Proprioception (5 points)
To demonstrate the use of proprioception, close your eyes and hold your arms out to the side, forming a “T.” Now touch your nose with the index finger of your dominant hand. Repeat with your nondominant hand. Speculate as to why this exercise is sometimes used to test drivers suspected of drinking?
Again, close your eyes. Raise your leg so that your thigh is parallel to the floor. Open your eyes and check your leg’s position. Repeat the exercise, bringing your arm in a position parallel to the floor. How accurate was your positioning? How did you accomplish this activity in the absence of vision? Explain.
Knee Jerk Reflex (5 points)
You will need a partner. Have your partner sit on a chair and cross his or her legs so that the lower knee fits into the hollow at the back of the upper knee. Now, using the edge of your open hand, firmly tap the soft part just below your partner’s kneecap. You may have to try a couple of times to find the spot that initiates the reflex. Switch places with your partner.
Repeat the activity, but this time the sitting person should try to voluntarily prevent the reflex from occurring. Can you do it?
How might this explain inappropriate or unplanned movements in some sport settings? Give examples.
Chapter Review Questions (20 points)
Be sure to have read the entire chapter before answering and include the question with your answer.
1. Compare and contrast exteroceptors, interoceptors, and proprioceptors.
2. Which photoreceptor is specialized for vision in dim light? Which one is specialized for visual acuity?
3. Define visual acuity.
4. What is the significance of the optic chiasm?
5. Compare and contrast focal and ambient vision. Which one of the two deals with peripheral vision?
6. How do performers use tau?
7. Define fixation. How can we use fixations to infer visual attention?
8. Compare and contrast golgi tendon organs, muscle spindles, joint kinesthetic receptors, and the vestibular apparatus.
9. What functional problems would be associated with damage to the dorsal column pathways? The extrapyramidal pathway?
10. What are the five components of a reflex arc? Explain why reflexes are faster than voluntary movements.
11. Speculate as to the result of damage to the general interpretive area.
12. What is Parkinson’s disease?
13. What are the three memory systems? Compare each with respect to capacity and duration.
14. Explain why phone numbers are traditionally seven digits long.
15. Why is STM also referred to as working memory?
16. Two theories have been suggested as explanations for forgetting. Explain each.