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
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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
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Language
Combination 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” <->
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)
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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!
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Categorization
1. Discreteness
• 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
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• e.g., background noise, food in mouth, etc.
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Categorization
1. Discreteness
• 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/ (nonaspirated: both considered equivalent.
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Segmentation
1. Discreteness
• 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…
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Learning Phonemes
1. Discreteness
• 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
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Learning Phonemes
and Perception of Speech
1. Discreteness
Interaction of innate mechanisms
and
exposure to environment
just like learning to see…
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Notes
1. Discreteness
Note 1: reduction of phonemes not necessarily bad
-increases robustness of recognition
Note 2: (Janet Werker) phonemes in other languages
can still be distinguished by unconscious
(“zombie”?) system, even in adults
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Test: Forced-choice guessing
- present two sounds
- Is there a difference? [Yes or no]
- guessing is more accurate than chance.
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Visual Representation
1. Discreteness
• 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”)
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Notes
1. Discreteness
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/)
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Phonemes to Syllables
1. Discreteness
• 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”
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Graphemes versus
Syllables and Phonemes
1. Discreteness
• In some writing systems, graphemes
correspond to syllables
– e.g., Japanese Hiraganga
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Graphemes versus
Syllables and Phonemes
1. Discreteness
• 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
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• e.g., rhythm
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Syllables to Words
1. Discreteness
• 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
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Summary of Discreteness
• phonemes
– categorization and segmentation
• syllables
– simple combinations of phonemes
• graphemes
– visual form
• words
– combinations of syllables
– basic semantic/symbolic items
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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
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How are words combined?
2. Generativity
• 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”
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Associationism
2. Generativity
• Grammar is a set of Stimulus-Response links
– cf Behaviourism
“the” -> “dog”
the
“the” -> “cat”
the dog
“dog” -> “chased”
the dog chased
“chased” -> “the”
the dog chased the
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the dog chased the cat
PSYC202-005, Copyright 2002 Jason Harrison
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Associationism: problems
2. Generativity
1. 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
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Phrase Structure Grammar
Chomsky (1957)
2. Generativity
• 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”
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Grammar =
rules on phrase structures
2. Generativity
S
NP
Det
the
Adj
angry
VP
N
boy
V
hit
NP
Adv
Det
Adj
N
the
yellow
ball
hard
S  NP + VP
NP  Det + Adj + N (Det=determiner; Adj=adjective)
VP  V + NP + Adv (V=verb; Adv = adverb)
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Phrase structures allow different
meanings
2. Generativity
(Can’t show difference using word-by-word analysis)
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Chomsky (1957)
2. Generativity
• 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”)
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Broca’s aphasia
2. Generativity
• “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
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Broca’s aphasia
2. Generativity
• autopsies: lesion to area of left hemisphere
• Broca’s area needed for grammatical speech
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Broca’s area (Rizzolatti)
2. Generativity
• Area evolved from area concerted with
understanding motion actions
– hierarchical structure of motor actions
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body
arm
arm
shoulder elbow
hand
finger finger
finger finger
movement of finger, which is part of
movement of hand, which is part of
movement of arm, which is part of
movement of body
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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
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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
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Morphemes:
3. Meaning
• 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
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Wernicke’s aphasia
3. Meaning
• “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.
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Wernicke’s aphasia
3. Meaning
• autopsies: lesion to area of left hemisphere
• Wernicke’s area needed for meaning
• Broca’s and Wernicke’s connected by arcuate
fasciculus
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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
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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
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2002/03/19
: www.driesen.com/
posterior_language_areas.htm
PSYC202-005, CopyrightFrom
2002
Jason Harrison
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From :
www.driesen.c
om/
speech_langu
age_areas.htm
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From :
www.driesen.c
om/
speech_langu
age_areas.htm
2002/03/19
4: production of
speech
3
formulation
of speech
plan
2: code transferred
1: meaning
produced
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