topic 1a memory

Question 1

describe sensory register

Answer 1

• capacity: large
• duration: 0.5 seconds
• coding: sense specific

Question 2

describe STM

Answer 2

• capacity: 5-9 items (7+/-2)
• duration: 18-30 seconds
• coding: acoustic

Question 3

describe LTM

Answer 3

• capacity: unlimited
• duration: up to a lifetime
• coding: semantic

Question 4

describe the research study on the capacity of STM

Answer 4

jacobs (1887) investigated capacity of STM using digit span technique.
findings: average capacity is 7+/-2
conclusion: STM has a limited capacity and new information displaces the old information

Question 5

describe the research study on the duration of STM

Answer 5

peterson and peterson (1959) investigated duration of STM in lab experiment using a nonsense trigram. pp’s were asked to count backwards from a specified number (to prevent rehearsal) after 3, 6, 9, 12, 15, or 18 seconds pp’s had to immediately recall the trigram.
findings: 80% was recalled after 3 seconds, 50% recalled after 6 secs and 10% after 18 secs. overall, duration is 18-30 seconds
conclusion: STM is lost through displacement/decay when no opportunity for rehearsal

Question 6

describe the research study on encoding of STM

Answer 6

baddeley (1966) presented pp’s with list A (acoustically similar) and list B (acoustically dissimilar) and were given a word list and asked to put in the correct order
pp’s with list A performed poorest, with only 10% recall, compared to those who heard list B
conclusion: if items are acoustically similar, it results in acoustic confusion and poorer recall

Question 7

describe the research study on coding of LTM

Answer 7

baddeley (1966) presented pp’s with list C (semantically similar) and list D (semantically dissimilar) and were given a 20 min interval before recall
findings: words with similar meanings were poorly recalled in comparison to distinct meanings
conclusion: coding in LTM is mainly semantic

Question 8

describe the research study on duration of LTM

Answer 8

bahrick (1975) asked american pp’s aged 17 to 74 to do a free recall test (where you list names of individuals in graduating class), a photo recognition test and name recognition test for ex-school friends
findings: 90% accuracy on recognition after 15 years, which dropped to 80% after 48 years. free recall was less at 60% after 15 years and 30% after 48 years
conclusion: recognition better than recall, LTM has long duration but may need clues to access it.