The nature of working memory
capacity in sentence comprehension:
Evidence against domain-specific
working memory resources
Federenko, Gibson, & Rohde
Journal of Memory and Language, 2006
Kacey Wochna
Psycholinguistics
November 3rd, 2010
Background
What is the nature and functional organization of working
memory?
 Domain-general or domain-specific?
Is verbal working memory general or specific?
 All verbally mediated tasks use the same pool of VWM
resources (King & Just, 1991; Just & Carpenter, 1992)
 Linguistic and non-linguistic verbal tasks use different
VWM pools (Caplan & Waters, 1999)
Background
Dual-Task Approach: On-line sentence processing and a nonlinguistic verbal task are performed simultaneously
If VWM is domain-specific...
 Memory load in a non-linguistic verbal task should not
interact with syntactic processing (as in Caplan & Waters,
1999)
If VWM is domain-general...
 The two tasks should interact
 Interaction found using the individual differences approach
(Just and colleagues)
 Caplan and Waters found off-line interactions, but argued that
off-line processing goes beyond linguistic processing
Current Study
Based on Gordon, Hendrick, and Levine (2002)
 In previous research, memory load was defined as the number of
items kept active in memory
 Proposed that load should be measured by the amount of
interference produced by the items kept active in memory
 Similarity-based interference probably affects retrieval
Low syntactic complexity (subject-extracted cleft)
It was the dancer that liked the fireman before the argument began.
High syntactic complexity (object-extracted cleft)
It was the dancer that the fireman liked before the argument began.
Match (high similarity): poet – cartoonist – voter
Non-match (low similarity): Jim – Greg – Andy
Current Study
 Difference in rate of comprehension errors between low
and high complexity was larger when memory load was
matched
 BUT on-line reading times only showed a trend towards
this interaction
Federenko et al.
 Moving-window instead of center-screen presentation
 Amount of interference is possibly a function of both the
similarity of the items and the number of items
Method
32 experimental items, self-paced moving-window presentation
Low syntactic complexity (subject-extracted relative clause)
The physician who consulted the cardiologist checked the files in the office.
High syntactic complexity (object-extracted relative clause)
The physician who the cardiologist consulted checked the files in the office.
Match (high similarity): poet – cartoonist – voter
Non-match (low similarity): Joel – Greg – Andy
Easy load: (one noun)
Hard load: (three nouns)
Procedure:
memory nouns -> sentence -> recall -> 2 comprehension questions
Results
Comprehension questions:
 Better accuracy in the easy load condition than the hard
load condition
 Marginal three-way interaction of load, similarity, and
complexity – trend for load to affect high complexity
sentences more was more pronounced in the match
condition
 Didn’t replicate Gordon et al.’s finding, probably due to
procedural differences
Results
Reading times:
 Three-way interaction
in critical region
Easy load:
 Longer reading times
for high complexity
 No effect of match
Hard load:
 Match only caused
longer reading times for
high complexity
Results
 When the number of items that had to be kept in memory
was greater, people processed syntactically complex
sentences more slowly when the items to be kept in
memory were more similar to the nouns in the sentences.
 Non-linguistic verbal memory loads interact with syntactic
processing
 Both the similarity of items and the number of items
contribute to interference
 Support for domain-general VWM system