PSY-101 1st EditionLecture 9Outline of Last LectureI. Specialization in the Cerebral HemispheresII. Gender and the BrainOutline of Current Lecture I. Sensation vs. PerceptionII. Receptor CellsIII. Two Major Processes in Perceptual ProcessingIV. Sensory Receptors and the BrainCurrent LectureI. Sensation vs. Perceptiona. Sensation- process of receiving stimulus energies from external environment.b. Perception- the process of organizing and interpreting sensory information.c. The 6 Major Senses are:i. Visionii. Smelliii. Painiv. Hearingv. Tastevi. TouchII. Receptor Cellsa. Sensory receptor cells- specialized sells unique to each sense organ that respondto a particular form of sensory stimulations.b. Sensory adaptation- decline in sensitivity to a constant stimulusc. Transduction- process by which a form of physical energy is converted into a coded neural signal that can be processed by the nervous system.III. Two major processes in perceptual processing:a. Bottom-up processing- information about external environment, goes from sensory receptors to the brain, making sense of information.i. Emphasizes the important of sensory receptors in detecting the basic features of a stimulus.ii. Moves from part to wholeiii. Also called data-driven processingb. Top-down processing- starts with cognitive processing at higher levels of the braini. Emphasizes importance of observer’s cognitive processes at higher levels of the brain1. Emphasizes importance of observer’s cognitive processes in arriving t meaningful perceptions2. Moves from whole to part3. Also called conceptually driven processing.ii. The use of either can be influenced by cultural differences or nuances, such as found in collectivist vs. individualistic societies.IV. Sensory Receptors and the Braina. Sensory receptors- specialized cells that detect stimulus information and transmit it to sensory (Afferent) nerves and braini. Afferent nerves- bring information to brainii. Efferent nerves- send messages to brainb. Sensory Thresholdsi. Weber’s law- for each sense the size of a just noticeable difference is a constant proportion to the size of the initial stimulus.c. Perception of Sensory Stimulii. Attention- selective1. “Cocktail Party Effect”- we get easily distracted at a party by another person’s conversationii. Shiftable1. Novelty, size, color, movement2. Stroop effect3. Change blindness- we do not notice when something has changed in our environment because out attention was selectively shifted elsewhere.iii. Perception Set1. Predisposition or readiness to perceive something in a particular