Human Memory Systems Flashcards
define memory
- the ability to store and retrieve information over time
-There are different types of memory that are stored differently in the brain.
brain plasticity
from age 0 to 12 years
Types of Memory:
- iconic memory
- any modality - touch, vision, sound
- immediate and continue for under a second
- short-term memory - always conscious
- info held for less than 30 seconds,
- through rehearsal (sub-vocal),
- capacity; 7(-2/+2) items,
- interference = preservation - limits capacity due to competition of resources
- working memory - always conscious
- modern term for short-term memory
- gut instinct
- intermediate-term memory
- from 30 sec to 2 weeks
- e.g. what you had for breakfast
- from 30 sec to 2 weeks
- long-term memory
- invite connections
- episodic memory (autobiographical)
- events - personal
- semantic memory
- facts
- declarative memory
- can be either semantic or episodic = info that you know
- retrieval failure
- procedural memory
- actions - non-conscious
- prospective memory
- future intentions
- 30 active intentions
- automatic = unconscious
Memory components
- phonological loop
- visuospatial cortex
- smell - unconsciously
- central executive
- iconic memory
- any modality - touch, vision, sound
- immediate and continue for under a second
- short-term memory - always conscious
- info held for less than 30 seconds,
- through rehearsal (sub-vocal),
- capacity; 7(-2/+2) items,
- interference = preservation - limits capacity due to competition of resources
- working memory - always conscious
- modern term for short-term memory
- gut instinct
- intermediate-term memory
- from 30 sec to 2 weeks
- e.g. what you had for breakfast
- from 30 sec to 2 weeks
- long-term memory
- invite connections
- episodic memory (autobiographical)
- events - personal
- semantic memory
- facts
- declarative memory
- can be either semantic or episodic = info that you know
- retrieval failure
- procedural memory
- actions - non-conscious
- prospective memory
- future intentions
- 30 active intentions
- automatic = unconscious
- iconic memory
dissociation and double dissociation
- help to identify neural substrates of various brain functions.
- It explains how brain damage or lesions can affect different types of memory functions.
Dissociation
- When you know localisation of brain damage or lesion and find that one function is knocked out but other related functions are preserved
- e.g. individual looses ability to name category of animals but can name all other objects.
double dissociation:
-functional loss in a brain area
- Lesion in specific brain area impairs function x but not y then demonstrate that lesion of separate brain area impairs y but not x.
-Patternson & Plaut “the gold standard was always a double dissociation” (2009)
Outline the three key processes in memory:
-encoding
-storage
-retrieval
encoding
- processes occurring during initial encounter with to be remembered stimulus = stage 1
- process it through senses or relate to yourself
storage
- attention via central executive → working memory → intemediate → LTM
retrieval
- recovering stored info from the memory system = stage 3
Forgetting can result from…
-a failure in any of key stages in memory (ESR), rather than a process in itself
recognition memory:
retrieval hard despite knowing it so hard to retrieve
-> tip of the tongue phenomenon
The Multi-Store model of memory by Atkinson & Shiffrin (1974), which includes:
- sensory inputs → sensory store + encoding → short-term memory + rehearsal → ←long-term memory + retrieval
Sensory Memory:
- Auditory (echoic)
- holds info for approx 3 sec
- visual (iconic) memory
- holds info for approx. 250 ms
Short Term Memory:
-Now termed as working memory by Baddeley & Hitch (1974)
- Three components:
1. the central executive; resembles what we would call ‘attention’
2. phonological loop; holds info in a speech-based form
3. visuo-spatial sketchpad; specialised for holding visual and spatial info
Working Memory:
- Working memory is more dynamic than unitary STM
- with a limited capacity (differentiates it from long-term memory which is unlimited in capacity and duration of storage)
- usually found that we can only store around 7+/- 2 pieces of info in memory (Miller, 1956)
- chunking - grouping bits of info to make remembering easier
Double Dissociation in Memory:
- Explores whether short-term and long-term memories are distinct?
- If they are we would presumably see patients with impaired STM and preserved LTM?
- If we also saw the reverse pattern preserved STM and impaired LTM this would be an example of a double dissociation.
- Researchers and clinicians have found this pattern to be supported.
- E.G. KF = patient with impaired STM but fine LTM
(Shallice & Warrington, 1970) - single association
- E.G. KF = patient with impaired STM but fine LTM
Interference in WM
- Traces only remain in WM with repeated rehearsal (i.e. attending to the information)
- They are therefore prone to interference
Retroactive interference:
- New information interferes with the retention of old information in WM (trying to remember your old phone number, having used your new number for a few months; finding it difficult to revert back to manual gear changes having recently been shown how to use an automatic)
Proactive interference:
- Old information interferes with the recall of new information (mistakenly giving your old phone number instead of your new one; attempting to change gears manually in a newly bought automatic)
Primacy-Recency Effect:
- Primacy-Recency or the Serial Position Effect
- When presented information in serial order, we remember more from the beginning and end of the list, at the expense of the intermediate items
Craik & Lockhart (1972) on levels of processing
- Depth of encoding determines later memory for information
- Processing at encoding can be shallow or deep. -The greater the processing the meaning of stimuli at encoding the deeper the level of processing and greater likelihood of later storage and retrieval.
- Importantly Craik & Lockhart disagree that rehersal will improve LTM as it just repeats previous operation.
- BUT rehersal has beneficial effects but they are small and not for every type of memory e.g. Prospective Memory may not benefit.
Long Term Memory:
- There is a transfer process from working memory to long-term memory - as a result of rehearsal and elaboration
- very large capacity
- storage can be for a few minutes but in theory can be for a lifetime
- In general, meaning is encoded rather than exact representation (Sachs, 1960s)
Storage into long-term memory is known as…
-consolidation
Consolidation
- Involves structural change: the pattern of neural pathways are changed
- Long term potentiation: strengthening of synapses, believed to be the cellular foundation for memory
- Research in to how to induce LTP useful for dementia treatment
- Rats given NMDA receptor antagonists display memory deficits. Mice bred with enhanced NMDA function show greater LTP and better memory
-Requires metabolic activity for minutes/hours after the stimulus has been presented
- Rats given NMDA receptor antagonists display memory deficits. Mice bred with enhanced NMDA function show greater LTP and better memory
which brain region is involved in consolidation
hippocampus
what is required for Retrieval?
- Cue required (e.g. prompt, reminder, question)
- Original stimulus reconstructed using information from cue
- The more information available, the easier the retrieval
what aids retrieval?
- A good ‘filing system’:
- e.g. mnemonic’s (memory aids, Method of Loci)
- Make something personally relevant to you and you’re more likely to remember it
what can retrieval be affected by?
- interference
- Proactive - new phone number replaces old number
- Retroactive - old route home blocks new route home
Factors Affecting Retrieval:
- Levels of processing,
- the more something is elaborated at time of encoding the easier it will be to retrieve
- organization,
- of concets in memory (also associations between concepts stored inLTM may facilitate recall)
- context,
- being in the same place/emotional state as time of encoding facilities recall
- state-dependent memory
- being in the same place/emotional state as time of encoding facilities recall
state/emotion dependent recall
- Information is better recalled when the individual is in the same state during encoding and retrieval
- this includes both the environment and their internal mental state
- E.G. works with drugs and alcohol too (Weissenborn 2000).
- Godden & Baddely 1975 - Divers learned words on land and underwater - recall was best when the learning environment matched the retrieval environment.
Declarative (explicit) memory
- Memory for facts, for information that can be conveyed by statements
- Involves conscious recollection of events / facts
- Encompasses semantic and episodic memories
- e.g. Your birthday
Non-declarative (implicit) memory
- Generally doesn’t involve conscious recollection e.g. procedural memory
- Priming Subtle; subtle cues/hints
procedural memory
- Memory for skills and actions
- often in the absence of conscious recollection
- e.g. how do you tie your shoelaces?
name types of declarative memory
Semantic & Episodic Memory
semantic memory
- facts and ideas
- what is the capital of Peru?
- the meaning of the word ‘DOG’
episodic memory
- Memory for events, situations - centered around you
- your first day at university
- what did you have for breakfast today?
Episodic/Autobiographical Memory:
- Most episodic memory decline over time however decline is not uniform over all memories e.g.
- Bahrick et al (1975) - memories of student days showed remarkable preservation -
Reminiscence bump
- Surprising perseverance of memories occurring between ages of 10 and 30. Why?
- early childhood amnesia = priming ⇒ attention bias
– Stability of early adulthood memories is remarkable as…
-> Majority of first time experiences.
- early childhood amnesia = priming ⇒ attention bias
why are novel experiences memorable?
because of the lack of proactive interference from previous learnings
evidence for reminiscence bump
- More evidence for reminiscence bump for positive than negative memories (Bertsen & Ruben, 2002).
Flashbulb memory
detailed and extremely vivid memories regarding circumstances surrounding very shocking event e.g. September 11th
-Only occur with shocking and emotionally significant events. Evolutionarily adaptive?
what enhances retention?
-Emotional arousal during encoding
-Also frequently rehearsed and talked about
Recognition
- Sensing that a stimulus has been previously encountered, sense of familiarity
- Generally easier than recall, as information is contained in the cue
- Recognition can be direct from a set stimuli or from a mental search of LTM store
Recall
- Reconstruction of a stimulus using the information available from the cue and information from LTM
- Checked by the process of recognition
- Greater ‘cognitive demand’ than recognition
- Recall can be direct from the cue or arise after problem-solving strategies have been employed
recall and recognition are entirely stable. True or False?
False - can be inaccurate
Eye Witness Reports (Loftus, 1979)
- Participants watch a film of an accident, one includes a STOP sign, the other a YIELD sign. Using specific wording, you can change people’s memory:
- ‘How big was the stop sign by the road?’
- The participant won’t remember the fact that they saw a yield sign
- ‘How big was the stop sign by the road?’
The main causes of forgetting from either working memory or long-term memory:
- Passage of time
- Rapid decay of information from WM
- Cell death leads to loss of LTM (can be accelerated e.g. dementia)
- Interference
- Interference to storage in WM e.g. pro-/retroactive
- Connections are remolded over time in LTM, influenced by pro- and retroactive interference of information
Infantile amnasesia
inability to remember events
from early childhood.
ageing affects memory
- Generally people can not remember anything before 2 years.
- First memories usually occur between 2 and 5 years.
- Probably because brain regions responsible for episodic memory are not sufficiently developed.
- Reminiscence bump = preserved memories for 10 to 30 years (many first time occurances)
Normative ageing
- Speed of processing declines (Perfect, 1994)
- Memory declines and forgetfulness increases but shouldn’t interfere with ongoing functioning
