1. Chapter 6: Sensation & Perception
Section 1: Our Sensational Senses

2. PDN:
Read Psychology in the News
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3. Sensation and Perception
Sensation: The detection of physical energy emitted or reflected by physical objects
it occurs when energy in the external environment or the body stimulates receptors in the sense organs.
Produce an immediate awareness of sound, color, form, etc

4. Perception: The process by which the brain organizes & interprets sensory information.
Foundation of learning, thinking, & acting
An understanding can help us think more critically about our own experiences

5. Ambiguous Figure
Colored surface can be either the outside front surface or the inside back surface
Cannot simultaneously be both
Brain can interpret the ambiguous cues two different ways
After figure on p 150, from
Wade, C., & Tavris, C. (2002). Invitation to Psychology, 2nd Ed. Upper Saddle River, NJ: Prentice Hall.

6. Our Sensational Senses
Skin- touch, pressure, hot, cold, pain, itching, & tickling
Ears- hearing & sense of balance

7. Measuring the Senses Absolute Threshold
The smallest quantity of physical energy that can be reliably detected by an observer

8. Difference Threshold
The smallest difference in stimulation that can be reliably detected by an observer when two stimuli are compared
also called Just Noticeable Difference (JND).

9. Absolute Sensory Thresholds
Vision: A single candle flame from 30 miles on a dark, clear night
Hearing: The tick of a watch from 20 feet in total quiet (measured in decibels)
Smell: 1 drop of perfume in a 3-room apartment
Touch: The wing of a bee on your cheek, dropped from 1 cm
Taste: 1 tsp. Sugar in 2 gal. water

10. Despite our impressive sensory skills, our senses are tuned to a narrow band of physical energies.
Other species can detect signals that we cannot.

12. Signal Detection Theory
Holds that responses in a detection task depend on a sensory process & a decision process.
These may vary with a person’s motivation, alertness, & expectations

13. Sensory Adaptations
Senses are designed to respond to change & contrast in the environment
Sensory Adaptation: The reduction or disappearance of sensory responsiveness that occurs when stimulation is unchanging or repetitious.
Picture page 179

14. Useful because it spares us from having to respond to unimportant information
Rarely adapt completely to visual stimuli

15. Sensory Deprivation: The absence of normal levels of sensory stimulation.

16. Sensory Overload Can lead to fatigue & mental confusion
“Cocktail Party Phenomenon”
A person typically focuses on just one conversation, ignoring other voices, music, laughter, etc

17. Selective Attention: The focusing of attention on selected aspects of the environment and the blocking out of others.