SAC2 Psych_visual+cns system PDF

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learning outcomes of VCAA qld syllabus for psychology...

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SAC 2 PSYCH TABLE OF CONTENTS NEAURAL PLASTICITY................................................................................................................................................. 3 Neuron-synapse.......................................................................................................................................................... 3 Long term potentiation................................................................................................................................................. 4 Long term depression.................................................................................................................................................. 4 Neurotransmitters & neurohormones........................................................................................................................... 5 Glutamate (LTP)........................................................................................................................................................... 5 Adrenaline & emotional arousal................................................................................................................................... 5 Emotional memories.................................................................................................................................................... 6 LEARNING...................................................................................................................................................................... 7 Facts about learning......................................................................................................................................................................7 CLASSICAL CONDITIONING........................................................................................................................................ 7 Phase 1:Before conditioning.........................................................................................................................................................8 Phase 2: During conditioning.......................................................................................................................................................9 Phase 3: After conditioning...........................................................................................................................................................9 Involuntary.......................................................................................................................................................................................9 Acquisition phase...........................................................................................................................................................................9 Extinction.......................................................................................................................................................................................10 Stimulus generalisation & discrimination..................................................................................................................................10 LITTLE ALBERT........................................................................................................................................................... 11 Method...........................................................................................................................................................................................11 According to classical conditioning............................................................................................................................................11 Ethical issues................................................................................................................................................................................11 OPERANT CONDITIONING......................................................................................................................................... 12 Skinner: the three phase model.................................................................................................................................................12 Skinner 1983 experiment............................................................................................................................................................12 Consequences..............................................................................................................................................................................12 Reinforcement...............................................................................................................................................................................13 Punishment...................................................................................................................................................................................13 Extinction & spontaneous recovery...........................................................................................................................................13 Generalisation & discrimination.................................................................................................................................................14 COMPARISON OF CLASSICAL & OPERANT CONDITIONING.................................................................................14 OBSERVATIONAL LEARNING.................................................................................................................................... 15 Elements of obeservational learning.........................................................................................................................................15 Vicarious learning.........................................................................................................................................................................16 The power of models to children................................................................................................................................................16 Summary of observational learning...........................................................................................................................................16 PROCESSES OF MEMORY......................................................................................................................................... 17

Three basic processes of memory............................................................................................................................................17 The multi-store model of memory..............................................................................................................................................17 Sensory memory..........................................................................................................................................................................18 Short-term memory......................................................................................................................................................................18 Long-term memory.......................................................................................................................................................................19 BRAIN AREAS INVOLVED IN MEMORY..................................................................................................................... 20 Flashbulb memories.....................................................................................................................................................................20 RELIABILITY OF MEMORY......................................................................................................................................... 21 Measures of retention..................................................................................................................................................................21 Savings score...............................................................................................................................................................................22 sensitivity.......................................................................................................................................................................................22 reconstruction...............................................................................................................................................................................22 BRAIN TRAUMA & MEMORY...................................................................................................................................... 22 Traumatic brain injury (TBI)........................................................................................................................................................22 Amenesia.......................................................................................................................................................................................23 Anterograde amnesia & atkinson-shiffrin..................................................................................................................................23 Brain sugery & amnesia..............................................................................................................................................................23 Patient H.M....................................................................................................................................................................................23 CONSOLIDATION THEORY......................................................................................................................................... 24 Details of consolidation theory...................................................................................................................................................24 Consolidation disruption..............................................................................................................................................................24 Time period for consolidation.....................................................................................................................................................24 Hippocampus & consolidation....................................................................................................................................................25 Consolidation in LTM...................................................................................................................................................................25 NEURODEGENERATIVE DISEASE............................................................................................................................. 25 Dementia.......................................................................................................................................................................................25 Alzheimer’s disease.....................................................................................................................................................................26 Process of Alzheimer’s disease.................................................................................................................................................26 Difference between Alzheimer’s & amnesia.............................................................................................................................27 Alzheimer’s brain damage..........................................................................................................................................................27 Hippocampus impact...................................................................................................................................................................27 Cerebral impact............................................................................................................................................................................28 Acetylcholine.................................................................................................................................................................................28 FALLIBILITY OF MEMORY.......................................................................................................................................... 28 Context & state dependent cues................................................................................................................................................28 Rehearsal......................................................................................................................................................................................29 SERIAL POSITION EFFECT........................................................................................................................................ 29 Primary effect................................................................................................................................................................................29 Recency effect..............................................................................................................................................................................29 Asymptote......................................................................................................................................................................................29

Delayed recall...............................................................................................................................................................................30 RECONSTRUCTING MEMORIES................................................................................................................................ 30 Eye-witness testimony.................................................................................................................................................................31 Leading questions........................................................................................................................................................................31 Loftus & Palmer research...........................................................................................................................................................31 Experiment 1.................................................................................................................................................................................31 Experiment 2.................................................................................................................................................................................32

NEAURAL PLASTICITY Plasticity: the ability to change the brains neural structure or function to be changed by experience through the lifespan. Developmental plasticity:

Changes I neural connections during development as a result of environmental interactions as well as neural changes induced in learning.

Adaptive plasticity:

The brains ability to compensate for lost of functionality due to brain damage as well as in response to interaction with the environment by reorganising its structure.

Synaptic plasticity: the ability of the synapse to change overtime. 

The brain

The brain is capable of learning because it is flexible in being able to adjust to new input. The brain can recognise neural connections & pathways based on what is being over-used & underused. Plasticity & learning:  

Learning can strengthen synapses & connect new synapses, resulting in memories of these learnt experiences. When something new is learned, physical changes occur in the brain at a neuronal level.

NEURON-SYNAPSE

LONG TERM POTENTIATION Long term potentiation: long lasting strengthening of synaptic connections resulting in enhanced or more effective synaptic transmission whenever activated. Therefore improves the ability of two neurons to communicate with one another at the synapse. LTP & neurons: Postsynaptic neurons become more responsive to the presynaptic neurons as a consequence of repeated stimulation by neurotransmitters. 

The more the neural pathway is strengthened, transferring information becomes more efficient  decreasing the likelihood that what has been learned will be forgotten.

Effects of long term potentiation:   

Increased release of neurotransmitters Increased receptor responsiveness/reactivity Increased growth of axon terminals

Synaptogenesis: when new synapses are formed, or old synapses strengthened. LONG TERM DEPRESSION Long term depression: a lack of stimulation or prolonged low-level stimulation, causes a postsynaptic neuron to become less responsive to the neurotransmitter released by a presynaptic neuron.   

The effect is to weaken the synaptic connections (silence communication at the synapse) LTD is the opposite of LTP Long lasting decrease in the strength of synaptic transmission.

LTD & memory: the weakening or elimination of unused synapses that aren’t used regularly, make space for new information to learnt, memories to be made by learning & new neural pathways to be or even modified. Effects of long term depression:    

Synaptic decline or silencing Decrease in number of neurotransmitters released Shrinkage in axon terminal Overall decrease in synaptic strength

NEUROTRANSMITTERS & NEUROHORMONES Neurotransmitters: a chemical substance that is made by the neuron & enables communication between neurons . it is the chemical messenger between neurons.   

The neurotransmitter works by attaching itself to the receptor site on the receiving neuron/ receptors are pre-set for different types of neurotransmitters. Electrical activity  transmission of neural impulses with the neuron. Chemical process  transmission between neurons.

Neurohormones: chemical messages that are manufactured by neurons & released from axon terminals into blood vessels where they are absorbed in the blood stream (adrenaline). Hebb’s rule: when neurotransmitters are repeatedly sent across the synaptic gap, the pre & post synaptic neuron are repeatedly activated at the same time. This changes the structure/chemistry of the synapse & strengthens the connection.



‘Those that fire together wire together’

GLUTAMATE (LTP) Glutamate: the excitatory neurotransmitter involved in memory and learning that promotes the strengthening of neuronal connections.    

The greater the abundance of glutamate the more likely the post synaptic neuron is to fire and contribute to LTP. If there is a lack of glutamate, this results in LTD. The repeated glutamate release stimulates the release of dopamine (emotional, arousal, pleasure & reward). The repeated glutamate release stimulates growth in the pro-synaptic neuron (growth of dendritic spines)

Dendritic spines: little outgrowths from the dendrites into the synaptic gap/cleft. 

Purpose  to make the dendrites more responsive to future fringes by neighbouring pre-synaptic neurons. This increases the efficiency of the neural pathway for the learnt behaviour.

ADRENALINE & EMOTIONAL AROUSAL Adrenaline & memory function: During emotionally heightened experiences, adrenaline released stimulate the release of noradrenaline in the amygdala, which helps to consolidate memories. This happens as the amygdala signals to the hippocampus to strengthen the detail in the long term memory, often creating a ‘flashbulb memory’.  

Emotional memory is created with use of adrenaline Emotional memory is very strong

Too much adrenaline/not enough adrenaline  being released when we form memories can cause a memory not to consolidate properly, causing problems with accurate & full recall. Process of emotional...