Ch. 3 Sensation and PerceptionSensation- Process of receiving stimulus energies from the external environment* This is a biological process* Sensory receptors- openings through which the brain and nervous system experience the world* Specialized cells that detect stimulus information and transmit it to sensory (afferent) nerves and brain. Take place in different forms of stimulation* Photoreception- Detection of light* Perceived as sight* Mechanoreception- Detection of pressure, vibration, and movement* Perceived as touch, hearing and equilibrium* Chemoreception- Detection of chemical stimuli* Perceived as smell and tastePerception- Process of organizing and interpreting sensory informationThis is a psychological processStimulus Energy (Light, sound, smell, etc)- Sensory Receptors (ears, eyes, nose etc)[- —————–sensation————————-Neural impulses Brain (visual, auditory, olfactory areas)————– Perception]—Absolute Threshold- The lowest level of stimulation that a person can consciously detect 50% of the time the stimulation is present. Minimum amount of detectable stimulus energy needed to reliably trigger a sensory receptorBottom Up Processing-* Stimulation works its way from the environment up to the level of the brain* Stimulation (Light)Sensory receptorsBrain* The Brain takes its first stab at understanding the informationTop-Down Processing- kicks in once bottom-up has taken place* Based on cognitive processing at higher levels of the brain* Brain uses previous experiences and memories to organize the information into something it understands* By doing this, simplifies the information. Rather than processing it as a large amount of sensory information, the brain can now apply a single label ex: “ This is a car” Gestalt Principles- Set of principles in psychology to account for the observation that humans.
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