1. Language

2. Using Language What is language for?

3. Using Language What is language for? – Rapid, efficient communication To accomplish this goal, what needs to happen in the brain?

4. Understanding Linguistic Input To accomplish this goal, what needs to happen in the brain? – Encode input (speech, writing, other?) Make neural representation(s) – transform the input (e.g. written word to internal sound) This probably involves many intermediate steps – Associate input with meaning – access the lexicon Lexicon – a mental representation of the meaning of words – Mental dictionary is a poor but useful analogy

5. Written Input Some terms: – Orthography – visual form of a word Non-trivial problem! Like all objects, words can have many different instances of the same item bird bird bird bird bird bird

6. Written Input Visual Word Form Area (WFA) is specialized for representing written words –Words are not just pictures –Specialization may be related to the need to “overcome” mirror- invariance E.g. b, p, d are all different letters but Dehaene (2009) Are all the same object !!

7. Spoken Input – Phonology – how the word sounds; acoustic Words are comprised of acoustic speech units called phonemes

8. Spoken Input – Phonology – how the word sounds; acoustic Phonemes are not invariant – different acoustic inputs are “mapped” onto the same phoneme

9. Spoken Input The Segmentation Problem: – The stream of acoustic input is not physically segmented into discrete phonemes, words, phrases, etc. – Silent gaps don’t always indicate (aren’t perceived as) interruptions in speech

10. Spoken Input The Segmentation Problem: – The stream of acoustic input is not physically segmented into discrete phonemes, words, phrases, etc. – Continuous speech stream is sometimes perceived as having gaps

11. Spoken Input The Segmentation Problem: – How do we solve the segmentation problem? Overlay additional information: Prosody – Inflection, syllabic stress, pauses

12. Spoken Input The Segmentation Problem: – How do we solve the segmentation problem? Overlay additional information: Vision – Read lips! – Demonstrated by the McGurk effect

13. Functional Anatomy of Spoken Input Note that the low-level auditory pathway is not specialized for speech sounds – Both speech and non-speech sounds activate primary auditory cortex (bilateral Heschl’s Gyrus) on the top of the superior temporal gyrus

14. Functional Anatomy of Spoken Input Which parts of the auditory pathway are specialized for speech? Binder et al. (2000) – fMRI – Presented several kinds of stimuli: white noise pure tones non-words reversed words real words These have non-word-like acoustical properties These have word-like acoustical properties but no lexical associations word-like acoustical properties and lexical associations

15. Functional Anatomy of Spoken Input Relative to “baseline” scanner noise – Widespread auditory cortex activation (bilaterally) for all stimuli – Why isn’t this surprising?

16. Functional Anatomy of Spoken Input Statistical contrasts reveal specialization for speech-like sounds – superior temporal gyrus – Somewhat more prominent on left side

17. Functional Anatomy of Spoken Input Further highly sensitive contrasts to identify specialization for words relative to other speech-like sounds revealed only a few small clusters of voxels Brodmann areas – Area 39 – 20, 21 and 37 – 46 and 10