Introduction to Cognitive Psychology - Department of Psychological ...

Greg Francis 1/6/11Statistics!! The previous paragraph creates coherentgroups of 4 words at a time (generator madesure 4 words were with high probability)!! Maybe by including a larger number of wordsgrouped together you can insure that everysentence is appropriate!! Actually you cannot!!Because sentences have no maximum lengthPurdue UniversityLong-term dependencies!! Language has rules that determine what types ofwords can be used and when!! A word choice early in a sentence can have an effectat the end of a sentenceHow Ann Salisbury can claim that Pam Dawber’s angerat not receiving her fair share of acclaim for Mork and Mindy’ssuccess derives from a fragile ego escapes me.1) “at not receiving ” --> noun “acclaim”2) “anger” --> “derives” (singular)3) “How” --> “escapes” (number)Purdue UniversityLong-term dependencies!! Chomsky demonstrated that long termdependencies can be very long!!Consider “If…then…” and “Either…or…” sentencesIf the girl eats ice cream, then the boy eats hot dogs.Either the girl eats ice cream, or the boy eats hot dogs.Recursion!! In fact, any sentence can go inside the “if…then”part of a sentence!! embed a sentence in a sentence!! Thus the following is a (ugly) valid sentenceEither if the girl eats ice cream, then the boy eats icecream, or if the girl eats ice cream then the boy eats candy.!! recursion cannot be learned by statistics, it has to bebased on rulesPurdue UniversityPurdue UniversityPhrases!! Every sentence is built out of phrasesThe happy boy eats candy.The first three words form a unit calleda noun phrase (NP)The happy boyWhat identifies anoun phrase?This is not the same analysis you didin grammar school!Purdue UniversityPhrases!! All noun phrases obey certain rules!!rewrite rulesNP-->(det)A*Nthe happy boy!!NP -- noun phrasethe boy!!det -- determinant: “the”, “a”, “an” John!!A -- adjectivethe tall slender woman!!N -- noun!!( ) -- optional!!* -- as many as you wantPurdue UniversityPSY200 Cognitive Psychology 3