Cognitive - Types of Memory

Question 1

What is Sensory memory?

Answer 1

The system that holds information in an unprocessed form, where each sense has its own brief ‘storage system’

Question 2

What is the capacity of Sensory memory?

Answer 2

As concluded by Sperling, about 9 or 10 items in the iconic (visual) memory

Question 3

What is the duration of Sensory memory?

Answer 3

Fractions of a second

Question 4

What is Short-Term memory?

Answer 4

System for storing information for brief periods of time

Question 5

What is the capacity of Short-Term memory?

Answer 5

7 items (plus or minus 2) as concluded by Jacobs

Question 6

Name and explain a study in the capacity of STM

Answer 6

Miller
Participants had to recall a series of numbers ascending in the number of digits and found that the average units of information is the ‘magic number 7’ plus or minus 2.

Question 7

What factors affect the capacity of STM?

Answer 7

• Reading aloud
• Rhythmic grouping
• Pronunciation time

Question 8

Name and explain a study into the pronunciation time determining the capacity of STM

Answer 8

Baddeley (1975)
Reading speed of participants was measured and the participants were then presented with sets of 5 words (either 1 syllable or polysyllabic) and asked to recall them in order.
He found that participants could recall more short words than long words, positive correlation between reading speed and memory span, and they were able to recall as many words as they could articulate in 2 seconds

Question 9

What is the duration of STM?

Answer 9

Around 20 seconds maximum

Question 10

Name and explain a study into the duration of STM

Answer 10

Peterson & Peterson
Participants shown a series of trigrams (e.g CDW) and asked to recall them after ascending periods of time.
Found a 90% loss after 18 seconds

Question 11

What factors affect the duration of STM?

Answer 11

• Maintenance rehearsal

- Amount of information to be retained

Question 12

Name and explain a study into the amount of information as a factor affecting the duration of STM

Answer 12

Murdock
Presented participants with either 3 letters that can form a word (e.g. c a t) or 3 unrelated words.
Found the words to be recalled as with Peterson study (18 seconds) but because the 3 letters could be chunked together to make just 1 word, correct recall was 90% after 18 seconds

Question 13

Name and explain a study into the encoding of STM

Answer 13

Conrad
Participants had to recall a series of letters, some acoustically similar (P, D, E) and some acoustically dissimilar (U,F,I).
Found that STM encodes acoustically (letters sounding similar were more easily confused than letters sounding dissimilar, despite visually looking different)

Question 14

Name and explain a study looking at the type of encoding which is preferred by LTM and STM

Answer 14

Baddeley (1966)
Participants given 4 word lists:
-acoustically similar
-semantically similar
-acoustically dissimilar
-semantically dissimilar

STM: made mistakes on words that sounded similar (supporting Conrad) concluded it encoded acoustically
LTM: made mistakes on words that were semantically similar, concluding it encoded semantically

Question 15

What is the capacity of LTM?

Answer 15

No upper limit

Question 16

What is the duration of LTM?

Answer 16

Seemingly unlimited duration

Question 17

Name and explain a study into the duration of LTM

Answer 17

Bahrick et al
392 ex-highschool students tested in free-recall of the names of former class mates using photo prompts. They found that accurate recall was possible for periods as much as 50 years later (80% accuracy at 48 years)

Question 18

Evaluate the studies into memory capacity, duration and encoding

Answer 18

They have low ecological validity as it is unlikely that on real life you would be asked to, for example, recall trigrams.

Question 19

What evidence is there for both STM and LTM?

Answer 19

• Multi-store memory model
• Primary and Recency effect
• Amnesiac case studies

Question 20

Name and explain a study into the primary and recency effect

Answer 20

Murdock
Gave 100 students lists of words to recall freely in 90 seconds.
Found that words and the start and end of the list were recalled most often (words at the beginning rehearsed into LTM, words at the end still in STM)

Question 21

How do amnesiac case studies give evidence for both LTM and STM?

Answer 21

Most people with memory problems either have impairment of their STM or their LTM, usually not both

Question 22

Give an example amnesiac case study

Answer 22

Henry M
Age 27 went under surgery attempting to cure his epilepsy. The surgeon removed an area known to be crucial to memory. Afterward Henry was unable to create new long term memories, but his STM remained in tact.