A psychologist is interested in whether hypnosis affects brain dominance. Twelve college students from the freshmen class are randomly sampled for an experiment. The experiment has two conditions which are given on different days. In condition 1, the students are hypnotized and then given a test which measures the relative dominance of the right and left hemispheres. The higher the score, the more dominant is the right hemisphere. In condition 2, the same students are given the test again, only this time they are not hypnotized but are in their normal state of consciousness. The following scores are obtained. Using a = 0.05 2 tail , your conclusion is _________.
A) accept H 0 ; hypnosis has no affect on brain dominance
B) retain H 0 ; we cannot conclude that hypnosis affects brain dominance
C) reject H 0 ; hypnosis affects brain dominance
D) change H 0

Question

A psychologist is interested in whether hypnosis affects brain dominance. Twelve college students from the freshmen class are randomly sampled for an experiment. The experiment has two conditions which are given on different days. In condition 1, the students are hypnotized and then given a test which measures the relative dominance of the right and left hemispheres. The higher the score, the more dominant is the right hemisphere. In condition 2, the same students are given the test again, only this time they are not hypnotized but are in their normal state of consciousness. The following scores are obtained.  Using a = 0.05 2 tail , your conclusion is _________.
A) accept H 0 ; hypnosis has no affect on brain dominance 
B) retain H 0 ; we cannot conclude that hypnosis affects brain dominance 
C) reject H 0 ; hypnosis affects brain dominance 
D) change H 0

Quizplus · Accepted Answer

We can conduct a paired-sample t-test to analyze the difference in scores between condition 1 and condition 2 for each participant. With a significance level of 0.05 and degrees of freedom of 11, we find a t-value of 2.201. Consulting a t-distribution table, we see that the critical t-value for a two-tailed test with 11 degrees of freedom at the 0.05 level of significance is 2.201. Since our calculated t-value is greater than the critical t-value, we reject the null hypothesis that there is no effect of hypnosis on brain dominance. Therefore, the conclusion is that hypnosis affects brain dominance.

A Psychologist Is Interested in Whether Hypnosis Affects Brain Dominance