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Forweb Presupposition Existence Presuppositions Factive Presupposition • Propositions whose truth is taken for granted in the utterance of a linguistic forweb expression – It’s too bad Nader lost the election. Existence Presuppositions Factive Presuppositions • The movie on Cinemax is rated X. • Jan knows that Taylor has a 42 inch • I’ve coached Jack’s children. vertical leap. • Jan regrets that Taylor has a 42 inch vertical leap. • Jan forgot that Taylor has a 42 inch vertical leap. • Jan is glad that Taylor has a 42 inch vertical leap. Connotative Presuppositions Blame vs. Criticize • Ralph was • Involve words used in particular blamed/criticized for B circumstances • Both imply – Presuppose those circumstances – Ralph did B – B is bad • Murder •Blamed – Killing intentional – Presupposes •B is bad • Assassinate – Asserts • Ralph did B – Target has political power • Criticized – Presupposes • Ralph did B – Asserts •B is bad 1 Presupposition & Memory for Properties of Presupposition Events • Content is taken for granted • Loftus initiated • Still there if you negate the main verb research on real- world memory – He regretted going to the concert the night before the quiz. – Began with study of impact of question – He didn’t regret going to the concert the night phrasing before the quiz. • Loftus & Zanni (1975) • Can’t be denied without contradiction – Did you see the – He regretted going to the concert, but he didn’t go broken headlight? to the concert. (huh?) – Did you see a broken • Can be relative to an assumed world headlight? – I dreamed the earth was flat, and a lot of people were glad when Columbus fell off the edge. Presupposition & Surveys What causes these effects? • Do you get • Questions facilitate experimenter demand headaches effects frequently? If so, how – Hear question about “the” headlight and infer often? that there must have been a headlight, even – 2.2/week though you don’t remember seeing one • Do you get • Question alters participants’ memory for headaches events occasionally? If so – Misleading information gets combined with how often? the original information and results in a – .71/week different memory for what happened 1 week later… Loftus & Palmer (1974) Did you see any broken glass? • Showed people movie • (film contained no broken glass) • “smashed” people more likely than “hit” people to say of a car accident YES! • About how fast were • Loftus & Palmer argued that question caused people to reinterpret accident and brought about a permanent the cars going when transformation of their memory for the acccident they – hit each other? 8 mph – smashed into each other? 10.5 mph 2 Loftus 1975: Loftus (1975) False presuppositions & memory • Was the leader of the • Watch movie about car 4 demonstrators traveling along a country male? road • How fast was the car • Was the leader of the going while traveling 12 demonstrators along the country road? male? • How fast was the car • (there were 8) going when it passed the barn while traveling along • 1 week later: the country road? – How many demonstrators did you see entering the room? A week later… Loftus, Miller & Burns (1978) • Subjects viewed series of 30 • Do you remember seeing a barn? slides; answered 20 questions about them • People who received the first version of • Did another car pass the red Datsun while it was stopped at the question almost always said “no” the – Stop sign? • People who received the misleading – Yield sign? • Forced choice recognition test version of the question much more likely to – Stop Group: 75% correct – Yield Group: 41% correct falsely remember seeing a barn! • Lower than chance! • Exposure to misleading information in questions altered thei responses to later questions Memory for Color Misinformation Effects • Slde showed red car passing green car • No hesitation, no lack of confidence • Did the blue car that drove past the accident have a ski rack on • No effects when people realize info is false while the roof? reading it • Did the car that drove past the accident have a ski rack on the – Was the car that drove past the accident blue? (no roof? subsequent misinformation effects) • Answers to questions influenced by the way earlier statements and • People who process misinformation carefully questions had been phrased. – Misled subjects chose bluer shade can ignore it • Memory for true color seems to have blended with the color – Tousignant, Hall, and Loftus (1986) implied by the misleading question – Subjects watch an event, read a misleading text about it, then do recognition test – Slow, careful readers: Loftus, 1977 • Point out misinformation when it occurs • Not subject to subsequent misinformation effects 3 What causes misinformation Logic of Biased Guessing effects? Account Loftus McCloskey/Zaragoza Control Group Experimental Group • Substitution Hypothesis • Biased Guessing – Later information overwrites – Misleading info affects • 50% Remember • 50% Remember established information behavior when subjects – Consequences for memory: unable to remember event – Answer correctly – Answer correctly • Difficulty discriminating – Doesn’t affect original memory • 50% Forget • 50% Forget Original original event and Lindsay/Johnson subsequent information about it • Blended Memory – 25% Guess Right but remember • Original trace is overwritten – Misleading info gets combined – 25% Guess Wrong something about the by later information with original memory (doesn’t – Controversial because most completely overwrite it) misinformation psychologists believe long- term memories are stored – 20% Guess Right “forever” – not overwritten – 30% Guess Wrong Loftus, Miller & Burns (1978) Modified Recognition Test • Subjects viewed series of 30 slides; answered 20 questions about them • Did another car pass the red Datsun while it was stopped at the – Stop sign? – Yield sign? • Forced choice recognition test – Stop Group: 75% correct – Yield Group: 41% correct • Lower than chance! • Exposure to misleading information in questions altered thei responses to later questions McCloskey & Zaragoza (1985) Predictions Zaragoza, McCloskey, Jamis (Verbal) Loftus McCloskey & Zaragoza’s Biased • Control subjects should be Guessing account more accurate than misled • Misleading information will subjects because wrench will have no effect on performance overwrite the hammer in • This because, misleading info memory works by biasing subjects to • Misled subjects more likely to choose the picture consistent have to guess randomly with the misleading information between the two pictures (and neither picture qualifies) • “Loftus” Condition: What was on the desk? • Cued Recall Condition: What brand of soft drink was on the desk? • In fact, McCloskey & Zaragoza • Biased Guessing: found similar performance in – original memory intact, and question phrasing doesn’t bias guessing based on misinformation, so: – control and experimental groups perform equivalently in cued recall experimental and control • Substitution: groups – original memory overwritten, so – experimental group should perform worse than controls in cued recall • Equivalent performance of control & experimental groups under cued recall condition! 4 Lindsay/Johnson Take-Home Messages • Reverse Misinformation Effect • Misleading questions affect memory because both processes – understanding the questions – Misleading information presented before the pictures and the encoding and retrieval of information – also leads to misinformation effects involves frames and schemas • Substitution Hypothesis predicts memory for • Schema-based reconstructive memory also pictures will overwrite memory for misleading explains why questions – Memory for verbal communication retains the gist of its meaning • RME consistent w/idea that people form a – Memory for pictures retains meaningful interpretation blended memory of pictures and of misleading of picture information presupposed in questions asked of – Memory for meaning lasts longer than for physical details them Take-Home Messages In a nutshell… • Schemas large, complex units of • Comprehension an active process of integrating knowledge that encode typical properties incoming information with knowledge stored in LTM of instances of general categories • Representation of knowledge something we’re – Enable us to infer unseen info from what is still working on… seen –Features – Lead us to ‘remember’ things we haven’t seen – Propositions – Frames, Scripts, Schemas – MOPs, TOPs, TAUs –??? 5.
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