1. Sensation and Perception
Chapter 4

2. Sensation & Perception
The Basics

3. What Are They? Sensation Perception
Stimulation of sensory receptors and sending of sensory info to brain
Automatic
Psychological process in how we interpret sensory stimulation
Reflects learning, expectations & attitudes

4. Absolute Threshold Weakest amount of stimulus that can be sensed
Differs from person to person

5. 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

6. Difference Threshold
The minimum amount of difference detected between two stimuli
Varies from person to person

7. Signal-Detection Theory
Distinguishing sensory stimuli that takes into account strengths, as well as setting, mood, attitude, motivations, etc….
High school vs. college

8. Sensory Adaptation
Process of becoming more sensitive to weak stimuli and less sensitive to unchanging stimuli
City noise, waves at beach

9. Vision
Featuring Your EYEBALLS

10. Let there be….LIGHT Electromagnetic energy
Comes in wavelengths
Main colors of spectrum- from longest to shortest wavelengths
ROY G. BIV

11. AHH…..MY EYE!!

12. The Blind Spot
Place in your eye that doesn’t have photoreceptors

13. Rods Vs. Cones Rods are sensitive to brightness of light
Cones provide color vision

14. Dark and Light Adaptation
Adaption to bright light happens more quickly that adaptation to dark

15. Visual Acuity The ability to see visual details in normal light
Nearsighted
farsighted

16. Color Vision

17. Cones and Color Vision
Blue, green & red cones, when all stimulated…color!
Images are made of many tiny dots of color, called pixels

18. After Images

23. Color Blindness Absence or malfunction of the cones
Red-green color blind is common
Totally color blind less common

24. Hearing
Featuring YOUR EARS

25. How does it work ?
SOUND WAVES

26. Pitch
How high or low a sound is

27. Loudness
Sound measured by dB
Zero dB is threshold of hearing

28. Locating Sounds
Yes.

29. Deafness Conductive Deafness Sensorineural
Occurs from damage to middle ear
Sensorineural
Damage to inner ear