Chapter 8 Sensation and Perception Psychology

Sensation  Sensation is created by colors sounds tastes smells ect..  Perception is the organization of this stimuli into meaningful information

Perception at work

Absolute Threshold  Least amount of stimuli that can be sensed  Ex: candle flame 30 miles on a dark night,

 ticking watch at 20 feet,

 1drop of perfume in a small house,

 1 tsp of sugar in a gallon of water

 wing of a fly.4in

Difference Threshold  The minimum amount of difference that can be detected between 2 stimuli

Signal Detection theory  Takes into account your setting, phy and psy state, mood and attitude

Sensory Adaptation  The process which we become more sensitive to weak stimuli and less sensitive to unchanging stimuli  Passing trucks in a new home

Vision  Light  Not all light is visible  Ultraviolet and infrared  Wave length vary

The eye  Like a camera  Light enters through pupil  It is focused onto the lens  It is projected onto the retina photoreceptors  The image is upside down and full of holes-brain puts it together

Eye  Blind spot  Located where the optic nerve leaves the eye  With out the blind spot the image would never make it to the brain

Eye  2 types of photoreceptors  Rods and Cones  Rods-light brightness allow us to see in black and white dim light  Cones-add color to our world

Eye  Visual Acuity  Sharpness in vision in normal light  The ability to see details  Near sighted brings object closer to see detail  Far sighted move objects away to see detail  Age=far sighted lens becomes brittle

Eye  Color vision  Dogs & cats see fewer colors  Color blindness-malfunctioning cones

Hearing  Pitch  How high of low the sound is  Speed of the sound wave  Number of cycles per second  The more cycles the higher the pitch

Hearing  Loudness  Height of sound waves  Measured in decibels db  0 is the thresh hold ticking watch at 20 ft away

The Ear  Shaped to catch sound  Outer and inner ear  Transmits sounds to the brain  Eardrum is the gateway between the inner and outer ear

The eardrum  A thin membrane that vibrates when a sound wave strikes it  The vibrations are sent to the 3 small bones  Hammer, anvil, stirrup-smallest in the body

The inner ear  Cochlea  Bony tube that looks like a snail  Filled with fluids and neurons that move in response to the vibrations of the fluids this generates neural impulses that are sent to the Auditory nerve

Deafness  Conductive Deafness  Naturally as we age  Damage to the middle ear

Deafness  Sensorineural deafness  Cased by damage to the innder ear  Damage to the cochlea  From loud noises

Heather Whitestone  Mrs. America 1995  Ballet dancer  American Sign language

Smell  Key to taste  Receptors in the nostrils  Olfactory nerve sends message to the brain  Adapts to smells

taste  Four basic tastes  Sweet, Salty, Bitter, Sour  Smell, texture, temperature

Skin  Pressure sensed by the hairs on your body  Different parts of the body are more sensitive than others

Skin  Temperature  Neurons just beneath the skin  We adapt to temp

Pain  Message to the brain  Why do we rub, blow, or scratch  Gate way theory  System overload

Vestibular sense  Ability to tell if you are upright with out using your eyes  falling

Kinesthesis  Where the other parts of our bodies are located  How newborns find their own mouths  Limb falls asleep