2002/03/19PSYC202-005, Copyright 2002 Jason Harrison1 Language: Syntax and Semantics “you've tasted two worms” - Rev. William Archibald Spooner (you've.

2002/03/19 PSYC202-005, Copyright 2002 Jason Harrison

1

Language: Syntax and Semantics

“you've tasted two worms” - Rev. William Archibald Spooner (you've wasted two terms)

2002/03/19 PSYC202-005, Copyright 2002 Jason Harrison 2

What is language?

• Modulation of sound [or light] into discrete units– e.g., words (spoken), words (written)– but: “big very or not almost dog under”

• Structured combinations of units into phrases– e.g., words put together grammatically– but: “fuzzy green ideas sleep furiously”

• Use of sound [or light] to communicate– e.g., writing, speaking, sign language– but: scribbles, tone of voice, pointing


LanguageCombination of at least three characteristics• Discreteness:

– Modulation of sound [light, touch] into well-defined units

• Generativity:– Units can be combined in a structured way into

many many possible phrases

• Symbolic:– Meaning conveyed via arbitrary connection of

symbols to ideas (e.g., [robin] <-> “robin” <-> )


1. Discreteness

• Language based on discrete elements• Each element unique• Each speaker has unique pronunciation

– e.g., say “horse”– everyone sounds slightly differently– physically different sounds– but these refer to the same conceptual

category [horse]

• Categorization problem!


Categorization

• Slightly different sounds mapped to the same word

• Robustness: small perturbations don’t disturb categorization– slightly different sounding words recognized

as the same thing– different speakers; different accents; different

ages– different conditions

• e.g., background noise, food in mouth, etc.

1. Discreteness


Categorization

• Lowest level of auditory input: speech sounds

• English has 44 basic sounds (phonemes)– /s/ sip, /t/ till, /sh/ shallow, /th/ thigh, /zh/ treasure– can hear other sounds (e.g., /!/), but these are

not considered to be speech in English

• Categorization exists at this level– nearby sounds considered to be the same– e.g., “paper” = /p^/ (aspirated) and /p/ (non-

aspirated: both considered equivalent.

1. Discreteness


Segmentation• Segment continuous audio stream into

phonemes and words– similar to identifying discrete objects visually

• Example 1: Speech of a foreign human language– audio stream appears to be continuous– have to learn to pick out discrete units

• Example 2: Speech of dolphins and whales– audio steam appears to be continuous– probably not a language…

1. Discreteness


Learning Phonemes

• Newborns: discriminate between phonemes of all languages– i.e., ready to learn any human language

• Six months: number of phonemes dropping to those of surrounding language

• Critical Period: phonemes not learned by adolescence, never regained

1. Discreteness


Learning Phonemesand Perception of Speech

Interaction of innate mechanismsand

exposure to environment

just like learning to see…

1. Discreteness


Note 1: reduction of phonemes not necessarily bad -increases robustness of recognition

Note 2: (Janet Werker) phonemes in other languagescan still be distinguished by unconscious(“zombie”?) system, even in adults

Test: Forced-choice guessing - present two sounds - Is there a difference? [Yes or no] - guessing is more accurate than chance.

Notes 1. Discreteness


1. Discreteness Visual Representation• Many languages represent phonemes with

written letters– sign language is actually a spoken language

• Grapheme: basic written unit• Ideally, each letter (or combination)

represents one sound• Spelling stays fixed, spoken language

changes faster– e.g., English “gh” in “light” or “night” in 1600s

was German /x/ (“Bach”, “Licht”, “Nacht”)


Note: categorization also found in written language

-e.g., handwriting - each person’s handwriting is different - refers to same underlying concept

-e.g., different fonts - B, b, B, B, and B - all refer to same phoneme (/b/)

1. Discreteness Notes


1. Discreteness Phonemes to Syllables• Simple combinations of consonants (C) and

vowels (V)– usually have the form of VC, CV or CVC– e.g., “ab”, “da”, “did”

• In some languages, strong constraints on how letters can be combined into syllables

• E.G., Japanese: five vowels and nine consonants– 5x9 + 9 x 5 + 9x5x9 = 495 possibilities– but only 47 possible syllables– “hi” and “fu” but “fi”


Graphemes versus Syllables and Phonemes • In some writing systems, graphemes

correspond to syllables– e.g., Japanese Hiraganga

1. Discreteness


1. Discreteness Graphemes versusSyllables and Phonemes• In other languages, graphemes

correspond to phonemes– e.g., old english “read while moving your

lips”

• In English, fewer constraints on syllables– double and triple consonants initially

• e.g., pliant, true, splay,

– and syllables without vowels• e.g., rhythm


1. Discreteness Syllables to Words

• Words are combinations of syllables• Words are basic semantic/symbolic items

of language• Constraints on combinations vary from

language to language• Most writing systems are syllable or

phoneme based• Japanese and Chinese kanji: elements are

words


Summary of Discreteness

• phonemes– categorization and segmentation

• syllables– simple combinations of phonemes

• graphemes – visual form

• words– combinations of syllables– basic semantic/symbolic items


2. Generativity

• All languages use structures formed by combining simple elements (words)– rules of combination: grammar

• Requirements of a grammar:1. Constraints: not all combinations are

possible• provides robustness (e.g., postal codes)

2. Must allow unlimited number of combinations• allows infinite number of sentences


2. GenerativityHow are words combined?• What process is used to combine words?• How do we learn and memorize grammar

rules?• Original answer (< 1957) - associationism

– words simply joined together in sequence– each word associated with adjacent words in

sequence– e.g., “the” can be followed by “dog’– e.g., “the” cannot be followed by “they”


“the” -> “dog” the

“the” -> “cat”

“dog” -> “chased”

“chased” -> “the”

the dog

the dog chased

the dog chased the

the dog chased the cat

“the” -> “dog”

“dog” -> “chased”

“chased” -> “the”

“the” -> “cat”

2. GenerativityAssociationism• Grammar is a set of Stimulus-Response links

– cf Behaviourism


2. GenerativityAssociationism: problems1. How can language be learned?

• many possible words could follow “the”• child get exposed to them rarely (or never), but:

• still learns the language• learns it relatively quickly• understands any new phrase encountered

2. Important relations exist between nonadjacent words• “Anyone who says that is lying”

• “anyone” and “is lying” are not adjacent

• Need to capture these relations


2. GenerativityPhrase Structure GrammarChomsky (1957)• Words combined via more complex

structures• Words are divided in different types

– noun: describes an object– adjective: modifies a noun– verb: describes an action– …

• basic unit is not words but phrase structures– noun phrase (NP) - “the angry boy”– verb phrase (VP) - “hit the yellow ball hard”


S NP + VPNP Det + Adj + N (Det=determiner; Adj=adjective)

VP V + NP + Adv (V=verb; Adv = adverb)

SS

NP VP

S

NP VP

Det Adj N

S

NP VP

Det Adj N

the angry boy

S

NP VP

Det Adj N V NP Adv

the angry boy

S

NP VP

Det Adj N V NP Adv

the angry boy hit hard

S

NP VP

Det Adj N V NP

Det Adj N

Adv

the angry boy hit hard

S

NP VP

Det Adj N V NP

Det Adj N

Adv

the theangry boy hit yellow ball hard

2. GenerativityGrammar = rules on phrase structures


S

NP VP

V NP

they are flying planes

N

N

S

NP VP

V NP

they are flying planes

N

NAdj

(Can’t show difference using word-by-word analysis)

2. GenerativityPhrase structures allow different meanings


2. GenerativityChomsky (1957)

• Phrase structures common to all human languages– universal grammar– (also the basis of computer languages)

• Phrase structure is innate, explains– why language is learned relatively quickly– why phrase structure grammar is universal– why some strokes cause lose of grammar

• Note: particular words are learned (e.g, “banana”)


2. GenerativityBroca’s aphasia

• “So you’re going to dentist on Thursday?”“Yes… ah… Monday er… Dad and Peter H…, and Dad… er… hospital… and ah… Wednesday… Wednesday, nine o’clock… and oh… Thursday… ten o’clock, ah doctors… two… and doctors…and er… teeth… yeah.” (Goodglass & Geschwind)

• Patient unable to compose sentences (frustrating!)• What does this tell us?

– existence of a specialized neural system for speech


Broca'sarea

2. GenerativityBroca’s aphasia• autopsies: lesion to area of left

hemisphere• Broca’s area needed for grammatical

speech


body

arm arm

shoulder elbow hand

finger finger finger finger

movement of finger, which is part ofmovement of hand, which is part ofmovement of arm, which is part ofmovement of body

2. GenerativityBroca’s area (Rizzolatti)• Area evolved from area concerted with

understanding motion actions– hierarchical structure of motor actions


Summary of Generativity

• Grammar defines rules of combination– constraints and unlimited combinations

• Phrase structure grammar– explains ability to understand novel

sentences

• Broca’s aphasia– demonstrates specialized neural grammar

circuits


3. Meaning

• Language is symbolic– discrete units of language– discrete units of cognition (concepts)– meaning of any “word” is arbitrary

• So, what is the basic unit of meaning?– sentence?– word?– morpheme


3. MeaningMorphemes:

• Meaningful parts of words– prefixes: “un” + “sure” = “unsure”– suffixes: “er” + “talk” = “talker”– stems

• Word stem: “port” = “carry”– “import” = “im” + “port” = carry in– “export” = “ex” + “port” = carry out– “report” = “re” + “port” = carry back– “transport” = “trans” + “port” = carry across– “porter” = “port” + “er” = carrier


3. MeaningWernicke’s aphasia

• “Can you tell me what is happening in this picture?”– (picture of two boys stealing cookies behind

mother’s back)– “Well this is… mother is away her working her

work out of here to get her better, but when she’s looking in the other part. One their small tile into her time here.” (Goodglass & Geschwind)

• Patient can compose sentences but without much meaning.


Wernicke'sarea

3. MeaningWernicke’s aphasia• autopsies: lesion to area of left hemisphere• Wernicke’s area needed for meaning• Broca’s and Wernicke’s connected by arcuate

fasciculus


Summary of Meaning

• Meaning is symbolic– morphemes: “form” or “thing” referred to

• Prefixes and Suffixes (and Infixes!)– modify meaning of stems

• Wernicke’s aphasia– demonstrates specialized neural meaning

circuits


How does this all work?

• Meaning to be expressed: Concept– Wernicke’s area encodes meaning – phrase structure grammar

• Structure of expression transferred– arculate fasciculus transfers to Broca’s area

• Detailed speech plan: grammar– Broca’s area

• Production of speech– Motor cortex

2002/03/19 PSYC202-005, Copyright 2002 Jason Harrison 36From : www.driesen.com/ posterior_language_areas.htm


From : www.driesen.com/ speech_language_areas.htm


1: meaning produced

2: code transferred3formulation

of speechplan

4: production of speech

From : www.driesen.com/ speech_language_areas.htm

2002/03/19PSYC202-005, Copyright 2002 Jason Harrison1 Language: Syntax and Semantics “you've tasted two worms” - Rev. William Archibald Spooner (you've.

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