Even more on Speech Even more on Speech Perception: It s not just - PowerPoint PPT Presentation

LIGN171: Child Language Acquisition http://ling.ucsd.edu/courses/lign171 http://ling.ucsd.edu/courses/lign171 LIGN171: Child Language Acquisition Even more on Speech Even more on Speech Perception: It’ ’s not just s not just Perception: It phonemes phonemes

Word Segmentation Word Segmentation PL Chapter 3 PL Chapter 3 LDER Chapter 4 LDER Chapter 4

How do I find words? How do I find words? iamforcedintospeechbecausemenofsciencehaverefusedtofoll iamforcedintospeechbecausemenofsciencehaverefusedtofoll owmyadvicewithoutknowingwhyitisaltogetheragainstmywillth owmyadvicewithoutknowingwhyitisaltogetheragainstmywillth atitellmyreasonsforopposingthiscontemplatedinvasionofthea atitellmyreasonsforopposingthiscontemplatedinvasionofthea ntarcticwithitsvastfossilhuntanditswholesaleboringandmelting ntarcticwithitsvastfossilhuntanditswholesaleboringandmelting oftheancienticecapsandiamthemorereluctantbecausemywarn oftheancienticecapsandiamthemorereluctantbecausemywarn ingmaybeinvaindoubtoftherealfactsasimustrevealthemisinevit ingmaybeinvaindoubtoftherealfactsasimustrevealthemisinevit able;yetifisuppressedwhatwillseemextravagantandincrediblet able;yetifisuppressedwhatwillseemextravagantandincrediblet herewouldbenothingleftthehithertowithheldphotographsbotho herewouldbenothingleftthehithertowithheldphotographsbotho rdinaryandaerialwillcountinmyfavorfortheyaredamnablyvivida rdinaryandaerialwillcountinmyfavorfortheyaredamnablyvivida ndgraphicstilltheywillbedoubtedbecauseofthegreatlengthstow ndgraphicstilltheywillbedoubtedbecauseofthegreatlengthstow hichcleverfakerycanbecarriedtheinkdrawingsofcoursewillbeje hichcleverfakerycanbecarriedtheinkdrawingsofcoursewillbeje eredatasobviousimposturesnotwithstandingastrangenessofte eredatasobviousimposturesnotwithstandingastrangenessofte chniquewhichartexpertsoughttoremarkandpuzzleover chniquewhichartexpertsoughttoremarkandpuzzleover

Detecting Word Boundaries Detecting Word Boundaries Infants don’ ’t know any words t know any words Infants don � � How can they be found (and then How can they be found (and then � � learned)? learned)? What information in the speech stream What information in the speech stream � � can a baby use to find words? can a baby use to find words? Frequent sounds Frequent sounds 1. 1. Frequently co- -occurring sounds occurring sounds Frequently co 2. 2. Phonotactics (combinations of legal sounds in words) Phonotactics 3. (combinations of legal sounds in words) 3. Prosodic Patterns Prosodic Patterns 4. 4.

Frequent Sounds Frequent Sounds I’ ’ll give you a pot of sugar ll give you a pot of sugar I Put some tea in the pot Put some tea in the pot His pot is full of water His pot is full of water Pot of tea or coffee? Pot of tea or coffee? Put the red pot on the table Put the red pot on the table � Infants were habituated on sentences like these Infants were habituated on sentences like these � � Tested with Tested with “ “pot pot” ” and and “ “car car” ” � � Showed preference for Showed preference for “ “pot pot” ” � � Infants extracted sound pattern Infants extracted sound pattern – – despite not despite not � knowing meaning! knowing meaning!

Frequently co- -occurring sounds occurring sounds Frequently co � Sounds that co Sounds that co- -occur may form words occur may form words � � Transitional probabilities for syllables within Transitional probabilities for syllables within � words higher than for between words words higher than for between words � (given a syllable X, what is probability that next syllable will (given a syllable X, what is probability that next syllable will be Y) be Y) � � pretty baby pretty baby � � Probability of Probability of – –by following by following ba ba- - is higher than is higher than � probability of – –ba ba following following – –ty ty probability of � (compare pretty doggie, pretty (compare pretty doggie, pretty mommie mommie, pretty flower, etc.) , pretty flower, etc.) �

Saffran, Aslin Aslin and Newport and Newport Saffran, � Created 3 syllable nonsense words Created 3 syllable nonsense words � � bidaku bidaku padoti golabu tupiro padoti golabu tupiro � � Strung them together in two minute block Strung them together in two minute block � � bidakupadotigolabubidakutupiropadoti bidakupadotigolabubidakutupiropadoti… … � � Words were arranged in random order Words were arranged in random order � � (transition probability between words is lower than within words (transition probability between words is lower than within words) ) � � Tested for infants Tested for infants’ ’ listening preference for listening preference for � words (tupiro tupiro) vs. non ) vs. non- -words ( words (dapiku dapiku) ) words ( � Infants (8 months) preferred words to non Infants (8 months) preferred words to non- - � words words

Phonotactics Phonotactics � Certain sequences of phonemes are not Certain sequences of phonemes are not � legal within a word, or at the beginning or legal within a word, or at the beginning or end of a word end of a word � “ “tb tb” ” is not legal at the start of an English word is not legal at the start of an English word � � Possible word boundary between /t/ and /b/? Possible word boundary between /t/ and /b/? � � “ “sp sp” ” is legal at start of English word ( is legal at start of English word ( special special ) ) � and middle ( especial especial ) and end ( ) and end ( lisp lisp ) ) and middle ( � “ “sp sp” ” is not legal at start of Spanish word is not legal at start of Spanish word � � Phonotactic Phonotactic cues are language specific cues are language specific �

Prosodic Patterns Prosodic Patterns � Certain patterns are legal both within and across Certain patterns are legal both within and across � words words � - -rimen rimen- - � � expe expe rimen rimen tal tal vs. vs. ve ry ry men men acing acing ve � � Subtle differences in prosody between the two Subtle differences in prosody between the two � � Infants can detect the differences between Infants can detect the differences between � � - -rimen rimen- - � � - -ry_men ry_men- - � � Infants are also sensitive to stress patterns Infants are also sensitive to stress patterns � � 6 6- -9 month old (English 9 month old (English- -learning) infants prefer the learning) infants prefer the � typical strong- -weak stress pattern ( weak stress pattern (TAble TAble, , CARpet CARpet) ) typical strong � 10 10- -11 month old infants can identify weak 11 month old infants can identify weak- -strong strong � pattern found less typically (girAFFE girAFFE) ) pattern found less typically (

Words in sequential and Words in sequential and abstract (structural) patterns abstract (structural) patterns LDER Chapter 4 LDER Chapter 4

Learning the form of language Learning the form of language � Using Artificial Languages Using Artificial Languages � � Real language is really complex! Real language is really complex! � � We don We don’ ’t fully understand it t fully understand it � � We don We don’ ’t know exactly what input the infant was exposed to t know exactly what input the infant was exposed to � � Meaning can Meaning can’ ’t easily be separated from grammar t easily be separated from grammar � � With Artificial languages With Artificial languages � � We control the input We control the input � � We know exactly what the infant was exposed to We know exactly what the infant was exposed to � � We can examine grammar separately from meaning We can examine grammar separately from meaning � � Can infants start to learn grammar based just on Can infants start to learn grammar based just on � form (before they learn what words mean)? form (before they learn what words mean)?

What is grammar? What is grammar? � A system for A system for generating generating an infinite number of an infinite number of � phrases and sentences from a finite set of words phrases and sentences from a finite set of words � The grammar of a language enables you to The grammar of a language enables you to � describe which combinations of words belong to describe which combinations of words belong to the language (are ‘ ‘grammatical grammatical’ ’) and which don ) and which don’ ’t. t. the language (are � A good theory of grammar enables a simple, A good theory of grammar enables a simple, � elegant description of how such phrases and elegant description of how such phrases and sentences can be produced sentences can be produced

Precedence Precedence � What order do words go in? What order do words go in? � � big red apple big red apple � � *red big apple *red big apple � � What order do constituents go in? What order do constituents go in? � � SVO in English SVO in English � � SOV in Japanese; SVO and SOV in German SOV in Japanese; SVO and SOV in German �