Memory Flashcards
Encoding
Memory
How information is taken in and recorded
Capacity
memory
How much information can be taken in and held
Duration
memory
How long information can be held
Sensory memory
encoding
capacity
duration
and examples
Encodes: based on senses
Capacity: large
Duration: less than 3 seconds
Takes information from the sense organs and holds them in that same form
Echoic memory - Auditory input from the ears - things you hear - stored as sounds
Iconic memory - visual info from the eyes - things you see - stored as images
Sensory memory research on capacity
Sperling experiment 1960:
* Presented with grid of letters for less than a second
* Sperling used tones to cue participants to recall a specific row
* Recall on the specified row was high
Demonstrates we have a large capacity in sensory memory
Short term memory
encoding
capacity
duration
Encodes: Acoustically
Capacity: 5-9 items
Duration: 18-30s
Encoding in STM experiment
Conrad (1964)
Visually presented students with letters one at a time
Found that letters which are acoustically similar (rhyming) are harder to recall from STM than those which are acoustically dissimilar (non rhyming)
This suggests STM mainly encodes things acoustically (as sounds) even though the items were presented visually
Capacity of STM research
Miller (1956)
STM can hold 5-9 items of information
Capacity can be extended by organising separate bits of information into chunks
CHUNKING involves making the info more meaningful, through organising it in line with existing knowledge from your LTM
Duration of STM experiment
Temporary- very short time
May only last a few seconds if we don’t rehearse it
Peterson & Peterson (1959)
* Got students to recall combinations of 3 letters (trigrams), after longer and longer intervals
* During the intervals, students were prevented from rehearsing by a counting task
Duration is 18-30s
Long term memory
encoding
capacity
duration
Encodes: Semantically (meaning based)
Capacity: Potentially unlimited
Duration: Anything up to a lifetime
Encoding in LTM experiment
Baddeley (1966)
Presented with lists of 10 short words one at a time
Some lists were semantically similar, others not
Tested immediately and then after 20 min delay
Found that after 20 mins, they did poorly on semantically similar words
Suggests we encode LTMs according to what they mean - so we get similar-meaning things confused
Duration of LTM experiment
Anything up to a lifetime (minutes to years)
Difficult to test exact duration but
* Bahrick et al. (1975) tested US graduates
* Shown classmate photos years later
* 90% accuracy for remembering faces & names 34 years after graduation
Declined after 48 years, particularly for faces
Positive of Multi store model of memory
The first model of memory is positive as it was the first to establish that memory has constituent parts, and can be broken down into sensory memory, STM, and LTM. It contrasts to prior ideas that memory was only one unknown system. It also suggests that there is more than one type of rehearsal. There is a difference between the rehearsal loop, used to keep memories in STM for longer, and elaborative rehearsal, which moves memories from STM to LTM.
It allows for future models, provided clear direction for research.
Limitation of Multi store model of memory.
- oversimplified.
- It incorrectly suggests that STM and LTM operate in a single and uniform way. It is know understood that STM and LTM are more complicated and may be split down into further separated stores.
- Model is a reductionist explanation of memory.
- oversimplifies the role of rehearsal. The model ignores factors such as motivation, effect and strategy (eg acronyms and pneumonic) that underpin learning. This essentially means that if you know that you are going to need to recall information for a test, you are more motivated to practice the information and find ways to transfer into your LTM. Rehearsal is also non essential for moving information into LTM.
How can the study of HM be applied to the multi store model of memory
HM supports the model as he shows memory can be split into constituent parts (sensory, STM, LTM), and that information must move between them. HM’s STM was in tact because he could remember a word up to 15 mins if rehearsing, and 5 mins if not. HM is not moving any info from STM to LTM after the operation, but he still had memories from more than 10 years before the surgery, so LTM, is in tact to some degree.
However, it may be unethical to complete case studies on people with retrograde amnesia, as they cannot understand what is happening to them. As they will likely forget what has been said to them, they can never fully consent to the research.
Why does flashbulb memory contradict the multi-store model of memory
A flashbulb memory is a highly vivid and detailed ‘snapshot’ of a moment in which a consequential, surprising and emotionally arousing piece of news was learned. The model does not take flashbulb memories into account as it does the model says that you have to do rehearsal in order for a memory to transfer from STM to LTM. Flashbulb memory suggests that this is not true.
Capacity of sensory memory
Information is stored in an unprocessed form
Transferred to short term memory through attention
Crowder 1993:
Sensory register retains iconic information for a few milliseconds
Echoic store lasts 2-3 seconds
What is the working model of memory split into
- Central exexutive
- Phonological loop
- Episodic buffer
- Visuo-spatial sketch pad
The working model of memory
Phonological loop
Phonological store - Uses a sound based code to store information, but this information decays after about 2 seconds, unless it is rehearsed by the articulacy loop.
Articulatory loop - Rehearses information verbally and has a time based capacity of about 2 seconds. It is the system that you use to mentally rehearse stuff by repeating it over and over again.
The working model of memory
The visuo-spatial sketchpad
- Stores and manipulates visual information, input is from the eyes or long term memory. If you imagine an object then picture it rotating, you are using your visuo-spatial sketchpad.
- Visual Cache- stores visual data (things you can see)
- Inner Scribe - records the arrangements of objects in the visual field (where they are)
The working model of memory
Central executive
- Drives the system
- Decides how attention is directed to particular tasks
- Allocates the resources (phonological loop and visuo-spatial sketchpad) to tasks
- Data arrives from the senses or from the LTM
- Has limited storage capacity, so cannot attend to many things at once
The working model of memory
Episodic buffer
Takes information from the other slave systems and adds information about time and order, ready for episodic LTM.
The working model of memory can help to explain learning differences
- DE Jong 2006
- dyslexia involves deficits in phonological loop. It affects children’s learning of phonics (relationship between letters and sounds)
- The ability to take apart and analyse sounds in words requires the student to have a strong active working memory.
- This also affects spelling.
- Research has shown a distinct link between working memory and reading comprehension.
- This knowledge means we can apply the WMM to help children with dyslexia by giving them information written down as well as verbally.
Support for Working model of memory comes from clinical evidence
Shallice and Warrington both carried out a case study of a patient, KF, with severe brain damage. After the injury, the patient had poor STM for verbal information but could process visual information normally. This suggests that his phonological loop had been damaged, leaving other parts of his memory intact. This supports the existence of a separate acoustic and visual store. However, it may be unreliable to use evidence from damaged brains, as the people have had unique experiences, and may also be traumatised. He is also only one person so his results cannot be generalised.
