The nature of working memory capacity in sentence comprehension: Evidence against domain-specific working memory resources

Federenko, Gibson, & RohdeJournal of Memory and Language, 2006

Kacey WochnaPsycholinguistics

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 non-linguistic 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 – voterNon-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

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