PSY 369: Psycholinguistics Language Comprehension: From sentences to discourse

Comprehension roadmap Last week: Role of syntax Important for getting on-line comprehension right Doesn’t stick around as long as meaning This week: Meaning in comprehension Propositions Embodied representations Comprehension in Discourse

Propositions How do we represent sentence meaning? Propositions Two or more concepts (arguments) with a relationship between them Arguments – particular times, places, people, objects, etc. (nouns) Relationships - May be used for any kind (e.g., actions, attributes, positions, class memberships) Smallest unit of knowledge that can be judged as true or false Complex sentences consist of combinations of smaller propositional units

Propositions A mouse bit a cat bit (mouse, cat) How do we represent sentence meaning? Propositions Two or more concepts with a relationship between them Can represent this within a network framework mouse bit cat agent patient relation

Deriving Propositions More complex example: Children who are slow eat bread that is cold Slow children Children eat bread Bread is cold relation subject time relation subject SlowChildren PastEat Cold Bread

Evidence for propositions Bransford and Franks (1971, 1972) Ratcliff and McKoon (1978)

Evidence for propositions Bransford and Franks (1971, 1972) Study-Recognition Test Task Read sets of sentences, answered a question about each, later presented sentences and asked whether they were new (not previously presented) or old (previously presented) The girl broke the window on the porch.Broke what? The hill was steep.What was? The cat, running from the barking dog, jumped on the table. From what? The tree was tall. Was what? The old car climbed the hill.Did what? The cat running from the dog jumped on the table.Where? The girl who lives next door broke the window on the porch. Lives where? …

Evidence for propositions Bransford and Franks (1971, 1972) Study-Recognition Test Task All of the sentence came from 4 complex sentences. The full complex sentences were not presented at study. e.g., The girl who lives next door broke the large window on the porch … The girl lives next door. The girl broke the window. The window was on the porch. The window was large.

Evidence for propositions Bransford and Franks (1971, 1972) Study-Recognition Test Task Test: Old - same sentences that were presented at study New - based on the propositions in the complex sentence, but not presented at study (including the full complex sentences) Noncase - based on new propositions not based on the complex sentences (mixing of propositions across the different situations)

Evidence for propositions Bransford and Franks (1971, 1972) Study-Recognition Test Task Results: False recognition of sentences that they were not previously presented with Accurate rejections of noncases (different propositions) Unable to distinguish between the old and new cases that came from the same complex sentences Recognition confidence 0 Yes 5 foursthreestwosones  noncases # of propositions Yes 4 Yes 3 Yes 1 Yes 2 No 2 No 3 No 4 No 1 No 5     ★ new old

Evidence for propositions Bransford and Franks (1971, 1972) Study-Recognition Test Task Conclusions: Participants remembered the basic meaning (propositions) Participants spontaneously combined the propositions into larger units Recognition confidence 0 Yes 5 foursthreestwosones  noncases # of propositions Yes 4 Yes 3 Yes 1 Yes 2 No 2 No 3 No 4 No 1 No 5     ★ new old

Evidence for propositions Ratcliff and McKoon (1978) Tested 3 hypotheses: 1. Sentences stored as single unit 2. Sentences stored as connected propositions 3. Sentences stored verbatim

Evidence for propositions Ratcliff and McKoon (1978) Study-Recognition Test Task Read sets of 4 unrelated sentences, then presented words (one at a time) and asked whether the words were in the preceding sentences Dependent Measure: Priming - manipulated the order of the words at test The mausoleum that enshrined the tsar overlooked the square. The clutch failed to engage. The beggar forgave injustice but resented hunger. Satire hurt the incumbent. hunger Y Saturn N square Y mausoleum Y beetle N

Evidence for propositions Ratcliff and McKoon (1978) Involves two propositions: P1 [OVERLOOK, MAUSOLEUM, SQUARE] P2 [ENSHRINE, MAUSOLEUM, TSAR]. The mausoleum that enshrined the tsar overlooked the square. The clutch failed to engage. The beggar forgave injustice but resented hunger. Satire hurt the incumbent.

Evidence for propositions Ratcliff and McKoon (1978) Predictions ( if Hypothesis 2: propositions are the memory representation ): If prime word from the same sentence, then should respond faster If prime word from the same proposition, then should respond faster than if from a different proposition (within the same sentence) The mausoleum that enshrined the tsar overlooked the square. The clutch failed to engage. square clutch Across sentences Between two propositions in the same sentence square tsar square mausoleum Within a single proposition

Evidence for propositions Ratcliff and McKoon (1978) Predictions ( if Hypothesis 2: propositions are the memory representation ): If prime word from the same sentence, then should respond faster If prime word from the same proposition, then should respond faster than if from a different proposition (within the same sentence) square clutch Across sentences Between two propositions in the same sentence Within a single proposition Results **111 msec**91 msec square mausoleum square tsar

Evidence for propositions Ratcliff and McKoon (1978) Predictions ( if Hypothesis 2: propositions are the memory representation ): If prime word from the same sentence, then should respond faster If prime word from the same proposition, then should respond faster than if from a different proposition (within the same sentence) square clutch Across sentences Between two propositions in the same sentence Within a single proposition Results **20 msec square mausoleum square tsar

Evidence for propositions Ratcliff and McKoon (1978) Predictions ( if Hypothesis 2: propositions are the memory representation ): If prime word from the same sentence, then should respond faster If prime word from the same proposition, then should respond faster than if from a different proposition (within the same sentence) Conclusions Support the hypothesis that propositions are used to organize our memories of sentences

Inference in comprehension Not all propositions come from the bottom-up Elaboration - integration of new information with information from long term memory Memory for the new information improves as it is integrated Inferences - a proposition (or other representation) drawn by the comprehender From LTM, not directly from the input

We draw inferences in the course of understanding new events. The inferences get encoded into our memory of the events. e.g., drawing inferences of instruments Bransford, and colleagues (1972, 73) Inference in comprehension

Saw (or heard): John was trying to fix the birdhouse. He was looking for the nail when his father came out to watch him and to help him do the work. Bransford, and colleagues (1972, 73) Tested: John was using the hammer to fix the birdhouse when his father came out to watch him and to help him do the work. Inference in comprehension was not mentioned in the text, but was inferred Result: Participants falsely believed that they had heard this sentence So memory is not only of propositions in the original sentence, but may also include additional propositions that may have been inferred

Arguments against propositions Propositions are symbolic and amodal Referential problem: Disconnected with outside world (symbols referring to other symbols) Implementation problem: Has been very difficult to develop a propositional parser Lack of scientific productivity: More work on what you can do with propositions than is there evidence of the psychological reality of propositions Lack of a biological foundation: How do biological (or neurological) data constrain propositions

Embodiment in language Embodied Representations Perceptual and motor systems play a central role in language production and comprehension Theoretical proposals from many disciplines Linguistics: Lakoff, Langacker, Talmy Neuroscience: Damasio, Edelman Cognitive psychology: Barsalou, Gibbs, Glenberg, MacWhinney, Zwaan Computer science: Steels, Feldman

Embodiment in language Embodied Representations Perceptual and motor systems play a central role in language production and comprehension Words and sentences are usually grounded to perceptual, motoric, and emotional experiences. In absence of immediate sensory-motor referents, words and sentences refer to mental models or simulations of experience  Simulation hypothesis  Simulation exploits some of the same neural structures activated during performance, perception, imagining, memory… Language gives us enough information to simulate

Embodiment in language Evidence for Embodied representations Stanfied & Zwaan (2001) Presented participants with sentences John put the pencil in the cup. John put the pencil in the drawer Reults: faster at saying horizontal pencil with drawer and vertical pencil with cup See a picture and ask “does this describe what you read about?”

Embodiment in language Evidence for Embodied Representations Zwaan et al (2004) Presented participants with a sentence A: The pitcher hurled the softball at you. B: You hurled the softball at the pitcher. Reults: faster at saying ‘Yes’ when sentence matched the pictures (e.g., sentence A and pictures in A, if the ball is small and then gets big, it is coming towards you) See two pictures and ask “are these pictures the same object” A B

Summing up The results of sentence comprehension are meaning representations Some debate over what these representations are Whatever they are, they get integrated with each other and with existing knowledge from LTM

Discourse Psycholinguistics Traditional Psycholinguistics Determining what happens when we understand sentences Broader View How we resolve/understand sentences against the current discourse representation Sentence comprehension is a process that anchors the interpretation of the sentence to the representation of the prior text