ACT science practice test 32

Directions: Each passage is followed by several questions. After reading a passage, choose the best answer to each question and fill in the corresponding oval on your answer document. You may refer to the passages as often as necessary.

You are NOT permitted to use a calculator on this test.


A student wanted to test human reaction time to different stimuli to determine the conditions that cause the fastest reaction. The student conducted three experiments to test reaction time.

Experiment 1

The student used a computer program to record the time between the sounding of a tone and the student pressing the spacebar on the keyboard. This process was repeated 10 times per trial. The program then averaged the 10 response times to produce an average for the trial. The student conducted three trials using a tone length of 200 milliseconds (ms) and three trials with a tone length of 400 ms. Results are shown in Table 3.6.

TABLE 3.6 Experiment 1

Experiment 2

The student then used the same computer program to record the time between the sounding of a tone or the appearance of an image on the screen and the student pressing the spacebar. This process was repeated 10 times per trial, with the computer again averaging the 10 response times for each trial. The student conducted three trials using the tone as the stimulus and three trials using the image. Each stimulus lasted for a duration of 400 ms. Results are shown in Table 3.7.

TABLE 3.7 Experiment 2

Experiment 3

The student repeated the previous experiment but alternated the stimulus (tone versus image) with each trial. Results are shown in Table 3.8.

TABLE 3.8 Experiment 3

1. In the three experiments, response time is measured as the time between:

A. exposures to two consecutive stimuli.
B. exposure to a stimulus and the subsequent response.
C. the registering of two consecutive responses.
D. the beginning and end of one trial.

2. The stimulus in Experiment 1 was the:

A. sounding of a tone.
B. appearance of a screen image.
C. pressing of the spacebar.
D. use of a computer program.

3. How do Experiments 2 and 3 differ?

A. Experiments 2 and 3 used different stimuli to test response times.
B. The length of exposure to the stimulus was greater in Experiment 2.
C. Experiment 3 included more trials than Experiment 2.
D. In Experiment 3, the type of stimulus was alternated with each trial.

4. Based on the data in Table 3.7, the sense of hearing is:

A. twice as fast as sight.
B. more complex than sight.
C. not as readily testable as sight.
D. more acute than sight.

5. A stimulus duration of 400 ms was used during which experiment(s)?

A. Experiments 2 and 3 only
B. Experiment 1 only
C. Experiments 1 and 2 only
D. Experiments 1, 2, and 3

6. The fastest reaction time occurred in response to:

A. an auditory stimulus lasting 200 ms.
B. an auditory stimulus lasting 400 ms.
C. a visual stimulus lasting 400 ms.
D. a visual stimulus lasting 200 ms.

7. Based on the data in Table 3.6, what is the relationship between reaction time and length of stimulus exposure?

A. Lengthening the stimulus improves reaction time.
B. A shorter stimulus produces the fastest reaction time.
C. Stimulus length has no measurable effect on reaction time.
D. A longer stimulus produces the slowest reaction time.

8. Scientists have found that it takes 20-40 ms for a visual signal to reach the brain. Based on the data in Experiments 2 and 3, how long can an auditory signal be expected to take to reach the brain?

A. 25-45 ms
B. 50-55 ms
C. 8-10 ms
D. 20-40 ms

9. The data in Tables 3.7 and 3.8 best support the conclusion that alternating between two stimuli:

A. increases the average response time for both stimuli.
B. improves auditory response time but not visual response time.
C. decreases the average response time for both stimuli.
D. improves visual response time but not auditory response time.

10. Scientists have found that a specific response time range exists for each particular sense. Which of the following would be the range for auditory stimuli?

A. 140-160 ms
B. 180-200 ms
C. 150-170 ms
D. 125-145 ms

11. How many total responses were recorded during Experiment 2?

A. 10
B. 6
C. 60
D. 30

12. Which graph best represents the data collected during Experiment 3?

A.
Figure 3.4
B.
Figure 3.5
C.
Figure 3.6
D.
Figure 3.7

13. The student wants to test how varying the length of exposure to a visual stimulus affects response time. The best way to do this is to repeat:

A. all three experiments using visual stimuli only.
B. Experiment 1, replacing the tone with an image.
C. Experiment 3, using a visual stimulus only.
D. Experiment 2, using a stimulus duration of 200 ms.

14. What was the slowest auditory response time recorded during the three experiments?

A. 199 ms
B. 152 ms
C. 142 ms
D. 158 ms

15. Based on the data from the three experiments, what can be done to improve response time?

A. Alternate exposure to two different stimuli.
B. Decrease the duration of each exposure to a stimulus.
C. Repeat exposure to the same stimulus.
D. Increase the number of stimuli used at one time.