PSY 369: Psycholinguistics Language Comprehension: The role of memory Memory and comprehension The man that the woman that the child hugged kissed laughed. Most readers having trouble figuring out who did what to whom (called thematic role assignment). The trouble: Easier to assign thematic roles in the two sentences that form it: The man that the woman kissed laughed. The woman that the child hugged kissed the man. Insufficient working memory resources to retain the intermediate products of computation made building the complex syntactic structure The Capacity Theory of Comprehension Carpenter, 1992) (Just & Measuring memory span Daneman and Carpenter (1980??) Technique: This technique involves presenting sequences of 2 to 6 sentences, each of 13 to 16 words. The subject has to read the sentences out loud, and attempt to remember the last word of each. He is then asked to recall as many last words as possible (in any order). Used to classify readers as high and low span Measuring memory span Insert example of span test Memory and comprehension Just and Carpenter (1992) Studied garden path sentences The animacy of the first noun may constrain the possible interpretation of the sentence The defendant examined by the lawyer shocked the jury. The defendant that was examined by the lawyer shocked the jury. The evidence examined by the lawyer shocked the jury. The evidence that was examined by the lawyer shocked the jury. Memory and comprehension Just & Carpenter (1992) 600 The defendant examined by the lawyer shocked the jury. 550 500 msec Just the ambiguous sentences animate NP Inanimate NP 450 400 The evidence examined by the lawyer shocked the jury. 350 300 Low-span High-span High span readers can use the semantic information to resolve the ambiguity Memory and comprehension King and Just (1991) Verbs which could provide strong pragmatic cues as to which of the two potential actors in the sentence was the agent : The robber that the fireman rescued stole the jewelry. The robber that the fireman rescued watched the program. The robber that the fireman detested stole the jewelry. The robber that the fireman detested watched the program. Results High-capacity subjects did not improve Low-capacity subjects did The opposite of the Just and Carpenter (1992) results. Memory and comprehension Garnsey, Pearlmutter, Pirog (2003) The professor (who was) confronted by the student was not ready for an argument. The professor (had) confronted the student but was not ready for an argument. Question: Do readers differ specifically in how quickly they can use disambiguating words to rule out incorrect alternatives? Memory and comprehension Garnsey, Pearlmutter, Pirog (2003) Eye fixations were analyzed separately - By whether preview of “by” while still fixating on verb likely If last fix was here, trial not used The professor confronted by the student was not ready to … If last fix was here, trial coded as Preview Unlikely If last fix was here, trial coded as Preview Likely Memory and comprehension Readers who score high on the Reading Span test - Make better use of a peripherally visible disambiguating word - To quickly rule out a preferred but incorrect interpretation Memory and comprehension Read sentence, then decide if it makes sense Y/N Waters & Caplan (19960 Mean reading time per word 700 600 500 400 300 200 100 0 Garden path Non-garden path A Non-garden path B Low Medium Span Group High Memory for sentences Fillenbaum (1966) Given: The window is not closed Tested: The window is closed <-- surface similar, meaning different The window is not open <-- surface similar, meaning different The window is open <-- surface different, surface different Meaning gets preserved, surface structure (and syntax) forgotten Memory for sentences Sachs (1967, 1974) Heard (read): Tested: He sent a letter about it to Galileo, the great Italian scientist.” Same: He sent a letter about it to Galileo, the great Italian scientist. Act/Pass: A letter about it was sent to Galileo, the great Italian scientist. Formal: He sent Galileo, the great Italian scientist, a letter about it. Meaning: Galileo, the great Italian scientist, sent him a letter about it. Measured accuracy of detecting changes Memory for sentences Percent correct Sachs (1967) semantic change active/passive change formal change 100 90 80 70 60 50 identical sentence 0 80 160 Amount of interpolated material (number of syllables) Meaning gets preserved, surface structure (and syntax) forgotten Just good enough representations Ferreira and colleagues (Christianson et al 2001) Garden-path sentence While Anna dressed the baby played in the crib While Anna dressed, the baby played in the crib Did the baby play in the crib? Did Anna dress the baby? 100% correct 40% correct Comprehenders don’t always get all of the meaning right, but get enough to get by Summing up summary