2OVERVIEW Definition of language Stages of language perception Stages of language productionTheories of language acquisitionCritical period hypothesisCase studyBilingualism
3WHAT IS LANGUAGE?‘The systematic, conventional use of sounds, signs, or written symbols in a human society for communication and self-expression.’David Crystal
4STAGES OF LANGUAGE PERCEPTION At birthAlready prefer the sounds of their mother’s voiceCan discriminate between mother’s native language an other languages
5Discriminating sounds Adult speakers have difficulty discriminating between language sounds that are not phonemic contrasts in their native languageYoung infants do not demonstrate this difficulty initiallyThey can discriminate any contrasting phonetic sounds in the world’s languages
6How can we possibly know that? Are /s/ and /ç/ different sounds for you, baby?
7Testing Infants Some helpful things infants do for experimenters: They look longer at new stimuli compared to familiar stimuliThey suck faster when exposed to new stimuli
8Testing Infants Habituation-dishabituation method Habituate infant on one stimulusShow new, different stimulusDoes the infant react to the new stimulus as new?Habituation-dishabituation measuresTime looks to stimulusHigh-amplitude sucking paradigmDoes the infant start sucking faster on a pacifier (that’s hooked up to a monitoring device)?
11Limited-time OfferHowever, infants can only discriminate all phonemes for a limited period of timeAt 4 to 6 months phonetic sensitivity diminishes.By 12 months, infants are very poor at distinguishing foreign contrastsThe (speech) perceptual system is being reorganized around these time periods (4-6 months & months)
12TheoryExposure and habituation to the sounds of the target language impedes an infant’s ability to perceive phonetic contrasts that the native language does not makeThere are innate language abilities that are lost due to experience with a first languageOne is born with all language sounds available, but sound distinctions are lost as sound system develops
13Phonemic Organization Account Loss of perceptual ability is related to development of phonemic categories for the first language- phonemic organization
14Infant-directed Speech 7-week-old infants prefer infant-directed speech (‘motherese’) to adult-directed speechRegardless of gender of speakerOlder infants show this preference as well, but younger infants are more responsive, both in terms of attention and affect
15STAGES OF LANGUAGE PRODUCTION The larynxAt birth- the larynx is relatively high, and entire vocal tract is quite different from adultsAt 3 months- larynx begins to descend (won’t reach adult location until ~3 years old)At 4 months- the vocal tract begins to resemble an adult vocal tract
16Infant Speech Production Because of their maturing vocal tract, some sounds are genuinely difficult for young children to produce
17Stage I (0-8 weeks): Basic biological noises ReflexiveHunger, pain and discomfort resulting in cryingVegetativeSucking, swallowing, coughing, burpingAirstream mechanism and vocal folds used to produce pitch patterns in a rhythmical fashion
18Stage II (2-5 months): Cooing and laughing Cooing sounds develop alongside cryingQuieter, lower-pitched and more musical than cryingShort-vowel-like sounds preceded by a consonant-like sound produced at the back of the mouthNo rhythm or intonational contourLaughing sounds emerge at around 4 months
19Stage III (5-7½ months): Vocal Play High-pitched segments over one second long, frequently repeated (longer in duration than cooing)Wider intonation ranges (low to high)Large inventory of consonant and vowel sounds, with periodic focus on particular places of articulation
20Stage IV (~6-12 months): Babbling Features of babbling:Sounds are a subset of possible sounds found in spoken languageSyllabic organisationReduplicationSame two sounds repeated (“babababa” “papapapap”)Variegated babbling (~12 months)Sounds change between syllables (“bamipabo”)
21Stage IV (~6-12 months): Babbling Features of babbling:Lack of meaning/ referenceRhythm and intonation reminiscent of speechContinuity of phonetic form and syllable type between a child’s babbling and first wordsInfants will often seem to ‘practise’ when aloneSuggests that babbling is related more to practising speech sounds than communication
22Babbling & Sign Language Deaf infants also babbleOften delayed (11-24 months) compared to hearing infantsOften different in character (e.g. fewer different kinds of consonants)This indicates that exposure to a spoken language influences babblingInfants (hearing and deaf) who are exposed to sign language will babble manually
23Stage V (9-18months): Melodic Utterance Variations in melody, rhythm and intonation become a major feature toward the end of the first yearBegins to sound language-like
24First Words Around 12 months Focus on words related to the here and now, concrete things:People’s names, toys, clothes, food they eatWords for things that they can influence (one-word stage)“ball” likely to be learned earlier than “chair” or “tree”
25First Words Two kinds of errors children can make: Overextension- refer to all four legged animals as dogsUnderextension- refer to only the family dog as dog
26The Mapping Problem Child says “What’s that?” and points to: So…how could this possibly go wrong?
27The Mapping Problem Potential problems: More than one referent could apply to the word, “teacup”
28The Mapping Problem Potential problems: More than one word may apply to a referent:Tea?Teacup?Saucer?A drink?Cup?
29The Mapping Problem Apparent solutions: Whole object bias- children prefer to attach new labels to the whole objectMutual exclusivity bias- children prefer to have only one name for an object
30Early “Multiword” Utterances By about 15months babies have a vocabulary of about wordsTwo yearsVocabulary rapidly increases to 100’s of wordsChild constructs primitive sentences- two-word stage (“no eat, throw ball”)
31Early “Multiword” Utterances Thirty monthsUtterances progress beyond 2- word stage and show basic propositional structure (telegraphic stage)Functional words appear (“the, in, of”)Children overgeneralise rules (“goed”)Five years oldBasic structure of language is in placeVocabulary of words
32THEORIES OF LANGUAGE ACQUISITION Nativist TheoriesLanguage is entirely innateLearning TheoriesLanguage is entirely learnedCognitive TheoriesLanguage development is related to other cognitive developmentsSocial Interactionist TheoryLanguage is acquired through communicative interaction
33NATIVISM Emphasizes a child’s inborn capacities for language Language is acquired through a genetic programLanguage acquisition is distinct from other cognitive processes
34NATIVISM Noam Chomsky- the language acquisition device (LAD) Children are born with a basic understanding of language and a mental capacity to learn it quicklyBrain is ‘over- connected’ at birth. Connections that are not used die or become dormant, and new connections based on experience formThere is a specific time period of function
35NATIVISM Universal grammar: Key assumption: Children are pre-programmed with a kind of default language which can be altered with exposure to a specific languageKey assumption:Infants develops language even when other cognitive skills are low
36Evidence in Favour of a Pre-determined Biological Language System: Other primates don’t learn language simply by being treated like human infantsGua (chimp, 1993)Raised alongside a 9½month-old boy for 9 monthsNever spoke but learned to comprehend spoken requestsViki (chimp, 1951)Raised alone from 3 days- 7 years oldCapable of picture recognition, sorting of pictures and objects into conceptual categoriesUnderstood large number of words and phrasesBut, comprehension contextually determined
37Evidence in Favour of a Pre-determined Biological Language System: Children with other cognitive deficits still learn languageLanguage skills can persist even in cases of profound mental retardation
38Evidence in Favour of a Pre-determined Biological Language System: Poverty of the stimulusLanguage input to children is ill-formed and incomplete (motherese)Children don’t receive explicit rules about what not to doThey don’t get it even if you do tell them
39Evidence in Favour of a Pre-determined Biological Language System: CreolesPidgins develop in language contact situations (mostly colonial)(Pidgin = a language that has been constructed from two or more shared languages for communication between communities. A pidgin is not a mother tongue)Creoles develop from children exposed primarily to pidgins(Creole = a language that has developed from a mixture of languages)Children are, in essence, filling the gaps of pidgins
40Evidence in Favour of a Pre-determined Biological Language System: Evidence for critical period of language acquisition
41THE CRITICAL PERIOD HYPOTHESIS Eric Lenneberg, 1967
42THE CRITICAL PERIOD HYPOTHESIS Lenneberg theorized that…The acquisition of language is an innate (you are born with it) processBiological factors limit the critical period for acquisition of a language to a ‘window of opportunity’ from roughly two years of age to pubertyIf a child does not learn a language before the onset of puberty, the child will never master language at all
43Bird Song and the Critical Period Hypothesis Some birds (like Sparrows) have courtship songsSongs have dialectal variationIndividual song is a version of other songs it hears during the ‘critical period’ of first 100 days of lifeBird learns song by trial and error (babbling)When deprived of song input early in life, they fail to produce a normal song
44THE CRITICAL PERIOD HYPOTHESIS The critical period and the human brain…Lenneberg believed that after lateralization (a process by which the two sides of the brain develop specialized functions), the brain loses plasticityLenneberg claimed that lateralization of the language function is normally completed at puberty, making post-adolescent language acquisition difficult
46The Story of Genie Read about Genie and decide for yourself… How does Genie’s language development relate to Lenneberg’s theory?What is the strongest evidence in support of the Critical Period HypothesisWas Genie’s early language deprivation the ONLY thing that contributed to her abnormal language development?
47The Story of Genie Main points… From 20 months- 13 years old Genie was not allowed to make noise and was not spoken to (father barked or growled at her)When found could not speak or understand words (except name and ‘sorry’)Over time, vocab increased and she learned to speak in 2/ 3- word sentencesBUT, speech has remained garbled and she has never mastered grammar needed for language
48Genie and the Critical Period Hypothesis At first, a number of researchers thought that Genie would prove Lenneberg’s theory wrong as…1 year after her escape she was producing 2/ 3- word sentencesShe could distinguish between singular/ plural nouns and positive and negative sentencesGenie’s language resembled that of a normal month old child
49Genie and the Critical Period Hypothesis BUT,As time went on, Genie’s vocab did not ‘explode’ as is the case with normally developing childrenFour years later…She still had not mastered grammarShe could not ask questions properly (“where is may I have a penny”)She confused pronouns, using ‘you’ and ‘me’ interchangeably
50Genie and the Critical Period Hypothesis Has Genie supported Lenneberg’s theory? NO!Why?Genie’s personal history was so disastrous that it is not clear why she did not make progress with her languageIt is possible that Genie did not master language because she had passed the ‘critical period’BUT, other explanations are available
51Genie and the Critical Period Hypothesis Genie’s brain may have been abnormalBrain scans showed that Genie’s brain was unusualAs we know, for most people, the areas of the brain responsible for language functions are located in the left hemisphereBUT, Genie’s brain was dominated by the right hemisphere
52Genie and the Critical Period Hypothesis Conclusions…Genie’s lack of progress does suggest that, over a certain age, any child who has not learnt a language will have difficulty acquiring oneBUT, other explanations can not be ruled outTherefore, Lenneberg’s hypothesis is not proven, but it is strongly supported
53LEARNING THEORIES Associated with Skinner, Pavlov, etc Language is learned through basic processes like associations, reinforcement and imitationLanguage acquisition occurs through three processes:
54LEARNING THEORIES Classical Conditioning US UR US + CS CR “bottle”
55LEARNING THEORIES Operant Conditioning Reinforcement/ rewards Children are rewarded for early attempts at languageSelective reinforcement shapes children’s language as the requirement for a reward becomes more specific
56LEARNING THEORIES Social learning Observation and imitation of others, especially those who are powerful, nurturing and similar to the child
57Limitations of Learning Theories BUT, these processes can not fully account for language development in children because…Not enough to explain the complexities of language itselfMost parents do not consistently reinforce proper speechChildren say things they would not have heard an adult sayAspects of language development are universal and do not vary with different experiences
58COGNITIVE THEORIES Language is unique to humans But, not a modular, pre-programmed abilityGeneral disposition for learning that allows languagePattern recognitionImitationLanguage development is related to other forms of developmentFor these kinds of theories to be true infants must have general skills that clearly contribute to language
59Cognition and Language Cognitive skills that are not language specific but none-the-less contribute to languageNewborns prefer face-like to non-face-like stimuliQuickly learn to recognize their mother’s faceYoung infants focus on the eye region more than other facial regionsMore inclined to look at a pleasantly moving face than a still one
60Cognition and Language Infants know much more than they can demonstrate physicallySo, infants come to the language environment with a much more sophisticated view of the world than has been previously thoughtLAD not necessarily needed!
61INTERACTIONIST VIEW Both inborn capacities and learning are important Emphasizes the use of language and the fit between the child and the language environmentJerome Bruner- the language acquisition support system (LASS)Social context of language development is importantLanguage- skilled adults structure and support the child’s language learning environment
62INTERACTIONIST VIEWParent- child language interaction characterised by:Infant- directed speech (‘motherese’)High- pitched, simple, redundant speech adults use with babiesRecastingRephrasing what child says, often as a questionEchoingRepeating what a child saysExpandingRestating in a more advanced way what a child saysLabellingNaming objects
63SUMMARY OF THEORIES OF LANGUAGE ACQUSITION Language is clearly genetically specifiedIt appears that only humans develop a full version of itBut not yet established to what extent language is directly specified and to what extent its development is tied up with other aspects of cognitive and social development
65Bilingualism and the Critical Period Hypothesis What is a bilingual?A person who uses or is able to use two languages, especially with equal fluencyIs there a cognitive advantage to bilingualism?Early studies showing a disadvantageStudies of immigrantsConfounded by social classLater studies showing an advantageAvoided social class confoundsPicked up new confounds eg. ‘who is bilingual?”
66Bilingualism and the Critical Period Hypothesis Evidence for…It is significantly harder for older adults to master a second languageEvidence against…Some late L2 learners can become ‘perfectly fluent speakers’ (Long, 1990; Birdsong, 1992)
67Brain and Bilingualism: Issues Are the separate languages of bilinguals stored in separate parts of the brain?Does neural representation vary with age of acquisition?Is there a “language switch” somewhere in the brain?
68Brain and Bilingualism Mixed evidence for differing brain regions in early and late bilinguals…Some studies have found similar patterns in early and late bilinguals (Chee et al., 1999b)
69Brain and Bilingualism But, some fMRI studies have found different patterns of activation in sentence production in early and late bilinguals (Kim et al., 1997)
70Bilingualism Conclusions The two or more languages of bilinguals are distributed across the same brain regions that are used by monolinguals (Broca’s and Wernicke’s)For both monolinguals and bilinguals, the regions involved in language use vary by task, expertise and strategyThe same areas may have to “work harder” and additional areas may be recruited for processing in the weaker languageSecond language learning appears to be easier in the critical period than later in life, BUT it is possible to become fluent in a second languageSecond language is not necessarily the weaker language!
71LANGUAGE REFERENCESGleitman, H : Language in Psychology. Chapter 9, ppBee, H. The developing Child