Step 2: Continue reading the selection from the psychology textbook, and then answer the questions that follow.

The Perceptual Experience
3      Whenever you are exposed to a stimulus in the environment—a word on a page or a breeze through your hair—the stimulus initiates an electrochemical change in sensory receptors in your body. That change in turn initiates the processes of sensation and perception. Psychologists study sensation and perception because what people sense and perceive determines how they will understand and interpret the world. Such understanding depends on a combination of stimulation, past experiences, and current interpretations. Although the relationship between perception and culture has not been extensively researched, it is clear that culture can affect perception—by establishing what people believe, pay attention to or ignore, and expect in their environments. For example, composers have long known that a person exposed only to Western music will find non-Western melodies unfamiliar and dissonant.

Sensation and Perception Definitions
4     Traditionally, psychologists have studied sensation and perception together. Sensation is the process in which the sense organs' receptor cells are stimulated and relay initial information to higher brain centers for further processing. Perception is the process by which an organism selects and interprets sensory input so that it acquires meaning. Thus, sensation provides the stimulus for further perceptual processing. For example, when light striking your eyeball initiates electrochemical changes, you experience the sensation of light. But your interpretation of the pattern of light and its resulting neural representation as an image are part of perception.

5      Some researchers who examine sensation and perception start at the most fundamental level of sensation—where the stimulus meets the receptors—and work up to more complex perceptual tasks involving interpretation. This approach is often called bottom-up analysis. Other researchers examine perceptual phenomena starting from the more complex level—not surprisingly, called top-down analysis. This type of analysis focuses on aspects of the perceptual process such as selective attention and active decision-making, which are top-down processes. Perception is more than a reflexive discrimination process; rather, it involves integration of current sensory experiences with past experiences and even cultural expectations.

6     These two approaches, from the top down and from the bottom up, are both useful, because sensation and perception are not accomplished merely by the firing of a single group of neurons, but involve whole sets of neurons, as well as previous experiences and stimulation that occurs at the eyes, ears, or other sense organs. Today, perceptual psychologists generally think in terms of perceptual systems—the sets of structures, functions, and operations by means of which people perceive the world around them. And psychologists know that perceptual systems interact. Sensory and perceptual processes rely so heavily on each other that many researchers think about them together. So sensation and perception together form the entire process through which an organism acquires sensory input, converts it into electromechanical energy, and interprets it so that it gains organization, form, and meaning. Through this complex process people explore the world and discover its rules. Doing so involves the nervous system and one or more of the perceptional or sensory systems: vision, hearing, taste, smell, and touch.

—Lefton &Brannon, Psychology, 8^th ed., pp. 143–145.

		3. The topic of the entire passage is    a. the pain of athletes   b. the five senses   c. the process of sensation and perception   d. bottom-up analysis
		4. The central idea of the entire passage is stated in the thesis statement, which is    a. Psychologists study the pain of athletes to help people push themselves and break through a mental block.   b. Psychologists study athletes' experience with their perceptions of pain and how they overcome them.   c. Psychologists are interested in the process of sensation and perception for a number of reasons.   d. Lance Armstrong is an inspiration to the writer as well as many athletes facing difficulties in life.
		5. "Although the relationship between perception and culture has not been extensively researched, it is clear that culture can affect perception—by establishing what people believe, pay attention to or ignore, and expect in their environments." This sentence expresses     a. a fact   b. an opinion   c. a combination of fact and opinion
		7. "Sensation is the process in which the sense organs' receptor cells are stimulated and relay initial information to higher brain centers for further processing." This sentence states     a. a fact   b. an opinion   c. a combination of fact and opinion
		8. "Perception is the process by which an organism selects and interprets sensory input so that it acquires meaning." This sentence expresses     a. a fact   b. an opinion   c. a combination of fact and opinion
		9. "These two approaches, from the top down and from the bottom up, are both useful, because sensation and perception are not accomplished merely by the firing of a single group of neurons but involve whole sets of neurons, as well as previous experiences and stimulation that occurs at the eyes, ears, or other sense organs." This sentence states     a. a fact   b. an opinion   c. a combination of fact and opinion
		10. "And psychologists know that perceptual systems interact." This sentence expresses     a. a fact   b. an opinion   c. a combination of fact and opinion

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