Sensation and Perception

Sensation•The process by which sensory systems (eyes, ears, and other sensory organs) and the nervous system receive stimuli from other environment.

Bottom-up processing

•Information processing that analyzes the raw stimuli entering through the many sensory systems.

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Top-down processing

• Information processing that draws on expectations and experiences to interpret incoming sensory information.-Was it the flavor you were expecting?-From your experience what did you think it would taste like?

Perception

•The process of organizing and interpreting incoming sensory information.

Absolute Threshold

•The minimum amount of stimulation needed to detect a particular stimulus. -Why was the time different for the two different students to notice the change?

Difference Threshold

• Just noticeable difference

•The minimum amount of difference needed to detect that two stimuli are not the same.

Signal Detection Theory•A theory that predicts how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise)-Drive to Brigham city, it took me 2-3 miles on the freeway before I detected the sun bothering my vision. -When you decide that its too hot in your house/car

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Sensory Adaptation

•Diminished sensitivity to constant and unchanging stimulation. -When did you stop feeling the rubber band?-When did you realize the quarter was gone?

•https://www.youtube.com/watch?v=nZoNl2t_3tc

How Many Passes?

• https://www.youtube.com/watch?v=xAFfYLR_IRY

Selective Attention•Focusing conscious awareness on a particular stimulus to the exclusion of others.

Structure of the eye• Cornea: The clear, curved bulge

on the front of the eye that bends light rays to begin focusing them.

• Iris: A ring of muscle tissue that forms the colored portion of the eye and regulate that size of the pupil.

• Pupil: The adjustable opening in the center of the iris, which controls the amount of light entering the eye.

Structure of the Eye• Lens: A transparent structure

behind the pupil in the eye that changes shape to focus images on the retina.

• Retina: The light-sensitive surface at the back of the eyeball.

• Receptor cells: Specialized cells in every sensory system of the body that can turn other different kinds of energy into action potentials that the brain can process.

Structure of the Eye• Rods: Visual receptor cells

located in the retina that can detect only black, white, and grey. Work under dim light.

• Cones: Visual receptor cells located in the retina that can detect sharp details and color. -Fovea: in center of retina, detail center-bipolar cells/ganglion cells

• Optic Nerve: The nerve that carries visual information from the eye to the occipital lobes of the brain.

• Trichromatic theory: A theory of color vision that says cones are sensitive to red, green, or blue light---the three colors that combine to create millions of color combinations.

• Opponent-process theory: A theory of color vision that says color is processed by cones organized in opponent pairs (red-green, yellow-blue, and black-white); light that stimulates one half of the pair inhibits the other half.

Ear• Auditory canal: the opening

through which sound waves travel as they move into the ear for processing.

• Eardrum (tympanic membrane): tissue that seals the inner, transfers sounds vibrations from the air to the three tiny bones of the middle ear. Can be damaged.

• Ossicles: the tiny bones that transfer sound to the cochlea; hammer, anvil, stirrup

Ear• Cochlea: the major organ of hearing; a

snail-shaped, bony, fluid-filled structure in the inner ear where sound waves are changed to neural impulses.

• Oval window: takes the vibration from the stirrup and transfers it to the fluids in the cochlea.

• Hair cells: the receptor cells for hearing; these are located in the cochlea and are responsible for changing sound vibrations into neural impulses.

• Auditory nerve: the nerve that carries sound information from the ears to the temporal lobes of the brain.

Taste

• 5 main Teste senses:-Salty-Sweet-Sour-Bitter-Umami (fatty/savory)

• Natural attraction to salty and sweet

• Natural dislike of bitter/sour

Smell

• Chemical Sense

• Olfactory cells: top of nasal passages, they project from the brain and process the smells.

• Once damaged they can’t be regenerated.

• Lose smell as we get older

• Taste and smell interact to produce flavor.

Body Senses

• Kinesthetic sense: The system for sensing the position and movement of individual body parts.

• Vestibular sense: the system for sensing body orientation and balance, which is located in the semicircular canals of the inner ear.

• https://www.youtube.com/watch?v=AJFW3eXX8Qc

• https://www.youtube.com/watch?v=vp2k_Rkw5f0