132


  • Basic Principles of Sensation and Perception
    • From Outer Energy to Inner Brain Activity
    • Thresholds
    • THINKING CRITICALLY ABOUT: Can Subliminal
      Messages Control Our Behavior?
    • Sensory Adaptation
    • Perceptual Set
    • Context Effects

  • Vision
    • Light Energy: From the Environment Into the Brain
    • The Eye
    • Visual Information Processing
    • Color Vision
    • Visual Organization
    • Visual Interpretation

  • The Nonvisual Senses
    • Hearing
    • Touch
    • Taste
    • Smell
    • Body Position and Movement

  • Sensory Interaction
    • THINKING CRITICALLY ABOUT: ESP—Perception
      Without Sensation?
5 Sensation and Perception

133

My friend, Heather Sellers, an acclaimed writer and teacher, cannot recognize faces. Her vision is perfect, but her perception is not. In her book, You Don’t Look Like Anyone I Know (2010), she tells of awkward moments resulting from her lifelong prosopagnosia—face blindness.

In college…I returned from the bathroom and plunked myself down in the wrong booth, facing the wrong man. I remained unaware he was not my date even as my date (a stranger to me) accosted Wrong Booth Guy, and then stormed out…. I do not recognize myself in photos or videos. I can’t recognize my stepsons in the soccer pick-up line; I failed to determine which husband was mine at a party, in the mall, at the market.

People sometimes see Sellers as snobby or cold. “Why did you walk past me?” a neighbor might later ask. Hoping to avoid offending others, Sellers sometimes fakes recognition. She smiles at people she passes, in case she knows them. She may pretend to know the person with whom she is talking. But there is an upside to these perception failures. When she runs into someone who previously irritated her, she typically feels no ill will. She doesn’t recognize the person.

134

Unlike Sellers, most of us have an area on the underside of our brain’s right hemisphere that helps us recognize a familiar human face as soon as we detect it—in only one-seventh of a second (Jacques & Rossion, 2006). This ability is an example of a broader principle. Nature’s sensory gifts enable each animal to obtain essential information. Some examples:

In this chapter, we’ll look more closely at what psychologists have learned about how we sense and perceive the world around us. We begin with some basic principles.