Chapter 5 (3) Study Guide Answers

Chapter 5 (3) Study Guide Answers - Answers for Chapter 5:...

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Answers for Chapter 5: Sensation Introduction Introduction Preview 1. Sensation refers to how we detect physical energy from the environment and encode it as neural signals. Perception refers to how we select, organize, and interpret sensory information. Sensory analysis, which works at the entry level, is called “bottom - up” processing. Perception, which draws on our experience and expectations, is called “top - down” processing. Stepping Through the Introduction 1. sensation; perception 2. bottom - up processing; top - down processing 3. prosopagnosia Sensing the World: Some Basic Principles Section Preview 1. An absolute threshold is the minimum stimulation necessary to detect a particular environmental stimulus 50 percent of the time. A difference threshold, or just noticeable difference ( jnd ) , is the minimum difference a person can detect between any two stimuli 50 percent of the time. Weber’s law states that the difference threshold is a constant proportion of the stimulus. Signal detection studies indicate that thresholds depend not only on the strength of stimuli but also on experience, expectations, motivation, and alertness. Thus, thresholds are not constant. 2. Stimuli at or above the “absolute” threshold are detected half the time; subliminal stimuli, which are below the absolute threshold, are therefore detected less than half the time. Experiments show that under certain conditions, a weak stimulus may reach a part of the brain where it evokes a feeling but not conscious awareness. Claims that subliminal stimulation may lead to thought persuasion have not been supported, however. While subliminal messages may have a fleeting effect on thinking, they do not have an enduring effect on behavior. 3. Sensory adaptation refers to our diminishing sensitivity to an unchanging stimulus. By allowing us to focus our attention on informative changes in the environment, it keeps us from being distracted by the uninformative, constant stimulation of unchanging stimuli. Stepping Through the Section 1. psychophysics 2. absolute threshold; 50 3. signal detection; psychological 4. subliminal 5. conscious 6. difference threshold; just noticeable difference 7. Weber’s law; stimulus 8. sensory adaptation Although sensory adaptation reduces our sensitivity, it enables us to focus our attention on informative changes in the environment without being distracted by the uninformative, constant stimulation that bombards our senses. Vision Section Preview 1. Visible light is a small portion of the larger spectrum of electromagnetic radiation. Light can be described by two physical characteristics, wavelength, which determines hue, and intensity, which influences brightness. Vision begins when light enters the eye
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Chapter 5 (3) Study Guide Answers - Answers for Chapter 5:...

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