Psych 101 1nd Edition Lecture 7 Outline of Last Lecture I Nervous System Outline of Current Lecture II Sensation Vision Current Lecture Chapter 3 Module 8 Sensation 1 Define sensation and perception a Sensation The activation of the sense organs by a source of physical energy b Perception The sorting out interpretation analysis and integration of stimuli by the sense organs and brain c What is a sense receptor i Free nerve endings d Stimulus Energy that produces a response in a sense organ 2 Distinguish between the methods used to study sensory thresholds a Absolute threshold The smallest intensity of a stimulus that must be present to be detected b Difference threshold Smallest level of positive or negative stimulation required to sense a change 3 Weber s Law A basic law of psychophysics stating a just noticeable difference is a constant proportion to the intensity of an initial stimulus rather than constant 4 Sensory adaptation An adjustment in sensory capacity after prolonged exposure to unchanging stimuli Chapter 3 Module 9 Vision 1 Describe the structural components of the eye a Cornea transparent protective window b Pupil Dark hole in the center of the Iris c Iris Colored part of the eye d Lens Behind pupil These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 2 3 4 5 6 e Retina Converts electromagnetic energy of light to electrical impulses for transmission to brain What happens to light when it reaches the retina a Rods thin cylindrical receptor cells in retina highly sensitive to light b Cones Cone shaped light sensitive receptor cells in retina responsible for sharp focus and color c Fovea Focus Where cones are concentrated How the message gets from the eye to the brain a Rods and cones bipolar cells ganglion cells optic nerve primary visual cortex b What is the blind spot The opening of the optic nerve passes through the retina there are no rods or cones in the area c Why is the optic chiasm important Where each optic nerve splits Explain and describe the two theories of color vision a Trichromatic theory of color vision i Theory that there are 3 kinds of cones in retina each responds primarily to a specific range of wavelengths 1 Blue Violet colors 2 Green colors 3 Yellow Red colors b Opponent process theory of color vision i Receptor cells for color vision are linked in pairs working in opposition 1 Blue Yellow 2 Red Green 3 Black White Which theory of color vision best explains afterimages a Opponent process theory of color vision How do we know that both opponent processes and trichromatic mechanisms produce the perception of color vision a Different parts of the visual system b Tri retina c Opponent retina and neuronal processing