Models of Memory

Information Processing
Stages of information reception, storage, retrieval, transfer.

Sensory Memory
Short Term / Working Memory

Long Term
encoding / learning
storage / holding on to
retrieval / remembering

Types of Memory (systems of organisation/data bases)

explicit vs. implicit memories
recall vs. recognition

Encoding specificity
Context & State Dependent Memory

Amnesia / forgetting & the brain
anterograde vs. retrograde

The self and Memory
Brief History
Autobiographical memory

Episodic Memory
Identity Crisis

Reconstruction of memory
totalitarian ego
FMS & Crime Reporting

Models of Memory
What is it? Various Metaphors:

A place where we leave things? A tape recorder?

An activity / behaviour, hologram, electrical network?

Information Processing: A computer model
(New form of Behaviourism?)

Various Levels of information

Reception - 'cognitive' memory models show information being processes at the sensory level (perception) where initial organization occurs.

Attention - Draws awareness (late selection Cocktail Party phenom.) for further (deeper) processing and encoding.

Storage - 'place' models of memory indicate that there are three main storage sites: sensory, short-term, & long-term.

Retrieval - depending on the 'input' organisation, information may be recovered or left behind.

Transfer - once stored, information can be moved and reformatted into other 'data bases' and systems.

Memory Stores (place model)
Sensory >> Short Term>>>>> Long Term

Sensory Memory - Information received by sensory neurons is held in storage for very brief periods of time.

Iconic - (visual) memory held as icons in eyes for about 300 - 1000 milliseconds. Trailing light from sparkler.

Classic Study: Sperling (1960) gave auditory cue to recall 1 of 3 lines and found that capacity is about 10 items not five for a 200 ms 'partial report' of 12 items. Echoic- (auditory) memory held only a few echoes for about 2 or 3 seconds.

Short Term - Working memory requires resources: (using attention can keep working on it for some time).

Capacity - has been found to be about 7+2 by George Miller (1956). Limited capacity, attention-working storage.

Chunking can improve capacity by placing many into few

Maintenance Rehearsal can also help to keep those items in storage for longer than 10-20 seconds. Repetition!

Baddeley (1992). Two types of working memory. Tends to function on verbal/sound basis: homophonic errors but also have visuo-spatial working memory.

Note: Requires "Central Executive" or Homunculus!

Serial Position - Early and later items in a list are remembered best, suggesting limited capacity working model of memory. Revealing "U" shaped curve.

Early items get more work before getting 'bumped' late one still in store, not displaced by 'newer' items. Distinctive?  Demonstration

Long Term Memory

Encoding / learning - beyond early organisation.

Craik & Tulving (1975) get elaborative rehearsal that tends to get at meaning and "deeper" conceptual levels of processing than surface sight or sound - words & faces.

"Self referencing", "over learning" & "spacing effect"

Storage / holding on to information through semantic-verbal, visual, acoustical, olfactory, emotional,...

Semantic Networks - Priming and spreading activation of thought and concepts through the networks.

Memory Systems (data bases)

Procedural - Know How - Actions, processes, rules, ...

Declarative - Knowing That  - Semantic meaning through language specific statements of fact.


Explicit memories - those of which one is fully conscious

Recognition - identifying items from memory based upon the cueing or selection of them from a collection of others

Recall - reporting the contents of memory verbatim, or with minimal cueing. Self-generated

Improve Recall - through Practice and Elaborative Rehearsal (critical, related to self, hierarchical organisation-outline or schema)
- Also verbal mnemonics, methods of loci, peg-word.

Interference reduction- increase recall through reduced confusion. Block / separate domains, practice

How does storage work?
Synaptic changes
Long-term Potentiation is an increase in synapse’s firing potential after brief, rapid stimulation. Single Nerve Cells are altered and Glutamate is a key neurotransmitter invovled in LTP.

Limbic System (and Olfaction) Strong emotions make for stronger memories some stress hormones boost learning and retention.

This has implications for PTSD and memory for other stressful events such as "flashbulb memories" like when 911 happened.

However, prolongued stress may deteriorate memory.

Sleep and dreaming is a time when our memories get improved - mental housekeeping. Recent study shows the reversal of memory loss due to sleep deprivation.

Why we forget: Forgetting curve

1. Decay: Initially thought that memory fades in time, now is thought that with sleep there is interference & inhibition

2.Interference: two kinds

Proactive Interference occurs when first learned items reduce the recall of more recently learned items. (older interferes with newer).

Retroactive Interference - occurs when newer items reduce recall of older items. Recently learned stops previous items

3. Encoding Specificity

Context dependent memory - where memory is tied or linked to the place or situation in which it was encoded

State dependent memory - where memory is tied or linked to the psychological state (of consciousness) during encoding. Similarity of mood or state shows in recall.

4. Head Trauma . ...

Amnesia & the Brain

Retrograde - loss of memory for events that took place prior to brain damage / surgery

Anterograde - loss of memory for events that occur after the surgery. Suggests that hippocampus is involved in memory consolidation - the transfer from STM to LTM.

E.g. Brenda Milner's Case of H.M. - some retrograde, but sever anterograde following surgery of medial lateral temporal lobe. could still complete words E.g., k---ht, & kni--.  Priming works here.

Clive Waring  30 second memory    Video part 2 3 

Implicit memories - 'unconscious' memory where behaviour or performance is altered by experience.

Hippocampus is important for declarative & spatial memories. E.g, some birds have larger hippocampi and Taxi Drivers have larger posterior hippocampi

Implicit Memory in Everyday Life
Retention without awareness leads to:
1. False Fame Effect - think people are famous
2. Illusion of Truth - familiar must be true
3. Eyewitness Transfer - mug shot recognition
4. Unintentional plagiarism - forget the source

Prefrontal Cortex Damage - loss of memory for temporal order. E.g., Which face was seen most recently? Also difficulties with Self-ordered tasks (some done, some not)

Memory loss also due to ECT, Concussion, Alcohol, …

->Equipotentiality of all sites in brain needed for memory.

The Self and Memory

A brief history of self....

Locke - memories are the ties from the present self to past and future selves. Prince and pauper, memory & plan.

Artificial Intelligence - Daniel Dennett suggests that functional properties of memories constitute consciousness which can be recognised in machines (computers) e.g. self-reflection or self-reference = consciousness  or reacting to environment?

 Autobiographical memory

Episodic Memory - Memories that are recorded and accessed with reference to one's own life experiences. This temporal memory is marked by 'episodes'.

Generally recall more recent than distant memories, except for "reminiscence peaks," E.g., firsts, flashbulbs, childhood amnesia (not prior to 3).

Identity Crisis - Loss of access to or willingness to participate in past selves. Taking on new roles and relations, ideas and ideologies, ways of living.

Reconstruction of memory Greenwald (1980) suggests we have a totalitarian ego which revises our history to make self more important

Hindsight bias occurs when we knew how things would work out, but only after it has happened.

Bartlett (1932) - Retelling stories people made errors

Eliminated or changed details - added others details to make it more coherent - even with a "moral" to the story.

-Report "Gist" of scenario eg. 'office'

Memory is a reconstructive process -when remembering complex information we alter it to help us make sense of it, based upon what we already know. (e.g., HM made up stories to account for the candy wrapper he found.

Can we trust Eyewitness Testimony? 2022 2021 2020 - 2019 - 2018 - The Event 2014 RECALL12 2011 Leading Questons

We tend to observe some events and fill in the other details (i.e., closure, fill colour. make use of schemas, ...)

Loftus & Palmer (1974) viewed film of a car accident - then asked what were average speed estimates when cars:

smashed,  collided, bumped, hit, contacted
40.8 39.3 38.1 34.0 31.8 

other leading questions were: THE or A broken headlight

Children as Eyewitnesses: Ceci & Bruck (1993, 1995) show that most young children do recollect accurately, however, with leading questions will get some alterations (e.g., when asked about a visit to the doctor, they say yes when they were not touched etc.)

pre-schoolers are more susceptible, where there is more blurring of reality and fantasy.

desire to please the interviewer may also lead them to say that they were hugged and kissed, photographed and bathed while at the doctors office

What leads to Confabulation ?
(& the misinformation effect)
1. Thought about the imagined event many times
(e.g., same stories come up a parties again and again)

2. Imagined event contains a lot of details
(complex - easy to add or forget details)

3. Event is easy to imagine
(easy to confuse image with reality)

4. Rememberer focuses his/her emotional reactions to the event rather than on what really happened

(a strong feeling is not a reliable cue) (other elements: weapon focus, schemas, transference, wording, line-up composition & instructions, confidence)

False Memory Syndrome Controversy

In 1992 the foundation was established by parents and John's Hopkins Medical Institute to

"document and study the problem of families that were being shattered when adult children suddenly claimed to have recovered repressed memories of childhood sexual abuse." FMSF (2000) It was believed that certain (feminist) therapists were coaching clients into creating false memories of events that never actually happened.

Freud (1895) published the seduction theory of neurosis, two years later retracted the seduction hypothesis because unconscious cannot distinguish reality from fantasy.

Masson (1984) suggested that Freud was trying to 'cover up' for his own father and his friend Fleiss in retraction Traumatic therapies can have long-lasting effects on mental health

Remembering Dangerously

Loftus (1995) suggests that "Like witch-hunt trials of old, people are being accused and even imprisoned on 'evidence' provided by memories of dreams and flashbacks"

Memory is easily altered through misinformation, as was the case for 29% of subjects with "lost in mall story" in two follow up interviews.