Hearing and the brain 1

• Note that both sides (speech processing and speech perception) cannot be clearly separated
• Phrenology


  Early functional morphology, isomorphic localisation (maps) of 27 psychological relevant entities in specific brain areas based on individual particularities of the skull

  
• John Hughlings Jackson: '"To locate the damage that destroys speech and to locate speech are two different things."'
• Broca's area


  Left inferior frontal gyrus, anterior to speech motor area, 1861
• Wernicke's area


  Left posterior superior temporal cortex and underlying structures, 1874
• Wernicke's and Broca's areas in fMRI
• Brodman Areas
• Heschl's gyrus: primary auditory cortex
• Ventral dorsal stream hypothesis


  Structural connectivity between the language cortices
• Auditory sequence processing reveals evolutionarily conserved regions of frontal cortex in macaques and humans

  
• Left hemisphere dominance


  • For linguistic components of speech
  • Intelligibility of speech
  • Word recognition (left posterior STP)
  • Semantic processing (left STS)
  • Syntactic processing (BA 44/45)
• Right hemisphere dominance


  • For affective components of speech
  • Recognition of emotions
  • Prosodic processing
  • Voice recognition
  • Music processing
• Imaging evidence for locus of speech intelligibility (Scott et al)
• Uncinate fasciculus
• Hemispheric asymmetry (revisited)


  • Linguistic (LH) vs emotional (RH) information
  • Rapid (LH) vs slow (RH) speech
  • Voice specific areas in RH
  • Fronto-opercular activation stronger in RH for prosody
• Asymmetric sampling in time (AST)


  LH: 15-80ms (VOTs, formant transitions, formants)

  RH: 120-250ms (F0, pauses)
• Structural connectivities between the language cortices
• Left and right hemisphere in different sagittal sources
• The core and beyond in the language-ready brain
• Language Pathways - a different approach
• The Infrastructure of the Language-Ready Brain