objective 4 & 5

What did Hubel and Wiesel discover?

Hubel and Wiesel discovered that certain neurons in the occipital lobe's VISUAL CORTEX responds only to specific features of what is viewed. They call these neurons FEATURE DETECTORS

In the brain, what is routed by ___ to the cortex?

In the brain, it is routed by the THALAMUS to the cortex.

How does light enter the eye?

Light enters through the CORNEA, and passes through a small opening called the PUPIL; the size of this opening is controlled by the colored IRIS.

stimulus energy

TRANSDUCED into NEURAL messages by our eyes

What happens when you change the curvature of the light?

The LENS can focus the image of an object onto the RETINA, the light-sensitive inner surface of the eye.

What do the axons of ganglion cells converge form?

The axons of ganglion converge to form the OPTIC NERVE, which carries the visual information to the BRAIN.

What do the neural signals produced in the rods and cones activate?

They activate the neighboring BIPOLAR cells, which activates a network of GANLION cells.

What are the rods and cones?

They are the retina's receptor

What is the fovea?

This is where most cones are clustered around the retina's point of central focus, whereas the rods are concentrated in more PERIPHERAL regions of the retina. Many cones have their own BIPOLAR cells to communicate with the visual cortex

Blind spot

This is where the nerve leaves the eye, and has no receptors

Abstract Levels

Visual information percolates (filters) through progressively more ABSTRACT levels.

visible spectrum of light

a small portion of the larger spectrum of ELECTROMAGNETIC energy

What do the cones do for vision?

cones of the eyes permits the perception of color.

Feature detectors

pass their information to higher-level cells in the brain, which responds to specific visual scenes. Research has shown that in monkey brains such cells specialize in responding to a specific GAZE, HEAD ANGLE, POSTURE, or BODY MOVEMENT. In many cortical areas, teams of cells (supercell clusters) respond to complex patterns.

What do the rods do for vision?

rods of the eyes enable black-and-white vision. In dim-lights RODS are SENSITIVE. Adapting to a darkened room will take the retina approximately 20 MINUTES.

Intensity

the amount of energy in light waves, is determined by a wave's AMPLITUDE, or height, influences the BRIGHTNESS of a light.

Wave length

the distance from one light wave peak to the next (THINK CREST TO CREST). This determines the wave's color, or HUE

Accomidation

the process by which the lens changes shape to focus on images