Chapter 12 : Language in the Brain

Neurolinguistics

            -The study of the relationship between language and the brain

Language Areas in the Brain

    -Shaded areas in the picture indicate the general locations of those language functions involved in speaking and listening

• Broca's Area -Part of the brain in the left hemisphere involved in speech production called "Anterior speech cortex" (1)
• Wernicke's Area -Part of the brain in the left hemisphere involved in language comprehension called "posterior speech cortex" (2)
• Motor Cortex and Arcuate Fasciculus -Motor Cortex: part of the brain that controls muscle movement -Arcuate Fasciculus: bundle of nerve fibers connecting Broca’s area and Wernicke’s area
• Localization View -The belief that specific aspects of linguistic ability have specific locations in the brain

Tongue Tips and Slips

• Tip of the Tongue Phenomenon
  -The experience of knowing a word, but being unable to access it and bring it to the surface in order to say it
• Slips of the Tongue
  -Speech error in which a sound or word is produced in the wrong place
• Slips of the Brain
  -Preservation: sound carried over to next word
  -Anticipation: sound used before next word
  -Exchange: initial sounds change places
• Slips of the Ear
  -Processing error in which one word or phrase is heard as another

Aphasia

    -Impairment of language function due to localized brain damage that leads to difficulty in understanding and/or producing language

• Broca’s Aphasia -Serious language disorder characterized by reduced speech production, distorted articulation and slow effortful speech =>led to the characterization of lacking grammatical forms, or “agrammatic” In agrammatic speech, the grammatical markers are missing
• Wernicke’s Aphasia -Language disorder in which comprehension is typically slow while speech is fluent, but vague and missing content words
• Conduction Aphasia -A language disorder associated with damage to the arcuate fasciculus in which repeating words or phrases is difficult 

Dichotic Listening

    -Experiment in which a listener hears two different sounds simultaneously, each through a different earphone

• Left Brain, Right Brain
          -  In this process, the language signal received through the left ear is first sent to the right hemisphere and then sent to the left hemisphere (language center) for processing and it take more time than received through the right ear => the right-ear advantage
• Right-ear advantage - Fact: humans typically hear speech sounds more readily via the right ear. In contrast, the right hemisphere is better at non-language tasks. In dichotic listening tests, non-verbal sounds are recognized better from the left ear, indicating faster processing in the right hemisphere.

The Critical Period

    -The apparent specialization of the left hemisphere for language is usually described in terms of lateral dominance or lateralization

    -During childhood, there is a period when the human
brain is most ready to receive input and learn a particular language, called the critical period

• In 1970 , a girl called Genie grew up in isolation, lacked of language yet later developed the communication skills. This suggests language learning may be possible beyond a critical period, though complexity might be limited. Interestingly, Genie's language processing seemed to occur in her right brain, challenging the idea of a single dominant language area