Neurolinguistics

Neurolinguistics is the study of the relationship between language and the brain.

Language Areas in the Brain

Scientific Name Regular Name Named After Study Purpose
anterior speech cortex Broca’s area Paul Broca, French surgeon damage to site cause difficulty in producing spoken language involved in generation of spoken language
posterior speech cortex Wernicke’s area Carl Wernicke, German doctor damage to site causes speech comprehension difficulties involved in understanding spoken language
motor cortex motor cortex electric interference caused speech production issues controls muscle movement
arcuate fasciculus curved bundle connection between Broca’s area and Wernicke’s area
graph TD; A[Broca's Area] --> B[Anterior Speech Cortex] C[Wernicke's Area] -->D[Posterior Speech Cortex] B --> E[Expressive Aphasia] D --> F[Receptive Aphasia]

The idea that language ability is controlled by certain parts of brain is called localization view.

Tongue Tips and Slips

Experience Example Happening Theory Alternate name
Tip of the tongue secant, sextet = sextant have accurate phonological outline and number of syllables word storage system organised on phonological information malapropism
Slip of the tongue long shorty stort spoonerism
Slip of the brain we’ve had some sexbacks = setbacks word substitutions viewed as articulation error, may be brain organising linguistic messages see table for types
Slip of the ear has a pimple = has a pit bull brain tries to make sense of auditory signal
Slips of the brain
Perseveration sound carried over to next word black bloxes
Anticipation sound used before next word noman numeral
Exchange initial sounds change places shu flots
final sounds change places stick neff

Aphasia

Aphasia is the impairment of a language function due to localized brain damage.
Broca’s Aphasia reduced amount of speech, distorted articulation, agrammatic speech expressive aphasia
Wernicke’s Aphasia difficulty in auditory comprehension, fluent speech that is difficult to understand, not able to find the correct word (anomia) receptive aphasia
Conduction Aphasia damaged arcuate fasciculus, mispronounce words with no articulation problems, word repetition is difficult, also difficult to write or read, occurs in dementia and Alzheimer’s

Dichotic Listening

Dichotic listening is an experiment in which the listener hears two different sound simultaneously each from a different earphone. Sounds in left ear processed by right hemisphere and vice versa. Research showed preference for identifying sound from right ear. This is called right ear advantage. Non-verbal sounds are recognized quicker through left ear. We still need right hemisphere because it specializes in contextual understanding and inferences and pragmatics.

The Critical Period

The left side dominance for language processing is called lateralization. It begins in early childhood and occurs as language acquisition takes place. This time period is called the sensitive period for language acquisition or the critical period. The period lasts from birth till puberty.

Genie was an abused child raised in physical, sensory, social and emotional deprivation until her rescue at thirteen. As she was able to learn to speak later it proves that language can be acquire after critical period. She was not able to acquire advanced grammar likely due to the left hemisphere not having had a “program installed” when she was younger so the facility closed down. Studies showed that she was using her right hemisphere for basic language testing, and dichotic listening tests showed left ear advantage for both verbal and non-verbal signals.

Study Questions

  1. What is a more common name for the posterior speech cortex? Wernicke’s area.
  2. What kind of difficulty did Wernicke discover among his patients? Difficulty understanding spoken language.
  3. Which part of the brain has been described as “the curved bundle”? Arcuate Fasciculus.
  4. In the use of fire distinguisher instead of fire extinguisher a spoonerism or a malapropism? It is a malapropism.
  5. What type of slip is illustrated by: I like pop porn (for popcorn)? It is a slip of the brain, specifically perseveration.
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