Question

Individuals experience various mood states or emotions at varying times every day, both subtle changes and obvious changes, that can result in attitude alternations with both negative and positive effects and impair or facilitate performance. The connections in the brain between emotion and memory have been particularly interesting to researchers given that neural networks that are activated by mood states are linked with neural networks that process basic perceptual functions such as word processing. Dr. Siebert has conducted a number of research experiments inducing various mood states through the use of music and then studying the effects of mood on lexical processing. (Dr. Pennie S. Siebert) Research suggests that an individual’s mood state or emotion influences cognition and memory, but to investigate the influence of mood on cognition and memory, researchers must first be able to induce mood states in their research participants. One strategy for inducing mood is through the use of various types of music. To assess the effectiveness of mood induction, researchers divided participants into two groups and had them listen to a set of songs which had independently been rated as upbeat and cheerful (to induce happiness) or a set of songs that had been rated as somber and mournful (to induce sadness). After listening to the music (happy or sad), participants were asked to complete a self-evaluation of their mood by drawing an X to represent their position on a line with happy at one end and sad at the other. Lines were then measured in distance from the sad end of the scale, creating a mood score wherein higher scores indicated happier mood and lower scores indicate a sad mood. Research Question: Is there a difference in mood between subjects who listen to happy music versus sad music? Sad: 1.20, 3.20, 2.10, 2.10, 4.90 Happy: 5.20, 6.10, 4.10, 4.10, 5.80 1. Write null and alternative hypotheses (in words and notation) appropriate for this research scenario. 2. Compute an independent samples t-test to test the hypotheses, use an α = .05, two-tailed. Clearly describe the independent and dependent variables. How do you identify M1 and M2? 3. Calculate r2 measure of effect size and 95% confidence interval. 4. Write a results paragraph that interprets and explains the results of your test.

Answer 1

1)

H₀: There is no difference in mood between subjects who listen to happy music versus sad music.

1 = 2

H₁: There is difference in mood between subjects who listen to happy music versus sad music.

1 2

2)

M1 = 2.70

M2 = 5.06

3)

R - squared : 0.3392

95% confidence interval: (- 4.1614291 , - 0.5585709 )

4)

Interpretation:

Since p-value = 0.01745 < 0.05 ,we reject H₀ at 5 % level of significance.Therefore,we can conclude that there is difference in mood between subjects who listen to happy music versus sad music.

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