Memory Flashcards
What is the sensory memory/register
Initial contact for stimuli
Stores information from senses
SM is only capable of retaining information for a very short time and if we don’t pay attention to it it fades quickly (spontaneous decay)
What are the types of memory
Sensory memory/register
Short term memory
Long term memory
What is memory
The process by which we retain information about events that have happened in the past
What is short term memory
The information we are currently aware of or thinking about
The information found in short term memory comes from paying attention to sensory memories
What is long term memory
Continual storage of information which is largely outside of our awareness, but can be called into working memory to be used when needed
What is duration of memory
How long (in time) a memory lasts before it is no longer accessible
STM and LTM differ in duration
What is the duration of short term memory
Short term memories last for a very short period of time, unless they are rehearsed or paid attention to.
Therefore STM is limited in duration.
What is the duration of long term memory
Long term memories can last anywhere from 2 minutes to 100 years.
LTM has an unlimited duration
How are the different types of memory coded
Sensory register:
Coded through visual, auditory or tactile
Short term memory:
Coded through acoustic (sound)
Long term memory:
Coding is usually semantic (the meaning of the information)
Different types of long term memory
Episodic memory
Semantic memory
Procedural memory
What is episodic memory
Stores information about events you have experiences
Can contain information about time and place, emotions you felt, and the details of what happened
Memories are declarative - means they can be consciously recalled
What is semantic memory
Stores facts and knowledge that have been learnt and can consciously recall
It doesn’t contain details of the time or place where you learnt the information - it’s simply the knowledge
What is procedural memory
Stores the knowledge of how to do things
E.g. walking, swimming or playing piano
This information can’t be consciously recalled
What is rehearsal
Rehearsal: a way of transferring information into LTM
E.g. by repeating it over and over again or by attending to it
Method for Peterson and Peterson study of the duration of STM
Participants were shown nonsense trigrams (3 random consonants, e.g. CVM) 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 for Peterson and Peterson study of the duration of STM
After 3 seconds, participants could recall about 80% of trigrams correctly.
After 18 seconds, only 10% were recalled correctly
Conclusion for Peterson and Peterson study of the duration of STM
When rehearsal is prevented, very little can stay in STM for longer than about 18 seconds
Evaluation for Peterson and Peterson study of the duration of STM
The results are likely to be reliable- it was a laboratory experiment where the variables can be tightly controlled.
However, nonsense trigrams are artificial, so the study lacks ecological validity
Only one stimulus was used- the duration of STM may depend on the type of stimulus.
Each participant saw many different trigrams. This could have led to confusion, meaning the first trigram was the only realistic trial
Method for Bahrick et al’s study for long term memory
N= 392 were asked to list names of their ex-classmates (called a ‘free-recall’ test)
They were then shown photos and asked to recall the names of the people shown (photo-recognition test) or given names and asked to match them to a photo of the classmate (name-recognition test)
Results for Bahrick et al’s study for long term memory
Within 15 years of leaving school, participants could recognise about 90% of names and faces.
They were about 60% accurate on free recall.
After 30 years, free recall had decline to 30% accuracy.
After 48 years, name-recognition was about 80% accurate and photo-recognition was about 40% accurate
Conclusion for Bahrick et al’s study for long term memory
This study is evidence of VLTMs in a real-life setting.
Recognition is better than recall, so there may be a huge store of information but it is not always easy to access all of it- you just need help to get to it
Evaluation for Bahrick et al’s study for long term memory
This was a field experiment and had high ecological validity.
However, in a real-life study like this, it is hard to control all the variables, making these findings less reliable- there is no way of knowing exactly why information was recalled well.
It shows better recall than other studies on LTM but this may be because meaningful information is stored better.
This type of information could be rehearsed, increasing the rate of recall.
This means the results cannot be generalised to other types of information held in LTM.
Method for Baddeley’s study for investigating coding in STM and LTM
Participants were given four sets of words that were either acoustically similar, acoustically dissimilar, semantically similar or semantically dissimilar.
The experiment used an independent groups design- participants were asked to recall the words either immediately or following a 20- minute task
Results for Baddeley’s study for investigating coding in STM and LTM
Participants had problems recalling acoustically similar words when recalling the word list immediately (from STM).
If recalling after an interval (from LTM) they had problems with semantically similar words
Conclusion for Baddeley’s study for investigating coding in STM and LTM
The patterns of confusion between similar words suggest that LTM is more likely to rely on semantic coding and STM on acoustic coding
Evaluation for Baddeley’s study for investigating coding in STM and LTM
This is another study that lacks ecological validity.
There are other types of LTM and other methods of coding which this experiment did not consider.
The experiment used an independent groups design so there was not any control over participant variables.
Method of Jacobs study on the capacity of STM
Participants were presented with a string of letters or digits
They had to repeat them back in the same order
The number of digits or letters increased until the participant failed to recall the sequence correctly
Results of Jacobs study on the capacity of STM
The majority of the time, participants recalled about 9 digits and about 7 letters (aged 8 years)
This capacity increased with age during childhood
Conclusions of Jacobs study on the capacity of STM
Based on the range of results, Jacobs concluded that STM has a limited storage capacity of 5-9 items.
Individual differences were found, such as STM increasing with age, possibly due to use of memory techniques such as chunking.
Digits may have been easier to recall as there were only 10 different digits to remember, compared to 26 letters
Evaluations of Jacobs study on the capacity of STM
Jacobs’ research is artificial and lacks ecological validity- it is not something you would do in real life.
Meaningful information may be recalled better, perhaps showing STM to have an even greater capacity.
Also, the previous sequence recalled by the participants might have confused them on future trials
How do we use chunking to remember information
Miller found that people could remember about 7 items
He said that the capacity of STM is 7 plus or minus 2
We can use chunking to combine individual letters or numbers into larger, meaningful units
STM can hold around 7 pieces of chunked information, increasing STM’s capacity
How can information be encoded
Visually
Acoustically (sounds)
Semantic (meaning)
How is STM and LTM encoded
STM is encoded acoustically
LTM is encoded semantically
What are the two subdivisions of LTM
Explicit and implicit
Explicit subdivision of LTM
Explicit (declarative) as you can put it into words
These have to be consciously thought about to be recalled
Often formed through several combined memories
These include semantic and episodic memories
Implicit subdivision of LTM
Implicit (non-declarative) which is more difficult to put into words
These can be recalled without conscious thought
These include procedural memories
(Actions that happen unconsciously)
What is episodic memory
Personal experiences, these are time stamped
Conscious effort to recall
Strength of memory is influenced by emotion
Where is episodic memory stored
Right prefrontal cortex:
The prefrontal cortex in the forward part of the frontal lobe is associated with initial coding of episodic memory
Hippocampus:
Memories of the different parts of an event are located in the different visual, auditory, olfactory areas of the brain, but are connected together in the hippocampus to create a memory of an episode
What is semantic memory
Concerns factual knowledge an individual has learned
These are not time stamped
Linked to episodic as new knowledge is linked to experience
Where is semantic memory stored
Hippocampus
Left prefrontal cortex
Coding associated with the frontal and temporal lobes