Psych 100 Unit Exam 2 Prof LeBreton Study Guide 2 Your exam will have 50 MC questions and covers chapters 3 6 7 and 8 Distinguish between sensation information coming into your brain Perception organizing and interpreting the information Understand the absolute threshold smallest magnitude of a stimulus that can be detected weakest detectable stimulus vision candle flame 30 miles away hearing watch ticking 20 ft away smell a drop of perfume in a six room house taste a teaspoon of sugar in a gallon of water touch a wing of a fly on your cheek difference threshold intitial stimulus big you need a bigger difference The Difference Threshold between two things depends on the strength of the original stimulus the stronger the original stimulus the bigger the changes must be in order for them to be noticed Understand how the human visual system works including the parts of the eye and how they function Must have light to see Light is composed of waves that give us Hue wavelength of light gives us color Brightness intensity of light Saturation complexity of light gives us pure versus paler colors Cornea protective coating on the surface of the eye Iris the colored part of the eye that regulates the amount of light that enters Pupil the opening of the iris the black part Lens the transparent portion of the eye that focuses light onto the retina Retina images fall here sensory receptor cells are here Rods receptor cells that code information about light and dark located outside the center of the retina 120 million cells each eye Cones receptor cells that code information about light dark and color located at the center of the retina 6 million cells each eye Fovea the spot where the cones are concentrated images focused directly onto the fovea are clearest because of the highest concentration of cones Optic Nerve the nerve that carries visual neural message to the brain the area where the optic nerve attaches contains no rods or cones and therefore is a blind spot Understand the two theories of color vision Trichromatic Theory The first level of color processing There are three different kinds of cones in the eye and that each respond to light in either red blue or green wavelengths therefore all sensations of colors result from stimulating a combination of these three cones The Opponent Process Theory second level of color processing In addition to three types of cones one for red blue and green there are opponent process mechanisms which respond to either the red green or the yellow blue wavelengths Most animals only see black white and shades of gray Psych 100 Unit Exam 2 Prof LeBreton Total color blindness in humans is extremely rare due to lack of cones or malfunctioning cones Color Blind people can usually see some colors and not others Most common Red Green color blind can see Yellow Blue spectrum Rarer Yellow Blue color blind can see Red Green spectrum 8 of males are color blind Extremely rare in females Understand the Gestalt principles of visual organization ex proximity similarity etc and the rules of perceptual constancy The 4 Gestalt Principles of Perceptual Organization 1 2 3 4 Proximity things that are close together are grouped together in the mind as if they belong together Closure incomplete figures tend to be seen as complete because our brain fills in missing information Similarity similar things are seen as being related Continuation images are seen in ways that produce smooth continuation Visual Constancy the perception of objects remains unchanged even when the sensation of the object is changing Brightness Constancy we understand the brightness of an object does not change even when the object is dimly lit Color Constancy we understand that colors do not change despite different conditions of light Size Constancy size does not change Shape Constancy shape does not change Know the key monocular and binocular depth cues Monocular Cues cues in the environment that suggest depth can be seen by only one eye Binocular Cues uses both eyes Convergence eyes angle inward as an object gets closer to us Retinal Disparity because each retina is a few inches apart they have slightly different images and this helps with depth perception Hearing Sound energy travels in waves Choclea transfers sound waves into neural impulses Smell Called olfaction Airborne molecules enter the nose and are transferred to olfactory bulb in the brain for processing Difficult to classify smells Processed directly through the amygdala and hypothalamus and hippocampus Smells can often trigger strong emotions memories Be familiar with pain gate theory of pain perception Pain messages are sent through two distinct pathways rapid first pain slow second pain Gate Control theory of pain there are neural gates endorphins that control the transmission of pain impulses The gate can be open slow pain messages are not blocked therefore we experience pain or closed slow pain Psych 100 Unit Exam 2 Prof LeBreton messages are blocked and we do not experience the pain Women have an additional pain gate mechanism that comes from the hormone estrogen that men do not have only activated in childbirth Men and women have different ways of processing and reporting pain Women process pain in emotional centers Men process pain in logic centers Women report feeling pain sooner than men Men delay treatment for pain longer than women Phantom Limbs Phantom Pain amputees often feel the amputated limb as if it is still there and sometimes feel pain in the missing limb Theory muscle memory the neurons in charge of missing limb don t know that it is gone but eyes see that the limb is gone mismatch between eyes and neurons As of July 2009 there are 904 soldiers who have lost limbs in the wars in Afghanistan and Iraq o Know all of the stages of sleep both REM and non REM including brain waves associated with each stageNon REM Sleep Cycles o Stage 1 Lightest sleep Hypnogogic state o Myoclonia startle awake feeling of falling Theta waves occur o Stage 2 Somewhat more deeply asleep mid sleep Sleep spindles occur K complex occurs o Stage 3 Deep Sleep Delta Waves 20 Slow wave deep sleep begins Heart and breathing slow and regular o Stage 4 Deepest sleep Delta waves reach nearly 100 Blood pressure and brain activity at lowest points in 24 hour period REM Sleep o Rapid Eye Movement sleep o Called active sleep or paradoxical sleep 20 25 of a night s sleep Internally Intense brain activity Brain temperature rises rapidly Psych 100 Unit Exam 2