This is called a two-tailed test. Because frankly, a super high response time, if you had a response time that was more than 3 standard deviations, that would have also made us likely to reject the null hypothesis. So we were dealing with kind of both tails. You could have done a similar type of hypothesis test with the same experiment, where you only have a one-tailed test. And the way we could have done that is we still could have had the null hypothesis, we still could have had the null hypothesis be that the drug has no effect. Drug has no effect. Or that the mean with the drug is still going to be 1.2 seconds, our mean response time.