Psychology Study Guide Chapter 6

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1 Psychology Study Guide Chapter 6 Sensation: process by which our sensory responses and nervous system receive and repeat stimulus from our environment. Perception: process organizing and interpreting sensory information enabling us to recognize meaningful objects and events Brain gets input from sensory organs Brain makes sense out of input from sensory organs Making sense of the world Bottom up processing: taking sensory information and then assembly and integrating it Top down processing: using models ideas and expectations to interpret sensory information Sensory organ to brain Reception: stimulation of sensory receptor ells by energy (sound light heat waves etc.) Transduction: transferring the cell stimulation into neural impulses Transmission: delivering this neural information to brain to be processed Threshold Absolute threshold: refers to minimal level of stimulus intensity needed to detect a stimulus half of the time Anything below the threshold is considered to be subliminal Absolute threshold not absolute Signal detection theory: whether or not detect a stimulus especially amid background noise Depends not on just intensity of the stimulus but on psychological factors (persons experience expectations alertness ) Subliminal detection Subliminal: below our threshold for being able to consciously detect a stimulus Although we cannot learn complex knowledge from subliminal stimuli we can be primed affecting our subsequent choices May look longer at the side of a paper where you were just showed a nude image for an instant Just noticeable difference Difference threshold refers to minimum difference (color pitch height temperature etc.) For a person to be able to detect the difference ½ of the time Weber s law: refers to the principle that for 2 stimuli to be perceived as different they must differ by a constant minimum percentage and not a constant amount Sensory adaptation To detect nothing in air surroundings, our senses tune out constant stimulus Harder to notice clock ticking Don t notice this visually because our eyes are always moving Made By Abby Carroll 1

2 Concentrate on keeping your eyes in one place you will see the effects as your eye adjusts to the stimuli Perceptual set Perceptual set: what we expect to see which influences what we do see, it is an example of top down processing Effect emotion physical state and motivation on perception Destinations appear farther away when we are tired Vision Encounter waves of electromagnetic radiation Eyes respond to some of these waves Brain turns those energy waves into colors Color hue and brightness Perceive wavelength and frequency of electromagnetic waves as color and hue Perceive height and amplitude of the waves as intensity and brightness Eyes Light from a candle will pass through the cornea and the pupil and gets focused and inverted by lens then light lands on the retina where it begins the process of transduction into neural impulses to be sent through the optic nerve Lens is not rigid can perform accommodation by changing shape to focus on near or far objects Retina Light enters eye triggering photochemical reactions in rods and cones in back of the retina Chemical reaction in turn activates bipolar cells Bipolar cells then activate ganglion cells the axons of which converge to form optic nerve. The nerve transmits information to the visual cortex (via the thalamus in the brain) Blind spot The area of missing information in our field of vision known as the blind spot. This occurs because the eye has no receptor fells at the place where the optic nerve enters the eye Photoreceptors, rods and cones When the light reaches the back of the retina it triggers chemical changes in the receptor cells called the rods and cones. The rods and cones in turn send messages to ganglion and bipolar cells and on to the optic nerve Rods help us see the black and white actions in out peripheral view and in the dark. Rods are about 20 times more common than cones who help us se sharp colorful details in bright light Visual information processing The images we see are not made up of light they are made up of neural signals which can be produced even by pressure on the eyeball Made By Abby Carroll 2

3 Once neuro-signals enter the optic nerve they are sent to the thalamus to the visual cortex Neural signals into images Some ganglion cells in the eye send signals to (directly) the visual cortex in response to certain features such as visual patterns certain edges lines or movement In and around the visual cortex of the occipital lobe super cells integrate these signals to recognize more complex forms such as faces Parallel processing Light to retinal act seeing Light wave chemical reaction neural impulse feature object et. Parallel processing refers to building perceptions put of sensory details processed in different areas of the brain Retinal processing (1) feature detection (2) parallel processing recognition (1) Receptor rods and cones bipolar cells ganglion cells (2) brains detector cells respond to specific features (edges lines and angles) Color vision Young-Helmholtz trichromatic three color theory There are three types of color receptor cells green red and blue al the colors we perceive are created by light waves stimulating combinations of these cones Color blindness Opponent process theory: refers to the neural process perceiving white as the opposite of perceiving black simultaneously yellow vs. blue and red vs. green are opponent processing Perceptual organization Perceptual process enabling us to organize perceived color objects and lines into objects Grouping incomplete parts into gestalt wholes Seeing figures stand out behind a background Perceiving form motion and depth Keeping sense of shape and color constancy despite change in visual information Using experience to guide visual interpretation Figure ground perception In most visual scenes we pick out objects and figures standing out gains a background Come art muddles this ability by giving us two equal choices about what a figure is and what is ground Grouping and gestalts Gestalts refers to a meaningful pattern of configuration forming a whole that is more than the sum of the parts Three ways that we group visual information into wholes are proximity continuity and closure Depth of image Made By Abby Carroll 3

4 Binocular (using both eyes) cues exist because humans have two eyes in the front of our head that gives us the retinal disparity the two eyes have slightly different views and the more different the views are the closer the object must be Like with how close your eyes are you your nose, each eye will see a different half How we perceive depth from a 2D image by using monocular cues (need one eye) Interposition: one object appears to block the view of another and we assume that the blocking object is in a position between our eyes and the blocked object Relative size: intuitively know to interpret familiar objects (of a known size) as farther away when they appear smaller Linear perspective and interposition: flowers in the distance seem farther away because the rows converge. Our brain reads this as a sign of distance Relative height: tend to perceive the higher part of a scene as farther away Shading effects: help our perception of depth light and shadow create depth cues Relative motion: when moving we can tell which objects are farther away because it takes longer to pass them Motion perception Perceive motions in many ways Object moving towards us perceive this motion by watching and changing apparent size of the object objects moving to one side perceive relative motion although we often judge huge objects inaccurately objects traveling in a more complex path (object moving in an arc towards you) baseball players and dogs can run right to where the ball will land by keeping the ball in a constant apparent position in the sky perceptual constancy perceptual constancy: our ability to see objects as appearing the same even under different lighting conditions at different distances and angles top down process example: color brightness constancy and shape and size constancy color constancy ability to see a consistent color in changing illumination shape constancy the ability to see objects as having a consistent shape despite reviving different sensory images helps us see the door as a rectangle as it opens moon illusion moon appears larger on the horizon than overhead size constancy we have an ability to use distance related context cues to help us see objects as the same size even if the image on the retina becomes smaller Ames room invented by Albert Ames Jr. in 1934 Made By Abby Carroll 4

5 Manipulative distance making two girls of the same size look shorter and or taller Nature vs. nurture People grown without vision surgically gained sight in adulthood. As a result they could interpret depth motion and figure ground distinctions but not difference in shapes and faces Animals raised at every age without seeing horizontal lines later seem unable to learn to perceive such lines If humans don t have full visual sensation experience at a critical periods of development we seem to acquire limits to what our brain can interpret from visual stimuli. Perceptual adaptation After our sensory information is distorts such as by new glasses of delays audio on television humans may at first be disoriented but we can learn to adjust and function Hearing Frequency corresponds to pitch Length of the sound wave = high of low sounds Amplitude corresponds to the intensity of the sound wave in loudness and softness (volume) Complexity corresponds to our perception of timbre Previewed as sound quality resonance Ear Outer ear collects sound and funnels it to the eardrum Middle ear: sound waves hit the eardrum and move the hammer and anvil and stirrup in ways that amplify the vibrations the stirrup then sends these vibrations to the oval window of the cochlea Inner ear waves of the fluid move from the oval window over the cochlea s hair receptor cells these cells end signals through the auditory nerves to the temporal lobe of the brain Middle and inner ear Conduction hearing loss: middle eat isn t conducting sound well in cochlea Sensori-neural hearing loss: receptor cells aren t sending messages through the auditory nerves Preventing hearing loss Exposure to sounds that are too loud to talk over can cause damage to the inner ear especially hair cells Structures or the middle/inner ear can be damaged by disease Prevention methods include limiting exposure to noises over 85 decibels and treating ear infections Treating hearing loss People with conduction hearing loss may be helped by hearing aids. These aids amplify sounds striking the ear drum ideally amplifying only soft sounds of higher frequencies Made By Abby Carroll 5

6 People with sensori-neural hearing loss can benefit from a cochlear implant the implant does the work of the hairs in translating sound waves into electrical signals that can be sent to the brain Sound perception: loudness Loudness refers to more intense sound vibrations this causes a greater number of hair cells to send signals to the brain Soft sounds only activate certain hair cells louder sounds move those hair cells and their neighbors Pitch Place theory: at high sound frequencies signals are generated at different locations in the cochlea depending on pitch by reading the location where the signals are coming from Frequency theory: at low sound frequencies hair cells send signals at whatever rate the sound is received Volley principle: ultra-high frequencies receptor cells fire in succession combining signals to reach higher firing rates Four components of touch Warm Cold Pressure Pain Stroking adjacent pressure spots creates a tickle Adjacent cold and pressure sensation feels wet Adjacent warm and cold feels searing hot Pain Pain tells the body that something has gone wrong it warns of severe injury of even just a to shift positions in a chair to keep blood flowing Not being able to tell we are injured sick of causing damage to our bodies can be dangerous Biological factors in pain perception Nociceptors are sensory receptors whose signals are interpreted by the brain as pain The pain circuit refers to signals that travel to the spinal cord up through small nerve fiber s which then conduct pain signals to the brain Gate control theory: hypothesis that the spinal cord contains a neurological gate that blocks pain signals or allow them to pass on to the brain. The gate is opened by the activity of pain signals traveling up the small nerve fibers and is closed by activity in larger fibers of by information coming from the brain stimulation large nerve fibers in the spinal cord through acupuncture massage or electrical stimulation seems to close that gate Endorphins: hormones can be released by the body to reduce pain perception Made By Abby Carroll 6

7 Phantom limb sensation: as the brain produces false sounds (ear ringing) and signals (aura light with migraines) it can produce pain or other perceptions of amputates or missing limbs Psychological influences on pain Distraction such as during intense athletic competition can limit the experience of pain Pain and memory Memories of pain focus on peak moments more than duration Tapered pain is recalled as less painful than abruptly ended pain Social cultural influences on pain perception Social contagion: we feel more pain if other people are experiencing pain. This occurs wither out of empathy/mirroring of a shared belief that an experience is painful Cultural influences: we may not pay as much attention to pain if we feel a high level of pain endurance as the norm for our family peer group or culture Controlling managing and reducing pain Pain can be reduced through drugs acupuncture electrical stimulation exercise hypnosis surgery relaxation training and distractions Even the placebo effect influences on pain perception when we think we are taking pain killers of receiving acupuncture out bodies can release endorphins Distraction with virtual reality immersion has helped burn victims manage intense pain Taste Our tongues have receptors for 5 different tastes each of which may have had survival functions Bitter: potential positions Salty: sodium essential to psychological process Savory: (umami) proteins to grow and repair tissue Sour: potentially toxic acid Sweet: energy source Neurochemistry of taste No regions of the tongue just different types of taste receptor cells projecting hairs into each taste buds pore Cells are easily triggered to send messages to the temporal lobes of the brain If you burn your tongue receptors reproduce every week (or two) or so but with age taste buds become less numerous and less sensitive Top down process still can override the neurochemistry expectations do influence taste Mix senses together Sensory interaction occurs when different senses influence each other Burst of sound makes dim light source ore visible Flavor: experience not only of taste but also smell and texture Synesthesia: when perception in one sense is triggered by a sensation in another sense Embodies cognition Made By Abby Carroll 7

8 No coincidence that we can use sensation words to describe feelings, studies show If you are holding a warm mug then you are more likely to be socially warm (outgoing) Social rejection looks like pain in your brain Definition refers to the effect of body experience on feelings attitudes thoughts ad judgments Smell odor: receptors Humans have a poor sense of smell for and animal even so humans have 350 different types of smell receptors allowing us to detect about 10,000 different odors Smell is a shortcut sense Sensations of smell take a shortcut to the brain skipping trip through sensory switchboard (thalamus) made by all other senses Information from the nose goes not only to the temporal lobe but also to the limbic system (memory/emotion) Smell links lovers parent and child and other creatures to each other through chemistry Sensing body position and movement Kinesthesis (movement feeling) refers to sensory and movement and position of individual body parts relative to each other How it works: sensors in the joints and muscles send signals that coordinate with signals from the skin and ears Without this we would have to watch out limbs constantly to coordinate movement Vestibular sense refers to the ability to sense the position of the head and the body relative to gravity including the sense of balance How it works: fluid filled chambers in the inner ear (vestibular sacs and semicircular canals have hair like receptors that send messages about the heads position to the cerebellum) Vestibular sense serves as the human gyroscope helping us stay upright and balanced ESP (extrasensory perception) Can be defined as literally perception without sensation however this definition would also include dreams and hallucinations (both involve perception without sensation) Believers in ESP think it involves getting accurate information directly to the mind skipping the known senses Types of ESP include Telepathy (reading the messages of the mind) Clairvoyance (seeing remote events) Precognition (knowing future events) Evidence of ESP is controversial Diagrams Made By Abby Carroll 8

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