SAC 2 Flashcards
learning
a relatively permanent change in behaviour due to experience (passive or active). closely related to and depends on memory
memory
an active information system that receives, organises, stores and recovers information when we need it. closely related to and depends on learning
synaptogenesis
the process by which synapses are formed between neurons, occurs all throughout life but is most rapid during early brain development, neurons are strengthened by stimulation and pruned if not used
effects of experience on the synapses
enriched environment =sensory stimulation - greater synapse formation - strong neural circuits - strengthens learning and memory = positive brain development
deprived environment = limited sensory stimulation - limited synapse function - weak neural circuits - impedes learning and memory
types of neural plasticity
developmental: ability of synapses to be modified, takes place in infants, children and adolescence due to growth and development
adaptive: ability of the brain to change and develop as a result of new experiences, happens in adults as they have experiences which modify the brain, can develop and recover from serious injury. sprouting: new neural connections, re-routing: finding another connection
how neural plasticity works + define
the brains ability to reorganise neural pathways and change its structure and function in order to adapt to changing conditions. works by modifying the strength or effectiveness of synaptic connections, producing growth of new synaptic connections or pruning old ones, by changing the excitability properties of the neuron
long term potentiation
the increase in synaptic strength through high frequency stimulation of the synaptic pathway. Hebbs rule: neurons that fire together, wire together. hippocampus is important for this memory consolidation
long term depression
the decrease in synaptic transmission resulting from a lack of stimulus
factors that affect plasticity
genetic: specific traits and characteristics encoded in our genes that we inherit from our parents
environmental: the amount of stimulation our nervous system receives
role of glutamate in memory
has an excitatory effect meaning it makes an action potential more likely to fire on the post synaptic neuron. long term potentiation involves increased amounts of glutamate and increased sensitivity of the neuron. long term depression is decreased amount of glutamate
role of adrenaline in memory
consolidation of emotional memory = biological process of make a newly formed memory stable and long lasting, moving info from STM to LTM. adrenaline when released as a neurotransmitter the brain activates the amygdala which stores and processes emotions such as fear
neurotransmitter vs neurohormone
neurotransmitter: chemicals released by a pre-synaptic neuron, released directly into the synapse, can only effect neurons that are directly linked, carry messages form preSN to postSN travel short distances + effect is quick
neurohormone: chemicals released by preSN, released directly into bloodstream, carry messages throughout the body so can affect distant target cells, effect is not as quick but is longer lasting
neurotransmitter define
a chemical messenger synthesised within a pre synaptic neuron and transmitted across the synapse. can be excitatory or inhibitory.
neurohormone define
a chemical synthesised in the neuron that is recreated directly into the bloodstream to act on distant sites
LTP vs LTD
LTP: synapses are strengthened when AMPA receptors on postSN are increased in number and efficiency allowing more calcium to enter increasing excitatory response, increased glutamate is produced and released by preSN, involved in memory and learning as neurons become more efficient at transmitting information
LTD: synapses are weaker when AMPA receptors are reduced on postSN decreasing calcium and response, decreased glutamate is produced by the preSN, involved in learning and memory as neurons become less efficient synaptic pruning could happen
models of learning
classical conditioning
operant conditioning
observational learning
classical conditioning define
learning in which a stimulus that does not elicit a response is repeatedly linked with a stimulus that does automatically get a response. the two stimuli are paired until the neutral stimulus becomes the conditioned stimulus. the learner is passive and it is an involuntary response. is a 3 phase process, before, during and after conditioning
classical conditioning words
neutral stimulus (NS): produces no naturally occurring response unconditioned stimulus (UCS): a stimulus that can produce a naturally occurring response unconditioned response (UCR): an unlearned innate response to an unconditioned stimulus conditioned stimulus (CS): a stimulus that produces a response after learning has occurred and it has been paired with the UCS conditioned response: a response similar to UCR that is produced by the CS after learning has taken place
Classical conditioning: stimulus generalisation stimulus discrimination extinction spontaneous recovery
SG: when stimuli similar to the CS produce the CR e.g pavlova dog salivating to doorbell
SD: the ability to discriminate between stimuli so only a specific stimulus produces the CR
E: the gradual decrease in strength or frequency of a CR when the UCS is no longer available
SR: the reappearance of a CR to the CS after a period of apparent extinction
acquisition
the learning itself, gaining the skill. the process of learning the conditioned response. the phase is the period of time between presentation of the stimulus and receiving reinforcement
three phases of classical conditioning
phase 1: before conditioning, a neutral stimulus that does not elicit any specific response is found. a stimulus that is innately capable of eliciting a response is found (ucs) and the response to that ucs is called the ucr
phase 2: during conditioning, the ns is presented before the ucs numerous times and this process must be repeated many times = acquisition phase and by association the ns begins to elicit the same response as the ucs, works best when ns immediately follows ucs
phase 3: after conditioning, the learner consistently produces a conditioned response to a previously ns without it being paired with the ucs, the ns becomes the cs
operant conditioning
is a learning process where the likelihood of a behaviour being repeated is determined by the consequences of that behaviour, has 3 phases: antecedent, behaviour and consequence
antecedent (operant conditioning)
the stimulus that is the precursor to the response, it creates the conditions or environment that primes an organism to behave towards a stimuli in a particular way e.g “get to work” or traffic lights
behaviour (operant conditioning)
the response to the antecedent stimulus the organism makes, generally considered voluntary because the leader decides the response playing an active role