(2) STM and LTM Flashcards
What two types of memory did Freud suggest?
-Freud: 2 layers Surface (transitory) vs. Deep (permanent)
What two types of memory did William James suggest?
-James: Primary (stream of consciousness) vs. Secondary Memory
What are the Three basic memory systems?
- Sensory memory
- Short term/working memory (RAM)
- Long-term memory (hard drive)
What are the general characteristics of sensory memory?
- Large capacity
- Literal record of perceptual experience
- But lost quickly (transient)
How long does Iconic memory (or ‘Visual sensory register’) hold visual input for?
-Holds visual input for 250 msec – Representation is pre-categorical (literal record of percept)
How long does Echoic memory (or ‘Auditory sensory register’) hold auditory input for?
-Holds auditory input for 2-3 seconds
What was Sperling’s Iconic Memory Demonstration?
- A matrix of 12 letters and numbers will be very briefly flashed
- As soon as you see the information, write down everything you can remember in its proper location
What was the free recall task?
- Present participants with a list of words (about 1015), e.g., trumpet, shirt, table, ….
- Participants to recall them in any order
- Plot the results according to how well the words were recalled at each serial position
What causes Primacy gradient?
First few items can be rehearsed a lot and so more likely to move into long-term memory
What causes Recency gradient?
last few items of the list are still in STM when you start to write the list down
How can you reduce recency gradient?
If that’s true, a delay before writing down the items should allow time for STM to decay, and so reduce or eliminate the recency gradient…
What is the free recall task with a filled delay?
- Present participants with a list of words (about 1015), e.g., trumpet, shirt, table, ….
- ADDITIONAL STEP: A ‘filled delay’ between last item and recall: participants undertake some secondary activity (e.g., counting backwards)
- Participants to recall them in any order
- Plot the results according to how well the words were recalled at each serial position
Evidence for phonological coding in short-term memory?
- Phonological similarity effect
- Words that ‘sound’ alike more poorly recalled than dissimilar sounding words
- Baddeley (1966a, cited in Baddeley, 1990)
What is the word length effect? (phonological coding in the STM)
- recall of words is worse for longer words than for shorter words
- The word-length effect is eliminated if phonological coding is prevented through ‘articulatory suppression’ (e.g., counting or repeating an Irrelevant word, “the, the, the…”)
What was Atkinson and Shiffrin’s (1968) 3-Stage Memory Model?
Stimuli - sensory stores - STM (if repeated) - LTM
What was Baddeley’s Working Memory model (short-term stores + controlled processing)?
SEE PIC
What are the main characteristics of the short term memory?
- STM has a very limited duration
- STM also has a limited capacity: about 4 or 5 chunks
- STM tends to rely on a phonological code
What did Standing (1973) find about the Capacity of long-term memory?
“Learning 10,000 Pictures”
- Participants could recognise 133/160 pictures selected randomly from about 10,000 pictures studied earlier
- Must have had a long-term memory trace of ~6,600 of the pictures
- “The capacity of recognition memory for pictures is almost limitless.”
- Pictures better recognised than words
What is Explicit memory?
when retrieval of a memory is deliberate/requires conscious recollection. Also called declarative memory
-note that short-term remembering is also typically ‘explicit’
What is Implicit memory?
when behaviour indicates that memories are being retrieved in the absence of a deliberate, conscious, attempt to retrieve them
-E.g., procedural memory - much of recognition memory is implicit (e.g., for very familiar faces; the meaning of common words)
Explicit memories typically divided into two types (Tulving, 1983):
- Semantic memories (general knowledge about the world)
- Episodic memories (memories for experiences/events)
What is semantic memory?
- Knowledge of facts, concepts, ‘general knowledge’
- Do dogs bark? – may be based on experience of dogs barking (i.e., an episodic memory) but doesn’t have to be, and you don’t have to remember any particular event
- Do dogs breathe air? – Very unlikely to be based on a specific episode
What are the key features of LTM?
- LTM has (possibly) limitless capacity
- LTM has (can have) a very long duration
- LTM is better when we can rely on multiple different codes (hence picture superiority effect and imageability effect)
- There are different types of LTM
- Evidence that semantic memory is organised as a hierarchically structured network
What are partial matches?
Due to spreading activation, and reliance on partial matches (Kamas & Reder, 1995) - We don’t always encode information perfectly, because it’s typically safe to rely on a partial match
