Short-Term memory Flashcards
What are the three subcomponents of the Working Memory Model?
The three subcomponents involved are:
- Phonological loop (or the verbal working memory),
- Visuospatial sketchpad (the visual-spatial working memory),
- Central executive which involves the attentional control system
Central Executive
- Limited Capacity – Data arrives from the senses but it can’t hold it for long.
- Determines how resources (slave systems) are allocated.
- It involves reasoning and decision making tasks.
- They also select strategies but can only do a limited number of things at the same time.
Phonological Loop
- Limited Capacity
- Deals with auditory information and preserves
word order – Inner Ear - Phonological store (holds words heard)
- Articulatory process (holds words heard/seen and silently repeated (looped) like an inner voice. This is a kind of maintenance rehearsal.
Visuo-spatial sketch pad
Visual and/or spatial information stored here – Inner Eye
- Visual = what things look like
- Spatial = relationships between things
- Limited capacity – 3-4 objects
Logie (1995) suggested subdivision:
- Visuo-cache (store)
- Inner scribe for spatial relations.
Episodic Buffer
- Baddeley (2000) added episodic buffer as he realised model needed a more general store.
- Buffer extra storage system but with limited capacity of 4 chunks
- Integrates information from all other areas.
Word-length effect
- The phonological loop explains why the word-length effect occurs.
- The fact that people cope better with short words than long words in working memory (STM).
- It seems that the phonological loop holds the amount of information that you can say in 1.5 - 2 seconds
Articulatory process
- Word length effect disappears if a person is given an articulatory suppression task (‘the, the, the’ while reading the words).
- The repetitive task ties up the articulatory process and means you can’t rehearse the shorter words more quickly than the longer ones, so the word length effect disappears.
Trace Decay Theory of
Forgetting
- This explanation of forgetting in STM assumes that memories leave a trace in the brain. A trace is some form of physical and/or chemical change in the nervous system.
- Trace decay theory states that forgetting occurs as a result of the automatic decay or fading of the memory
trace. Trace decay theory focuses on time and the limited duration of short-term memory.
Retrieval failure
- Retrieval failure is where the information is in long-term memory, but cannot be accessed. Such information is said to be available (i.e. it is still stored) but not accessible (i.e. it cannot be retrieved). It cannot be accessed because the retrieval cues are not present.
Tulving (1974)
- Argued that information would be more readily retrieved if the cues present when the information was encoded were also present when its retrieval is required.
What was George Miller’s research on STM?
He concluded that on average we can recall 7 items (7 plus or minus 2), with a range of between 5-9 items.
- We can remember more if we break information down into 5-9 manageable chunks.
- Miller discovered that we can remember 5 words as easily as we can remember 5 letters…. Through chunking…
What is the capacity of STM?
- Limited, between 5-9 items on average.
What is the duration of STM?
- Between 18-30 seconds.
What was the procedure of Peterson and Petersons research on the duration of STM?
- 24 participants, who were psychology students
- Asked to recall trigrams (e.g. UDB)
- The trigrams were presented one at a time and had to be recalled
after 3,6,9,12,16 or 18 second intervals per trial - No two consecutive trigrams had the same letters
- After the trigram was heard, the participants had to count backwards in threes or fours from a specified random number until a red light was shown.
What were the results of Peterson and Petersons research on the duration of STM?
Their results showed that the longer each student had to count backwards, the less well they were able to recall the trigram accurately.
- After 3 seconds, average recall was about 80%, after 18 seconds it was 3%.
- Peterson and Peterson’s findings suggested that STM duration may be about 18 seconds, unless we repeat the information over and over (i.e. verbal rehearsal).
- The results of the study also show how short term memory is different from long term memory in terms of duration about
What are the evaluations to Joseph Jacobs study on STM?
- One strength is that it has been replicated. Jacobs findings have been confirmed by other, better controlled studies since.
- One limitation of the study was that he may ahve overestimated STM capacity. Nelson Cowan reviewed other research and concluded that the capacity of STM is only about 4 chunks.
What are the evaluations for Peterson and Peterson’s study on STM?
- One limitation was that the stimulus material was artifical. The study is not completely irrelevant because we do sometimes try to remember fairly meaningless material.
- Even so, recalling constant syllables does not reflect most everyday memory activities where what we are trying to remember is meaningful.
- This means it lacks external validity.
What was the Bahrick’s experiment procedure on the duration of STM?
- Bahrick studied 392 pp’s from the American state of Ohio who were between 17 and 74.
- High school yearbooks were obtained from the pp’s or directly from some schools. They tested memory recall in various ways including photo recognition tests consisting of 50 photos - some from the pp’s high school yearbooks.
- There was a recall test where pp’s recalled all the names of their graduating class.
What were the results of Bahrick experiment on the duration of LTM?
- Participants tested within 15 years of graduation were about 90% accurate in photo recognition. After 48 years, recall declined to about 70% for photo recognition.
- Free recall was less accurate than recognition - about 60 % after 15 years, dropping to 30% after 48 years. This shows that LTM may last up to s lifetime for some material.
What are the limitations to Bahrick’s experiment on the duration of STM?
- Bahrick’s research used a sample of 392 American university graduates and therefore lacks population validity. Psychologists are unable to generalise the results of Bahrick’s research to other populations, for example students from the UK or Europe. As a result, we are unable to conclude whether other populations would demonstrate the same ability to recall names and faces after 47 years.
- Furthermore, Bahrick found that the accuracy of long-term memory was 90% after 14 years and 60% after 47 years. His research is unable to explain whether long-term memory becomes less accurate over time because of a limited duration, or whether long-term memory simply gets worse with age.
What are the strengths to Bahrick’s experiment on the duration of STM?
- High levels of ecological validity as the study used real life memories. In this study participants recalled real life information by matching pictures of classmates with their names. Therefore, these results reflect our memory for real-life events and can be applied to everyday human memory.
What are reflex actions?
- A reflex action is an automatic (involuntary) and rapid response to a stimulus, which minimises any damage to the body from potentially harmful conditions, such as touching something hot. Reflex actions are therefore essential to the survival of many organisms.
- A reflex action follows a general sequence and does not involve the conscious part of the brain. This is why the response is so fast
What is a reflex arc?
The nerve pathway followed by a reflex action is called a reflex arc. For example, a simple reflex arc happens if we accidentally touch something hot.
1. Receptor in the skin detects a stimulus (the change in temperature).
2. Sensory neuron sends electrical impulses to a relay neuron, which is located in the spinal cord of the CNS. Relay neurons connect sensory neurons to motor neurons.
3. Motor neuron sends electrical impulses to an effector.
4. Effector produces a response (muscle contracts to
move hand away).
Organisms are able to modify a reflex action and overcome it, but this uses the brain and has to be learnt
What is the order of the Multi Store Memory model by Atkinson & Shiffrin?
What was the procedure applied by Baddeley & Hitch 1976?
- Gave participants two tasks to perform simultaneously.
- Asked to say ‘the the the’ – a task involving the Articulatory Loop.
- Asked to say random digits – a task involving both the Central Executive and Articulatory Loop.
What were the results found by Baddeley & Hitch 1976?
- The true or false task was slower when given the 2nd task involving both the Central Executive and Articulatory Loop.
- They concluded that completing two tasks that involve the same component causes difficulty. This supports the Central Executive and the Working Memory Model.
