Memory Flashcards
Short term memory
Capacity - 7+/-2 items
Duration - 6-30 seconds
Encoding - acoustic
Long term memory
Capacity - unlimited
Duration - lifetime
Encoding - semantic
Sensory register
Capacity - less than 2
Duration - 2-3 seconds
Encoding - 5 senses
Evidence for the duration of the short term memory.
Peterson and Peterson (1959)
24 students, shown a consonant trigram (e.g. CPW)
They were asked to count backwards to prevent mental rehearsal.
After 3 seconds - 80% were recalled
After 6 seconds - 50% were recalled
After 18 seconds - fewer than 10%
Evidence for the duration of the long term memory.
Bahrick (1975)
392 participants, testing recall with a yearbook
1) photo recognition 2) free recall of names
Faces recognised 90% after 15 years of graduation and recall of names 60%. Recognition dropped to 70% after 48 years and recall was 30%.
Less was recalled after a log time but still lots.
Evidence for the capacity of the short term memory.
Miller (1956)
Directional hypothesis - as the number of digits increase the rate of accuracy decreases.
IV - number of digits.
DV - accuracy of recall.
Evidence for the coding in the short term memory and long term memory.
Baddley ( 1966)
Group 1 - acoustically similar words (cat,cab)
Group 2 - acoustically dissimilar (pit, few, cow)
Group 3 - semantically similar (great,large,big)
Group 4 - semantically dissimilar (good, huge, hot)
STM did worse with acoustically similar words.
LTM did worse with semantically similar words.
Non- declarative memories are for things we “know how” to do, for example knowing how to ride a bike
Procedural memories - performing skills and actions, which become unconscious over time. E.g. swimming, driving, cycling
Semantic memories- learnt facts and information, which we always have to consciously remember. E.g. address, capital cities
Episodic memory- for past events and experiences which we have consciously remember. Usually associated with the times, place and emotions a. E.g. birthdays, funeral
Working memory model
Baddeley and hitch (1975)
Phonological loop - sound based info e.g. songs
Episodic buffer - extra storage system
Visio-spatial sketchpad - visual tasks e.g. picturing your house
Articulatory suppression - when trying to do two sound based tasks at the same time.
Central executive - co ordinated the activities of the three subsystems.also allocates processing resources to those activities. Has limited capacity
Proactive interference - involves old information interfering with new information.
Retroactive information - involves new information interfering with old information.
Interference - forgetting because one memory blocks another, causing one or both memories to be distorted or forgotten.
Effects of similarity
Mcgeoch and McDonald (1931)
Participants learned a list of 10 words, until they knew it 100% and then learned another.
6 groups;synonyms (same), antonyms (opposite), unrelated, consonant syllables, 3 digit numbers, no list
Findings
When recalling original list their performance depended on the 2nd list. Synonyms produced the worse recall. This shows interference is strongest when meteorites are similar.
Evaluation- a strength, using lab experiments control extra variables, giving the study validity.
A weakness is an artificial task, interference may not be as likely an explanation for forgetting in everyday life as it is in the lab.
Context forgetting - cues aren’t available because of the environment.
“Deep sea divers”
Godden and baddeley (1975)
Divers learned a list of words underwater or on land and had to recall. 4 conditions: land - water, water - land, land - land, water - water.
Accurate recall was 40% lower in the non_matching conditions. The external cues at learning were different from the ones at recall and this lead to retrieval failure.
