Chapter 9: Fact and Opinion
Lab Activity 45: Fact and Opinion in a Textbook
To identify facts and opinions in a textbook passage.
Step 2: Continue reading the selection from the psychology textbook, and then answer the questions that follow.
The Perceptual Experience
Sensation and Perception Definitions
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.