Memory Research

Baddeley

• Different list of words to 4 groups
  • Acoustically similar
  • Acoustically dissimilar
  • Semantically similar
  • Semantically dissimilar
• When asked to recall immediately, acoustically similar words was worse
• When asked to recall after 20 minutes, semantically similar words was worse

Jacobs

• Digit span technique
• Participant given 4 digits to recall immediately
• If correct, extra digit added to the sequence
• Mean span for digits = 9.3 items, letter = 7.3

Miller

• Noticed that things come in 7s (e.g. 7 notes of scale, 7 days of the week, etc)
• Capacity of STM is 7+-2
• Noted people can recall 5 words as well as they can 5 letters
  • chunking --> grouping sets of digits/letters into units/chunks

Peterson + Peterson

• 24 undergraduate students, each took part in 8 trials
• Given a consonant syllable (trigram) to remember, and a 3-digit number
• Asked to count back from the 3-digit number until told to stop
  • Prevents any mental rehearsal of consonant syllable
• Each trail asked to stop after different amount of time (e.g. 3s, 6s, 9s, etc)
• STM has short duration unless verbal rehearsal participated in
  • 18-30 seconds

Bahrick et al

• 392 participants from Ohio, aged 17 to 74
• High school yearbook obtained to test recall + recognition
  • photo-recognition of 50 photos, some from participant's yearbook
  • free recall of names from participant's graduating class
• Photo recognition: 90% after 15yrs, 70% after 48yrs
• Free recall: 60% after 15yrs, 30% after 48yrs

Clive Wearing

• Professional musician
• Contracted herpes
  • Damaged his hippocampus
• Duration of STM is 7 seconds
• Unable to transfer new memories to LTM
• Procedural memory intact - still able to play the piano

KF

• Suffered brain damage
• Had poor STM ability for verbal information, but could process visual information normally
  • Difficulty with sounds, but could recall digits/letters
  • STM poor when digits read to him, but much better when he read them to himself

McGeoch and McDonald

• Studied retroactive interference by changing amount of similarity between two materials
• Participants learn list of 10 words until 100% accurate
• Learn a second list
  • synonyms
  • antonyms
  • words unrelated to original list
  • consonant syllables
  • three-digit numbers
  • no new list
• Recall performance of first list dependent on the nature of the second list
• Synonyms condition produced worst recall

Godden and Baddeley

• Study of deep-sea divers
• Learned a list of words either on-land or underwater
• Recall either on-land or underwater
• Accurate recall was 40% lower when conditions did not match (i.e. learnt on-land, recall underwater)

Carter and Cassaday

• Participants given anti-histamine drugs for hay fever
• Drugs contained a mild sedative making participants slightly drowsy
• Creates a internal psychological state different from 'normal' state of alert and awake
• Participants given list of words, and passages of prose to learn and recall
• 4 conditions created
  • learn on drug, recall on it
  • learn on drug, recall off of it
  • learn not on drug, recall on it
  • learn not on drug, recall off of it
• Where internal states were mismatched, performance was significantly worse
  • Absent cues (e.g. drowsy when learning, but alert when recalling)

Loftus and Palmer pt1

• Paticipants to watch film clips of car accidents and then given questions to answer
• Participants asked "about how fast were the cars going when they ___ each other?"
  • Hit
  • Contacted
  • Bumped
  • Collided
  • Smashed
• Mean estimated speed was calculated for each group
  • Contacted = 31.8mph
  • Smashed = 40.5mph

Loftus and Palmer pt2

• Wording of leading question can change participant's memory
• Those who orginially heard 'smashed' more likely to say there was broken glass compared to those who heard 'hit'

Gabbert et al

• Participants studied in pairs
• Each participant watched a video of the same crime, but from different perspectives
• Participants discussed what they had seen before being individually tested
• 71% of participants mistakenly recalled apects of the event that they had not seen, but picked up in discussion
• Control group (no discussion) had corresponding figure of 0%
• Memory conformity - change either to win social approval or believe other witness is right/they are wrong

Johnson and Scott

• Participants led to believe they were taking part in lab study
• While in waiting room, participants heard argument in next room
• Low-anxiety condition - man walked through room carrying a pen with grease on his hands
• High-anxiety condition - heard breaking glass, and man walked through the room carrying a paper knife covered in blood
• Participants later asked to pick out man from line-up of 50 photos
• 49% in low-anxiety condition were able to identify the man
• 33% in high-anxiety condition correctly indentified the man
• Tunnel theory - witness's attention drawn to focus on the weapon

Yuille and Cutshall

• Study of a real-life shooting in a gun shop in Canada
• Shop owner shot dead the thief
• 13 out of 21 witnesses agreed to take part
• Interviews took place 4-5 months after incident, to be compared with original police interviews
• Accuracy determined by number of details reported in each account
• Asked to rate how stressed they felt at the time using 7-point scale + emotional problems since
• Witnesses very accurate in accounts + little change in amount/accuracy 5 months later
• Those who reported highest levels of stress were most accurate
  • 88% compared to 75% for less-stressed group