Learning Objectives

1.) Distinguish between touch sensitivity and touch acuity. In addition, explain how each one is measured and specify the general human threshold for both.

2.) Discuss the effects of various surface textures on the perception of touch.

3.) Describe those properties of tactile discrimination that make reading embossed letters more difficult than reading Braille.

4.) Explain the influential effect of an individual's mental set on tactile sensitivity.

5.) Distinguish between the four categories of touch fibers found in the human hand and discuss in detail the specific properties of each.

6.) Describe the approaches used to assess the functional significance among the four types of fibers and specify the overall findings regarding their individual roles.

7.) Describe the relative location and function of the following mechanoreceptors: Meissner corpuscles, Pacinian corpuscles, Merkel disks, and Ruffini endings.

8.) Trace the ascending pathway for touch, and describe the location and function of the two major classes of neurons involved at this level of tactile perception.

9.) Explain what is meant by cortical magnification and discuss the possible benefits of such an anatomical layout to species survival.

10.) Define the term haptic and relate it to what Lederman and Klatzky refer to as "exploratory procedures." Specify the importance of both for tactile perception.

11.) Explain why chronic pain management is so challenging and discuss the current therapies used in its management.

12.) Explain in detail the gate control theory of pain perception.

13.) Explain why the somatosensory cortex is said to be plastic and discuss the possible benefits of such cortical plasticity.