Sensation Chapter 5 Myers AP Psychology

Transduction  Conversion of one form of energy into another.  In sensation, the transforming of stimulus energies, such as light waves, sound waves, smells, and tastes, into neural impulses our brains can interpret.  Vision: Transduction is the transforming of light waves into neural impulses received by the brain. Our brain then tells us what we are seeing based on its perception.

Eye; Vision Structure and Function  Image reversed: All images seen by the eye are reflected upside down and somehow turned right side up by the brain.

Eye: Vision Structure and Function  Light waves: The eye light waves in the direction you are looking to reflect all things in your field of vision. The beams are brought into focus by the cornea and the lens… much like a camera focus.

Eye: Vision Structure and Function  Cornea: Rounded, transparent covering over the front of the eye.  Light passes through cornea; its curved surface bends, or focuses, the light waves into narrower beams.

Eye: Vision Structure and Function  Pupil: round opening at the front of your eye that allows light waves to pass into the eye’s interior.  The pupil grows larger or smaller because of a muscle called the iris.

Eye: Vision Structure and Function  Iris: circular muscle that surrounds the pupil and controls the amount of light entering the eye.  In dim light the iris relaxes, allowing more light to enter (pupil dilates).  In bright light the iris constricts, allowing less light to enter.  Contains pigment that gives your eye its color.

Eye: Vision Structure and Function  Lens: transparent, oval structure whose curved surface bends and focuses light waves into an even narrower beam.  Lens is attached to muscles that adjust the curve of the lens which adjusts the focusing.  Accommodation: the process by which the eye’s lens changes shape to focus near or far objects on the retina.

Eye: Vision Structure and Function  Retina: located at the very back of the eyeball  Thin film that contains cells that are extremely sensitive to light.  These light sensitive cells, called photoreceptors, begin the process to transduction by absorbing light waves.

Rod and Cones  Rods: retinal receptors that detect black, white, and grey. These are necessary for peripheral and twilight vision (when cones don’t respond).  Cones: retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

Other Retinal Parts  Optic Nerve: the nerve that carries neural impulses from the eye to the brain.  Blind Spot: the point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there.  Fovea: the central focal point in the retina, around which the eye’s cones cluster.

Acuity  Acuity; the sharpness of vision.  Nearsighted vision; a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in from of the retina.  Farsighted vision; a condition in which far away objects are seen more clearly than near objects because the image of near objects is focused behind the retina.

Parallel Processing  The processing of several aspects of a problem simultaneously.  The brain’s normal mode of information processing for many functions (including vision).  This is in contrast of normal step-by-step processing of most computers and of standard conscious problem solving.  Complete vision study by reading pgs !

Color Constancy  Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.