Slobodanka Krajnovic 31562193 PSY 351
Cognitive processes of non-literal language
Language may be perceived as one big function, however different brain areas are involved in the process of producing and understanding language. The two main areas for language are Wernicke's area and Broca's area. Broca’s area is in the left frontal lobe and is responsible for language expressions, while Wernicke’s area, which is positioned back in the temporal lobe, has a role of understanding language. Therefore, the question is how these different areas pass information to each other. Due to the recent technology, it is possible to see how these areas are connected. These new technologies have provided better understanding of the electromagnetic spectrum and radiofrequency waves, which has made it possible to observe the processes that are occurring in the brain during the certain tasks. In this essay different techniques that are used in order to identifying the particular neural networks within the brain that are involved when a person listens to non-literal language are going to be discussed and compared.
EEG-electroencephalogram is used to measure brain waves, or in another words, electrical activity that is produced by firing of neurons in the brain. There are different waves that are being measured such as ALPHA, BETA, DELTA…This activity is measured by placing electrodes on the scalp that pick up the signal. Different areas of the brain show different brain waves frequency. In order to examine how language context and existing knowledge are used by both hemispheres for meaning to be constructed, Coulson and Williams (2005) have conducted study using ERPs. The study resulted in findings indicating that the RH is more activated than LH when joke-related information is presented. Similarly, study of metaphor processing was conducted by Coulson and Van Petten (2007) and found no differences between the LH and RH in comprehension of metaphorical words in sentences. Based on this studies it could be concluded that the use of ERPs technique help determine which areas are involved in particular cognitive tasks. Advantage of using this technique is the speed by which the changes are detected and the limitation is that it has poor spatial resolution.
PET-Positron Emission Tomography is a nuclear medical imaging technique that produces images of functions within the brain. Radioactive glucose is injected and works as a tracer enabling researches to monitor the areas of the brain that are most active during particular activity. Brain functions can be mapped, for example, hearing, seeing and speaking the words. Young (1999) argues that this technique also measures the degree of activity that is occurring in the brain together with locating the activity. A pet study was done by Caplan at al (1999) measuring the blood flow in the brain. The study resulted in finding out that the blood flow increases in Broca’s area when participants are presented with more complex sentences. As shown in these studies, advantage of using the PET scan is that the amount of brain activity can be measured across different areas, however drawback is that the radioactivity wears off quickly.
fMRI-Functional magnetic resonance imaging is technique that is measuring the blood flow in the brain. It is showing what areas of the brain are activated and involved with particular brain processes, also how much energy is being used in each area of the brain. When neurons are firing in certain parts of the brain, more blood is sent to that part. This method captures the area that needs more oxygenated blood during the task. In another words, fMRI is mapping the brain responses, highlighting the area of the brain that is used in order to carry out certain cognitive tasks (Dyson, Banks and Stewart, 2006). An fMRI study done by Zempleni et al (2007) was conducted in order to identify the...
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