How do different types of cognitive stress affect participants’ resting heart rate? We can test some hypothetical answers to this question with the MIDUS2 data set.

SPSS

1. First, write out the null and alternate hypotheses reflecting the question: Does the mean resting heart rate of participants differ between the Math and Stroop cognitive stress conditions? (For the sake of brevity, we will only be looking at the Math and Stroop cognitive stressor conditions.)
2. Since we are only looking at the Math and Stroop conditions, we need to filter our cases again like we did in Chapter 8. Go to DATA > SELECT CASES > Click the “If” button > Select the B4VCS1 variable in the left box, and then click the transfer arrow button to move it to the right box. Click the "=" button and then type “1”; now also type “OR B4VCS1 = 2” and then Click OK.
3. Now we are ready to test our hypothesis. To do this, we will run an independent samples t test to examine the mean differences in heart rate between the two treatment conditions.
   
   1. Analyze < Compare Means < Independent Samples T Test
   2. Select B4VS1HR (heart rate for Stroop condition) for the “test variables” box. (If you’re having trouble finding the variable, right click on the Variable list in the “Independent-Samples T Test” window and select “Sort Alphabetically.”)
   3. Select B4VCS1 for the “grouping variable” box and click “define cases” > type “1” into the Group 1 box and “2” in the Group 2 box > Continue
   4. Click OK to run the test
4. Look at the p value for the t test of the heart rate variable (based on the F-test result, use the “equal variances assumed” t test. Explain whether or not you should reject your null hypothesis from Question 1.

Online Analysis

1. First, write out the null and alternate hypotheses reflecting the question: Does the mean resting heart rate of participants differ between the Math and Stroop cognitive stress conditions? (For the sake of brevity, we will only be looking at the Math and Stroop cognitive stressor conditions.)

1. Click on Analysis > Comparison of means
   
   1. Type B4VS1HR (heart rate for Stroop condition) into the dependent variable box
   2. Type B4VCS1 (1,2) into the “selection filters” box
   3. Under TABLE OPTIONS, be sure the boxes for Z/T-statistic and P-value are checked
   4. Under CHART OPTIONS, select “no chart” and check the “show means” box
   5. Run the table.
2. Look at the p value for the t test of the heart rate variable. Explain whether or not you should reject your null hypothesis from Question 1.