the hypothetical, the future, and ideological problems
  • psychosocial crises stages
    • trust vs mistrust - birth - 1yr => drive & hope
    • autonomy vs shame/guilt - 1-2yr => self-control & willpower
    • initiative vs guilt - 2-4yrs => direction & purpose
    • industry vs inferiority - 5yrs-puberty => method & competence
    • identity & repudiation vs identity diffusion - adolescence => devotion & fidelity
    • intimacy & solidarity vs isolation - early adulthood => affiliation & love
    • generativity vs self-absorption - young & middle adulthood => production & care
    • integrity vs despair - later adulthood => renunciation & wisdom
  • moral values
    • premoral
      • punishment & obedience orientation - obeys in order to avoid punishment
      • naive instrumental hedonism - obeys to receive rewards
    • morality of conventional role-conformity
      • "good boy morality" - conforms to avoid disapproval & dislike by others
      • authority maintaining morality - to avoid censure by legitimate authorities
    • morality of self-accepted moral principles
      • morality of contract, of individual rights & democratically accepted law - conforms to maintain respect of impartial spectator judging in terms of community welfare
      • morality of individual principles of conscience - conforms to avoid self-condemnation
  • psychoanalytic theory psychosexual stages:
    • oral stage - birth-1yr
    • anal stage - 1-2yrs
    • phallic stage - 3-6yrs
    • latency period where less concerned with body & turns attention to dealing with environment
    • genital stage - adolescence
• learning:
  • learning is defined as the process of acquiring new information or skills
  • memory refers to the persistence of learning that can be revealed at a later time 
    • memory is stored in certain neural synapses see Learning And Memory Biology 2003.pdf
    • short term memory:
      • neural activity results in short term increase in synaptic activity
    • long term memory:
      • repeated stimulation of the same neural circuit results in an enduring synaptic response that requires gene transcription and translation of new protein (ie. the brain becomes "hard-wired")
  • classical conditioning:
    • Pavlov's dog
    • acquisition:
      • involves trials where an unconditioned stimulus is associated temporally with a conditioned stimulus so that soon the conditioned response occurs after the unconditioned stimulus even when the conditioned stimulus does not occur
      • it is reinforced by further pairings of the unconditioned stimulus and the conditioned stimulus
        • reinforcement occurs by stimulation of reinforcement area in the brain - usually the hypothalamus
        • negative reinforcement can occur by stimulation of other parts of the brain
      • the response is generalised to other similar stimuli
      • selective reinforcement & extinction results in discrimination so that response only occurs to certain stimuli
    • extinction:
      • repetition of the conditioned stimulus without reinforcement results in extinction of the response to the unconditioned stimulus
  • operant conditioning:
    • similar to classical conditioning however the response is initially spontaneous and not produced by a conditioned stimulus. This response is then rewarded so that the response is more likely to occur given the same environmental conditions
    • eg. a hungry rat accidentally hits a lever which gives him food, he then will learn to hit the lever when he is hungry again
    • eg. dolphins are trained through operant responses
    • eg. gambler blowing on a dice before he throws it is rewarded enough often enough to reinforce this behaviour
  • multiple response learning:
    • repeated practice & memorisation
    • eg. learning to ride a bike, play a musical instrument, write
    • eg. rote memorisation which takes 2 forms:
      • serial memorisation - a word is a stimulus for the next consecutive word in a sentence
      • paired association - stimulus-response pairs eg. learning new language tend to learn the equivalent word
  • cognitive learning:
    • cognitively organising & understanding what is learned resulting in a cognitive structure in memory & thus can solve problems using insight into the nature of the problem rather than by trial & error
  • examples:
    • how we learn to deal with the primal protective emotion of anger:
      • the physiological aspects of anger is driven by activation of the amygdala with resultant release of sympathomimetics into the circulation
      • the pre-frontal cortex is then responsible for analysing the true threat and determining how we should deal with this feeling and physiology of rising anger
        • violent people have significantly less prefrontal cortex grey matter as well as significantly less pre-frontal cortical activity than non-violent persons
        • low cerebral serotonin levels and high dopamine levels are thought to be associated with violent behaviour.
        • what is the role of testosterone here?
      • the extent to which we are able to control the rising anger depends on many factors including genes and learned patterns of responses during infancy:
        • experiments in monkeys showed that it is not enough for a monkey to have a genotype that predisposes to violent outbursts, but that the lack of mothering in early infancy is a key trigger to allow expression of this genotype. That is, the mothering process creates a learned environment that teaches impulse control, presumably creating pre-frontal neural wiring, while the lack of mothering in susceptible monkeys leads to lack of impulse control and resultant violent behaviour.
        • it is likely that similar occurs in humans, those who had abusive childhoods and were genetically susceptible, tended to perpetuate violent behaviour down the generations.