STM - takes information from the sensory store (from the
environment), it encodes acoustically. Conrad: string of letters
presented on a screen for 3/4 a second. Lasts for a few seconds,
capacity is 5-9 items. Jacobs: serial digit span is 9 numbers, 7 letters,
chunking increases capacity. Peterson and Peterson: 24 students,
auditory trigrams, told to either repeat, count back in 3s from 100
(retention interval). After 0s - 90% recall, after 18s - 5%. Lab
experiment not reflective, students not generalizable.
LTM - encoded semantically,, unlimited capacity and life long duration. Bahrick -
US participants with yearbooks. Free recall (remember names), visual
recognition (identify pictures) and verbal (recognise names). Those who left
after 15 years had 60% free recall and 90% visual and verbal recognition. Those
after 48 years had 70% free recall and 80% visual recognition.
Strengths - supported by research. Murdock - Serial Position Effect:
Primacy effect (remember first words through LTM) and Recency
effect (last few in STM). Distinction between STM and LTM is
supported by case studies of amnesia. Shallice adn Warrington - KF
could recal 1/2 items in digital span and had no recall problems.
Weaknesses - more than one LTM store, episodic (experiences) and
semantic (general). Exaggerate role of rehearsal Shallice and Warrington -
brain damaged subjects have LTM of events after damage without using
STM.
Working Memory
The Phonological Loop - auditorily,
phonological store (perception of
sound) and articulartory loop
(production of speech), last 2
seconds.
The Central Executive -
controls other components.
Visuo-Spatial - sketchpad
which visually organises
information.
Baddeley and Hitch - task 1 - statement A then B,
had to decide if they were in teh correct order
(occupied central executive). Task 2 - either repeat
'The' (articularly loop), random digits (articulary loop
and central executive) or no task. Task 1 and 1 or 3
showed okay performance. Task 1+2 showed speed
dropped.
Strengths - support from effects of brain damage - Farch - LH was
good at spatial tasks. Word length effect - shorter words take less
time. Bran scans - Cohen - prefrontal cortex (central executive),
Wernicke (perception), Brochas (production), occipital lobe
(visuo-spatial).
Weaknesses - no experimental evidence for the central executive. Not clear how information
is taken to the LTM. Individual differences - Engle - differences in reading, spelling and
writing not clear why.
Eye Witness Testimony
Loftus and Palmer - film of multiple car crashes, participants were asked
how fast was it going when it_? hit, smashed, contacted. Smashed - 41mph,
contacted - 32mph. Eval - video (not emotionally arousing, lacks ecological
validity), demand characteristics (clues make it unvalid and unreliable).
Second Experiment - 3 groups, smashed, hit, no indication, asked "any
broken glass?" there was no glass but smashed group said yes.
Anxiety - sense of unease or worry. Peters - clinic where patients were having
injections. Met a nurse and researcher, 1 week later asked to identify nurse an
researcher from photographs, researcher was more readily recognised. Loftus -
weapon focus - monitored gaze of participants. When shown a crime film, less
able to identify robber with fewer details recalled than others without a gun.
Age - young age are more sensitive to leading questions. Ceci - 3-4 year olds most
susceptible. Warren - children and adults given a story followed by 20 questions, 15
misleading. Children were more likely to be influenced. Elderly - Cohen and Falkner - young
adults and elderly participants were shown a silent clip of a kidnapping,. 10 minutes later
given one of two versions of a written summary. When tested, elderly were more likely to
be influenced by incorrect summary.
Cognitive Interview - 1. Reinstate context (before, during and after, the environment and
mood). 2. Change Sequence (recall in different orders to fill in any gaps). 3. Change
Perspective (report as another observer). 4. Report everything. EVAL - little training -
Geiselman - 35% more accuracy with only a brief guidance. interview - inexperience could ask
leading questions. Limitations - Eysenck and Keane - erroneous recall, doesn't help culprit
recognition, less effective as time passes.
Improving Memory
Acronyms - word that is formed out of the first letter of a string of other words. EVAL - only
useful for memory of things that need to be recalled exactly. Difficult to create, may have to
change order of words, difficult to commit to memory (spend longer thinking of one), Bower -
making material meaningful with visual imagery makes it easier to remember.
Method of Loci - visualising a familiar place such as home, then placing things to
remember around it. EVAL - mental imagery idea is well established (used a lot
in Ancient Greece), dual code theory (encoded with both visual and auditory
codes, making it stronger), Covitz - 2 groups of participants had to remember 32
words, 1 with the loci method - 78%.