The Mind's Machine 3e Student Resources is no longer available and it was replaced by The Mind's Machine, 4e.
Chapter 7 Outline
Introduction: When Seeing Isn’t Seeing
PART I Vision Pathways
The Visual System Extends from the Eye to the Brain
Visual processing begins in the retina
Photoreceptors respond to light by releasing less neurotransmitter
Different mechanisms enable the eyes to work over a wide range of light intensities
Acuity is best in foveal vision
Neural signals travel from the retina to several brain regions
The retina projects to the brain in a topographic fashion
PART II Visual Analysis
Neurons at Different Levels of the Visual System Have Very Different Receptive Fields
Neurons in the retina and the LGN have concentric receptive fields
RESEARCHERS AT WORK: Neurons in the visual cortex have varied receptive fields
Spatial-frequency analysis is unintuitive but efficient
Neurons in the visual cortex beyond area V1 have complex receptive fields and help identify forms
Visual perception of motion is analyzed by a special system that includes cortical area V5
PART III Color Vision
Color Vision Depends on Special Channels from the Retinal Cones through Cortical Area V4
Color perception requires receptor cells that differ in their sensitivities to different wavelengths
BOX 7.1: Most Mammalian Species Have Some Color Vision
Some retinal ganglion cells and LGN cells show spectral opponency
Some visual cortical cells and regions appear to be specialized for color perception
SIGNS & SYMPTOMS: Correcting “Color Blindness”?
PART IV What versus Where
The Many Cortical Visual Areas Are Organized into Two Major Streams
Visual Neuroscience Can Be Applied to Alleviate Some Visual Deficiencies
Impairment of vision often can be prevented or reduced
Increased exercise can restore function to a previously deprived or neglected eye