Language

Psy391h - Classes 17-18

(This page last updated 10 April 2006.)
 

  Hierarchy of Linguistic Units

• sentence
• phrase
• word
• morpheme
• phoneme

 Different Aspects of Linguistics

• Phonology: How phonemes are combined to form words.
• Syntax: How words are combined to form sentences.
• Semantics: How meaning is extracted from language.
  • Words
  • Sentences

   

Phonemes

• A set of distinct sounds used to form words.
• Different languages use different sets of phonemes.
• There is a set of phonemic rules that govern how sounds are combined to form words in English.

Syntax

• Our ability to combine words into sentences.
• There is a large and complex set of syntactic rules that determine whether a sequence of words is a grammatical sentence.

Semantics

• Syntax is separate from semantics, which governs how meaning is assigned to words and sentences.
• Chomsky's example: Colorless green ideas sleep furiously.
  • Constructed according to the rules of syntax, but has no meaning.

Two questions to consider

• Does the evidence from cognitive neuroscience support this division between phonology, syntax, and semantics?
• What can the evidence tell us about each of these aspects of language?

Single Words: identifying, understanding, and speaking

• Hierarchy of brain regions for auditory word recognition, starting near primary auditory cortex in superior temporal lobe.
  • Identifying tones.
  • Identifying speech sounds.
  • Identifying words.
• Temporal lobe also includes regions important for recalling names of things.
  • Separate brain areas for people, animals, and tools.
  • Evidence from both lesion studies and brain activation.
• Reading words (Well, actually, just letter strings)
  • Activity in occipitotemporal sulcus

In understanding and producing single words, we see many different brain regions specialized for different aspects of the task. Is there also specialization in combining words into sentences?

Syntax vs. Semantics

• Evidence from aphasia
  • Wernicke's Aphasia
    • Can produce syntactically correct sentences, but they are meaningless. No semantics.
    • Also difficulties in understanding language.
  • Damage to Angular Gyrus
    • Cannot understand language.
    • Can repeat what is heard.
      • Can even correct semantic errors.
    • Semantic deficit, but connection from Wernicke's area to motor areas is functional.
  • Broca's Aphasia
    • Severe problems in producing speech.
    • Also some problems in understanding speech.
      • Agrammatism
      • Don't know which role applies to which noun in sentences such as "The boy was hit by the girl."
      • This aspect seems to be primarily of syntactic deficit.
• Evidence from ERP studies
  • P600 - Syntactic Positive Shift (SPS)
    • After a word with a syntactic error:"The spoiled child throw the toys on the floor."
    • The P600/SPS also appears in garden path sentences.
  • N400
    • After a word that does not fit semantically:
    • "He spread the warm bread with socks."

next: cerebral lateralization

Psych 391h: Cognitive Neuroscience Kyle Cave Psychology Dept. U. Mass.