Presentation on theme: " What is Short-Term Memory? How can you fit more information into STM? Is STM different from LTM? How does STM compare to Working Memory?"— Presentation transcript:
What is Short-Term Memory? How can you fit more information into STM? Is STM different from LTM? How does STM compare to Working Memory?
Lasts about 18 seconds without rehearsal (Peterson & Peterson,1959): count backwards by threes and then remember a set of letters Capacity is 7 +/- 2 chunks
The amount of information in a chunk can vary (12 chunks) (3 chunks) You can use mnemonics to make very large chunks
Primacy Effect – LTM Recency Effect – STM Double-dissociation: H.M.: loss of LTM with intact STM K.F.: loss of STM with intact LTM
Letters that sound similar (b and v) are more likely to be confused than letters that look similar (q and p) (Conrad, 1963) Bilingual Welsh-English speakers can remember more digits in English than in Welsh - the names for numbers are longer in Welsh (Baddeley, 1982)
Two letters are presented with a brief delay between them. Time to say whether the letters are the same is less when they match visually (Posner & Keele, 1967) Faster to match A-A or a-a than A-a
Different view of STM Emphasizes processing ability Need to coordinate storage and processing “Mary and John got into a fight and she refused to speak to him”
Central Executive Phonological Loop Visual - Spatial Scratchpad - makes decisions - coordinates rehearsal
Phonological loop Phonological similarity effect (Conrad,1964) Word length effect (Baddeley et al.,1984) Articulatory suppression (Baddeley et al.,1984)
Visual-Spatial Scratchpad Pointing to a yes-no response interferes with performance on a visual task but not on a verbal task (Brooks, 1968) Neurons in primary visual cortex active in monkeys during delayed-response task (Super et al., 2001)
What is the adaptive value of working memory?