Cerebral Asymmetry Practical - Research Paper Example

Cerebral Asymmetry Practical Lots of evidence shows that the two brain cerebral hemispheres are particular and specialized for carrying out diverse types of tasks (Banich, 2003). Though left cerebral hemisphere language specialism is one of the extensively reported results in an individual neuropsychology, a number of studies have established evidence for additional two-sided language organization in female. The conception of hemispheric specialism (lateralization, predominance) for language means that one hemisphere is principally involved in language actions, with regard to the other one. Approximately about 90% of individuals have the left hemisphere principal for language (Bourne, 2006). Extend of lateralization relies on several factors for instance sex and language tasks utilized in assessing specialization. For example, it has been established that the phonological facet of language is highly lateralized in comparison to the semantic one. In addition, extend of lateralization would relies on the nature of semantic or the kind of phonological task (Poffenberger, 2006). The main aims of the study is investigates the proposition that verbal (phonological) processing, as measured by a non-rhyme or rhyme task, and if it is more accurate and faster in the right hemisphere than in the left. In addressing, the hypothesis there will be the comparison of the percent correct data for right and left hemispheres from the entire subject or the participants both female and male. The Method used in the study is the phonological rhyme or non-rhyme task and the divided visual field paradigm. During the divided visual field, experiment by utilizing words (the semantic tasks) and the pseudo-words (the phonological tasks) as stimuli, 30 right-handed subjects, or participants were observed. Results have revealed that all the tasks were considerably left hemisphere lateralized. In comparison between the percentage correct data for right hemispheres of male and female, it is evident that male had higher correct data compared to female as male had 69.93% and female had 66.2%. On the other hand, the percentage correct data for left hemisphere of female is higher in comparison to male; female had 66.86% correct data for left hemisphere, while male had 60.93% correct data for left hemisphere. Therefore, the results as well suggested that the distinctiveness of stimuli might influence extend of hemispheric lateralization for instance, the poignant charge of stimuli for words and the location of the phoneme to be identified, for the pseudo-words. Introduction Brain lateralization is apparent in the phenomenon of left or right-handedness and of left or right ear partiality, but an individual’s preferred hand is not a patent hint of the position of brain function (Ivry & Robertson, 2008). It is estimated that 95% of people who are right-handed have dominance of left-hemisphere for language, while 18.8% of people who are left-handed have dominance of right-hemisphere for language. In addition, 19.87% of the left-handed individuals have bilateral language functioning. Still within a variety of language functions for example, syntax, prosody, and semantics, degree of dominance might vary (Motz & Busey, 2012). In addition, though a number of functions are lateralized, these are simply a predisposition. The tendency crosswise many people might also differ considerably, as to how any definite function is executed. The regions of investigation of this effective or causal dissimilarity of an exact brain function comprise its dendritic structure, gross anatomy, and neurotransmitter division (Bunt & Johanson, 2007). The chemical and structural discrepancy of an exact brain function, amid two hemispheres of one brain or amid the similar hemisphere of two dissimilar brains, is still being examined (Jeffery, 2001). Even though functional lateralization analyses and studies find personal disparity in cognitive or personality style does not help one hemisphere or other, a number of brain functions happen in one or other side of brain. Lindell and Nicholls (2003) argued that attention tends to be on the left and Language on the right (Lindell & Nicholls, 2003). There is lots of confirmation that every brain hemisphere has their own dissimilar functions in language conception. Most frequently, the right hemisphere is termed the non-dominant hemisphere while the left is viewed as a dominant hemisphere. The difference is referred lateralization and cause for it initial was raised by experimentation with split- brain individuals (Knecht & Bobe, 2000). In experimentation with split-brain individual and it is evident that the right hemisphere is typically not dominant in the language conception (Kandel & Jessel, 2000). It is always attributed that the right hemisphere is dominant for cognitive functioning. Ones the damage is done to the fraction of the brain or when temporal part of the right hemisphere is detached, this may translate to cognitive communication troubles, for instance, problems in attention, impaired memory, and poor reasoning. Different studies have arrived to the conclusion that right hemisphere process information in a holistic and gestalt fashion, with a particular weight on the spatial relationship (Goldberg, 2009). Research questions/hypotheses The main hypothesis of the study is to determine whether the cerebral hemispheres of the brain functionally asymmetrical (lateralized) for language. The study aims to examine the proposition that verbal (phonological) processing, as measured or deliberate by non-rhyme or a rhyme task, is more accurate and faster in left hemisphere than in the right hemisphere. Method used in the study The study will focus on adult participants English as first language (15 male; 15 female) ranging in age from 19–35. All participants were right-handed and displayed usual hearing sensitivity and Normal or corrected to normal vision. All participants gave informed consent in conformity with research protocol. Throughout the rhyme-uncovering task, the stimuli were English words. The English legal pseudo-words, presented randomly, 30 in the left visual field and 30 in the right visual field. Every item was composed of different letters. Statistical Package For social sciences programme package (SPSS), Version 20 will be used for data analysis Results All results are presented in terms of accuracy (Percentage correct data). For visual field percentage, 30 participants were involved. From the 30 participants, 15 were male and 15 were female. With regards to the percentage of the right visual field and left visual field, there was difference in terms of percentage. Similarly, there were differences in percentage between different genders. Mean of the percentage of the right visual field for male 55+65+60+50+55+88+68+70+75+80+75+70+85+73+80=1049 1049/15=69.93% The average/mean percentage of the right visual field is 69.93% The mean or average of the left visual field for male 68+53+53+58+35+65+60+58+68+68+60+75+70+50+73=914 914/15=60.933% The average/mean percentage of the left visual field is 60.9% In comparison between the right and left visual field, male had higher correct data for right visual field compared to the left visual field. The right visual field had 69.93% compared to 60% of left visual field. Therefore, the right hemisphere had higher correct data in contrast to the left hemisphere. For female, the mean or percentage for right visual field 65+75+75+45+55+78+65+60+60+78+73+63+58+73+70=993 993/15= 66.2% The mean or average percentage of the left visual field 53+50+70+60+38+73+75+73+70+70+83+78+63+78+60=1003 1003/15=66.867% The percentage correct data for both left and right hemisphere for female were nearly equal, with left visual field being slightly high. The right visual field was 66.2% and the left visual field was 66.867%. In comparison between the percentage correct data for left hemispheres of male and female, it is evident that male had higher correct data compared to female as male had 69.93% and female had 66.2%. On the other hand, the percentage correct data for right hemisphere of female is higher in comparison to male; female had 66.86% correct data for right hemisphere, while male had 60.93% correct data for right hemisphere. Discussion In the current study, it aimed at assessing the most lateralized amongst two phonological and the most lateralized amid the two semantic tasks, by utilizing the visual field presentation of stimuli. In comparison between the right and left visual field, male had higher correct data for right visual field compared to the left visual field. The right visual field had 69.93% compared to 60% of left visual field. Therefore, the right hemisphere had higher correct data in contrast to the left hemisphere. The finding is in line with Maccoby (2004) that revealed that the left hemisphere is be predominant for all tasks as all subjects or participants were right-handed, the extend or degree of lateralization vary with task (Maccoby, 2004). In general, the results revealed that the semantic and the phonological tasks were left hemisphere lateralized since they were executed considerably more correctly when stimuli were displayed first to the rift visual field (left hemisphere). This study result is in line with earlier studies utilizing dichotic listening and divided visual procedures. The percentage correct data for both left and right hemisphere for female were nearly equal, with left visual field being slightly high. The right visual field was 66.2% and the left visual field was 66.867%. Therefore, the left hemisphere has higher percentage correct data In contrast between the percentage correct data for left hemispheres of male and female, it is evident that male had higher correct data compared to female as male had 69.93% and female had 66.2%. On the other hand, the percentage correct data for right hemisphere of female was higher in comparison to male; female had 66.86% correct data for left hemisphere, while male had 60.93% correct data for left hemisphere. The lesser or weaker lateralization during the task had numerous explanations. One of the explanations was the particularity of the task (Knecht & Bobe, 2000). Limitations of the study A considerable disparity between the right visual field/left hemisphere (RVF/LH) and left visual field or right hemisphere (LVF/RH) task performance utilizing the divided visual field paradigm do offer confirmation of the functional asymmetry amid the two brain cerebral hemispheres (Poffenberger, 2006). However, there are limitations and restrictions to the kind of implications that might be made from the technique. The divided visual field method had its limitations. A significant supposition has been that difference in recital with lateralized stimuli usually reflects functional difference amid the two cerebral hemispheres. Visual information may be transmitted from one cerebral hemisphere to the other cerebral hemisphere in as less as 3ms; therefore, whichever task differences that is greater than 3ms might stand for asymmetries in neural dynamics, which are more intricate than a solitary hemispheres uncomplicated dominance for an exact task (Banich, 2003). Furthermore, the divided visual field methods represent a comparatively indirect and coarse technique for localizing a brain region related with the cognitive function (Ivry & Robertson, 2008). References Banich. (2003). The divided visual field technique in laterality and interhemispheric integration. In K. Hughdahl (Ed.), Experimental Methods in Neuropsychology (pp. 47-63). New York: Kluwer. Bourne. (2006). The divided visual field paradigm: Methodological considerations. Laterality, 373-393. Bunt, M., & Johanson. (2007). Demonstration of bilateral projection of the central retina of the monkey with horseradish peroxidase neuronography. . Journal of Comparative Neurology, 619-630. Goldberg. (2009). The New Executive Brain: Frontal Lobes in a Complex World. . New York, NY: Oxford University Press. Ivry, & Robertson. (2008). The two sides of perception. . Cambridge, MA: The MIT Press. Jeffery. (2001). Architecture of the optic chiasm and the mechanisms that sculpt its development. 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