MYTH SCIENCE? Is it true . That subliminal messages in advertising can make you buy particular products? That an object’s color is not an intrinsic property of the object? That pheromones can make some people irresistible to members of the preferred sex? That different tastes are detected on different parts of your tongue? That most psychologists study ESP? That magnets can relieve pain? (inset) monkeybusinessimages/Getty Images Images (bkgrd) Erik Isakson/Tetraimages/Getty Erik Isakson/Tetra images/Getty Images Sensation and Perception adult, he earned a master’s degree in It was through skiing that Mike met international affairs from Johns Hop- his wife, Jennifer. An accomplished kins University, went to work for the skier herself, she volunteered to be Learning to See CIA, and then became a successful his guide at a ski slope. Today, Mike Mike was just three years old when businessman. and Jennifer and their two sons are all a jar of chemicals, left in an old He also learned to skydive, wind- avid skiers ( Abrams, 2002 ). storage shed, exploded in his face. surf, water ski, and snow ski. How does In his forties, Mike started a suc- The blast destroyed his left eye and a blind person ski down mountains? If cessful company that develops global severely damaged his right eye. For you answered, “Very carefully,” you’d positioning devices— along with more than four decades, Mike May be wrong— at least in Mike’s case. With other mobility devices— for the blind. was completely blind ( Kurson, 2007 ). a guide skiing in front of him shouting The portable navigation system gives But despite his blindness, Mike expe- “left” or “right” to identify obstacles, visually impaired people informa- rienced—and accomplished—much Mike hurtled down the most difficult tion about their location, landmarks, more than most people ever dream black diamond slopes at speeds up streets, and so forth wherever they of achieving. Always athletic, Mike to 65 miles per hour. In fact, Mike has travel. With his white cane and guide played flag football in elementary won several medals in national and dog, Josh, Mike traveled the world, school and wrestled and played soc- international championships for blind both as a businessperson and as a cer in high school and college. As an downhill speed skiing. tourist, ever optimistic and open to 78 Copyright ©2018 Worth Publishers. Distributed by Worth Publishers. Not for redistribution. 04_HOC_13639_Ch03_078_121_pp4.indd 78 25/07/18 8:47 PM CHAPTER 3 adventure (Kurson, 2007). His per- the truth is, I knew exactly what she sonal motto: “There is always a way.” looked like, so it wasn’t all that dra- IN THIS CHAPTER: But Mike’s keen sensory world of matic to see her. The same with my INTRODUCTION: What Are Sensation touch, sounds, and aroma was on the kids. Now, seeing other people that and Perception? verge of expanding. A new surgical I can’t touch, well, that’s interesting Vision: From Light to Sight technique offered the chance that because I couldn’t see them before.” Hearing: From Vibration to Sound Mike’s vision in his right eye might be But what did Mike see? Anatom- The Chemical and Body Senses: Smell, restored. Forty- three years after Mike ically, his right eye was now nor- Taste, Touch, and Position lost his sight, Jennifer held her breath mal. But rather than being 20/20, his Perception as the bandages were removed. “It vision was closer to 20/1,000. What Perceptual Illusions was so unexpected— there was just that means is his view of the world The Effects of Experience on Perceptual a whoosh! of light blasting into my was very blurry. He could see col- Interpretations eye,” Mike later recalled (May, 2002). ors, shapes, lines, shadows, and light PSYCH FOR YOUR LIFE: Strategies to For the first time since he was three and dark patches. So why wasn’t the Control Pain years old, Mike May could see. world crystal clear? And what was it like when Mike Although the structures of his eye could see Jennifer for the first time? were working, his brain did not know “It was incredible,” he explained, “but how to interpret the signals it was 79 Copyright ©2018 Worth Publishers. Distributed by Worth Publishers. Not for redistribution. 04_HOC_13639_Ch03_078_121_pp4.indd 79 25/07/18 8:47 PM 80 CHAPTER 3 SENSATION AND PERCEPTION receiving. As neuropsy- surgery? Mike was dazzled by the Mike’s Moment of Sight: A Little Bit of chologist Ione Fine (2002) sight of the tall, dark green trees, the Vision . Although Mike could “see” from the moment the bandages were removed explained, “Most people snow, and the distant peaks against from his eye (below), he still had trouble learn the language of the blue sky ( May, 2004 ). But although identifying objects, especially stationary vision between the you might think that vision, even ones. Mike tells this story of a walk down age of birth and two blurry vision, would be a distinct an unfamiliar street in Barcelona, Spain: years old. Mike has advantage to an expert skier, this was “I picked my way through some street had to learn it as an not the case. Mike found it easier to construction. I saw a fluorescent green object in my path and tapped it with my adult.” Indeed, there is ski with his eyes closed, with Jen- cane. It wasn’t hard like a sign so I tapped much more to seeing nifer skiing ahead and shouting out it a bit harder as I still couldn’t figure out than meets the eye. directions. With his eyes open, he visually what it was. I was startled as a Faces posed a partic- was overwhelmed by all the visual burst of Spanish profanity came from the ular challenge for Mike. stimuli and the frightening sense that workman bent over digging out a hole in the sidewalk. He didn’t take too kindly During conversations, objects were rushing toward him. “By to me poking him in the behind with my he found it very dis- the time I thought about and guessed cane. A little bit of vision can be dangerous tracting to look at at what the shadows on the snow sometimes” ( May, 2004 ). people’s faces. As meant, I would miss the turn or fall on Mike wrote in his my face. It was best to close my eyes,” Florence Low journal, “I can see he explained. their lips moving, Throughout this chapter, we will eyelashes flickering, head nodding, come back to Mike’s story. We’ll also and hands gesturing. It was easiest to tell you what neuropsychologists close my eyes or tune out the visual Ione Fine and Don MacLeod learned input. This was often necessary in after conducting fMRI scans of Mike’s order to pay attention to what they brain. And, later in the chapter, we’ll were saying” ( May, 2004 ). see how well you do, compared to And what was it like the first time Mike, at deciphering some visual he went skiing, just weeks after his illusions. Florence Low INTRODUCTION: What Are Sensation and Perception? Glance around you. Notice the incredible variety of colors, shades, shadows, and images. Listen carefully to the diversity of sounds, loud and soft, near and far. Focus on everything that’s touching you— your clothes, your shoes, the chair you’re sitting on. Now, inhale deeply through your nose and identify the aromas in the air. With these simple observations, you have exercised four of your senses: vision, hearing, touch, and smell. As we saw in the chapter on neuroscience, the primary function of the nervous system is communication— the transmission of information from one part of the body to the other. Where does that information come from? Put simply, your senses are the gateway through which your brain receives all its infor- mation about the environment. It’s a process that is so natural and automatic that we typically take it for granted until it is disrupted by illness or injury. Nevertheless, as Mike’s story demonstrates, people with one nonfunctional sense are amazingly adap- tive. Often, they learn to compensate for the missing environmental information by relying on their other senses. sensation The process of detecting a physical In this chapter, we will explore the overlapping processes of sensation and perception. stimulus, such as light, sound, heat, or pressure. Sensation refers to the detection and basic sensory experience of environmental stim- perception The process of integrating, uli, such as sounds, images, and odors. Perception occurs when we integrate, organize, organizing, and interpreting sensations. and interpret sensory information in a way that is meaningful. Here’s a simple example Copyright ©2018 Worth Publishers. Distributed by Worth Publishers. Not for redistribution. 04_HOC_13639_Ch03_078_121_pp4.indd 80 25/07/18 8:47 PM Introduction: What Are Sensation and Perception? 81 to contrast the two terms. Your eyes’ physical response to light, splotches of color, and lines exemplifies sensation. Integrating and organizing those sensations so that you interpret the light, splotches of color, and lines as a painting, a flag, or some other object represents perception. Mike’s visual world reflects this distinction. Although his eye was accurately transmitting visual information from his environment (sensation), his brain was unable to make sense out of the information (perception). Where does the process of sensation leave off and the process of perception begin? There is no clear boundary line between the two processes as we actually experience them. However, we’ll discuss sensation and perception separately. We’ll begin with the basics of sensation— how our sensory receptors respond to stimulation and transmit that information in usable form to the brain.