VL15 Sentence Processing

• phonemes

• morphemes

• words

• sentences

• syntax

semantics

smalles significant units of speech

smallest units of meaning in a language

• limited set of words can be combined to express an unlimited number of concepts / ideas

• structure of language supports generativity

activation in auditory cortex for words, tones, white noise but overlap

• encoding of phonetic features in superior temporal cortex

• brain activation

  • intelligible(understandable) speech —> inferior parts

    • semantic analysis?

    • syntactic processing?

  • not understandble —> superior parts

• word onsets not clearly alighned to boundaries in physical speech signal

  • words can be spoken differently

• robustness against differences in voice, tone, pronounciation, contextual noise

• speech follows certain pattern that is characterized by certain frequency

• picked up by brain activity

STG -> superior temporal gyrus includes part of wernickes area -> language comprehension

IFG -> inferior frontal gyrus -> Brocas area

MTG -> middle temporal gyrus -> semantic processing

TP temporal pole -> anterior part of temporal lobe -> semantic memory, complex stimuli

Area 8 Frontal eye fields -> prefrontal cortexvisual attention

• unclear since activated in

  • story in tamil

  • pseudo words

  • semantically anamalous sentences

  • story in french

Garden Path Model

• minimal attachment principle: noun phrase, verb, noun phrase, the second noun phrase will be interpreted as the direct object

• while the man hunted the deer ran into the woods

• requires reanalysis

• judgment tasks

• self-paced reading

• cross-modal priming

• eye-tracking

• neurocognitive methods

• grammaticality judgment

• comprehension questions

• ERP

• fMRI

• three sentences with different endings

  • unexpected last word

    • spread the warm bread with socks

    • highest negative activation

  • expected word

    • high heeled shoes

    • highest positive activation

  • bad prediction possible

    • first day at work

    • slightly positive activation

three types of sentences

• correct

• world knowledge violation

• semantic violation

n400 effect for both violations

• to be able to define different processing stages

• provoking an effort when expectations are violated

• idea is identifying the time point when certain information is processed

  • defining different processing stages

• graded response to predictability of last word

• = degree of expectancy

• difficulty of integrating a new element into previous context

• ELAN (early left anterior negativity)

• early processes of rule based sentence processing

  • word category identification

  • before 200 ms post-onset (after incorrect stimulus)

  • negative deflection

• a late ERP positivity p600

• probably reflects repair of ungrammatical sentences

• and/or reanalysis of ambiguous sentences

1- ELAN - early phrase-structure building

2- N400 - lexical semantic integration

3- P600 - re-analysis

• expected

• unexpected

• anomalous

• pseudowords

unexpected -> more BOLD signal change

anomalous

pseudoword

expected

• neurolinguistic studies in the 70s and 80s

  • brocas aphasics have problems with

    • speech production

    • processing of syntactic structures —> agrammatism

    • studies: the more complex the sentence, the more activation in brocas area (pars opercularis of left inferior frontal gyrus

hypothesis: neural assembly = constituent

• constituent size is approximately indexed by the number of words

but: temporal areas integrate structural complexity and semantic processing

• IFG areas respond to structural complexity as such

• anterior to pars opercularis

brain regions of temporal lobe

• ERPs —> relative timing of syntactic vs. semantic processing stages

• ELAN

• N400

• P600

• 
  

• in vicinity of wernickes area

• but semantic representations may be more widespread in the human brain