Biopsychology Lab Report (EEG Experiment) - Research Paper Example

Studying to find out how the brain works or functions has long been a major consideration in the field of biopsychology. There are varying results however, especially concerning the left-brain and right-brain hemisphere activation. Concerning this, more relevant studies are necessary to ensure confirmation of the appropriate findings. This study found out the level of difference linked to left-brain and right-brain hemisphere of 27 males and 27 females doing language tasks and spatial tasks while undergoing EEG. The varying activations using alpha and beta activity during the EEG tests were recorded. The results of the study support the idea that males may have left lateralized dominance over their female counterparts, and females may have that level of dominance particularly somewhere in the right hemisphere of the brain. This further suggests that for language tasks, the right hemisphere is most likely activated, while for the spatial tasks, the left hemisphere is used, which could be due to lateralization or specialized function of each hemisphere. Keywords: EEG, right-brain hemisphere, left-brain hemisphere. Introduction There are many things to understand about how the human brain works or functions. Scientists found that the right and left hemisphere of the brain perform essential and respective functions (Clarke, Dewhurst & Aminoff, 1996). In order to substantiate this claim, there are many studies conducted for the hope of validating it (Sperry & Trevarthern, 1990). Some studies show that males have left-brain lateral dominance over their female counterparts (Sommer et al., 2004; Frost et al., 1999; Gur et al., 2000). Thus, the right-brain hemisphere has become subjected as supporting entity of the left-brain hemisphere (Turgeon, 1993). For this reason, this study is aimed to provide a substantial contribution to the growing knowledge concerning the important information in line with the left-brain and right-brain hemisphere of male and female respondents. Regarding this, the following questions were answered at the end of the study. 1. What are the right and left-brain hemisphere activations for the language tasks for males and females, respectively? 2. What are the right and left-brain hemisphere activations for the spatial tasks for males and females, respectively? 3. How significant is the difference on brain hemisphere activations between males and females for the language task? 4. How significant is the difference on brain hemisphere activations between males and females for the spatial task? To answer these questions, the study established the following hypotheses. Hypothesis 1: There will be a significant difference in left and right hemisphere activation for the language tasks for males Hypothesis 2: There will be a significant difference in left and right hemisphere activation for the spatial tasks for males Hypothesis 3: There will be a significant difference in left and right hemisphere activation for the language tasks for females Hypothesis 4: There will be a significant difference in left and right hemisphere activation for the spatial tasks for females Hypothesis 5: There will be a significant difference between males and females for the language task Hypothesis 6: There will be a significant difference between males and females for the spatial task Method Participants There were 54 participants in the study, with equal number of male and female respondents. They were personally approached to take as the subjects of the study and their consents were primarily considered. Apparatus The primary instrument or device used in the study was electroencephalogram (EEG), a device that can measure tiny electrical signals produced by the brain. The gathering of data from the participants was initiated by a EEG specialist at the laboratory. Design The activation in each hemisphere is recorded in males and females whilst they are performing a language task and a visuospatial task. From the data, the proponents were able to statistically analyse the differences in hemispherical activity between left and right hemisphere. This will allow the testing of the hypotheses. As the sex of the participant has also been recorded statistical comparisons between males and females was also been made to identify differences in hemispherical activation during the language and visuospatial tasks. The independent variables were hemisphere for the repeated measures component and the hemisphere and sex for the independent measures component. These were all taken from the actual EEG activity. The dependent variables were alpha and beta activity, taken from the actual EEG procedure. Procedure The research was done by employing participants in the study, males and females of equal number. Those who gave their consent for the study underwent EEG test done by a EEG expert. Respondents were asked to perform language tasks and spatial tasks under two different beta activities, alpha and beta. Each time of this activity was initiated the participants left-brain and right-brain hemisphere activations were recorded under mV unit each. Results The analysis of variance (ANOVA) was implemented in order to find out the significant difference associated with the respondents’ sex differences in the functional organization of the brain for language and visual spatial tasks by employing two important periodic rhythms in the electroencephalogram (EEG), alpha and beta. Using the alpha and beta periodic rhythms of the EEG on the left and right hemisphere of the brain of the male and female respondents, data were generated and analyzed using ANOVA single factor and two-factor with replication. In Table 1, at alpha periodic rhythm of the EEG, the data left and right activation for the language tasks for male respondents generated F-computed value of 23.56 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is a significant difference in the left and right hemisphere activation for the language tasks for males at alpha periodic rhythm of the EEG. In Table 2, it is shown that the language tasks at right hemisphere are higher than those in the left hemisphere. Table 1. ANOVA: Left and right activation for the language tasks for males (alpha). Source of Variation SS df MS F P-value F crit Between Groups 57.99 1 57.99 23.56 0.00 4.03 Within Groups 127.99 52 2.46 Total 185.98 53         Table 2. Summary of the difference in the language tasks in males (alpha) Language Tasks Count Sum Average Variance Left (alpha) 27 51.7 1.91 0.40 Right (alpha) 27 107.66 3.99 4.53 In Table 3, at beta periodic rhythm of the EEG, the data left and right activation for the language tasks for male respondents generated F-computed value of 20.74 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is a significant difference in the left and right hemisphere activation for the language tasks for males at beta periodic rhythm of the EEG. In Table 4, it is shown that the language tasks at right hemisphere are higher than those in the left hemisphere. Table 3. ANOVA: Left and right activation for the language tasks for males (beta) Source of Variation SS df MS F P-value F crit Between Groups 155.72 1 155.72 20.74 0.00 4.03 Within Groups 390.36 52 7.51 Total 546.08 53         Table 4. Summary of the difference in language tasks in males (beta) Language Tasks Count Sum Average Variance Left (beta) 27 69.84 2.59 0.52 Right (beta) 27 161.54 5.98 14.49 In Table 5, at alpha periodic rhythm of the EEG, the data left and right activation for the spatial tasks for male respondents generated F-computed value of 41.31 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is a significant difference in the left and right hemisphere activation for the spatial tasks for males at alpha periodic rhythm of the EEG. In Table 6, it is shown that the spatial tasks at left hemisphere are higher than those in the right hemisphere. Table 5. ANOVA: Left and right activation for the spatial tasks for males (alpha) Source of Variation SS df MS F P-value F crit Between Groups 99.55 1 99.55 41.31 0.00 4.03 Within Groups 125.32 52 2.41 Total 224.87 53         Table 6. Summary of the difference in spatial tasks in males (alpha) Spatial Tasks Count Sum Average Variance Left (alpha) 27 168.56 6.24 2.93 Right (alpha) 27 95.24 3.53 1.89 In Table 7, at beta periodic rhythm of the EEG, the data left and right activation for the spatial tasks for male respondents generated F-computed value of 9.82 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is a significant difference in the left and right hemisphere activation for the spatial tasks for males at beta periodic rhythm of the EEG. In Table 8, it is shown that the spatial tasks at left hemisphere are higher than those in the right hemisphere. Table 7. ANOVA: Left and right activation for the spatial tasks for males (beta) Source of Variation SS df MS F P-value F crit Between Groups 110.54 1 110.54 9.82 0.003 4.03 Within Groups 585.15 52 11.25 Total 695.69 53         Table 8. Summary of the difference in spatial tasks in males (beta) Spatial Tasks Count Sum Average Variance Left (beta) 27 191.81 7.10 12.34 Right (beta) 27 114.55 4.24 10.17 In Table 9, at alpha periodic rhythm of the EEG, the data left and right activation for the language tasks for female respondents generated F-computed value of 0.80 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.37 which is higher than .05. This confirms the hypothesis that there is no significant difference in the left and right hemisphere activation for the language tasks for females at alpha periodic rhythm of the EEG. Table 9. ANOVA: Left and right activation for the language tasks for females (alpha) Source of Variation SS df MS F P-value F crit Between Groups 6.09 1 6.09 0.80 0.37 4.03 Within Groups 394.40 52 7.58 Total 400.49 53         In Table 10, at beta periodic rhythm of the EEG, the data left and right activation for the language tasks for female respondents generated F-computed value of 0.50 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.48 which is higher than .05. This confirms the hypothesis that there is no significant difference in the left and right hemisphere activation for the language tasks for females at beta periodic rhythm of the EEG. Table 10. ANOVA: Left and right activation for the language tasks for females (beta) Source of Variation SS df MS F P-value F crit Between Groups 9.64 1 9.64 0.50 0.48 4.03 Within Groups 1002.40 52 19.28 Total 1012.04 53         In Table 11, at alpha periodic rhythm of the EEG, the data left and right activation for the spatial tasks for female respondents generated F-computed value of 40.91 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is significant difference in the left and right hemisphere activation for the spatial tasks for females at alpha periodic rhythm of the EEG. In Table 12, it is shown that the spatial tasks at left hemisphere are higher than those in the right hemisphere. Table 11. ANOVA: Left and right activation for the spatial tasks for females (alpha) Source of Variation SS df MS F P-value F crit Between Groups 115.25 1 115.25 40.91 0.00 4.03 Within Groups 146.48 52 2.82 Total 261.73 53         Table 12. Summary of the difference in the spatial tasks in females (alpha) Spatial Tasks Count Sum Average Variance Left (alpha) 27 146.18 5.41 4.53 Right (alpha) 27 67.29 2.49 1.10 In Table 13, at beta periodic rhythm of the EEG, the data left and right activation for the spatial tasks for female respondents generated F-computed value of 52.82 and F-critical value of 4.03 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is significant difference in the left and right hemisphere activation for the spatial tasks for females at beta periodic rhythm of the EEG. In Table 14, it is shown that the spatial tasks at left hemisphere are higher than those in the right hemisphere. Table 13. ANOVA: Left and right activation for the spatial tasks for females (beta) Source of Variation SS df MS F P-value F crit Between Groups 86.26 1 86.26 52.82 0.00 4.03 Within Groups 84.92 52 1.63 Total 171.18 53         Table 14. Summary of the difference in the spatial tasks in females (beta) Spatial Tasks Count Sum Average Variance Left (beta) 27 138.71 5.14 2.44 Right (beta) 27 70.46 2.61 0.83 On the other hand, the analysis in order to know if there is a significant difference between males and females for the language task was employed. In Table 15, at alpha periodic rhythm of the EEG, the data left and right activation for the language tasks for male and female respondents generated F-computed value of 15.33 and F-critical value of 3.93 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is significant difference in the left and right hemisphere activation for the language tasks between males and females at alpha periodic rhythm of the EEG. In Table 16, it is shown that the language tasks in females are higher than their male counterparts. There is also a significant difference between the right and left activation for the two groups under the language tasks, by which right activation was generally higher than the left activation as showcased through a 10.12 F-computed value over the P-value of 0.00 and 3.93 at .05 level of significance. Table 15. ANOVA: Left and right activation for the language tasks between males and females (alpha) Source of Variation SS df MS F P-value F crit Sample 77.00 1 77.00 15.33 0.00 3.93 Columns 50.83 1 50.83 10.12 0.00 3.93 Interaction 13.25 1 13.25 2.64 0.10 3.93 Within 522.39 104 5.02 Total 663.47 107         Table 16. Summary of the difference in the language tasks between males and females (alpha) Summary L_Alpha_lang_amp R_Alpha_lang_amp Total Male       Count 27 27 54 Sum 51.70 107.66 159.36 Average 1.91 3.99 2.95 Variance 0.40 4.53 3.51         Female       Count 27 27 54 Sum 116.21 134.34 250.55 Average 4.30 4.98 4.64 Variance 6.00 9.17 7.56         Total       Count 54 54   Sum 167.91 242   Average 3.11 4.48   Variance 4.59 6.97   In Table 17, at beta periodic rhythm of the EEG, the data left and right activation for the language tasks for male and female respondents generated F-computed value of 16.97 and F-critical value of 3.93 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is significant difference in the left and right hemisphere activation for the language tasks between males and females a beta periodic rhythm of the EEG. In Table 18, it is shown that the language tasks in females are higher than their male counterparts. There is also a significant difference between the right and left activation for the two groups under the language tasks, by which right activation was generally higher than the left activation as showcased through a 9.07 F-computed value over the P-value of 0.00 and 3.93 at .05 level of significance. Table 17. ANOVA: Left and right activation for the language tasks between males and females (beta) Source of Variation SS df MS F P-value F crit Sample 227.30 1 227.30 16.97 0.00 3.93 Columns 121.43 1 121.43 9.07 0.00 3.93 Interaction 43.93 1 43.93 3.28 0.07 3.93 Within 1392.76 104 13.39 Total 1785.42 107         Table 18. Summary of the difference in the language tasks between males and females (beta) Summary L_Beta_lang_amp R_Beta_lang_amp Total Male       Count 27 27 54 Sum 69.84 161.54 231.38 Average 2.59 5.98 4.28 Variance 0.52 14.49 10.30         Female       Count 27 27 54 Sum 182.62 205.44 388.06 Average 6.76 7.61 7.19 Variance 19.94 18.61 19.10         Total       Count 54 54   Sum 252.46 366.98   Average 4.68 6.80   Variance 14.48 16.91   In Table 19, at alpha periodic rhythm of the EEG, the data left and right activation for the spatial tasks for male and female respondents generated F-computed value of 8.97 and F-critical value of 3.93 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is significant difference in the left and right hemisphere activation for the spatial tasks between males and females at alpha periodic rhythm of the EEG. In Table 20, it is shown that the spatial tasks in males are higher than their female counterparts. There is also a significant difference between the right and left activation for the two groups under the spatial tasks, by which left activation was generally higher than the right activation as showcased through a 82.08 F-computed value over the P-value of 0.00 and 3.93 at .05 level of significance. Table 19. ANOVA: Left and right activation for the spatial tasks between males and females (alpha) Source of Variation SS df MS F P-value F crit Sample 23.45 1 23.45 8.97 0.00 3.93 Columns 214.52 1 214.52 82.08 0.00 3.93 Interaction 0.29 1 0.29 0.11 0.74 3.93 Within 271.79 104 2.61 Total 510.05 107         Table 20. Summary of the difference in the spatial tasks between males and females (alpha) Summary L_Alpha_spatial_amp R_Alpha_spatial_amp Total Male       Count 27 27 54 Sum 168.56 95.24 263.80 Average 6.24 3.53 4.89 Variance 2.93 1.89 4.24         Female       Count 27 27 54 Sum 146.18 67.29 213.47 Average 5.41 2.49 3.95 Variance 4.53 1.10 4.94         Total       Count 54 54   Sum 314.74 162.53   Average 5.83 3.01   Variance 3.83 1.74   In Table 21, at beta periodic rhythm of the EEG, the data left and right activation for the spatial tasks for male and female respondents generated F-computed value of 13.57 and F-critical value of 3.93 at .05 level of significance. The P-value is 0.00 which is lower than .05. This confirms the hypothesis that there is significant difference in the left and right hemisphere activation for the spatial tasks between males and females at beta periodic rhythm of the EEG. In Table 22, it is shown that the spatial tasks in males are higher than their female counterparts. There is also a significant difference between the right and left activation for the two groups under the spatial tasks, by which left activation was generally higher than the right activation as showcased through a 30.43 F-computed value over the P-value of 0.00 and 3.93 at .05 level of significance. Table 21. ANOVA: Left and right activation for the spatial tasks between males and females (beta) Source of Variation SS df MS F P-value F crit Sample 87.46 1 87.46 13.57 0.00 3.93 Columns 196.05 1 196.05 30.43 0.00 3.93 Interaction 0.75 1 0.75 0.12 0.73 3.93 Within 670.07 104 6.44 Total 954.34 107         Table 22. Summary of the difference in the spatial tasks between males and females (beta) Summary L_Beta_spatial_amp R_Beta_spatial_amp Total Male       Count 27 27 54 Sum 191.81 114.55 306.36 Average 7.10 4.24 5.67 Variance 12.34 0.18 13.13         Female       Count 27 27 54 Sum 138.71 70.46 209.17 Average 5.14 2.61 3.88 Variance 2.44 0.83 3.23         Total       Count 54 54   Sum 330.52 185.01   Average 6.12 3.43   Variance 8.23 6.07   Discussion Alpha as a periodic rhythm in the EEG, is a wave pattern linked to the brain when an adult is awake, but relaxed with eyes closed (Mulert and Lemieux, 2009). Beta on the other hand is a periodic rhythm in the EEG associated with the wave pattern of the brain when an individual is exerting mental effort (Stern, 2013). The experiment was initiated under these two sets. It was generally found that in either of these sets, there was a significant difference in the activation of the right and left hemisphere of the brain within the same sex and to the opposite sex. For the left and right hemisphere activation for the language tasks for males, there was a significant difference both at alpha and beta periodic rhythm in the EEG. It was found that the activation was higher at the right hemisphere. For the left and right hemisphere activation for the spatial tasks for males, there was a significant difference both at alpha and beta periodic rhythm in the EEG. It was found that the activation was higher at the left hemisphere. For the left and right hemisphere activation for the language tasks for females, there was no significant difference both at alpha and beta periodic rhythm in the EEG. For the left and right hemisphere activation for the spatial tasks for females, there was a significant difference both at alpha and beta periodic rhythm in the EEG. It was found that the activation was higher at the left hemisphere. Therefore, the result indicated that males vary in language tasks activation compared to the female group. For the spatial tasks activation, there was a significant variation among females and among males, and the higher activation occurs somewhere at the left hemisphere for these two groups. In general, there was a variation between male and female in the language tasks activation. Generally, activation was higher in females and somewhere in the right hemisphere for the two groups. Also, there was a variation between male and female in spatial tasks activation. Generally, activation was higher in males and somewhere in the left hemisphere for the two groups. The results show that the language tasks activate most of the right hemisphere of the brain, while the spatial tasks activate most of the left hemisphere of the brain. Males’ left brains are highly activated during spatial tasks compared to their female counterparts. Female’s right brains on the other hand are highly activated during language tasks compared to their male counterparts. It was also found that females do not vary in the brain’s language tasks activation when compared, unlike their male counterparts. This means that males’ brain vary in their language task activation. In the same way, there was a variation of brain’s spatial tasks activation for each group when compared together within their group. As found, the left hemisphere was highly activated and the male group was dominant on this side. The results support the idea that males may have left lateralized dominance over their female counterparts, and females may have that level of dominance particularly somewhere in the right hemisphere of the brain (Sommer et al., 2004; Frost et al., 1999; Gur et al., 2000). This further suggests that for language tasks, the right hemisphere is most likely activated, while for the spatial tasks, the left hemisphere is used, which could be due to lateralization or specialized function of each hemisphere. It has long been viewed that each hemisphere of the brain performs respective functions. It has also long been thought that the left-brain hemisphere is having its dominance in areas of language and logic, while the right-brain hemisphere focuses on nonverbal, intuitive, holistic level of thinking (Ray et al., 1981). The results presented in this study somehow try to provide a remarkable suggestion of the lateralization effect concerning the functioning of the hemispheres. Left-brain hemisphere has been regarded as the dominant overall, which controls all higher reasoning ability making the right-brain hemisphere as a mere subordinate to the left (Davidson et al., 1990). References Clarke, E., Dewhurst, K., & Aminoff, M. J. (1996). 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