Recall Capacity of Short-term Memory Michael Schielke

Objective Determine whether short-term memory store is based on time or chunks Determine capacity of short-term store

Baddeley vs. Cowan Baddeley 1-2second working memory Memory stores over a span of time Memory Decay Phonological loop model Cowan 4+/-1 chunk capacity Overload Effect of long-term memory Focus of attention

Baddeley’s Time Span Model Rate of Decay –Short-term memory fades over a few seconds –Rate of decay experiment –Subsequent silence vs. speech Phonological Loop Model –Evolved system to facilitate language acquisition –Phonological store of 1 to 2 seconds –Maximum capacity before fading occurs

Cowan’s Chunking Model What makes up a chunk? –Effect of Long-term memory Overload –More information than can be recalled Focus of Attention –Items must exist in the focus of attention directly preceding the response –Serial recall test

The Study Method –Syllabic chunks based on unfamiliar language –Stimuli recorded in Japanese by Native speaker 3-10 syllables ( seconds) Two words from each set –Items played to participants once each Participants repeat what is heard Correct and incorrect repetition recorded –25 participants with no Japanese exposure 14 males/11 females Age monolingual English/ 6 Bilinguals (English +)

Stimuli 3 Syllables waraji, hakari 4 Syllables kurogane, samehada 5 Syllables tarachineno, kusamakura 6 Syllables zashikiwarashi, warabukiyane 7 Syllables tanabatamatsuri, hokosugibayashi 8 Syllables kamakuramonogatari, yamagoyamitorizu 9 Syllables harimayabashimeguri, kikagakutekizushiki 10 Syllables kamagasakiyudetamago, hakodateyamashikimado

Results ChunkingTime Elapsed

Results cont. 84% recall of 3 and 4 syllables 48% recall of 5 syllables Highest probable recall time.715%

Monolinguals vs. Bilinguals ChunksTime Elapsed

Monolingual vs. Bilingual Results Higher level of recall by native bilinguals –32% increase in recall of 3-4 syllable words –Increased recall capacity on 5-10 syllable words

Discussion Influence of Chunks and Time –As word length increases, recall decreases Possible Explanations –Focus of Attention (Cowen 2001) –Rate of Decay (Baddeley 1998) Monolingual vs. Bilingual Recall –Phonological Inventory?

Conclusion Support towards Cowan’s 4+/-1 Model Evidence for a 1-second working memory Additional research needed to reveal contrast between monolingual and bilingual recall probability.