PSY 201 1st Edition Lecture 6Outline of Last LectureII. Cerebral Cortexa. Topographic organizationb. Contralateral connectionIII. Neural plasticitya. Movie: “Brain Transplant”, shown in classb. IntroductionOutline of Current Lecture*Beginning of class: continuation of movie “Brain Transplant” shown in classI. IntroductionII. Visiona. The eyeb. Visual pathwaysc. Coding of contrast and contour (based on pdf reading on Blackboard)d. Generalizations about processing in the visual systemi. Feature detectionii. Functional specializationCurrent Lecture*Brief Movie notes- Illustrates how the discovery of the neurotoxin fabricated by an underground drug dealer has stimulated research to fuel treatment for Parkinson’s o Illustrates what the disease is like in younger patientso Presents ethical and political controversyI. Introductiona. Everything depends on sensory perception and processingi. Fast and accurate; it has developed this way because it is essential for survivalb. Senses:i. Visionii. Hearing iii. TouchThese 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.iv. Tastev. Smellvi. Vestibular sense: balancevii. Kinesthesis: limb position and movementviii. Temperatureix. Pain1. Touch, temperature and pain are called somatosensationc. What is sensed:i. Light wavesii. Vibrations in the airiii. Deformation/temperature/pain of skiniv. Chemicals in the air we breathev. Chemicals in foodvi. Muscle stretch and joint anglesvii. Gravity and motion d. Sensation and Perceptioni. Sensation: initial coding of messages from senseii. Perception: interpretation of the messages1. This is a continuous process; it is the transformation of incoming signals into information about the worldiii. Receptors: structures that respond to a physical stimulus by producing electrical changes which initiate neural impulses1. They react directly to environmental stimuliiv. Transduction: the conversion of energy from a physical stimulus to neural responses (process in which receptors work)v. Sensory neurons: carry neural impulses from the receptor to the CNS (Central Nervous System)vi. Sensory areas: where the sensory neurons and pathways lead to1. Think of topographic maps from the last few lectures; they demonstrate how sensitive a body part isvii. Coding: representation of the stimulus in the pattern of action potentials1. A stronger stimulus means larger electrical changes in the receptors, causing faster firing rates of action potentials (also known as coding of quantity)2. Different receptors respond to different forms of energy (retinal receptors respond to light, touch receptors to pressure)II. Visiona. Due to our 2-D retina, we lose a lot of info about the 3-D worldi. Information given in the 2-D retinal image is transformed into a representation of the world (3-D)b. The eyei. Contrasted like a camera1. Cornea and lens: they concentrate on the outside points of an object and focus it on the retina, in the back of the eye, where sensitive cells (photoreceptors) respond to lighta. Retinal output cells send messages out of the optic nerve to the thalamusi. Also known as retinal ganglion cells2. Fovea: area of retina where receptor cells are densely packeda. What is being observed directly appears on the foveai. Where the best, most detailed vision occursb. Where the optic nerve leaves the eye, there are no receptors (known as the blind spot)i. The brain fills in the gap in the informationii. The retina1. Rods and cones; receptor cellsa. Light waves (2 aspects)i. Wavelength: determines colorii. Amplitude: determines brightnessb. Rods: outside of the fovea, and not sensitive to color, but sensitive to lighti. Operate at night or low light conditionsc. Cones: concentrated in the fovea, and less sensitive to lighti. Operate during the day or high light conditionsii. High acuity color visioniii. Three types that allow us to see