Essay - As Early as 1836, Marc Dax Found that Patients Who...

As early as 1836, Marc Dax found that patients who could not speak properly had damage to the left side of the brain, and in 1861 Paul Broca described a patient who could say only one word - Tan (The Brain, 2005). When the patient died, he carried out an autopsy ***** discovered damage to ***** patient's left frontal cortex, which became known as *****'s area. In 1876, Karl Wernicke found damage in the posterior temporal lobe (********** area), connected to Broca's area by a bundle of nerve fibers, ***** arcuate f*****ciculus, also caused speech problems. Damage to the arcuate fasciculus causes conduction aphasia, in which people c***** understand language but their speech does not make sense and they cannot repeat words.

To speak a word ***** is read, information must travel from the primary visual cortex to ***** posterior speech area, including Wernicke's *****, ***** from here to ***** area, and then to the primary mo*****r cortex (***** Brain, 2005). To speak a word th*****t is heard, the word must first get to the primary auditory *****, then to the posterior speech area, including ***** area, and from there ***** the ***** motor cortex. Damage to Broca's area results in the inability to speak, ***** inability ***** form ***** *****, ***** slow, slurred speech. Damage to Wernicke's area ***** in a loss of the *****bility to understand language, and the person can speak clearly but ***** put *****s together in a me*****ningful way. In most people, both ***** and Wernicke's areas are found only in the left hemisphere.

***** stimulation experiments have shown there can be large differences ***** the brain area that is important for language from one ***** to another (The Brain, 2005). Using amobarbital to anesthetize either the right or left hemisphere has also proved ***** ***** ability re*****s in ***** left hemisphere: when the right hemisphere is anesthetized, the person ***** still ***** and understand language, but ***** the ***** side is anesthetized, they cannot speak ***** ***** language. Dr. Patricia Kuhl of the University ***** Wash*****gton, *****s that before babies can speak ***** ***** syllable, they are at work "mentally calculating the statistical nuances of their parents' *****" and are capable of deciphering sounds, mapping how individual sounds ***** combined, how syllables are stressed, and what the information qualities are before they reach their first birthday.

Dr. Helen J. Neville of the University of Oregon is using event*****related brain potential and magnetic resonance imaging to look at which sections ***** ***** brain ***** ***** active when early and late learners of English ***** American Sign Language detect inaccuracies in semantics or syntax in the two languages and has found that ***** hemispheres play a role in cert*****in situations (New, 2002). She suggests ***** ***** hemisphere helps analyze the shape, motion and location of words in a signed sentence (spacial syntax). Positron emission tomography has shown ***** regions of ***** brain previously thought to be reserved for the processing ***** speech and sound, such as