Download Psychology : Concepts and Connections, Ninth Edition, Spencer A

Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Sensation and Perception
•
•
•
Sensation:
– is the stimulation of sensory receptors and the transmission of
sensory information to the central nervous system.
Perception:
– is an active process in which sensations are organized and
interpreted to form an inner representation of the world.
Five Senses:
– Vision.
– Hearing.
– Smell.
– Taste.
– Touch.
Psychophysics
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Focuses on ways in which we translate physical events such
as light and sounds into psychological experiences.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Absolute Threshold
•
refers to the weakest amount of a stimulus that a person can
distinguish from no stimulus at all 50% of the time.
– Examples include:
• Vision: candle flame viewed from about 30 miles on a clear,
dark night.
• Hearing: a watch ticking from about 20 feet away in a quiet
room.
• Taste: 1 teaspoon of sugar dissolved in 2 gallons of water.
• Smell: about one drop of perfume diffused throughout a
small house (1 part in 500 million).
• Touch: the pressure of the wing of a fly falling on a cheek
from a distance of about 0.4 inch.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Difference Threshold
•
•
the minimum difference in magnitude of two stimuli required
to tell them apart 50% of the time.
Similar to the just noticeable difference (jnd).
– Weber found that for:
• Light the fraction is 1/60th.
• Weight the fraction is 1/53rd.
• Constant pitch the fraction is 1/333.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Signal-Detection Theory
•
•
•
Considers the human aspects of sensation, and perception
Assumes that the relationship between a physical stimulus
and a sensory response is not just mechanical.
Other factors include:
– Training (learning).
– Motivation (desire to perceive).
– Psychological states such as fatigue or alertness.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Feature Detectors in the Brain
•
Brain cells that respond to different aspects of features of a
scene (e.g. angles, vertical, horizontal).
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Sensory Adaptation
•
The sensory process of adjustment.
– Sensitization (Positive adaptation)
• Becoming more sensitive to stimulation.
– Desensitization (Negative adaptation)
• Becoming less sensitive to stimulation.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Vision
•
•
More than half of our brain’s cerebral cortex is devoted to visual
functions.
Light
– All forms of electromagnetic energy moves in waves.
• Visible light at about 400 billionths of a meter in length
(violet) to 700 billionths of a meter (red).
• Radio waves extend for miles.
• Cosmic rays: wavelengths are only a few trillionths of an
inch long.
– Sir Isaac Newton discovered the prism that could break light
into different colors. Colors of the spectrum include:
• Red, orange, yellow, green, blue, indigo, violet (Roy G. Biv)
• The wavelength of visible light determines the color or hue.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.1 The Visible Spectrum. By passing a source of white light, such as sunlight, through a prism, we
break it down into the colors of the visible spectrum. The visible spectrum is just a narrow segment of the
electromagnetic spectrum. The electromagnetic spectrum also includes radio waves, microwaves, X-rays,
cosmic rays, and many others. Different forms of electromagnetic energy have wavelengths which vary
from a few trillionths of a meter to thousands of miles. Visible light varies in wavelength from about 400 to
700 billionths of a meter. (A meter = 39.37 inches.)
The Eye
•
•
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Light first passes through the transparent cornea.
The amount of light that is allowed to enter is controlled by
the muscle called the iris (the colored part of the eye).
The actual opening in the iris is called the pupil.
The lens adjusts or accommodates to the image by changing
its thickness. The thickness permits a clear image of the
object to be projected onto the retina.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.2 The Human Eye. In both the eye and a camera, light enters through a narrow opening and is
projected onto a sensitive surface. In the eye, the photosensitive surface is called the retina, and
information concerning the changing images on the retina is transmitted to the brain. The retina contains
photoreceptors called rods and cones. Rods and cones transmit sensory input back through the bipolar
neurons to the ganglion neurons. The axons of the ganglion neurons form the optic nerve, which transmits
sensory stimulation through the brain to the visual cortex of the occipital lobe.
The Eye
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
The retina
– consists of cells called photoreceptors that are sensitive
to light (photosensitive).
– The retina contains several layers of cells; the rods and
cones, bipolar cells, and ganglion cells. All of these are
neurons.
– The rods and cones respond to light with chemical
changes that create neural impulses that are picked up by
the bipolar cells. These then activate the ganglion cells.
– The axons of the million or so ganglion cells in our retina
ultimately converge to form the optic nerve.
– The optic nerve conducts sensory input to the visual area
of the occipital lobe.
The Eye
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Rods and Cones
– About 125 million rods and 6.4 million cones are
distributed across the retina.
– Cones are most densely packed in a small spot at the
center of the retina called the fovea.
– Rods are most dense just outside the fovea toward the
periphery of the retina.
– Rods allow us to see in black and white.
– Cones provide color vision.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Problems with the Rods and Cones
– Nearsighted:
• People who have to be unusually close to a distant
object to discriminate its details.
– Farsighted:
• People who see distant objects clearly but have
difficulty focusing on nearby objects.
– Presbyopia
• With age ( 30s to mid 40s) the lenses start to grow
brittle, making it more difficult to accommodate to, or
focus on, objects.
Light Adaptation
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Dark adaptation:
– the process of adjusting to lower lighting conditions.
Light adaptation
– Adapting to brighter lighting takes place much more
rapidly.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.5 Dark Adaptation. This illustration shows the amount of light necessary for detection as a
function of the amount of time spent in the dark. Cones and rods adapt at different rates. Cones, which
permit perception of color, reach maximum dark adaptation in about ten minutes. Rods, which permit
perception of dark and light only, are more sensitive than cones. Rods continue to adapt for up to about 45
minutes.
Color Vision
•
•
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
The wavelength of light determines its color or hue.
The value of color is its degree of lightness or darkness.
Saturation refers to how intense a color appears.
Warm and Cold Colors.
– Colors on the green-blue side of the color wheel are
considered to be cool in temperature.
– Colors on the yellow-red side are considered to be warm.
Color Vision
•
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Complementary Colors.
– The colors across from one another on the color wheel
are complementary.
Afterimages.
– Persistent sensations of color are followed by perception
of the complimentary color when the first color is
removed.
Theories of color vision
– Our ability to perceive color depends on the eye’s
transmission of different messages to the brain when
lights with different wavelengths stimulate the cones in
the retina.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.6 The Color Wheel. A color wheel can be formed by bending the colors of the spectrum into a
circle and placing complementary colors across from one another. (A few colors between violet and red are
not found in the spectrum and must be added to complete the circle.) When lights of complementary colors
such as yellow and violet-blue are mixed, they dissolve into neutral gray. The afterimage of a color is its
complement.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.9 Three Cheers for the…Green, Black, and Yellow. Don’t be concerned. We can readily restore
Old Glory to its familiar hues. Place a sheet of white paper beneath the book and stare at the black dot in
the center of the flag for at least 30 seconds. Then remove the book. The afterimage on the paper beneath
will look familiar.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
CONTROVERSY IN PSYCHOLOGY:
When Light With Different Wavelengths Stimulate The Retina
•
•
Trichromatic Theory.
– Young found that he could create any color from the visible
spectrum by varying the intensities of three lights: red, green,
and blue-violet.
– Helmholtz suggested that the retina in the eye must have three
different types of color photoreceptors or cones.
– The trichromatic theory is known as the Young-Helmholtz
theory.
Opponent-Process theory.
– Hering proposed that there are three types of color receptors
but they don’t respond just to red, green and blue-violet.
– They are pairs including red-green; blue-yellow; and a type that
perceives differences in brightness.
– These pairs of receptors are what make afterimages possible.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.21 The Hering–Helmholtz and Müller–Lyer Illusions. In the Hering–Helmholtz illusion, are the
horizontal lines straight or curved? In the Müller–Lyer illusion, are the vertical lines equal in length?
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
CONTROVERSY IN PSYCHOLOGY:
When Light With Different Wavelengths Stimulate The Retina
•
Research suggests that each theory of color vision is partially
correct.
– The cones may be as Helmholtz claimed.
– The transmission of the signals to the brain are as Hering
proposed.
Color Blindness
•
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
If you can discriminate among the colors of the visible
spectrum, you have normal color vision and are labeled a
trichromat.
People who are totally color blind are called monochromats.
Partially color-blind people are called dichromats.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.10 Plates from a Test for Color Blindness. Can you see the numbers in these plates from a test
for color blindness? A person with red–green color blindness would not be able to see the 6, and a person
with blue–yellow color blindness would probably not discern the 12. (Caution: These reproductions cannot
be used for actual testing of color blindness.)
Visual Perception
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Visual perception
– is the process by which we organize or make sense of the
sensory impressions caused by the light that strikes our
eyes.
Gestalt psychologists refer to closure as being
– the integration of disconnected pieces of information into
a meaningful whole, or
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.11 Closure. Meaningless splotches of ink or a horse and rider? This figure illustrates the Gestalt
principle of closure.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Perceptual Organization
•
•
Gestalt psychologists are interested in the way we integrate
bits and pieces of sensory stimulation into meaningful
wholes.
– Wertheimer discovered many rules that we use to do this
called the laws of perceptual organization.
Figure-Ground Perception.
– When figure-ground relationships are ambiguous, or
capable of being interpreted in various ways, our
perceptions tend to be unstable, shifting back and forth.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.13 The Rubin Vase. A favorite drawing used by psychologists to demonstrate figure–ground
perception. Part A is ambiguous, with neither the vase nor the profiles clearly the figure or the ground. In
part B, the vase is the figure; in part C, the profiles are.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.14 Necker Cube. Ambiguity in the drawing of the cube makes perceptual shifts possible.
Therefore, the darker tinted surface can become either the front or back of the cube.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Perceptual Organization
•
Other Gestalt Rules for Organization:
– Proximity
– Similarity
– Continuity
– Common Fate
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.15 Some Gestalt Laws of Perceptual Organization. These drawings illustrate the Gestalt laws
of proximity, similarity, continuity, and closure.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Perceptual Organization
•
Top-Down Versus Bottom-Up Processing.
– Top-Down Processing
• Use the larger pattern to guide subordinate tasks.
– Bottom-Up processing
• Begin with bits and pieces of information and become
aware of the pattern formed only after you’ve worked
on it a while.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Perception of Motion
•
•
Visual perception of movement is based on change of
position relative to other objects.
Types of apparent movement (illusions of movement).
– The Autokinetic Effect
• is the tendency to perceive a stationary point of light
as moving in a dark room.
– Stoboscopic Motion
• is what makes motion pictures possible.
– The Phi Phenomenon
• occurs as the on-off process of lights is perceived as
movement.
Depth Perception
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Monocular Cues: cues that can be perceived by one eye.
– Perspective:
• distances between far off objects appear to be smaller than
equivalent distances between nearby objects.
– Relative size:
• the fact that distant objects look smaller than nearby objects
of the same size.
– Clearness of an object:
• We sense more details of nearby objects.
– Interposition:
• Nearby objects can block our view of more distant objects.
• Interposition is placing of one object in front of another.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.17 The Effects of Interposition. The four circles are all the same size. Which circles seem
closer? The complete circles or the circles with chunks bitten out of them?
Depth Perception
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Monocular Cues continued.
– Shadows:
• opaque objects block light and produce shadows giving us
a relationship to the source of light.
– Texture Gradient:
• close objects are perceived as having rougher textures.
– Motion Parallax:
• the tendency of objects to seem to move backward or
forward as a function of their distance.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.18 Shadowing as a Cue for Depth. Shadowing makes the circle on the right look threedimensional.
Depth Perception
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Binocular Cues: cues that can be perceived by both eyes.
– Retinal disparity:
• The difference between projected images (e.g. different
angles).
• Closer objects have greater retinal disparity.
– Convergence:
• Causes feelings of tension in the eye muscles and provides
another binocular cue for depth.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Perceptual Constancies
•
•
•
•
Size constancy:
– Allows us to perceive objects to be the same size even when
viewed from different distances.
– Experiences teach us about perspective.
Color constancy:
– The tendency to perceive objects as retaining their color even
though lighting conditions may alter their appearance.
Brightness constancy:
– similar to color constancy.
Shape constancy:
– The tendency to perceive objects as maintaining their shape,
even if we look at them from different angles so that the shape
of their image on the retina changes dramatically.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.19 Brightness Constancy. The orange squares within the blue squares are the same hue, yet
the orange within the dark blue square is perceived as brighter. Why?
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.20 Shape Constancy. When closed, this door is a rectangle. When open, the retinal image is
trapezoidal. But because of shape constancy, we still perceive it as rectangular.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Visual Illusions: Is Seeing Believing?
•
The Hering-Helmholtz and Muller-Lyer illusions are named after the
people who devised them.
– These illusions work because of our life experience.
• Lifelong use of perceptual cues.
• Experience with perspectives.
– The Ponzo illusions seems to work because of size constancy.
Hearing
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Sound or auditory stimulation, travels through the air like waves.
– The changes in air pressure are vibrations that approach your
ears in waves.
– The human ear is sensitive to sound waves with frequencies
from 20 to 20,000 cycles per second.
Pitch and Loudness
– Pitch of a sound is determined by
• its frequency, or the number of cycles per second as
expressed in the unit hertz (Hz).
– Loudness of a sound roughly corresponds
• to the height or amplitude of sound waves and
• is expressed in decibels (dB).
.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.24 Sound Waves of Various Frequencies and Amplitudes. Which sounds have the highest
pitch? Which are loudest?
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.25 Decibel Ratings of Familiar Sounds. Zero dB is the threshold of hearing. You may suffer
hearing loss if you incur prolonged exposure to sounds of 85 to 90 dB.
The Ear
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
The ear has three parts: the outer ear, middle ear, and the inner ear.
– The outer ear is shaped to funnel sound waves to the eardrum.
• The eardrum is a thin membrane that vibrates in response
to sound waves and thereby transmits them to the middle
and inner ears.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.26 The Human Ear. The outer ear funnels sound to the eardrum. Inside the eardrum, vibrations of
the hammer, anvil, and stirrup transmit sound to the inner ear. Vibrations in the cochlea transmit the sound
to the auditory nerve by way of the basilar membrane and the organ of Corti.
The Ear
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
The middle ear functions as an amplifier.
– The stirrup is attached to another vibrating membrane (the oval
window) which transmits vibrations to the cochlea.
– The cochlea is a snail shaped structure that contains
membranes.
– One of these membranes is the basilar membrane.
– Attached to the basilar membrane is the command post of
hearing (organ of Corti).
– Here there are receptor cells called hair cells.
– Hair cells dance in response to basilar membrane vibrations.
– Their movements generate neural impulses which are sent to
the brain via the auditory nerve.
– Auditory input is then projected onto the hearing areas of the
temporal lobes of the cerebral cortex
Locating Sounds
•
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
A sound that is louder in the right ear is perceived as coming from
the right.
Both loudness and the sequence in which the sounds reach the
ears provide directional cues.
Perception of Loudness and Pitch.
– The loudness and pitch of sounds appear to be related
• to the number of receptor neurons on the organ of Corti that
fire, and
• how often they fire.
– Psychologists generally agree that sounds are perceived as
louder when more of these sensory neurons fire.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
CONTROVERSY IN PSYCHOLOGY:
Explaining Fluctuations in Hearing
•
•
•
Place theory: holds that the pitch of a sound is sensed according to
the place along the basilar membrane that vibrates in response to
it.
Frequency theory: notes that for us to perceive lower pitches, we
need the stimulation of neural impulses that match the frequency of
the sound waves.
The volley principle states that in response to sound waves groups
of neurons take turns firing.
Deafness
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
More than 1 in 10 Americans has a hearing impairment, and 1
in 100 cannot hear at all.
Two major types of deafness are conductive and
sensorineural deafness.
– Conductive deafness:
• stems from damage to the structures of the middle ear.
– Sensorineural deafness:
• stems from damage to the structures of the inner ear,
most often the loss of hair cells, or damage to the
auditory nerve.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
The Chemical Senses
•
Smell
– If you did not have a sense of smell an onion and an
apple would taste the same to you.
– Humans can detect the odor of 1 one-millionth of a
milligram of vanilla in a liter of air.
– An odor is a sample of the substance being sensed.
• Odors are detected by sites on receptor neurons in the
olfactory membrane high in each nostril.
• Their firing transmits information about odors to the
brain via the olfactory nerve.
– The sense of smell adapts rapidly to odors such that we
lose awareness of them.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
The Chemical Senses
•
Taste
– Four primary taste qualities: sweet, sour, salty, and bitter.
– Food flavor depends on its odor, texture, temperature as
well as taste.
– Taste cells are receptor neurons located on taste buds.
• Humans have approximately 10,000 taste buds most
of which are located on the edge and back of your
tongue.
• Taste cells reproduce rapidly enough to renew
themselves weekly.
The Skin Senses
•
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
The skin senses include touch, pressure, warmth, cold, and pain.
Touch and Pressure:
– Active touching involves reception of information concerning not
only touch per se but also pressure, temperature, and feedback
from the muscles involved in movements of our hands.
– Psychophysicists use methods such as the two-point threshold
to assess sensitivity to pressure.
• Sensory nerve endings are more densely packed in the
fingertips and face than in other locations.
Temperature
– The receptors for temperature are neurons located just beneath
the skin.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Kinesthesis and the Vestibular Sense
•
•
Kinesthesis:
– the sense that informs you about the position and motion of
parts of the body.
• Sensory information is fed back to the brain from sensory
organs in the joints, tendons, and muscles.
The Vestibular Sense
– Your vestibular sense tells you whether you are upright.
• Sensory organs located in the semicircular canals and
elsewhere in the ears monitor your body’s motion and
position in relation to gravity.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Sensation and Perception and Virtual Reality
•
Virtual reality is perception of events fed directly into senses
via electronic technology
Virtual Reality
•
•
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Virtual Room
– Can transform ways that people gather and interact.
Cybersex: What are psychological implications?
– Deterioration of sense of self?
– Decreased sensitivity to real life romantic partners?
– Would virtual sex be adultery?
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Extrasensory Perception
•
•
Hard research does not support the existence of ESP.
– Nonetheless 60% of Americans believe that some people
have psychic powers or ESP.
Examples of ESP phenomena:
– Precognition.
– Psychokinesis.
– Telepathy.
– Clairvoyance.
– Psi communication.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Research in Extrasensory Perception
•
•
•
Rhine studied ESP for several decades with the conclusion
that some people might have some degree of ESP.
– Ganzfeld Procedure.
– File drawer problem.
People who have demonstrated ESP with one researcher
have failed to do so with another researcher.
Not one person has emerged who can reliably show psi
communication from one occasion to another and from one
researcher to another.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
LIFE CONNECTIONS:
Pain, Pain, Go Away-Don’t Come Again Another Day
•
•
A Gallup survey of 2,002 adults in the U.S. showed that 89%
experience pain at least once a month.
Pain means that something is wrong in the body.
– Pain is adaptive.
– There are no nerve endings for pain in the brain.
– Postaglandins (substance P) facilitate transmission of the
pain message to the brain and heighten circulation to the
injured area.
– Other aspects influence pain:
– Visual and other sensory inputs tell us what is happening
and influence the cognitive interpretation of the situation.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
Figure 4.28 Perception of Pain. Pain originates at the point of contact, and the pain message to the brain
is initiated by the release of prostaglandins, bradykinin, and substance P.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
LIFE CONNECTIONS:
Pain, Pain, Go Away-Don’t Come Again Another Day
•
•
•
Phantom Limb Pain.
• Seems to involve activation of nerves in the stump of
the missing limb.
Gate Theory.
– The nervous system can process only a limited amount of
stimulation at a time.
Acupuncture.
– Research has shown that acupuncture stimulates nerves
that reach the hypothalamus and may also result in the
release of endorphins.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
LIFE CONNECTIONS:
Pain, Pain, Go Away-Don’t Come Again Another Day
•
Modern Psychological Methods for Coping with Pain.
– The primary treatment has been chemical; pain-killing
drugs.
– Accurate Information:
• Knowledge of medical procedures reduces stress.
– Distraction and Fantasy:
• Diverting attention from pain helps many cope with it.
– Hypnosis has been used to reduce chronic pain, as an
anesthetic in dentistry, childbirth, even in some forms of
surgery.
Psychology : Concepts and Connections, Ninth Edition, Spencer A. Rathus
Chapter 4
LIFE CONNECTIONS:
Pain, Pain, Go Away-Don’t Come Again Another Day
•
Modern Psychological Methods for Coping with Pain.
– Relaxation Training and Biofeedback.
– Coping with Irrational Beliefs.
– Other methods.
• Sense of commitment.
• Supportive social networks help as well.