PSYCH 101 1st Edition Exam 2 Study Guide Lectures 10 18 Lecture 10 February 16 What is sensation and perception Sensation is a process by which our sensory receptors and nervous system receive and represents stimulus energies from our environment The brain receives input from the sensory organs Perception is a process of organizing and interpreting sensory information allowing us to recognize meaningful objects and events The brain makes sense out of the input from sensory organs How does our mind process the world through what Our mind processes the world through bottom up processing and top down processing Bottom up processing is taking sensory information and then assembling and integrating it what am I seeing hearing etc Top down processing is using models ideas and expectations to interpret sensory information have I seen this before What are the three processes of sensation and there functions Reception the stimulation of sensory receptor cells by energy transduction transforming this cell stimulation into neural impulses and transmission delivering this neural information to the brain to be processed What is the Absolute Threshold It is the minimum level of stimulus intensity needed to detect a stimulus half the time Only involves one stimulus What is the Difference Threshold It is the minimum difference for a person to be able to detect the difference half the time involving two stimuli What is Weber s Law It is the principle that for two stimuli to be perceived as different they must differ by a constant minimum percentage and not a constant amount Lecture 11 February 18 What does sensory adaptation mean Detects novelty in our surroundings our senses time out a constant stimulus What is perceptual set Perceptual set is what we expect to see which influences what we do see an example of top down processing How does emotion and motivation relate to how we view things Experiments show that Destinations seem farther away when you re tired A target looks farther away when your crossbow is heavier A hill looks steeper with a heavy backpack or after sad music or when walking alone Also something you desire looks closer What is vision Our eyes respond to some electromagnetic radiation waves and then our brain turns these energy wave sensations into colors What is hue We perceive the wavelength frequency of the electromagnetic waves as hue What happens when wavelengths are longer When the wave lengths are longer the frequency is lower What is brightness The height or amplitude of these electromagnetic waves What happens when wavelengths amplitude is larger The larger the amplitude the brighter the color What s the process of light going through the eye Light passes through the cornea and the pupil and gets focused and inverted by the lens The light then lands on the retina where it begins the process of transduction into neural impulses to be sent out through the optic nerve What do the rods and cones do When light reaches the back of the retina it triggers chemical changes in the receptor cells called rods and cones The rods and cones in turn send messages to ganglion and bipolar cells and on to the optic nerve What was Young Helmholtz Trichromatic theory The Trichromatic theory says that here are three types of color receptor cones red green and blue All the colors we perceive are created by light waves stimulating combinations of these cones What is the Opponent Process Theory Opponent Process Theory refers to the neural process of perceiving white as the opposite of perceiving black similarly yellow vs blue and red vs green are opponent processes What does Figure Ground Perception mean In most visual scenes we pick out objects and figures standing out against a background What is a Gestalt A Gestalt is a meaningful pattern configuration forming a whole that is more than the sum of its parts Name the three ways we group visual information into wholes We use proximity perceive things close together continuity we like to perceive things as smooth and continuous and closure we like to fill in gaps Lecture 12 February 20 What does the Visual Cliff test The visual cliff tests our depth perception and our depth perception is an innate part of humans How do we perceive depth from 2D images two ways We have binocular methods which means using both eyes cues exist because humans have two eyes in front of our head This gives us retinal disparity the two eyes have slightly different views and the more different the views are the closer the object must be Also by a Monocular cue interposition which is when an object appears to block the view of another we assume that the blocking of the eyes Relative size interpret familiar objects of known size Linear perspective and Interposition Relative height higher objects tend to be farther away What is perceptual constancy and what kind of process is it Perceptual constancy is the ability to see objects as appearing the same even under different lighting conditions at different distances and angles It is top down processing What is frequency pitch Frequency pitch is the length of the sound wave perceived as high and low What is height amplitude in terms of hearing It is the height or intensity of a sound wave perceived as loud What is meant by complexity in terms of hearing Complexity is perceived as sound quality or resonance Describe the ear and some of its parts The outer ear collects sound and funnels it to the eardrum The eardrum is a tight membrane that vibrates with sound waves The middle ear is where the sound waves hit the eardrum and 3 bones make up the middle ear the hammer anvil and stirrup The inner ear is where waves of fluid move from the oval window over the cochlea s hair receptor cells These cells sends signal the auditory nerves In sound perception what does loudness refer to Loudness refers to more intense sound vibrations This causes a greater number of hair cells to send signals to the brain What are two theories of pitch There is the Place theory which says that at high sound frequencies signals are generated at different locations in the cochlea depending on pitch The brain reads the pitch by reading the location where the signals are coming from There is also the Frequency theory which says that at low sound frequencies hair cells send signals at whatever rate the sound is received What is localization and how does it work Localization is how we seem to know the location of the source of a sound Sounds usually reach one