Chapter 13 Overview
Touch
Somatosensation (the “body senses”), the subject of this chapter, is really a conglomeration of four to eight (depending on how you count them) different sensory systems, responsible for:
- Detecting damage or potential damage to our bodily tissues (pain; top-left photo)
- Determining the position of our body parts (proprioception) and where our muscles are moving (kinesthesis; top-right photo)
- Sensing temperature changes (bottom-right photo)
- Feeling deformations, low- and high-frequency vibrations, and sustained pressure on our skin, the sensations most commonly referred to by the generic word touch (bottom-left photo)
The activities and essays in this chapter will explore various aspects of somatosensation. Do you like to touch products while making a decision whether to buy them or not? The first activity in this chapter measures your Need for Touch. The next two activities cover two important physiological features of touch perception: the Somatosensory Receptors and The Sensory Homunculus.
The Rubber Hand Illusion activity demonstrates how our minds can be tricked into creating inaccurate body images, resulting in out-of-body experiences. In the Two-Point Touch Thresholds activity, you’ll map out how sensitive your various body parts are to detecting fine details of objects touching your skin. The Haptic Object Recognition activity discusses how we use touch to identify objects (see also the essay on Haptic Memory). The essay on Body Image explores our sense of our body’s position in space while the essays on Living without Kinesthesis and Phantom Limbs discuss some intriguing consequences of damage to the somatosensory system.
Once you’ve read the chapter in the textbook and done the activities here, use the study aids (Study Questions, Flashcards, and Chapter Summary) to review.