Chapter 8 Flashcards
what is the story of HM?
- H.M. was 27 years old in 1953 when he had most of his hippocampus and surrounding brain tissue removed
- operation was successful, but he could no longer form new memories
- However, H.M. could learn new tasks but showed improvement on mirror-trace task over trials but yet no memory of doing the task
memory
processes that allow us to record and retrieve experiences and information
3 behaviours that show evidence of memory
1.) recall - retrieve previously stored information
2.) recognition - identify which stimulus, out of a bunch of choices, match your stored information
3.) relearning - compare rates of learning information on successive occasions to the first occasion
3 basic processes of memory
encoding –> storage –> retrieval
encoding
getting information in by translating it into a neural code that your brain can process
storage
retaining the same information over time
retrieval
getting information back out of storage when we want to use it
what is the Atkinson-Shiffrin model?
- believed that STM could be transferred to LTM if the information was processed and learned fast enough
- LTM has a limitless capacity and is capable of lasting a lifetime.
working memory
- limited capacity to hold information temporarily (short term)
- integrates info from LTM with new info from sensory memory
- stores information and actively processes it
- supports problem solving and planning
automatic processing
when some information unconsciously and with no effort goes straight from sensory experience to long term memory
sensory memory
- information picked up by our senses and enters
sensory memory - sensory memory is the initial information processor that selects what details to pay attention to and send to working memory for rehearsal and further processing
ways to process information in working memory
- auditory rehearsal (phonological loop)
- executive function
- visuospatial “sketchpad”
how is information represented in short term/working memory?
- images (visual)
- sounds (phonological)
- meaning (semantic)
- physical action (motor)
capacity of short term/working memory
- the magic number is 7 (+/- 2)
- adults can store between 5 and 9 items in their short-term memory; idea was put forward by Miller (1956)
how can you increase the capacity of short term/working memory?
- chunking!
- combining individual items tinto large units of meaning
duration of short term/working memory?
- shelf life of 20 seconds for information
- rapidly lost unless we actively do something with it
- maintenance rehearsal and elaborative rehearsal
two types of rehearsal for working memory
maintenance rehearsal - simple repetition
elaborative rehearsal - focus on meaning and using memory aid (more effective)
long term memory
- library of durable, long lasting memories
- storage capacity unlimited and can endure for a lifetime
what is the serial position curve?
- is a “U”-shaped learning curve
- normally obtained while recalling a list of words due to the greater accuracy of recall of words from the beginning (primary effect) and end of the list (recency effect) than words from the middle of the list
primacy effect
- an individual’s tendency to better remember the first piece of information they encounter than the information they receive later on
- information stored to LTM
recency effect
- items, ideas, or arguments that came last are remembered more clearly than those that came first
- information is still in short-term memory
explicit memory
- facts and experiences that we can consciously know and recall
- acquired through effortful processing (studying, rehearsing, thinking etc.)
implicit memory
- memories of which we are not fully aware
- acquired through automatic processing (no awareness that memory is being formed)
types of implicit memory
- procedural memory = knowing how to ride a bike
- conditioned associations = taste aversions
- info about space = being able to imagine a room after walking through it
- info about time = able to re-enact sequences
- info about number = aware you’ve 3 police officers on the way to work
effortful processing
information is processed with effort and consciously by the person
automatic processing
- unintentional and requiring minimal attention
3 levels of processing
→ structural: is the word in capitals?
→ phonological: does the word rhyme with course?
→ semantic: does the word fit in the sentence?
what is the self reference effect?
relating material to you to help encode and increase retention
ways to organize information
1.) hierarchy = association and understanding of how elements are related
2.) chunking = combining items into larger units of meaning
3.) mnemonic devices = memory aids to connect info to existing memory
what is the dual coding theory?
- memory enhanced if use both verbal and visual codes
- method of loci = using imaginary physical environment and placement of images
- easier with concrete objects than abstract concepts
memory storage
- memory acts as a web of combinations
- conceptual, contextual and emotional can all be represented
storage priming
activation of one concept leads to activation of another related concepts
what are retrieval cues?
stimuli that lead to activation of stored information in LTM
what is known about retrieval cues?
- multiple cues lead to better retrieval = involves deeper processing
- self generated cues lead to better retrieval = have personal meaning
- retrieval of distinctive events = greater change of etching vivid, clear, long term memories
context-dependent memory
→ the context of where learning occurred can also become part of the memory and used as a retrieval code
→ we retrieve memory more easily when in the same context as we formed the memory
state-dependent memory
→ ability to retrieve is better when internal state at retrieval matches the encoding
→ mood congruent recall = tend to recall information or events congruent with current mood
summary of forgetting
- forgetting can occur at any memory stage
- as we process information, we filter, alter, or lose much of it
what is the course of forgetting?
rapid loss of memory at first then a more gradual decline
why do we forget?
- brain damage
- encoding failure
- storage decay
- retrieval failure
- interference
- motivated forgetting
brain damage as a cause of forgetting
1.) retrograde amnesia: the inability to retrieve memory of the past
2.) anterograde amnesia: the inability to form new long-term memory and explicit memories BUT implicit memory is still intact
encoding failure as a cause of forgetting
information is never encoded into long-term memory
storage decay as a cause of forgetting
- long term physical trace in nervous system fades away over time and with disuse
- tend to see most decay (forgetting) soon after learning
- what doesn’t decay tends to stay intact long term
retrieval failure as a cause of forgetting
- sometimes the memory is intact but the associations and links to the memory are decayed (tip of the tongue phenomenon)
- building multiple associations and links at the time of encoding can help prevent retrieval failure
interference as a cause of forgetting
- information forgotten because other items in LTM impair ability to retrieve it
- proactive interference and retroactive interference
proactive interference
past material interferes with recall of newer material (typing your old password)
retroactive interference
new information interferes with ability to recall older information
motivated forgetting as a cause of forgetting
- choosing to forget or change our memories
- based on the freudian concept of repression
why is motivated forgetting controversial
- difficult to verify
- recall is often full of errors
- people try not to think about painful memories and without this rehearsal, the memories can fade
why is memory a constructive process?
- memories are imagined, selected, changed and rebuilt
- memories are altered every time we “recall”
- memories are altered again when we reconsolidate the memory
- later information alters earlier memories
what is the disinformation effect?
→ distortion of memory by misleading post-event information
what occurred in the Loftus and Palmer study?
- Loftus and Palmer (1974) had participants watch a video of a minor car accident and were asked “how fast were the car going when they ___ into each other” with the answers being “hit” or “smashed”
→ “Hit” = remembered slower speeds and less accidental damage
→ “Smashed” = remembered faster speeds and more accidental damage
what are implanted memories?
- false memories that have been successfully implanted in people’s memories
→once we have an inaccurate memory, we tend to add more imagined details
source monitoring error
when a memory is misattributed to another source
reality monitoring
deciding whether a memory is based on external or internal sources
in what ways can someone recover memories of abuse?
- abuse memories are more likely to be “burned in” memory than forgotten
- accidental reminders can activate a forgotten memory for minor accidents
- actively searching for memories can create detailed memories that feel real
- an implanted, constructed memory can be just as troubling as a memory from a direct experience.
why is the brain not like a hard drive?
- memories are not in isolated files, they’re overlapping neural networks
- the storage capacity is never full, instead gets elaborately rewired and intertwined
3 basic approaches of studying memory
1.) human lesion studies = study memory loss due to brain damage
2.) nonhuman animal lesion studies = deliberate damage to brain regions
3.) brain imaging studies = examine healthy brain as participants perform memory tasks
where in the brain are memories formed?
hippocampus and cerebral cortex
what occurs in the hippocampus?
- encoding station
- convert short term memories to long term memories
- memory consolidation
what is memory consolidation?
binding process in the brain for where something happened, what the scene or people looked like, sounds heard, meaning of events
what occurs in the cerebral cortex?
- encoding information from sensory memory
- store explicit memories
what occurs in the prefrontal cortex?
involved in functions of working
what other brain regions are involved in forming memories?
1.) thalamus: damage results in extensive anterograde and retrograde amnesia
2.) amygdala: emotional aspect of memory
3.) cerebellum: stores conditioned responses
4.) basal ganglia: procedural memory
how do emotions affect memory?
strong emotions, specially stress, can strengthen memory formation
flashbulb memory
refer to emotionally intense events that become “burned in” as a vivid memory
how are emotions, hormones, amygdala and memory connected?
- emotions trigger an increase in stress hormones
- hormones trigger the amygdala, next to the memory-formation hippocampus
- the amygdala increases memory-forming activity and engages the frontal lobes and basal ganglia to “tag” the memory as important
- as a result, the memories are stored with more sensory and emotional detailsq
long term potentiation
when signals are sent across the synapse more efficiently as a result of repetition
→ see a decrease in the prompting needed to send a signal
→ see an increase in the number of neurotransmitter receptor sites
what occurs when long term potentiation is messed up?
- chemicals and shocks that prevent LTP can prevent learning and even erase recent learning
- preventing LTP keeps new memories from consolidating into long-term memories
- drugs that boost LTP help mice learn a maze more quickly and with fewer mistakes
