 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?