short and long term memory

Question 1

distinguish between long term memory and short term memory

Answer 1

your memory for events that have happened in the past, compared to your memory for immediate events.

Question 2

define capacity

Answer 2

a measure of how much data can be held in a memory store.

Question 3

define duration

Answer 3

a measure of how long a memory lasts before it is no longer available.

Question 4

define coding/encoding

Answer 4

the way information is changed so that it can be stored in memory, it i described as a code in which it is held in the form of sounds (acoustic), images (visual) or meaning (semantic).

Question 5

capacity of STM and LTM

Answer 5

STM - limited capacity
LTM - infinite capacity

Question 6

duration of STM and LTM

Answer 6

STM - short duration (less than 18 seconds)
LTM - unlimited

Question 7

coding of STM and LTM

Answer 7

STM - acoustic (sound)
LTM - semantic (meaning)

Question 8

who assessed STM capacity; mean span?

Answer 8

jacobs (1887); mean span for digits was 9.3 items and mean span for letters was 7.3.

Question 9

who assessed STM capacity; memory and chunking?

Answer 9

miller (1956); capacity of STM is 7 items (plus or minus 2).

also noted that people can recall 5 words as well as 5 letters by chunking; grouping sets of digits or letters into units and chunks.

Question 10

who assessed STM duration?

Answer 10

peterson and peterson (1959); 24 participants were asked to recall a consonant syllable after a retention interval of 3,6,9,12,15,18 seconds. during the retention interval they had to count backwards from their 3 digit number.

Question 11

findings of peterson and peterson

Answer 11

on average, 90% correct over 3 seconds, and only 2% correct after 18 seconds.

Question 12

who assessed LTM duration?

Answer 12

bahrick et al (1975); test 400 people of various ages on their memory of classmates. participants tested within 15 yrs of graduation were about 90% accurate inidentifying faces. after 48 years, this declined to about 70% for photo recognition.

Question 13

who assessed coding of STM and LTM?

Answer 13

alan baddeley used word lists to test the effects of acoustic and semantic similqrity on STM and LTM.

participants had difficulty remembering acousticially similar words in STM but not in LTM, whereas semantically similar words posed little problems for STMs but led to muddled LTMs.

Question 14

evaluation on coding

Answer 14

one limitation of baddeley’s study is that it used artificial stimuli rather than meaningful materials. the word list had no personal meaning to participants thus we should be cautious about generalising the findings to different kinds of memory task.

Question 15

evaluation on capacity

Answer 15

the capacity of STM is not the same for everyone. jacobs also found that recall increased steadily eith age; 8 yr olds could remember an abverage of 6.6 digits whereas the mean for 19 yr olds was 8.6 digits.

this age increase mighy be due to changes in brain capacity, and/or to the development of strategic such as chunking. suggesting that the capacity of STM is not fixed.

Question 16

evaluation on duration

Answer 16

a limitation of peterson and peterson’s study is that the stimulus material was artifical. trying to memorise consonant syllables does not reflect most real-life memory activities where we are trying to rmb something meaningful; lacking external validity.

however we do sometimes try to remember meaninful things such as groups of numbers; phone numbers. meaning that although the task was artifical; the study does have some relevance to everyday life.