Behavioral Neuroscience, Lecture on November 26 th
Language and the Brain
Many nonhuman species show elaborate vocal behavior.
Signal readiness to mate
Alert group to danger
Species-specific birdsongs, sung only by males, are learned from “tutors,”
imitated and crystalized in the brain.
Language in humans:
Phoneme: sound produced for a language.
Morpheme: smallest meaningful unit of a language.
Semantics: meanings of words (in sentences).
Syntax: grammatical rules of a language.
Prosody: rhythm and tone of a language.
Multimodal (spoken, written, sign language)
Receptive and expressive components.
Challenges of speech:
o Within speakers (coarticulation)
o Across speakers (accents)
A trivial problem?
Attention supports speech perception:
Cocktail party effect,
Spatially selective attention
o Select for speech at a given location.
What about a single speaker?
o Temporally selective speaker
Select for important times in speech
Helps listeners focus on word onsets
Better attention is related to better language skills. Broca’s aphasia:
Non-fluent or expressive aphasia.
Damage to lower portion of left frontal lobe.
Difficulty in language production.
Fluent or receptive aphasia.
Damage to posterior portion of the left superior temporal gyrus.
Difficulty with language comprehension.
The Wernicke-Geschwind model:
In the 1960s, Geschwind revived and elaborated Wernicke’s ideas and came up
with the predominant theory of language localization: The Wernicke-Geschwind
Deficits result from breaking interconnected network of components.
Speaking a heard word: 1) primary-auditory cortex 2) Wernicke’s area 3)
arcuate fasciculus (below the surface) 4) Broca’s area 5) motor cortex
Speaking a written word: 1) primary visual cortex 2) angular gyrus 3) arcuate
fasciculus 4) Broca’s area 5) motor cortex
The arcuate f