Psych 1101 Chapter 6 Sensation and PerceptionBasic Principles of Sensation and Perception-sensation is the process by which our sensory receptors and nervous system receive and represent stimulus information from our environment. Bottom-up processing is analysis that begins with the sense receptors and works up to the brain's integration of sensory informationRods and cones (afferent neurons) - retinashair cells - luner earsolfactory receptors - nasal passagestaste buds - tonguetouch receptors - skin-perception is the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. Top-down processing is information processing guidedby our experience and expectations - breaking down into component parts.*sensory neurons are also known as afferent neurons* (they arrive at the central nervous system)*motor neurons are also known as efferent neurons* (they exit the central nervous system)Sensory Systems-all of our senses perform three basic steps:-they receive sensory stimulation-transform that stimulation into neural impulses-deliver the neural information to our brain-the process of converting one form of energy into another that our brain can use is called transductionSensory adaptation-sensory adaptation refers to diminished sensitivity as a consequence of constant stimulation. Thephenomenon of sensory adaptation enables us to focus our attention on information changes in our environment without being distracted by uninformative background stimulationPerception-perception is influenced by our experiences - our learned assumptions and beliefs - as well as bysensory input-through experience we form concepts (i.e. schemas) which organize and interpret unfamiliar information-a given stimulus may trigger radically different perceptions, partly because of our different schemas, but also because of the immediate contextAbsolute and Difference Thresholds -absolute threshold - the minimum stimulation needed to detect a particular stimulus 50 percent of the time-priming effect - we can process some stimuli too weak to recognize, indicating that much of our information processing occurs automatically and unconsciously - subliminal messages-difference threshold - the minimum difference between two stimuli that a person can detect 50 percent of the time-weber's law (just noticeable difference) - difference thresholds increase in proportion to the size of the stimulus Sensation and Perception Notes-Sensory receptors are specialized neuron cells transform one sort of information to another (translation to a different language)-perception is something you get unconsciously and judgment is a conscious perception-offaction is a sensory labeling system -bottom up processing is when you put individual components together and they form as a whole-virtual reality is exposing an individual to virtual...Color Perception-Young-Helmholtz Trichromatic (three-color) Theory - retina has three types of color receptors (red, green, and blue) Various combinations of these three result in different colors-for example, when both red and green sensitive cones are stimulated, we see yellow-Hering's Opponent-Process Theory - color perception is controlled by the activity of two opponent systems; blue-yellow and