Memory: types of memory

Question 1

What are the 3 types of memory

Answer 1

• Sensory register
• Short-term memory (STM)
• Long-term memory (LTM)

Question 2

What is the sensory register

Answer 2

• Temporarily stores info from senses -> constantly receives info from the environment.
• Unless you pay attention, this disappears quickly through spontaneous decay.
  -> trace just fades.
• Limited capacity and very limited duration.
• info is coded depending on the sense that has picked it up.
  -> e.g. visual or auditory.

Question 3

What is short-term memory (STM)

Answer 3

• STM has limited capacity and limited duration.
  -> coding is usually acoustic (sound).

Question 4

What is Long-term memory (LTM)

Answer 4

• has an unlimited capacity -> permanent -> coding usually semantic (the meaning of the info).
  Types of info:
  -> Episodic memory
  -> Semantic memory
  -> Procedural memory

Question 5

What is episodic memory

Answer 5

• Info about the EVENTS experienced, e.g. a concert or restaurant visit.
  -> Info of the time visit + place, emotions and what happened.
• memories are declarative -> can be consciously recalled.

Question 6

What is semantic memory

Answer 6

• stores facts + knowledge we learnt and can recall this consciously.
  -> no detail about the time + place where you learnt the info, simply the knowledge.

Question 7

What is procedural memory

Answer 7

• the knowledge of how to do things, e.g. walking, playing the piano.
  -> can’t be consciously recalled.

Question 8

List the key studies on the duration of memory

Answer 8

• Sperling (sensory register)
• Peterson + Peterson (duration of STM)
• Barhrick (very long-term memories VLTMs)

Question 9

Explain Sperling’s study on duration of memory (Sensory register)

Answer 9

• Method: lab experiment, ppts shown grid with 3 rows of 4 letters for 0.5 secs.
• Results: When recalling whole grid, only managed to recall 4 or 5 letters on average.
  -> when a particular row was indicated, participants recall average of 3 items no matter which row was selected.
• Conclusion: Participants were able to recall 3 items from ANY row -> almost the whole grid was held in the sensory register.
  -> couldn’t report the whole grid because the trace faded before they could finish recall.

Question 10

Evaluate Sperling’s study on the duration of memory (sensory register)

Answer 10

(+) lab experiment, high control of variables and easy to replicate -> highly scientific.
(-) artificial setting -> lacks ecological validity.
-> results and the task does not represent what would happen in the real world.

Question 11

Explain Peterson + Peterson’s study on the duration of STM

Answer 11

• Method: ppts were shown nonsense trigrams (3 random consonants, e.g. CVM).
  -> Asked to recall after either 3, 6, 9, 12, 15 or 18 secs.
  -> During the pause, were asked to count back a certain number -> this was an interference to prevent repeating letters internally (rehearsal).
• Results: after 3 seconds, participants recall about 80% of the trigrams correctly.
  -> after 18 seconds, only about 10% of the trigrams were recalled.
• Conclusion: When rehearsed prevented, little can stay in the STM for longer than 18 secs.

Question 12

Evaluate Peterson + Peterson’s study on the duration of STM

Answer 12

(+) Lab experiment = reliable results.
(-) Nonsense trigrams artificial -> lacks ecological validity.
-> meaningful / real-life memories may last longer in the STM.
(-) only one type of stimulus was used -> the duration may vary with the stimulus.
(-) ppts saw many trigrams -> can lead to confusion.

Question 13

Explain Bahrick’s experiment on VLTMs (duration of memory)

Answer 13

• Method: 392 people were asked to list names of ex classmates (Free-recall test).
  -> shown photos and were asked to recall names (photo-recognition test).
  -> or given names and asked to match them to a photo (name-recognition test).
• Results: Within 15 years, participants recognise 90% of names and faces -> 60% accurate on free recall.
• After 30 years -> free recall declined to 30% accuracy.
• Conclusion: evidence of VLTMs in ‘real-life’ setting.
• Recognition is better than recall, so there may be a huge store of info, but not always easy to access all of it.
  -> About 40% accurate.

Question 14

Evaluate Bahrick’s experiment on VLTMs (duration of memory)

Answer 14

(+) field experimented -> high ecological validity.
-> (-) however it is hard to control variables -> findings are less reliable.
(+) showed better results than other studies on LTM, this may be because meaningful info is stored better.
(-) Info could have been rehearsed (e.g. may still be in touch, talked to friends about their memories) which increases recall.
-> (-) results are not generalisable to other types of info in LTM.

Question 15

List the key studies on the capacity of memory

Answer 15

• Jacobs (capacity of STM)
• Miller (capacity of STM)

Question 16

Explain Jacobs experiment on capacity of STM

Answer 16

• Method: ppts were 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: most times, ppts recalled about 9 digits and about 7 letters.
  -> the capacity increased with age during childhood.
• Conclusion: Based on a range of results -> STM has limited storage capacity of 5-9 items.
  -> STM increased with age, possibly due to use of memory techniques such as chunking.
• Digits are easier to remember (10 digits vs 26 letters).

Question 17

Evaluate Jacobs experiment on the capacity of the STM

Answer 17

(-) research is artificial and lacks ecological validity.
(-) lacks meaningful info -> meaningful info could be recalled better -> showing STM to have an even greater capacity.
(-) previous sequences ppts recalled might have confused them on future trials.

Question 18

Explain Miller’s research on the capacity of STM

Answer 18

1) reviewed research into capacity of STM -> people remembered about 7 items.
2) argued the capacity of STM is 7 + or -2, Miller’s magic number.’
3) suggested we use ‘chunking’ to combine individual letters or numbers into larger, meaningful units.
-> E.g. 2, 0, 0, 3, 1, 9, 8, 7 is about all the digits the STM can hold.
-> ‘Chunked’ into meaningful recent years of 2003 and 1987, makes this easier to remember.
- the STM is able to hold about 7 pieces of chunked info, increasing the STM’s capacity.

Question 19

What is coding

Answer 19

• the way info is stored in memory.
• in the STM -> we keep info active by repeating it to ourselves -> this involves acoustic coding.
  -> acoustic coding -> how info sounds.
  -> semantic coding -> the meaning of info.
• In the LTM -> coding is generally semantic.

Question 20

Explain Baddeley’s study on coding in the STM and LTM (acoustic and semantic coding)

Answer 20

• Method: participants were given 4 sets of words:
  -> were acoustically similar (e.g. man, med, mat).
  -> acoustically dissimilar (pit, cow, bar).
  -> Semantically similar (big, large, huge).
  -> or semantically dissimilar (good, hot, pig).
• the experiment used the independent groups design.
• asked to recall immediately or following 20 minute task.
• Results: had problems recalling acoustically similar words when recalling immediately (from the STM).
  -> If recalling after an interval (from LTM), had problems with semantically similar words.
• Conclusion: there was confusion between similar words which suggests LTM more likely relies on semantic coding and STM on acoustic coding.

Question 21

Evaluate Baddeley’s study on coding in the STM and LTM

Answer 21

(-) lacks ecological validity.
-> Other LTM types (episodic, procedural) and other ways of coding (e.g. visual) which are not considered.
(-) independent groups design -> no control over ppt variables.