Sensation and Perception

Fall 2011

Understanding Sensation

Synesthesia

• http://www.youtube.com/watch?v=cRXk8jT5OPI&feature=related

• http://www.youtube.com/watch?v=0rSbtg7wohs&feature=related

• http://www.youtube.com/watch?v=EpCEI0sQuWw&feature=related

Processing: Detection and Conversion

• Transduction- process by which a physical stimulus is converted into neural impulses

Processing: Detection and Conversion

• Coding- process that converts a particular sensory input into a specific sensation

• Sensory reduction- filtering and analyzing incoming sensations before sending a neural message to the cortex

Adaptation: Weakening the Response

• Sensory adaptation- repeated or constant stimulation decreases the number of sensory messages sent to the brain, which causes decreased sensation:– Example: baby diapers

Adaptation: Weakening the Response

• Gate Control Theory- theory that pain sensations are processed and altered by mechanisms within the spinal cord.– Experience of pain depends partly on whether

the neural message gets passed the “gatekeeper” in the spinal cord.

• http://www.youtube.com/watch?v=f6idNSaG2pE

How We See and Hear

• Wavelength- the distance between successive peaks

• Wave amplitude- the height from peak to trough

• Range of wave-lengths- the mixture of waves

Hearing

• http://www.youtube.com/watch?v=stiPMLtjYAw

http://blogs.psychcentral.com/channeln/2011/01/tasting/

The Body Senses: More Than Just Touch

• Skin senses• Vestibular sense• Kinesthesia

Sensation and Perception

• http://video.nationalgeographic.com/video/player/national-geographic-channel/specials-1/brain-games/ngc-brain-games-pay-attention.html

Understanding Perception

Optical Illusions

• http://www.youtube.com/watch?v=TITFtgH_TcA

• http://www.youtube.com/watch?v=mf5otGNbkuc

• http://www.youtube.com/watch?v=6aJlX0AEWys&feature=BFa&list=PL28FC7F0D6025E36D&lf=results_main

Selection: Extracting Important Messages

• Selective attention– http://www.youtube.com/watch?v=vJG698U2Mvo

• Feature detectors– http://www.youtube.com/watch?v=vwCrxomPbtY

&feature=related– http://www.youtube.com/watch?v=bAUfCxxytwg

• Habituation– http://www.youtube.com/watch?v=Kfu0FAAu-10

Organization: Form, Constancy, Depth, and Color

• Gestalt- a German word meaning “form” or “whole”

• Gestalts emphasize the importance of organization and patterning in enabling us to perceive te whole stimuluse rather than perceiving its discrete parts as seprarate entities.

Gestalt Principles

• http://www.youtube.com/watch?v=nxKcpfFvuf8

Depth Perception

• Learned primarily through experience• Visual cliff:

Visual Cliff

• http://www.youtube.com/watch?v=4OelrPzpQ6Q

Binocular vs. Monocular Cues

Color Perception

• Trichromatic theory- theory that color perception results from mixing three distinct color systems-red, green, and blue.– First proposed by Thomas Young early 19th century– Refined by Herman von Helmholtz

• Opponent-process theory- theory that color perception is based on three systems of color receptors, each of which responds in an on-off fashion to opposite-color stimuli: blue-yellow, red-green, and black-white.

Color Aftereffects

• http://www.youtube.com/watch?v=Gznqc4tsPHU&feature=fvwrel

Color-Deficient Vision

• Most people perceive red, green, and blue and are, therefore, trichromats.

• Those who perceive only two colors are called dichromats.

• People who are sensitive to only the black-white syem are called monochromats.

Color-Deficient Vision

• http://www.youtube.com/watch?v=9f0-RerFUco

Interpretation: Explaining Our Perceptions

Sorting through incoming sensory

information

Organizing sensory

informationInterpretation

Interpretation

• Perceptual adaptation• Perceptual set• Frame of reference• Bottom-up processing• Top-down processing

Bottom-up, Top-down Processing

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Bottom-up, Top-down Processing

• http://www.youtube.com/watch?v=0jkaSIOqUgY

Sensation and Perception

• http://www.youtube.com/watch?v=VwfqUtDPwyM&feature=results_main&playnext=1&list=PLCE09901C1FA32E4D