The goal Paper is to use the correlational method to think more deeply about the divided brain. In particular, we want you to use correlations to study the psychological experience of split-brain patients. We learned in class that these patients provide a window into the separate functions of the two hemispheres. We called this separation of function laterality. In people with intact brains the separate functions seem to blend together seamlessly. We might hypothesize that, in intact brains, there would be a strong relationship between functions typically performed by the left hemisphere and those performed by the right hemisphere. We might hypothesize further that, in split brains, the relationship between hemispheres would disappear. The correlational method might be an appropriate technique for testing this hypothesis.
For Paper, we want you to write a paper that evaluates the adequacy of the correlational method to study laterality in split-brain patients. First, title your paper Using the Correlational Method to Study the Divided Brain. Next: FOLLOW EACH OF THE FOLLOWING FIVE INSTRUCTIONS EXACTLY (The following is a detailed outline on how you should write this paper):
Your paper should consist of five paragraphs corresponding to the 5 questions below. DO NOT write an outlined paper: it needs to be in essay format. Within each paragraph, please be clear on which letter you are answering by placing a bold letter in front of the sentences. If you are answering 1a place a letter a before the sentence/s. (Heres an example: The purpose of this paper is to use the correlational method to examine the relationship between functions of the left and right hemispheres. I will compare the performance of people with intact brains with the performance of so-called split-brain patients. In many ways, the brains of these two groups are very similar. 1 a. The location of the brainstem in the normal brain is)
1. Begin the first paragraph of the paper with these sentences: The purpose of this paper is to evaluate the correlational method as a means for examining the relationship between functions of the left and right hemispheres. I will compare the performance of people with intact brains with the performance of so-called split-brain patients. In many ways, the brains of these two groups are very similar.
a. Describe the location and function of the brainstem of the normal brain. What differences, if any, are there between the function of the normal brainstem and that of the split-brain brainstem? (4 pts).
b. Describe the location and function of the hippocampus of the normal brain. What differences, if any, are there between the anatomy of the normal hippocampus and the anatomy of the split-brain hippocampus? (4 pts).
c. Describe the location and function of the corpus callosum in the normal brain. What differences, if any, are there between the anatomy of the normal corpus callosum and that of the split-brain corpus callosum? (4 pts)
d. Describe the location and function of the cerebral cortex of the normal brain. What differences, if any, are there between the function of the normal cerebral cortex and that of the split-brain cerebral cortex? (4 pts).
2. Begin the next paragraph with this sentence: The split brain patient provides scientists with a window into the normal functions of the brain.
a. Describe the split-brain patient, including what condition they suffer from and the surgical technique used to treat it. (4 pts)
b. Describe a test of the split-brain patient used to demonstrate that language function is lateralized to one hemisphere. (5 pts)
c. Explain how the results with split-brain patients can be used to understand laterality in the general population. (3 pts)
3. Begin the next paragraph with these sentences: Cognitive tests performed on split-brain patients have identified a division of labor between hemispheres. It is conceivable that functions handled by the different hemispheres will show a strong relationship in the general population, but not in split-brain patients.
a. Identify four brain functions that are lateralized to the left hemisphere. Identify four functions lateralized to the right hemisphere. (6 pts)
b. State the hypothesis to be evaluated in your paper. (4 pts)
c. Describe how you will use the correlational method to evaluate the hypothesis. (5 pts)
4. At the bottom of this assignment are data from two groups of participants, one group of 10 split-brain patients and one group of 10 participants from the general population. Both groups were tested on three cognitive tasks: (1) a vocabulary test, (2) a logical reasoning task, and (3) a face recognition task. The tables contain the participants scores on these tests, higher scores indicating better performance. In Lab #1 we used the following formula to calculate the correlation coefficient:
The Formula: r = III/ I(II)
We broke this formula into three terms:
I= N (Sum X2) (Sum X)2
II= N (Sum Y2) (Sum Y)2
III= N (Sum of XY) Sum X (Sum Y)
Begin the fourth paragraph with these sentences: Data were collected from a group of split-brain patients and a group from the general population to test the hypothesis using the correlational method. Each group completed three tasks shown previously to be lateralized: (1) a vocabulary test, (2) a logical reasoning task, and (3) a face recognition task.
a. Indicate the hemisphere to which each of the three tasks is lateralized. (4 pts)
b. State your predictions about the pattern of correlations among the three tasks in each group if the hypothesis under investigation is correct. (7 pts)
c. Using the formula to compute the correlation coefficient between each pair of cognitive tasks, separately for each group of participants (N.B. Thats 6 correlation coefficients in total). For each coefficient, state the computed value of each of the four terms of the formula (i.e., r, I, II, and III). (6 pts)
5. Begin the final paragraph with these sentences: The results of the correlational method were valuable in addressing the hypothesis under study. However, future investigations may need to adopt techniques that improve upon those used here.
a. Restate the hypothesis under study. Are the results of the correlational analysis consistent with the hypothesis? Why or why not? ( 4 pts)
b. Is there any aspect of the results that does not readily fit with the hypothesis? What alternative explanation would you give for these findings? ( 4 pts)
c. Describe a feature of the current correlational technique that could be improved if you were to repeat the study. (3 pts)
d. Can correlational studies be used to evaluate hypotheses or should we only use experiments instead? Defend your answer. (4 pts)
e. Describe an experiment that you would perform to test the hypothesis evaluated in this paper. (5 pts)
A fifth of your grade will be based on the following:
a. Clarity of thesis development (4pts)
b. Clarity of papers structure and organization (4pts)
c. Thoroughness in development of evidence (4pts)
d. Good mechanics (grammar, punctuation, usage) and style of writing (4pts)
e. Competence in quantitative reasoning and analysis of research findings (4pts)
, in essay format & type written (double spaced) using Microsoft Word in .doc format.
Quoted, paraphrased or borrowed sentences or phrases are not allowed.
NO COVER PAGE NEEDED
