COGNITION: PSYC-316 DISCUSSION #5
Dee5
STMLeakyBucket.pptxLearning objectives: By the end of this presentation you will be able to…
recognize that the leaky bucket is one of two conceptualizations of STM
describe the duration of STM and explain why STM is so short by interpreting findings from research using the Brown-Peterson task.
describe the capacity of STM by interpreting findings of research using the Digit-Span and Change-Detection tasks; describe the effects of chunking and of increasing informational complexity on STM capacity.
explain how a multi-component model of working memory can handle disparate estimates of STM capacity.
Short-Term Memory: Leaky Bucket
I. STM as Leaky Bucket vs Working Memory
II. What Is the Duration of STM and Why So Short?
Brown-Peterson Task -participants recall trigrams after intervals of 3, 6, 9, 12, 15 or 18 seconds.
Peterson & Peterson (1959) found that participants were able to recall 80% of trigrams after a 3 seconds delay.
Really? You Try It! Oh, and you have to count backwards while remembering…
Interpretation: items in STM decay quickly.
Short-Term Memory: Leaky Bucket
I. STM as Leaky Bucket vs Working Memory
II. What Is the Duration of STM and Why So Short?
Brown-Peterson Task
Peterson & Peterson (1959)
Interpretation: items in STM decay quickly.
Keppel & Underwood (1962) found the first items on the Petersons’ list were remembered longer…
Revised Interpretation: items in STM suffer from proactive interference-forgetting due to interference from learning that occurred prior to the materials to be remembered.
Short-Term Memory: Leaky Bucket
I. STM as Leaky Bucket vs Working Memory
II. What Is the Duration of STM and Why So Short?
III. What is the Capacity of STM?
A. 7 ± 2 using Digit -Span task (Miller, 1952)
Miller (1956) found that STM capacity can be extended by chunking items…
chunk- a collection strongly associated elements, with weak associations to elements of other chunks
Short-Term Memory: Leaky Bucket
I. STM as Leaky Bucket vs Working Memory
II. What Is the Duration of STM and Why So Short?
III. What is the Capacity of STM?
A. 7 ± 2 using Digit-Span task (Miller, 1952)
B. about 4 items using Change- Detection task (Vogel et al, 2005)
# items decreases as item complexity increases (Alvarez & Cavanagh, 2004) …
Short-Term Memory
I. STM as Leaky Bucket vs Working Memory
II. What Is the Duration of STM and Why So Short?
III. What is the Capacity of STM?
A. 7 ± 2 using Digit-Span task (Miller, 1952)
B. about 4 items using Change- Detection task (Vogel et al, 2005)
C. How can we account for different estimates of STM capacity?
By reconceptualizing STM as a multicomponent model of “Working Memory”…
Short-Term Memory: Leaky Bucket
