EXPLORING PSYCHOLOGY EIGHTH EDITION IN MODULES David Myers

EXPLORING PSYCHOLOGY EIGHTH EDITION IN MODULES David Myers Power. Point Slides Aneeq Ahmad Henderson State University Worth Publishers, © 2011

Sensation and Perception 2

The Other Senses Module 15 3

Hearing § The Stimulus Input: Sound Waves § The Ear § Perceiving Loudness § Locating Sounds Kinesthesis and Vestibular Sense Touch 4

Pain § Understanding Pain § Controlling Pain Taste § Sensory Interaction Smell 5

Hearing The Stimulus Input: Sound Waves Audition is the act of hearing and sound waves, compressing and expanding air molecules, are the stimulus our ears detect then transform into nerve impulses that our brains decode as sound. 6

The Physical Properties of Waves The strength, or amplitude, of sound waves determines loudness. The frequency, or number of complete waves lengths to pass a point in a given time, determines pitch, a sounds perceived highness or lowness. 7

The Ear To convert sound waves into neural activity the outer ear first collects and sends sounds to the eardrum. The middle ear, transmits the vibrations via three tiny bones (hammer, anvil, stirrup) to the cochlea, a snail-shaped tube in the inner ear, causing it’s membrane to vibrate. This causes ripples in the basilar membrane, bending the hair cells lining its surface, triggering impulses in the nerve cells, whose axons form the auditory nerve, which sends neural messages to the auditory cortex. 8

The Ear 9

The Ear Damage to hair cells accounts for most hearing loss. Sounds that exceed 100 decibels, especially if prolonged or repeated are potentially harmful. 10

Locating Sounds Because we have two ears, sounds that reach one ear faster than the other ear cause us to localize the sound. 11

Kinesthesis and Vestibular Sense The vestibular sense monitors the head (and body’s) position. The semicircular canals and vestibular sacs in the inner ear contain fluid which moves when the head moves triggering hairlike receptors which send messages to the cerebellum enabling you to sense your position and maintain balance. 12

Kinesthesis and Vestibular Sense The sense of our body parts’ position and movement is called kinesthesis and is enabled by sensors in the joints, tendons, bones, ears, and skin. 13

Touch The sense of touch is a mix of distinct skin senses —pressure, warmth, cold, and pain. Only pressure has identifiable receptors. Other skin sensations are variations of the basic four. 14

Touch sensations involve more than tactile stimulation as illustrated by the rubber-hand illusion. When a researcher simultaneously touches a volunteer’s real and fake hands, the volunteer feels as though the seen fake hand is her own. 15

Pain tells the body that something has gone wrong. Usually pain results from damage to the skin and other tissues. A rare disease exists in which the afflicted person feels no pain. AP Photo/ Stephen Morton Ashley Blocker (right) feels neither pain nor extreme hot or cold. 16

Biological Influences No one type of stimulus triggers pain. Instead, there are different nociceptors— sensory receptors that detect hurtful temperatures, pressure, or chemicals. 17

Gate-Control Theory Melzack and Wall (1965, 1983) proposed that our spinal cord contains neurological “gates” that either block pain or allow it to be sensed. 18

Biopsychosocial Influences 19

Controlling Pain can be controlled by a number of therapies including, drugs, surgery, acupuncture, exercise, hypnosis, and even thought distraction. 20

Taste Traditionally, taste sensations consisted of sweet, salty, sour, and bitter tastes. Recently, receptors for a fifth taste have been discovered called “Umami”. 21

Taste is a chemical sense. Each taste bud on the tongue contains a pore that catches food chemicals. In each pore, 50 -100 taste receptor cells project antenna-like hairs that sense food molecules. Some receptors respond mainly to sweet-tasting molecules, others to salty, and so on. 22

Sensory Interaction When one sense affects another sense, sensory interaction takes place. So, the taste of strawberry interacts with its smell and its texture on the tongue to produce flavor. 23

Smell Like taste, smell is a chemical sense. Odorants enter the nasal cavity to stimulate 5 million receptors to sense smell. Unlike taste, there are many different forms of smell. 24

Smell and Memories The brain region for smell (in red) is closely connected with the brain regions involved with memory (limbic system). That is why strong memories are made through the sense of smell. 25