Vision Most Dominating Sense Visual Capture Overview of

Transduction • Transforming signals into neural impulses. • Information goes from the senses to

Phase One: Gathering Light • Wavelength = hue (color). – Longer = more red.

Wavelength (Hue) Violet Indigo 400 nm Short wavelengths Blue Green Yellow Orange Red 700

Intensity (Brightness) Amplitude Blue color with varying levels of intensity. As intensity increases or

The Structure of the Eye Cornea = outer covering of the eye, bends light

The Structure of the Eye Pupil = the adjustable opening in the center of

The Structure of the Eye Iris = a ring of muscle tissue that forms

The Structure of the Eye Lens = the transparent structure behind the pupil that

The Structure of the Eye Retina = the light-sensitive inner surface of the eye,

The Eye The Retina • Rods and Cones Rods

Phase Three: Transduction The Retina’s Reaction to Light

The Structure of the Eye Fovea = the central focal point in the retina,

The Structure of the Eye Optic Nerve = the nerve that carries neural impulses

The Structure of the Eye Blind Spot = the point at which the optic

Transduction Continued • Order is: 1) 2) 3) 4) 5) 6) Rods/Cones Bipolar Ganglion

Visual Information Processing Visual Cortex

Pathways from the eyes to the visual cortex

Phase Four: In the Brain Visual Information Processing • Goes to the Visual Cortex

Visual Information Processing Feature Detection • Feature detectors

Visual Information Processing Parallel Processing • Parallel processing

Parallel Processing • The processing of several aspects of a problem simultaneously. Color Motion

Reviewing the Process • http: //www. youtube. com/watch? v=Qk. Zn_yt urd. I&feature=related • http:

Trichromatic Theory Three types of cones: • Red • Blue • Green • These

Opponent-Process theory The sensory receptors come in pairs. • Red/Green • Yellow/Blue • Black/White

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Vision • Most Dominating Sense – Visual Capture

Overview of the Process

Transduction • Transforming signals into neural impulses. • Information goes from the senses to the thalamus, then to the various areas in the brain.

What is Color

Phase One: Gathering Light • Wavelength = hue (color). – Longer = more red. – Shorter = more blue. • Wave Amplitude (height) = intensity (brightness). – ↑ Amplitude = ↑Brightness – ↓Amplitude = ↓ Brightness • ROY G BIV

Wavelength (Hue) Violet Indigo 400 nm Short wavelengths Blue Green Yellow Orange Red 700 nm Long wavelengths Different wavelengths of light result in different colors.

Intensity (Brightness) Amplitude Blue color with varying levels of intensity. As intensity increases or decreases, blue color looks more “washed out” or “darkened. ”

Phase Two: Getting the light in the eye

The Structure of the Eye

The Structure of the Eye Cornea = outer covering of the eye, bends light to provide focus.

The Structure of the Eye Pupil = the adjustable opening in the center of the eye through which light enters.

The Structure of the Eye Iris = a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening. • The iris dilates/constricts in response to changing light intensity

The Structure of the Eye Lens = the transparent structure behind the pupil that changes shape to help focus images on the retina. (accommodation)

The Structure of the Eye Retina = the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

Nearsighted & Farsighted Vision

The Eye The Retina • Rods and Cones Rods

Rods versus Cones

Phase Three: Transduction The Retina’s Reaction to Light

The Retina’s Reaction to Light

The Structure of the Eye Fovea = the central focal point in the retina, around which the eye’s cones cluster.

The Structure of the Eye Optic Nerve = the nerve that carries neural impulses from the eye to the brain.

The Structure of the Eye Blind Spot = the point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there.

The Eye The Retina • Blind spot

Blind Spots

Transduction Continued • Order is: 1) 2) 3) 4) 5) 6) Rods/Cones Bipolar Ganglion Optic Nerve Thalamus Cerebral Cortex (Occipital Lobe)

Visual Information Processing Visual Cortex

Pathways from the eyes to the visual cortex

The Structure of the Eye Blind Spot = the point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there.

The Eye The Retina • Blind spot

Blind Spots

Transduction Continued • Order is: 1) 2) 3) 4) 5) 6) Rods/Cones Bipolar Ganglion Optic Nerve Thalamus Cerebral Cortex (Occipital Lobe)

Visual Information Processing Visual Cortex

Pathways from the eyes to the visual cortex

Phase Four: In the Brain Visual Information Processing • Goes to the Visual Cortex located in the Occipital Lobe of the Cerebral Cortex • Feature Detectors • Parallel Processing We have specific cells that see the lines, motion, curves and other features of this turkey. These cells are called feature detectors.

Visual Information Processing Feature Detection • Feature detectors

Visual Information Processing Parallel Processing • Parallel processing

Parallel Processing • The processing of several aspects of a problem simultaneously. Color Motion Form Depth

Visual Information Processing

Reviewing the Process • http: //www. youtube. com/watch? v=Qk. Zn_yt urd. I&feature=related • http: //www. youtube. com/watch? v=Jada. WSD x. BYk&feature=related

Color Vision Two Major Theories

Trichromatic Theory Three types of cones: • Red • Blue • Green • These three types of cones can make millions of combinations of colors. • Does not explain afterimages well. • Monochromatic vs. Dichromatic Vision

Opponent-Process theory The sensory receptors come in pairs. • Red/Green • Yellow/Blue • Black/White • If one color is stimulated, the other is inhibited • Explains Afterimages

After Images

After Image

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After Image

Blind Sight