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
consequence (operant conditioning)
a consequence follows a behaviour and may be either pleasant or unpleasant circumstances, they influence the likelihood of the behaviour being repeated. consequences can be reinforcement, punishment, or nothing. reinforcement = more likely
punishment = less likely
reinforcement (operant conditioning)
an event that follows a response or behaviour and increases the probability of a response or behaviour being repeated. two types:
positive reinforcement: a pleasant or desirable event follows a response and strengthens likelihood of that response e.g receiving praise for good work
negative reinforcement: an unpleasant stimulus is removed, reduced or prevented thus creating a positive consequence e.g aspirin for a headache
punishment
in the form of reprimands, jail, firing, failing grades is used to change an undesirable behaviour. a punisher is any unpleasant consequence that reduces the likelihood a behaviour being repeated e.g poor grade = getting yelled at
response cost: removal of a pleasant stimulus or circumstance as a result of undesirable behaviour reducing the likelihood of that behaviour occurring in the future e.g taking away car for speeding
variables affecting punishment
effectiveness of punishment depends on their timing, consistency and intensity. punishment works best when occurs immediately after the response (timing), when it is given each time that response occurs (consistency), if it is too harsh it may lead to avoidance behaviour or fear (intensity) but still needs to be harsh enough
operant conditioning: stimulus generalisation stimulus discrimination extinction spontaneous recovery
SG: tendency to respond to stimuli similar to stimuli that precede operant reinforcement
SD: ability to differentiate between stimuli similar to the stimuli that signal reinforcement
E: when the learnt response gradually decreases in strength or rate of response after reinforcement stops
SR: reappearance of a previously reinforced response after a period of extinction
observational learning
is a method of social learning where learning occurs by watching others and noting the consequences of their actions, then imitating or not imitating their behaviour, the model is the person who serves as an example for the learner, model is considered active but learning is latent as it is not shown until needed, elements are:
attention, retention, reproduction, motivation, reinforcement
elements of observational learning
ATTENTION: learner must pay attention to the model who must be perceived as interesting somehow if leaner does not pay attention then they will not learn, not every model will automatically become interesting
RETENTION: learner must remember what was done by the models that the information can be encoded and stored through two representational systems (images and verbal)
REPRODUCTION: learner must be able to reproduce the modelled behaviour so must have the psychological and physical capacity to do so
MOTIVATION: learner must have the desire to repeat the observed behaviour
REINFORCEMENT: learner must perceive some form of reward for repeating the behaviour
memory
encoding
storage
retrieval
memory is an active information processing system that receives, stores, organises and recovers information
encoding is when our brain takes external and internal information which cannot be processes in its raw form, and converts it into a usable form (code) that can be stored and represented in the memory system.
encoded information is stored which is the retention of information in the memory system over time.
retrieval involves locating the information stored in memory and bringing it to consciousness when needed to complete a cognitive task
Atkinson and Shiffrin’s multi store model of memory
the multi store model visualises memory through a system consisting of multiple memory stores through which a stream of data flows for processing
sensory memory (Atkinson Shiffrin)
first stage of multi-store model: sensory memory; receives and stores an unlimited amount of sensory information for up to a few seconds. two main sensory registers:
iconic memory: visual sensory memory, holds exact replica of visual information for approx 1/3-1/2 of a second. relatively unlimited
echoic memory: auditory sensory memory, holds exact replica of auditory information for 3-4 seconds, relatively unlimited
short term memory (Atkinson Shiffrin)
second stage of multi-store model: most active memory system; stores unlimited amount of information entering from sensory memory or retrieved from LTM. its the working memory, stores information whilst you’re working on it, information is lost through decay or displacement.
capacity: limited 7 + or - 2 (chunking can increase)
duration 12-30 seconds
factors affecting ability to remember: rehearsal
rehearsal: the process of doing something so that information can be retained in memory and then retrieved, two types:
maintenance rehearsal: involves simple rote repetition of information being remembered so it can be retained, does not guarantee LTM storage, needs conscious attention
elaborative rehearsal: attaching meaning to what is to be remembered
(used in improving STM duration)
long term memory (Atkinson Shiffrin)
third stage of multi-store model: used for relatively permanent storage of unlimited information that is encoded and stored, provided with the correct cues the information can be retrieved, informations encoded by meaning, semantically, and stored in semantic networks
capacity: unlimited
duration: unlimited
types of long term memory
implicit: unconscious recall of memories of how to do something = procedural memories: memories of learnt skills and actions
explicit: consciously recalled memories of facts of personally specific events = declarative which are either semantic or episodic, semantic = impersonal general factual knowledge. episodic = memories of personally significant events
LTM retrieval methods (list)
recall
recognition
relearning
reconstruction
LTM retrieval methods: recall
to supply or reproduce facts or information stored in LTM with few or no cues for assistance, verbatim, 3 types:
free recall: recalling info from memory in any order with no cues
serial recall: recalling info from memory in the order it was learnt with no cues for assistance
cued recall: recalling information form memory with some cues or help for assistance
LTM retrieval methods: recognition
identifying the correct answer from a list of possible alternatives knows as distracters, generally easier method of retrieval as it provides cues and prompts (multi choice question for example)
LTM retrieval methods: relearning
a measure of retention that involves learning information that has previously been learnt and stored in LTM, assessing whether any information was rained from original learning, a savings score calculates % information retained from original learning
time for og learning - time for relearning
over time for og learning
x 100
LTM retrieval methods: reconstruction
remembering past events and features of them that are stored in LTM and putting them together during memory recall at a later date. information will be distorted by personal interpretation
factors affecting ability to remember: serial position effect
a pattern of recall for list items where recall is better for items at the beginning or end of a list rather than in the middle
factors affecting ability to remember: primacy and recency effect
primacy: the serial position effect where recall is best for the first items on the list than those for the end or middle.
recency: the serial position effect where recall is best for items at the end of the list rather than those at the beginning or middle
factors affecting ability to remember: retrieval cues
context dependant: environmental cues in the specific context or environment where the memory was formed, which enhance the retrieval of memory formed there e.g hair cream = Switzerland
state dependant: retrieval cues associated with your internal physiological or psychological state at the time the memory was formed which enhance the retrieval of memories formed in that state
factors that affect the ability to remember
retrieval cues
rehearsal
serial position effect
brain areas involved in LTM
cerebral cortex
cerebellum
amygdala
hippocampus
cerebral cortex
explicit
processes short term declarative memories and stores long term ones
has a role in linking memories
neurons fire together from all parts of the brain to contribute to memory
hippocampus
explicit
consolidation and retrieval of long term declarative memories
encodes new explicit declarative memories does not store them!
role in spatial memory
close with amygdala
cerebellum
implicit
part of hindbrain
responsible for motor skills, balance and movement
classically conditioned memory = implicit memory
procedural memories that require muscle coordination
amygdala
implicit (& explicit)
role in emotional memories (explicit) particularly fear and anger
long term non declarative memories
damaged amygdala = no fear
classically conditioned fear responses (implicit)
effects of brain surgery
risks memory function being impaired
usually short term, temporary memory loss
most people recover occasionally memory impairment can be long lasting
effects of brain trauma
brain trauma involves physical damage to the brain
can impact ability to form, store or retrieve memories
could result from external sources e.g car accident or internal e.g neurodegenerative disease
amnesia + anterograde amnesia
loss of memory, partial or complete, temporary or permanent. anterograde amnesia is where events that occur after the injury are not remembered due to brain damage especially in hippocampus
brain can’t transfer information from STM to LTM
STM still works and can retrieve memories from LTM
can learn new implicit procedural skills
neurodegenerative disease
dementia: is a general term that refers to disorders affecting higher mental functions
involves loss of memory both short and long term
includes loss of intellect and is a progressive, irreversible cognitive decline
alzheimers disease and causes
most common form of dementia
gradual severe memory loss, confusion, depression, impaired attention
both retrograde and anterograde amnesia
hippocampus and pre frontal cortex damage.
caused by:
amyloid plaques which are proteins which form clumps in and around neurons inhibiting communication
neurofibrillary tangles which inhibit transport of essential substances through the neuron
*low levels of acetylcholine
Loftus: eyewitness testimony suggestion
loftus suggested eye witness testimonies are fallible due to the malleability of reconstruction and memory due to the different ways we encode information and memories
Loftus: leading question
a questions posed to a witness that is phrased in a way that is prompts or suggests the desired answer. using leading questions new false memories can be implanted and old ones unconsciously altered
Loftus: eyewitness testimony define
a statement (usually given in court) from an individual who has viewed an event that consists of their personal recollection of the event
