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 3 rd, 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 – 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