Sensation and Perception

Sensation and Perception Chapter 4

Sensation & Perception The Basics

What Are They?Sensation

Stimulation of sensory receptors and sending of sensory info to brain

Automatic

Perception Psychological

process in how we interpret sensory stimulation

Reflects learning, expectations & attitudes

Absolute Threshold

Weakest amount of stimulus that can be sensed Differs from

person to person

Sense Stimulus Receptors Threshold

Vision Electromagnetic energy

Rods and Cones in the skin

A candle flame viewed from a distance of about 30 miles on a dark night

Hearing Sound waves Hair cells of the inner ear

The ticking of a watch about 20 feet away in a quiet room

Smell Chemical substances in the air

Receptor cells in the nose

About one drop of perfume diffused throughout a small house

Taste Chemical substances in saliva

Taste buds on the tongue

About 1 tsp. of sugar dissolved in 2 gallons of water

Touch Pressure on the skin

Nerve endings on the skin

The wing of a fly falling on a cheek from a distance of about .4 inch

Difference ThresholdThe minimum

amount of difference detected between two stimuli

Varies from person to person

Signal-Detection Theory Distinguishing

sensory stimuli that takes into account strengths, as well as setting, mood, attitude, motivations, etc…. High school vs.

college

Sensory Adaptation Process of

becoming more sensitive to weak stimuli and less sensitive to unchanging stimuli City noise,

waves at beach

Vision Featuring Your EYEBALLS

Let there be….LIGHT Electromagnetic

energy Comes in

wavelengths Main colors of

spectrum- from longest to shortest wavelengths ROY G. BIV

AHH…..MY EYE!! http://www.biology

mad.com/resources/eye.swf

The Blind Spot Place in your eye

that doesn’t have photoreceptors

Rods Vs. Cones Rods are sensitive

to brightness of light

Cones provide color vision

Dark and Light Adaptation Adaption to

bright light happens more quickly that adaptation to dark

Visual Acuity The ability to see

visual details in normal light Nearsighted farsighted

Color Vision

Cones and Color Vision Blue, green & red

cones, when all stimulated…color!

Images are made of many tiny dots of color, called pixels

After Images

Color Blindness Absence or

malfunction of the cones Red-green

color blind is common

Totally color blind less common

Hearing Featuring YOUR EARS

How does it work ? SOUND WAVES

Pitch How high or low a

sound is

Loudness Sound measured

by dB Zero dB is

threshold of hearing

Locating Sounds Yes.

Deafness Conductive

Deafness Occurs from

damage to middle ear

Sensorineural Damage to inner

ear