Memory Flashcards
What is memory?
“the faculty by which the mind stores and remembers information.” - Oxford Dictionary
Memory Processes
Encoding: transforming information into a form that can be entered and retained in memory
Storage: retaining information in memory so that it can used at a later time
Retrieval: recovering information stored in memory so that we are consciously aware of it
Multi-Store Model (MODAL) - Atkinson and Shiffrin (1971)
Auditory and visual information
Stores:
Sensory Memory
Short Term Memory
Long Term Memory
MODAL - Sensory Memory
Store of sensory information
Modality specific - one for each sense
Iconic memory for visual information
Echoic memory for auditory information
- Sperling (1960)
Sensory Memory - Sperling (1960)
Task created by George Sperling:
- Letter array shown for 50ms - after it is gone, tone signals which row to report
- PPs could report 4 letters in partial reports
- PPs recalled more letters when signalled to recall only one row compared to trying to recall all the letters
- Iconic memory appears to decay rapidly
- We can selectively report on the basis of visual properties such as size, colour, brightness or shape
- But not by category (i.e. numbers only, vowels only) so category info is not represented in the icon
MODAL - Short Term Memory
Miller (1965) - Memory Span Test
Miller (1965) - Memory Span Test (STM)
Miller suggested there was a limited capacity for ST memory/attention and that this was approx. 7 items
An item can be a digit or a chunk (i.e. a word)
This allows us to remember short sentences of sets of numbers
Short and Long Term Memory Stores
Since the conceptualization of the MODAL model, people have argued that LTM and STM differ in various ways, and therefore they are separate stores
Differences in STM and LTM
Duration: LTM = Long, STM = Short
Capacity: LTM = Unlimited, STM = Limited
Type of Forgetting: Trace Decat vs. Interference
Forgetting STM
Trace Decay:
- Each item leaves a trace that decays over time so that information is no longer available (letter task and counting backwards)
- If you keep accessing the trace, it stays active
Forgetting - Interference
This suggests memories interfere with each other
We can search our memory, but due to competition end up selecting the wrong memory
We experience a lot, so there is a lot of interference
(While probably a valid explanation for some forgetting, this doesn’t explain most types of it)
Levels of Processing - Craik & Lockhart (1972)
Proposed a number of different levels of processing:
- Shallow/Physical: Detecting specific letters in words; detecting fonts/colours, etc.; detecting sounds (phonemic processing)
- Deep/Semantic: Recalling facts; creating sentences; associations
Info is memorable based on how deep the level of processing is
Elaborate, long-lasting and strong memory traces are produced by deeper levels of analysis
Limitations of the MODAL model
Exaggerates the role of rehearsal
Double dissociation between STM and LTM patients
Multiple Component Views
Working Memory - Baddeley & Hitch (1974)
Replaced the concept of the short term memory (Multi-store model)
More than just passive retention of info - memory operates on information too (storage plus processing; a temporary mental workspace)
Working Memory Model - Baddeley & Hitch (1974); Baddeley (2000-2007)
(WMM)
Central Executive
Phonological Loop
Visuo-Spatial Sketchpad
Episodic Buffer
Central Executive (WMM)
Drives the whole system (e.g. the boss of working memory) and allocates data to the sub-systems
Deals with cognitive tasks, i.e. mental arithmetic and problem solving
The central executive decides what working memory pays attention to
Arguably nothing to do with memory, but more with attention
Limited capacity
Phonological Loop (WMM)
Conceptualized as the “inner ear”
Two components:
- Phonological store - concerned with speech perception
- Articulatory control processes - concerned with speech production; rehearsal
Phonological similarity effect - Conrad (1964)
Word-length effect - Baddeley et al. (1975, 2002)
Phonological Similarity Effect
Conrad (1964)
Recall 25% worse with a phonologically similar list compared to a dissimilar list
Suggests speech-based rehearsal processes within the phonological loop
Word-Length Effect
Memory span is lower for words taking a long time to say, based on results from memory span task
- Participants tried to recall as many words as possible in the correct order given a fixed deadline
Baddeley et al. (1975, 2002):
- Articulatory suppression eliminated the word-length effect
- Word length effect persists even when output delay is controlled by using a recognition-memory test
- Suggests that capacity of phonological loop is determined by temporal duration
Visuo-Spatial Sketchpad (WMM)
Conceptualized as the “inner eye”
Used in the temporary storage and manipulation of spatial and visual information
- Visual information travels through this sketchpad
Involved in keeping track of where we are in relation to other objects as we move through our environment
Logie (1995)
- Argues there are two components of visuo-spatial working memory: Visual cache and inner scribe
Visual Cache (Logie, 1995)
Stores information about visual form and colour
A component of the visuo-spatial sketchpad
Inner Scribe (Logie, 1995)
Processes spatial environment information
Involved in rehearsal of information in visual cache
Transfers information from the cache to the central executive
A component of the visuo-spatial sketchpad
Episodic Buffer (WMM)
Baddeley (2000-2007)
- Integrative tool
- Explains how long-term memory can influence processing in STM
Episodic Buffer - Baddeley & Wilson (2002)
- Limited capacity system
Integrates information from a range of sources
- Acts as an intermediary between the phonological loop and the VSS
- A process of active binding
Limitations of the Episodic Buffer (WMM)
Unclear how all different information is integrated
Limited work on smell and taste memory
Long Term Memory
Unlimited capacity
Information lost due to interference more than decay
Encoding:
- Elaborative rehearsal
- Levels of processing - Semantic is more effective than visual or acoustic processing (Craik & Tulving, 1975)
- Self-referent effect - by viewing new info as relevant to the self, we consider that info more fully and are able to recall it
LTM - Capacity
Unlimited
Supporting evidence:
- Penfields neural stimulation
- Permanent storage? - Flashbulb memories (Brown & Kulick, 1977); Assassinations study (Talarico & Rubin, 2003); etc.
Flashbulb Memories
Vivid detailed memories that people have of certain dramatic world events (e.g. death of princess Diana, Kennedy assassination)
Brown and Kulick (1977):
- Argued that flashbuld memories are different from other memories in their longevity, accuracy and reliance on a special neural mechanism
Is flashbulb memory just strong LTM?
Bohannon (1988) - The Challenger Disaster:
- 2 weeks later recall was reduced to 77%, by 8 months 58%
- Decays like normal memory
- Stored in LTM, especially as it includes a strong emotional cue
- Amygdala (emotion centre of the brain) is used in laying down LTM
Criticism/Arguments:
- Conway et al. (1994)
- Talarico & Rubin (2003)
Flashbulb Memory - Conway (1994)
Argued that Bohannon’s study did not use an event that people felt impacted on their lives
He looked at the resignation af Margaret Thatcher in 1990
Flashbulb memories present in 86% of British participants compared with only 29% of European participants
Suggests that Bohannon’s findings were due to a lack of emotional attachment to the event
Flashbulb Memory - Talarico & Rubin (2003)
On the day after the event occurred, they asked 54 students to record their memories of the 9/11 attack, as well as recording a recent everday event
Participants were tested over 1, 6 or 32 weeks
Flashbulb memories decayed the same as everyday memories
Ratings for belief in accuracy, vividness and recollection only declined for the everyday memory
Participants “felt” that the flashbulb memory was stronger
Overview of Flashbulb Memory
Conway (1994) suggest it depends on:
- Prior knowledge, personal importance, surprise and emotion, and overt rehearsal
Deep levels of processing and elaborative rehearsal can mean that the events surrounding the tradgedy become more salient
Elaborative Rehearsal
A technique for transferring information into long-term memory by thinking about it in a deeper way
Levels of Processing
Semantic is more effective than visual or acoustic processing
Craik & Tulving (1975)
Self-Referent Effect
By viewing new info as relevant to the self, we consider that info more fully and are better able to recal it
Types of LTM
Explicit/Declaritive memory - Two types of declarative memory:
- Semantic
- Episodic
Autobiographical memory
Implicit/Procedural Memory
Explicit/Declarative Memory
Type of LTM
A memory that requires conscious recollection of information/a memory you can explain
Two types of declarative memory:
- Semantic
- Episodic
Semantic Memory
A type if declarative memory
Do not relate to a particular place or tiem
General encyclopaedic knowledge of the world and language
For example: meaings, relationships, rules, procedures, concepts, etc.
Episodic Memory
A type of declarative memory
Memories for episodes or events in our lives
For example: First day of school, GCSE results day, etc.
They are all events that occur at a particular place and time
For example, autobiographical memories are episodic memories
Autobiographical Memory
“Memory for events in ones life”
Similar to episodic memories in that it is about life events
Different to episodic memories - everday events, such as what you had for lunch yesterday, are unlikely to be included as autobiographical memory
- They must include some emotional response
Rubin, Wetzler & Nebes (1986) - Memories across the lifespan
Self Memory System - Conway & Playdell-Pearce (2000)
Memories across the lifespan - Rubin, Wetzler & Nebes (1986)
Infantile amnesia - lack of memories prior to 3 years old
Reminiscence bump - surprisingly large number of memories coming from between the ages of 10 and 30 when over 40
Retention for memories up to 20 years old with older memories being less likely to be recalled
Self Memory System
Conway and Pleydell-Pearce (2000)
Tried to narrow down what is special about autobiographical memory and how it might function:
- Contains an autobiographical knowledge base and the current goals of the working self
- Autobiographical knowledge contains info about lifetime periods and general events
- Working self - set of LTM schemas about the self which are in operation at any one time in a similar manner to working memory
Implicit/Procedural Memory
Non-conscious memory
“…is revealed when performance on a task is facilitated in the absence of conscious recollection” - Graf & Schacter (1985)
“knowing how…”
Refers to learned skills, for example, juggling, riding a bike, walking
These can become automated and require little attention (automaticity)
What is retrieval?
Process that controls flow of information from long term to working memory store
Retrieval - Explicit Memory
The types of memory elicited through the conscious retrieval of recollections in response to direct questions
- Recall tests: subject must reproduce information
- Free recall: Cued recall
Recognition vs. Recall
Tip of the tongue phenomenon: Recognising someone’s name is possible even when unable to recall the name - Brown & McNeil (1966)
Number of cues: More cues for recognition tasks
Marginal knowledge - Cantor et al. (2014)
- Can only be retrieved when given an appropriate memory cue
Retrieval: Getting information out of a new memory
Are memories reconstructions influenced by new information?
Barlett memory research (1932)
Loftus and Palmer (1974)
Barlett Memory Research (1932)
War of the Ghosts (Serial recall)
Memories shaped to conform to our personal beliefs
Memories recalled are not copies, but reconstructions
Tip of the tongue phenomenon
A failure in retrieval
Cannot recall the word, but can recall words of a similar form or meaning
Brown and McNeil (1966)
- Subjects given definitions to low-frequency words
- Attempt to recall word associated with definition
Recall can be guided by partial word info
Loftus and Palmer (1974)
PPs watch video of car collisions at different speeds
Asked “How fast were the cars travelling when they ____ into each other?”
Recalled speed influenced by the verb used (i.e. hit, smashed)
Recollection of the visual scene (i.e. broken glass) also affected
Context Cues
Godden & Baddeley (1975)
Free-recall experiment:
- Divers learned words from lists in two natural environments: dry land and underwater
- Words recalled in location of learning, or the alternative
Lists learned underwater are recalled better underwater, and vice versa
Lack of encoding (forgetting in LTM)
Often, we do not even encode the features necessary to ‘remember’ an object/event (i.e. details on a coin)
Do we forget what we were told, or not encode the information in enough detail?
Forgetting in LTM - Decay
Memory traces arode with the passage of time
- Jenkins & Dallenbach (1924):
- Examined memory recall of non-existing syllables
- Recall better after sleep
- Emphasis on ‘interference’ rather than ‘decay’
This is no longer a valid theory of forgetting in LTM
- Lack of physiological evidence for LTM’s decaying
- Older memories are not forgotten first
Forgetting in LTM - Interference
Some memories ‘interfere’ with other memories
Interference is stronger when material is similar
Two types of interference:
1) Proactive interference - Interference when retrieving new memories
2) Retroactive interference - Interference when retrieving old memories
Proactive Interference
Old memories interfere with ability to remember new memories
For example:
- Knowledge of the boundaries on a tennis court (may forget the boundaries of the court are larger in doubles if you are used to playing singles)
Retroactive Interference
New memories interfere with ability to remember old memories
Amnesia
A lot of our early knowledge about memory comes from patient case studies, such as H.M. or Clive Wearing
Amnesia Case Study - H.M.
Milner, Corkin and Teuber (1968)
Became amnesic in 1953 following a bilateral removal in the hippocampal zone (failed attempt at curing his epilepsy)
- Can remember childhood events (Scoville & Milner, 1957)
- Memory generally poor for events after the operation
“everyday is alone in itself, whatever enjoyment I’ve had, whatever sorrow I’ve had” (p. 217) - Milner, Corkin & Teuber (1968)
Amnesia Example - Clive Wearing
British musician and conductor
Acute and long-lasting case of anterograde and retrograde amnesia
- This means he lacks both the ability to form new memories and to recall some aspects of his past memories
Herpes virus attacked CNS damaging his hippocampus
He “wakes up” every 20 sec. and has no knowledge of ever learning music, but he can still play pian
Amnesia - Korsakoff Syndrome
This has been studied a lot
Alcohol related problem in metabolizing the vitamin thiamine, which leads to brain damage in areas of the hippocampus and diencephalon, resulting in loss of episodic memory
But, the amnesia from Korsakoffs is “less pure” as there is also subtle damage to other areas including frontal lobes - Cermak (1976)
Gradual onset and more widespread damage makes it harder to interpret findings
Limitations of Korsakoff patients in studying amnesia
Gradual onset
Widespread brain damage
Inconsistent in which areas of the brain are affected
Brain plasticity
Types of Amnesia
Retrograde amnesia
Anterograded amnesia
Retrograde Amnesia
Particularly affects episodic memories compared with semantic memories - Spiers et al. (2001)
Usually associated with damage to cortical and noecortical structures
Inability to recall information/events from before the critical incident
Often can occur with anterograde amnesia
Retrograde amnesia without anterograde amnesia is called Focal Retrograde Amnesia
Seems to be a problem in retrieval of information
Assessment is difficult - what questions can we ask to test this?
Less work on this as it is less common
Kapur, Young, Bateman & Kennedy (1989)
Russell (1935)
Temporal gradient of amnesia = Ribots’s law
Anterograde Amnesia
Problem with consolidation of memories - Isaac & Mayes (1999)
Could be caused by damage to subcortical areas
Kapur, Young, Bateman & Kennedy (1989) - Retrograde amnesia
Patient (E.D.) examined 5 years after diagnosis of retrograde amnesia
Selective deficit for public figures/events in the past 20-30 years (but fine on famous cars)
No anterograde amnesia
EEG - Temporal lobe abnormality
No structural lesion or dementia
Russell (1935) - Retrograde amnesia
Shrinking retrograde amnesia
Older memories return before more recent ones (See consolidation)
Ribot’s law
Temporal gradient of amnesia = Ribot’s law
Ribot’s law states that recent memories are more likely to be lost than the more remote memories
This is the typical finding for retrograde amnesia
Butters and Cermak (1986)
Butters and Cermak (1986) - Ribot’s law
PZ - experimental psychologist, completed memoirs before contracting Korsakoff
Memoirs enabled estimation of events and of how long he had known people
The earlier the info had occurred, the better recall he had from it
Retrograde Amnesia and Consolidation
The temporal gradient of retrograde amnesia and the link to hippocampus damage led to theories about how memories might be consolidated
Consolidation:
- Is this process in the brain that makes the memory for an event enduring
- It refers to the process of info being transferred from one region of the brain to another and gradual re-organisation of brain regions to support memory
- Maybe recent memories (before incident) are less consolidated
Models of Consolidation (amnesia)
A number of models (including the Standard Model by Squire, Cohen and Nadel, 1984)
All argue that retrograde amnesia is due to problems with consolidation
2 broad processes:
- Hippocampal consolidation
- Systems consolidation
The central idea is that LTM are stored in the cortex (outer layer of the brain) via some form of trace
Forming the trace takes time as different cortical sites cannot initially communicate
The hippocampus acts as a temporary memory and also then facilitates communication between different sites in the cortex to enable a cortical trace to be established that supports the memory
The interaction between the hippocampus and (neo)cortical regions is therefore crucial in supporting the formation of memories
Continued activation (offline or through rehearsal) of these memories graduall enables these different cortical sites to communicate
The process of consolidation then continues in cortical areas, but the hippocampus is no longer needed - Ribot’s law
