Memory Flashcards
What is the multi store model
- This model seeks to explain how the different types of memory work together (Sensory register,
STM and LTM) and was proposed by Atkinson and Shiffrin in 1968 - This model accepts that memory is composed of these three parts, and that information has to
move through all three to become a memory
Information from our environment is gained from our senses, and enters the sensory register. - Usually, we pay no direct attention to this information, and spontaneous decay happens: it fades
away swiftly. - If we do pay attention to this sensory information, then it continues on to STM
- STM has a finite duration and capacity: so for this information to become a
long term memory, we need to rehearse and repeat it. - Rehearsing and repeating information will either retain it in STM, or place into
LTM where it can theoretically remain forever. - If this information is not rehearsed or recalled for a long period of time, then it
will be forgotten and will leave both STM and LTM
What are the two peices of evidence for the multi store model
Primacy effect
Recency effect
What is the primary effect
1) The Primacy Effect - Research shows that participants are able to recall the
first few items of a list better than those from the middle. The multi-store model
explains this because earlier items will have been rehearsed better and transferred
to LTM. If rehearsal is prevented by an interference task, the effect disappears.
What is the recency effect
The Recency Effect
- Participants also tend to remember the last few items better than
those from the middle of the list. As STM has a capacity of around 7 items, the words
in the middle of the list, if not rehearsed, are displaced from STM by the last few words
heard. These last words are still in STM at the end of the experiment and can be recaller
Describe the korsakoff syndrome as evidence for multi store model
People with Korsakoff’s Syndrome (amnesia that’s mostly caused by chronic
alcoholism) provide support for the model. They can recall the last items in a list
(unimpaired recency effect), suggesting an unaffected STM. However, their LTM is
poor. This supports the model by showing that STM and LTM are separate stores.
What is the Milner case for evidence for the multi store model
Milner et al (1957) carried out a case study into a patient called HM who had suffered
from severe and frequent epilepsy. His seizures were based in a brain structure called the
hippocampus. Doctors decided to surgically remove part of the brain around this area.
The operation reduced his epilepsy, but led to him suffering memory loss. He could still
form short-term memories, but was unable to form new long-term memories. This case
study supports the idea that different types of memory are separate systems in the brain.
What are the three types of memory
Sensory register
Short term memory
Long term memory
What is the sensory register
Sensory Register
1)
The sensory register temporarily stores information
from our senses (sight, sound, touch, taste and smell)
- it’s constantly receiving information from around us.
2)
Unless we pay attention to it, it disappears quickly
through spontaneous decay - the trace just fades.
3) The sensory register has a limited capacity, and a
very limited duration (i.e. we can remember a little
information for a very short time).
4) Information is coded depending on the sense that
has picked it up - e.g. visual, auditory or tactile.
Describe short term memory
Short-term memory has a limited
capacity and a limited duration
(i.e. we can remember a little
information for a short time).
Coding is usually acoustic (sound).
What is long term memory
Long-term memory has a pretty much unlimited capacity and is theoretically permanent (i.e. it can hold lots
of information forever). Coding is usually semantic (the meaning of the intormation).
2) There are different types of long-term memory:
Episodic memory stores information about events that you’ve actually experienced, such as a concert or
a visit to a restaurant.
It can contain information about time and place, emotions you felt, and the details
of what happened. These memories are declarative
this means they can be consciously recalled.
Semantic memory stores facts and knowledge that we have learnt and can consciously recall,
such as capital cities and word meanings. It doesn’t contain details of the time or place where you
learnt the intormation-
it’s simply the knowledge.
Procedural memory stores the knowledge of how to do things, such as walking,
swimming or playing the piano. This intormation can’t be consciously recalled.
Who investigated sensory register using very breif displays
Sperling 1960
Describe spellings experiment
Sperling (1960) Investigated the Sensory Register Using Very Brief Displays
Sperling (1960) - An investigation of the sensory register
Method:
In a laboratory experiment, participants were shown a grid with three rows of four letters for
50 milliseconds (0.05 seconds). They then had to immediately recall either the whole grid, or a
randomly chosen row indicated by a tone (high, medium or low) played straight after the grid was shown.
Results:
When participants had to recall the whole grid, they only managed to recall tour or five letters on
average. When a particular row was indicated, participants could recall an average of three items,
no matter which row had been selected.
Conclusion: The participants didn’t know which row was going to be selected, so it could be concluded that they would
have been able to recall three items from any row, therefore almost the whole grid was held in their sensory
register. They couldn’t report the whole grid because the trace faded before they could finish recall.
Evaluation:
Because this was a laboratory experiment, it was highly scientific. The variables could be controlled, and
it would be easy for someone to replicate the study. However, the artificial setting of the study means that
it lacks ecological validity
people don’t normally have to recall letters in response to a sound, so the
results might not represent what would happen in the real world.
Who investigated the duration of stm
Peterson and Peterson
Describe Peterson and Petersons experiment
Method:
Participants were shown nonsense trigrams (3 random consonants, e.g. VM) and asked to recall them
after either 3, 6, 9, 12, 15 or 18 seconds. During the pause, they were asked to count backwards in threes
from a given number. This was an “interference task’ to prevent them from repeating the letters internally.
Results:
After 3 seconds, participants could recall about 80% of trigrams correctly.
After 18 seconds, only about 10% were recalled correctly.
Conclusion:
When rehearsal is prevented, very little can stay in STM for longer than about 18 seconds.
Evaluation:
The results are likely to be reliable -
It’s a laboratory experiment where the variables can be tightly
controlled. However, nonsense trigrams are artificial, so the study lacks ecological validity (see pages
100-101 for more about reliability and validity). Meaningful or ‘real-life’ memories may last longer in SIM.
Only one type of stimulus was used
the duration of STM may depend on the type of stimulus. Also,
each participant saw many different trigrams. This could have led to confusion, meaning that the first
What experiment tested Ltm in a natural setting
Bahrick et Al
