Question

Develop a 6 pages paper based on "Sensation and Perception" Chapter 6 of the textbook "Psychology 9th edition 2010 by D.G. Myers".

Answer 1

SENSATION AND PERCEPTION

Sensation -Experience of sensory stimulation, the activation or our senses
Perception -Process of creating meaningful patterns from raw sensory information

ENERGY SENSES
VISION

Vision is the dominant sense in human beings. Sighted people use vision to gather information about their environment more than any other sense. The process of vision involves several steps.

Step 1: Gathering light
Step 2: Within the eye

Cornea -The transparent protective coating over the front part of the eye
Pupil -small opening in the iris through which light enters the eye.
Iris -colored part of the eye.
Lens -transparent part of the eye inside the pupil that focuses light onto the retina
Retina -lining of the eye containing receptor cells that are sensitive to light

Step 3: Transduction

Transduction –process by which sensory signals are transformed into neural impulses
Receptor cell -Specialized cell that responds to a particular type of energy.
Rods -Receptor cells in the retina responsible for night vision and perception of brightness.
Cones -Receptor cells in the retina responsible for color vision
Fovea -Area of the retina that is the center of the visual field
Optic nerve - The bundle of axons of ganglion cells that carries neural messages from each eye to the brain.
Blind spot - Place on the retina where the axons of all the ganglion cells leave the eye and where there are no receptors Optic chiasm -Point near the base of the brain where some fibers in the optic nerve from each eye cross to the other side of the brain

Step 4: In the Brain

Theories or color vision-
Trichromatic theory -Theory of color vision that holds that all color perception derives from three different color receptors in the retina
Opponent-process theory - Theory of color vision that holds that three sets of color receptors respond in an either/or fashion to determine the color you experience
Colorblindness -Partial or total inability to perceive hues.
Trichromats -People who have normal color vision
Monochromats -People who are totally color blind
Dichromats - People who are blind to either red-green or yellow-blue

HEARING

The ears contain structures for both the sense of hearing and the sense of balance. The eighth cranial nerve (vestibulocochlear nerve made up of the auditory and vestibular nerves) carries nerve impulses for both hearing and balance from the ear to the brain.  

Amplitude – the height of the wave , determines the loudness of the sound, measured in decibels
Frequency - The number of cycles per second in a wave; in sound, the primary determinant of pitch
Hertz (Hz) - Cycles per second; unit of measurement for the frequency of waves
Pitch - Auditory experience corresponding primarily to frequency of sound vibrations, resulting in a higher or lower tone
Decibel -The magnitude of a wave; in sound the primary determinant of loudness of sounds
Parts of the ear-
Ear canal – also called the auditory canal
Eardrum-
Hammer, anvil, stirrup - The three small bones in the middle ear that relay vibrations of the eardrum to the inner ear
Oval window - Membrane across the opening between the middle ear and inner ear that conducts vibrations to the cochlea
Round window - Membrane between the middle ear and inner ear that equalizes pressure in the inner ear.
Cochlea - Part of the inner ear containing fluid that vibrates which in turn causes the basilar membrane to vibrate.
Basilar membrane -Vibrating membrane in the cochlea of the inner ear; it contains sense receptors for sound
Organ of Corti -Structure on the surface of the basilar membrane that contains the receptors cells for hearing
Auditory nerve -The bundle of neurons that carries signals from each ear to the brain

PITCH THEORIES- As with color vision, two different theories describe the two processes involved in hearing pitch: place theory and frequency theory.

Place theory -Theory that pitch is determined by the location of greatest vibration of the basilar membrane
Frequency theory -Theory that pitch is determined by the frequency wigh which hair cells in the cochlea fire

DEAFNESS

Hearing Loss

People can lose all or some of their ability to hear because of loud noises, infections, head injuries, brain damage and genetic diseases. Hearing loss is common in older people. There are several types of hearing loss:

• Conductive Hearing Loss: occurs when sound vibrations from the tympanic membrane to the inner ear are blocked. This may be caused by ear wax in the auditory canal, fluid buildup in the middle ear, ear infections or abnormal bone growth.
• Sensorineural Hearing Loss: occurs when there is damage to the vestibulocochlear (auditory) nerve. This type of hearing loss may be caused by head injury, birth defects, high blood pressure or stroke.
• Presbycusis: occurs because of changes in the inner ear. This is a very common type of hearing loss that happens gradually in older age.
• Tinnitus: people with tinnitus hear a constant ringing or roaring sound. The cause of this ringing cannot always be found. Some cases of tinnitus are caused by ear wax, ear infections or a reaction to antibiotics, but there are many other possible causes of this disorder.

TOUCH

When our skin is indented, pierced, or experiences a change in temperature, our sense of touch is activated by this energy.
Gate control theory - Theory that a ‘neurological gate in the spinal cord controls the transmission of pain messages to the brain

CHEMICAL SENSES
TASTE (GUSTATION)
Taste buds

Papillae-
Humans sense four different tastes: sweet, salty, sour, and bitter  

All other tastes come from a combination of these four basic tastes. Actually, a fifth basic taste called "Umami" has recently been discovered. Umami is a taste that occurs when foods with glutamate (like MSG) are eaten. Different parts of the tongue can detect all types of tastes. Morever, the simple tongue "taste map" that is found in many textbooks has been criticized for several reasons.

The actual organ of taste is called the "taste bud". Each taste bud (and there about about 10,000 taste buds in humans) is made up of many (between 50-150) receptor cells. Receptor cells live for only 1 to 2 weeks and then are replaced by new receptor cells. Each receptor in a taste bud responds best to one of the basic tastes. A receptor can respond to the other tastes, but it responds strongest to a particular taste.  

SMELL (OLFACTION)
The Nose Knows  

The smells of a rose, perfume, freshly baked bread and cookies...these smells are all made possible because of your nose and brain. The sense of smell, called olfaction, involves the detection and perception of chemicals floating in the air. Chemical molecules enter the nose and dissolve in mucous within a membrane called the olfactory epithelium. In humans, the olfactory epithelium is located about 7 cm up and into the nose from the nostrils.
Olfactory epithelium - Nasal membranes containing receptor cells sensitive to odors
Pheromone - Chemical that communicates information to other organisms through smell
VESTIBULAR SENSE – tells us about how our body is oriented in space.
Semicircular canals - Structure in the inner ear particularly sensitive to body rotation.
Vestibular sacs - Sacs in the inner ear that are responsible for sensing gravitation and forward, backward, and vertical movement
KINESTHETIC SENSES -Senses of forces and movement of muscles
Stretch receptors -Receptors that sense muscle stretch and contraction
Golgi tendon organs -Receptors that sense movement of the tendons, which connect muscle to bone.

PERCEPTION
THRESHOLDS

Absolute threshold -The least amount of energy that can be detected as a stimulation 50 percent of the time
Subliminal- stimuli below our absolute threshold
Difference threshold -The smallest change in stimulation that can be detected 50 percent of the time
just-noticeable difference – the smallest amount of change needed in a stimulus before we detect a change
Weber’s Law -The principle that the just noticeable difference for any given sense is a constant proportion of the stimulation being judged.

PERCEPTUAL THEORIES

Psychologists use several theories to describe how we perceive the world.
Signal detection theory- investigates the effects of the distractions and interference we experience while perceiving the world.
Response criteria
False positive

Top-Down Processing – we perceive by filling in gaps in what we sense
   Schemata
   Perceptual set
    Backmasking
Bottom-up Processing, also called feature analysis – we use only the features of the object itself to build a complete perception

GESTALT RULES
   Proximity
   Similarity
   Continuity
   Closure

CONSTANCY- Tendency to perceive objects as stable and unchanging despite changes in sensory stimulation
Size constancy - Perception of an object as the same size regardless of the distance from which it is viewed
Shape constancy - Tendency to see an object as the same shape no matter what angle it is viewed from
Brightness constancy - Perception of brightness as the same, even though the amount of light reaching the retina changes

DEPTH CUES
Visual cliff experiment-
Monocular cues - Visual cues requiring the use of one eye
Interposition - Monocular distance cue in which one object, by partly blocking a second object, is perceived as being closer.
Linear perspective - Monocular cue to distance and depth based on the fact that two parallel lines seem to come together at the horizon
Relative size - Monocular cue in which closer objects seem larger than distant objects
Texture gradient -Course objects appear closer than smooth objects
Shadowing-
Binocular cues - Visual cues requiring the use of both eyes
Retinal disparity - Binocular distance cue based on the difference between the images
Convergence - cast on the two retinas when both eyes are focused on the same object
Stereoscopic vision - Combination of two retinal images to give a three-dimensional perceptual experience.