Memory Flashcards
What is memory?
- Human memory can most broadly be defined as the process by which we retain information about events that have happened in the past - not just years ago but in immediate past too.
Types of memory
- sensory memory/register (SM)
- short term memory (STM)
- Long term memory (LTM)
What is the sensory memory/register (SM)?
- Initial contact for stimuli. SM is only capable of retaining information for a very short time
What is short term memory (STM)?
- 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 (LTM)?
- 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?
- how long (in time) a memory lasts before it is no longer accessible.
- STM and LTM differ in duration
Explain the duration of short term memory (STM)
- short term memories last for very short period of time, unless rehearsed or paid attention to.
- therefore STM is limited in duration
Explain the duration of long term memory (LTM)
- long term memories can last anywhere can last anywhere from 2 minutes to 100 years.
- LTM has an unlimited duration
Explain the features of the Peterson and Peterson experiment (1959)
- Participants presented with a 3 letter consonant nonsense syllable followed by a 3 digit number.
- Nonsense syllables were not memorable such as ‘BBC’.
- Participants were then asked to count backwards in 3’s or 4’s to prevent them from rehearsing the nonsense syllable.
- Each participant was given two practice trials followed by 8 real trials. On each trial the time spent counting backwards was different (3, 6, 9, 12, 15, 18 seconds).
What were the results of the Peterson and Peterson experiment?
- Participants remembered 90% when there was a 3 second interval, but only 2% when there was an 18 second interval.
List the positive evaluations of the Peterson and Peterson experiment (1959):
- Showed that forgetting in STM can occur if information is not rehearsed.
- Identified that duration of STM as approximately 18secs.
- Highly controlled therefore limited the effect of extraneous variables.
List the negative evaluations of the Peterson and Peterson experiment:
- Using artificial stimuli therefore they had no personal meaning to the participants – lacked mundane realism.
- means that we may not be able to generalise these findings to different kinds of memory task.
- This therefore lacks external validity.
- Relatively small sample and all students
What were the key features of Bahrick et al experiment (1975)?
- duration of LTM
- 392 participants from Ohio aged between 17 and 74, using High school year books. Recall was tested in various ways
1. Photo-recognition test of 50 photos
2. Free recall test where they had to recall the names of
students from their graduating class.
What were the results of Bahrick’s experiment?
- After 15 years 90% accurate in photo recognition.
- After 48 years 70% accurate in photo recognition.
- After 15 years 60% accurate for free recall.
- After 48 years 30% accurate for free recall.
List the positive and negative evaluations of Bahrick’s experiment:
Positive:
- High external validity, real-life meaningful memories were studied.
Negative:
- Confounding variables are not controlled in these experiments.
- These pictures could have been rehearsed over the years.
What is rehearsal?
- a way of transferring info into LTM (long-term memory).
- e.g. by repeating it over and over again or by attending to it
What is digital span?
- A way of measuring the capacity of STM.
- Participants have to repeat back a string of digits in order of presentation
List the features of Jacobs’ capacity of STM study:
- method: Participants presented with a string of letters or digits.
- 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: majority of the time, participants recalled about 9 digits and about 7 letters (aged 8 years).
- This capacity increased with age during childhood
What was concluded in Jacobs’ STM study?
- Based on the range of results, Jacobs concluded STM has 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
List the evaluations of Jacobs’ experiment on STM:
- research is artificial and lacks ecological validity - not something you would do in real life.
- Meaningful info 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
Explain Miller’s theory on span of memory and chunking:
- Miller (1956) noted that things come in sevens: 7 notes on musical scales, 7 days of the week…
- This suggests that the capacity of STM is 7 items (plus or minus 2).
- argued that capacity for remembering info can be increased if we chunk items together.
- If we find links between things and group them together then we will remember more.
- e.g. FBI, TNT, NHS, LOL, AQA etc.
List the evaluations on capacity and coding:
Negative:
- artificial stimuli.
- lacking validity: digital span.
- not so many chunks (overestimation of STM).
Explain how artificial stimuli is a negative evaluation for capacity and coding
- based on very old research.
- Lacked adequate control.
- Confounding variables.
- However: other studies have found similar results supporting its validity.