PSYA01H3 Chapter Notes - Chapter 4: Retinal Ganglion Cell, Occipital Lobe, Detection Theory
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Fechner: developed this approach to measure sensation and perception: methods that measure the strength of a stimulus and the observer"s sensitivity to that stimulus. Absolute threshold: the simplest quantitative measurement minimal intensity needed to just barely detect a stimulus; is a boundary. Jnd (just noticeable difference)- the minimal change in a stimulus that can just barely be detected. Weber"s law: the jnd of a stimulus is a constant proportion despite variations in intensity. Signal detection theory: response to a stimulus depends both on a person"s sensitivity to the stimulus in the presence of noise and on a person"s decision criterion. Sensory adaptation: sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions. Purity corresponds to what humans perceive as saturation, or the richness of colors. If eyeball is too long, images are focused in front of the retina, leading to nearsightedness (myopia)