Wednesday October 2 Chapter 4 Sensation stimulation of the sense organs Perception selection organization and interpretation of the sensory input Synesthesia stimulation of one sense evokes a sensation of another Absolute Threshold smallest quantity reliably detected minimal volume of sound that can be heard o What people can sense 50 of the time 1 See candle flame 30 miles away Just Noticeable Difference JND smallest difference in stimulus intensity detected can t feel difference between 0 9 oz and 1 0 oz but can tell between 1 0 oz and 2 0 oz o Weber s Law size of JND is proportional to initial stimulus 1 Lift 20 lb box and then 20 2 lb box can t tell the difference 2 Lift 1 2 oz pen and 1 4 oz pen can tell the difference can tell a difference in things that are smaller Social Desirability Bias try to create a favorable impression in an experiment o Signal Detection Theory stimuli depends on two things 1 Sensory Processes when you think you hear your name called in another room 2 Decision Processes and you must decide whether you should respond or keep quiet in case you are just hearing 1 2 3 4 things Hit there is a stimulus and you correctly say that there is Miss there is a stimulus but you say there isn t False Alarm you say you saw something but you didn t Correct Rejection there is no stimulus and you say there is no stimulus Sensory Adaptation a decline in sensitivity due to prolonged stimulation you get used to bad smells and eventually don t smell them anymore o Receptor eventually get tired and stop firing impulses o Rarely adapt to 1 Intense Stimuli Noxious Fumes ammonia 2 Visual Stimuli our eyes are always moving around Depth Distance Perception the interpretation of visual clues that indicate how near or far that objects are 1 Binocular cues clues about distance based on the different views of two eyes a Only works up to 25 feet b Works since both eyes are coming in at a different angle 1 Retinal Disparity slight different in field vision between the right and left eyes 2 Convergence eyes turn inward to focus on an incoming object 2 Monocular cues clues about distance based on one eyes 1 Pictorial Depth Cues 1 Linear Perspective 2 Texture Gradient can see individual flowers close up but they merge into one in the distance 3 Interposition 4 Relative Size things are closer appear bigger but we know that since its closer its actually the same size 5 Height in Plane 6 Light and Shadow edge of an object in dark because of shadow 2 Motion Parallax images of objects at differing distances move across the retina at different rates 1 Closer moves faster across the retina How we see colors o Trichromatic Theory there are three types of cones on your retina 1 Red Green and Blue 2 By missing the three colors you can get any color that you want 3 Color Blindness when a person is deficient in seeing one color three different type of color blindness supports the trichromatic theory o Opponent process Theory when one colors switches on another color switches off 1 Red Green 2 Yellow Blue 3 Black White After Image Visual images that persists after the actual image the stimulus in removed Perceptual processes o Perceptual constancies o Top Down Vs Bottom Up Processing Bottom Up Processing refers to what happens the sensory receptors Top Down Processing refers to concepts expectations and memory Ex THE CAT Ex Find the misspelled word Swimner for Swimmer o Gestalt German for form and shape The whole can be greater than the sum of its parts Proximity elements that are close to one another tend to be grouped together Closures viewers tend to supply missing elements to close or complete a similar figure Similarity elements that are similar tend to be grouped together Simplicity viewers tend to organize elements in the simplest way possible Continuity viewers tend to see elements in ways that produce smooth continuation Biases o Peak End Theory peak at end plays a lager subjective role showed two groups of people scary movies 1st Movie Pretty Scary throughout but ends nice not as scary even though it had more scary parts throughout 2nd Movie Started out not scary then really scary then happy then really scary to end it thought to be scarier o Hind Sight Bias people feel that they knew it all along when really they should have known it all along o Over Confidence Effect people tend to be over confident in their beliefs estimates and abilities Stocks doubling paper Test Review Chapter 4 DNK Visual System p 134 140 start Info Processing in the Visual Cortex Skip Wavelength amp freq Fig 4 18 4 20 4 21 p 155 175 Personal Application Chapter 5 KNOW Fig 5 4 p 179 Fig 5 12 p 189 DON T KNOW Key term dissociation Tables 5 2 and 5 3 psychoactive drugs Mechanisms of Drug Action p 217 218 o Fig 5 19 and 5 20 Critical Thinking alcoholism Chapter 6 DNK Generalization gradients o Fig 6 9 Fig 6 14 Fug 6 17 Reinforcemen t vs reward Personal Application Key terms o Elicit emit cumulative recorder Practice Question 5 Practice Question 6 Chapter 7 DNK In Search of Memory Trace p 302 304 o Except consolidation Ch 5