General Psych 1101 Module 17,18,19 PDF

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Detailed Chapter Text Notes from Cengage with Professor Peach...

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Video Notes ● When we listen to music, we hear a cohesive melody or song, not a note, a raw sensory information as a unified whole ● As a visual system, (white triangle) we instead have 3 pac men but our sensory draws us to look at it as a white triangle Module 17: Basic Concepts of Sensation and Perception Processing Sensation and Perception ● Curious mix of “perfect vision” and face blindness illustrates the distinction between sensation and perception ● Sensation: the process by which we detect physical energy in the environment and encode that energy as neural signals ○ Ex: experiencing sudden pain ○ Bottom-up processing: starts at your sensory receptors and works up to higher levels of processing; starts at the very basic level of sensory receptors and works toward more complex levels of processing ■ Absorbing info., this process enables your sensory systems to detect the lines, angles, and colors ● Sensory receptors: sensory nerve endings that respond to stimuli; are alert to novelty ● Perception: the top-down processes by which the brain organizes and interprets sensory input ○ Ex: Recognizing that you are suffering a heart attack ○ Top-down processing: constructs perception from this sensory input by drawing on your experience and expectations ■ The fact that perception involves more than the sum of sensations ■ Absorbing info., this process interprets what your senses detect ■ Our experiences, assumptions, expectations can shape and color our view of reality ○ Perceptual set: a set of mental tendencies and assumptions that affects what we hear, taste, feel, and see, or interpret stimuli ■ “Mind over mind” ■ Involves top-down processing because it draws on your experiences, assumptions, and expectations when interpreting stimuli ■ Determined by concepts, or schemas, that organize and interpret unfamiliar information ■ Racial and ethnic stereotypes can sometimes bias the way one sees others' behaviors ● Both work together to help us sort out complex images Transduction: ❖ Transduction: the process of converting one form of energy into another form ➢ Vision processes light energy

➢ Hearing processes sound waves ❖ All our senses ➢ Receive sensory stimulation, using specialized receptor cells ➢ Transform that stimulation into neural impulses ➢ Deliver the neural information to our brain ❖ Psychophysics: studies the relationships between the physical energy we can detect and its effects on our psychological experiences Thresholds: ➔ Absolute Thresholds: the minimum stimulation necessary to detect a particular light, sound, pressure, taste, or odor 50% of the time ❖ Subliminal stimulation: stimuli you cannot consciously detect 50% of the time; below your absolute threshold ➢ Experiment: people’s attention was unconsciously drawn to images in a way that reflected their sexual orientation ➢ Result: we can evaluate a stimulus even when we are not consciously aware of it ◆ Ex: Standing atop a mountain and seeing a candle flame 30 miles away ◆ Ex: Feeling the wing of a bee falling on our cheek ◆ Ex: Smelling a single drop of perfume in a 3-room apartment ❖ Signal detection theory: studying the impact of boredom and fatigue on people’s absolute thresholds ➢ Dennis, a nurse, notes that some parents of asthmatic children respond to very small changes in their children's breathing and seek care accordingly. However, other parents do not notice the same small changes ➢ Two Transportation Security Administration officers are scanning bags at the airport. One of the officers lets a bag go through, but the other officer yells, "Wait, didn't you see that?" Why one officer saw a weapon and the other did not ➔ Difference Threshold: the minimum difference a person can detect between any two stimuli 50% of the time ◆ Detectable difference increases with the size of the stimulus ◆ Weber’s Law: to perceive a difference, two stimuli must differ by a constant minimum % rather than a constant amount ● 2 lights must differ in intensity by 8% ● 2 objects must differ in weight by 2% ● 2 tones must differ in frequency by 0.3% ➔ Signal detection theory: how and when we detect the presence of a faint signal among background noise; detection depends partly on a person’s experience, expectation, motivation, and alertness

◆ Signal detection theorists seek to understand why people respond differently to the same stimuli, and why the same person’s reactions vary as circumstances change Sensory Adaptation: ❏ Sensory adaptation: constantly exposed to an unchanging stimulus, we become less aware of it because our nerve cells fire less frequently ❏ We focus primarily on changing stimuli ❏ Reduces our sensitivity ❏ Benefit: freedom to focus on informative changes in our environment ❏ Attention-grabbing power of changing stimulation: ❏ Explains why phone notifications are so hard to ignore ❏ Influences how we perceive emotions We perceive the world not exactly as it is, but as it is useful for us to perceive it Context, Motivation, and Emotion: ● Cultural context helps inform our perceptions ● Motivation gives us energy as we work toward a goal ● Reciprocal phenomenon: seeing a target as bigger improves performance ● Emotions can shove our perceptions in one direction ● Emotions + motives color our social perceptions Much of what we perceive comes not just from what’s “out there”, but also from what’s behind our eyes and between our ears Module 18: Vision - Sensory and Perceptual Processing Our eyes receive light energy and transduce (transform) it into neural messages From this neural input, our brain - one of life’s greatest wonders - creates what we consciously see Stimulus Input: Light Energy ➔ Pulses of electromagnetic energy allow your visual system to perceive colors than they actually are ◆ A bright red tulip isn’t actually red, but your eyes see it that way ➔ Visible light = a wide spectrum of electromagnetic energy ➔ Light spectrum: Shortest to longest wavelengths

➔ Light travels in waves

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Light’s wavelength: the distance from one wave successive peak to the next Wavelength determines hue, the color we experience Amplitude: aka height from peak to trough, determines intensity Intensity: the amount of energy the wave contains ◆ Influences brightness ➔ Snakes can detect higher-wavelength waves unlike humans

Eye ❖ Light enters the eye through the cornea: helps provide focus ❖ Then light passes through the pupil: small adjustable opening ❖ Iris: surrounds the pupil and controls size, a colored muscle that dilates/ constricts in response to light intensity ➢ Responds to your cognitive & emotional states ➢ Constricted (smaller) iris: ■ Looking at the sun ■ Answering “no” to a question ■ Feeling disgusted ➢ Dilated (bigger) iris: ■ A dark room ■ Feeling sexually aroused ➢ Full dilatation takes 20 minutes or more ❖ After light passes through your pupil, light hits the transparent lens ❖ This lens focuses the light rays into an image on your retina: a multi layered tissue on the eyeball’s sensitive inner surface ➢ Retinal cells are responsive to pressure that triggers them ❖ To focus the rays, the process called accommodation happens ❖ Accommodation: the lens changes its curvature and thickness ❖ Johannes Kepler: proved da Vinci wrong saying that the retina receives upside-down images of the world; aka inverted image

❖ Retina doesn’t “see” a whole image, as receptor cells convert particles of light energy into neural impulses which we perceive as an upright-seeming image Eye-to-Brain Pathway ● Retina’s buried receptor cells ○ Rods: retinal receptors that detect black, white, and gray, and are sensitive to movement ■ Necessary for peripheral and twilight (faint light) vision, when cones don’t respond ■ Located around the retina’s outer regions ○ Cones: retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions ■ Detect fine detail and gives rise to color sensations ■ Found in clusters around the fovea: the retina’s area of central focus ■ In light, they enable you to perceive color ■ In dim light, they become unresponsive - no color ● These cells then trigger chemical changes that spark neural signals in nearby bipolar cells ● The bipolar cells activate neighboring ganglion cells, whose axons twine together like the strands of a rope to form the optic nerve ● Optic nerve: the nerve that carries neural impulses from the eye to the brain ○ An information highway from the eye to the brain ● Final destination: the occipital lobe to receive information of your visual cortex

Color Processing ➔ Color rejects (reflects) long wavelengths meaning a certain object is other than the actual color perceived ➔ Isaac Newton: “The light rays are not colored” ➔ Any color can be created by combining the light waves of three primary colors ◆ Red, green, and blue ➔ Young-Helmholtz trichromatic (three-color) theory: measuring the response of various cones to different color stimuli revealed the retina does indeed have 3 types of color receptors ◆ Combinations of these color allow us to see other colors ➔ Color-deficient vision: usually males who simply lack functioning red or green sensitive cones rather than being “blind” to those colors ◆ Their vision is monochromatic or dichromatic instead of trichromatic ➔ Afterimages: staring at one color for awhile then looking away and seeing the opponent color ◆ Green vs. red ◆ Blue vs. yellow ➔ Opponent-process theory: opposing retinal processes enable color vision ◆ Two stages:

● The retina’s red, green, and blue cones respond in varying degrees to different color stimuli ● The cones’ responses are then processed by opponent-process cells Feature Detection: ➢ Feature detectors: nerve cells in the occipital lobe’s visual cortex that respond to a scene’s specific features - edges, lines, angle, and movements ○ Receive info. From individual ganglion cells in the retina ○ Pass info. to other cortical areas, where teams of cells, supercell clusters, respond to more complex patterns ➢ Specialized cells respond to one type of stimulus - gaze, head angle, posture, or body movement ➢ One temporal lobe can stimulate the fusiform face area which helps you spontaneously see faces ➢ Disrupted brain’s face-processing unables us to recognize faces ➢ Brain activity helps researcher detect what people are looking at Parallel Processing ❖ Parallel processing: processing many aspects of a solution at the same time ❖ Subdimensions and works divides to work simultaneously ❖ Retina projects info. for recognizing faces by the fusiform face area Perceptual organization ❖ Gestalt: a form or whole ❖ Our conscious perception is a seamless scene - an integrated whole ❖ Saying of Gestalt: In perception, the whole may exceed the sum of its parts ❖ Principle of organizing our sensations into perceptions ➢ Our brain does more than register information about the world ❖ We filter incoming information and construct perceptions Form Perception ❖ Figure-ground: to separate faces from their backgrounds; continually reverses ❖ First perceptual task: perceive any object, the figure, as distinct from its surroundings, the ground ❖ Grouping: the perceptual tendency to organize stimuli into coherent groups ❖ Proximity: group nearby figures together ❖ Continuity: perceiving continuous patterns rather than discontinuous ones ❖ Closure: filling in gaps to create a complete, whole object Depth Perception ❖ Depth perception: the ability to see objects in three dimensions although the images that strike the retina are two-dimensional ❖ Experiment using visual cliff: a model of a cliff with a “drop-off” area that was actually covered by sturdy glass

➢ Result: 6 to 14 month olds refused to crawl onto the glass thus indicating they could perceive depth ❖ Factors include learning and innate ❖ Binocular cues: depth cue that depends on the use of two eyes ❖ Binocular cues are used to judge the distance of nearby objects ❖ Retinal disparity: binocular cue; the brain computes distance ❖ Greater disparity = closer the object ❖ Greater distance = smaller disparity ❖ Monocular cues: depth cues available to each eye separately Motion Perception ❖ We are imperfect at motion perception ❖ Young children have not yet fully developed perceive approaching ❖ Large and small objects move at the same speed to us ❖ Large objects appear to move more slowly ❖ Stroboscopic movement: our brain perceives a rapid series of slightly varying images as continuous movement ❖ 2 adjacent stationary light blinking on and off is seen as one single light moving back and forth ❖ Phi phenomenon: an illusion of movement created when two or more adjacent lights blink on and off in quick succession Perceptual Constancy ❖ Perceptual constancy: top-down process; perceiving objects as unchanging even as illumination and retinal images change ❖ We can identify people and things in less time than taking a breath ❖ Context gives us the experience of color ❖ Color constancy: the perception of consistent color ❖ We see color thanks to our brain’s computations of the light reflected by an object relative to the objects surrounding it ❖ Brightness, or lightness, constancy depends on context ❖ Relative luminance: the amount of light an object reflects relative to its surroundings ❖ We perceive objects in their environmental context ❖ Comparisons govern our perceptions ❖ Shape constancy: the form of familiar objects; because our visual cortex neurons rapidly learn to associate different views of an object ❖ Size constancy: an object having a constant size ❖ Moon illusion: the moon looks up to 50% larger when near the horizon than when high in the sky ❖ Our brain constructs our perceptions Perceptual Interpretation

❖ Immanuel Kant said knowledge comes from our inborn ways of organizing sensory experiences ❖ John Locke argued through our experiences we learn to perceive the world ❖ Molyneux’s hypothetical case: adults who had cataracts got surgery and after could distinguish figure from ground and different colors ❖ Surgery on Indian children revealed they benefited from removal of cataracts; the younger, the more beneficial ❖ Critical period, for normary sensory and perceptual development, an optimal period when exposure to certain stimuli or experiences is required Perceptual Adaptation ❖ The ability to adjust to changed sensory input ❖ Baby chicks continue to peck where food grains seem to be ❖ We adapt to distorting lenses quickly ❖ George Stratton: first person to experience a right-side-up retinal image Module 19: The Nonvisual Senses Audition: the sense or act of hearing ● People with invisible disability (hearing loss) has double risk of depression ● Millions of neurons stimulate your ear’s receptors ● Sound waves vary in shape ● Amplitude, or height, of sound waves determines their perceived loudness ● Frequency, or length, determines the pitch (high or low tone) ● Long waves = low frequency + low pitch ● Short waves = high frequency + high pitch ● We measure sounds in decibels ● 10 decibels corresponds to a tenfold increase in sound intensity ● 60 decibels is 10,000x more intense than 20 decibels Eardrum: membrane starts to vibrate when sound waves strikes Middle ear: a piston made of 3 tiny bones - hammer, anvil, and stirrup - picks up vibrations and transmits them to the… Cochlea: a snail-shaped tube in your inner ear ★ Loud noise is detected through here; ex: concert Inner ear: contains cochlea, semicircular canals, and vestibular sacs Incoming vibrations cause ripples in basilar membrane and bends the hair cells lining its surface Hair cells trigger adjacent nerve cells converging to form auditory nerve Auditory nerve carries the neural messages to your thalamus & on to the auditory cortex in your brain’s temporal lobe Sensorineural hearing loss: nerve deafness resulting from damage to the cochlea’s hair cell receptors; more common than conduction

Conduction hearing loss: hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea Since 1990s, teen hearing loss has rinse by ⅓ + affects 1 in 5 teens Teen boys blast more loud music Nerve deafness cannot be reserved Cochlear implant: the only way to restore hearing in a sort of bionic ear; converts sounds into electrical signals and stimulates the auditory nerve through electrodes threaded into the cochlea ● Cna help children become proficient in oral communication ● Hearing and vision are critical periods ● Can only help adults if their brain learned to process sound during childhood ● Reduces social isolation and risk of depression Loudness is detected through soft, pure tones activated only by a few hair cells Your brain interprets loudness from the number of activated hair cells People like sounds compressed which means harder-to-hear sounds are amplified more than loud sounds Our perception of pitch: 1. Place theory: links the pitch we hear with the place where the cochlea’s membrane is stimulated; how we sense high pitches 2. Frequency theory: the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch, temporal theory; how we sense low pitches Placement of our two ears let us enjoy stereophonic hearing Ex: if a car honks to your right, your right ear will receive a more intense sound, and it will receive the sound slightly sooner than your left ear Sound travels 761 miles per hour Touch ❏ Aids our development ❏ Infant rats deprived of their mother’s grooming produce less growth hormone and have a lower metabolic rate ❏ Infant monkeys who weren’t allowed to touch their mother became desperately unhappy ❏ Sense of touch: ❏ Pressure ❏ Warmth ❏ Cold ❏ Pain Pain ● Pain tells you something has gone wrong, serves as psychological purpose, and arouses others’ empathy and promotes social connections ● Without the feeling of pain, people may experience severe injury or even death before early childhood

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Pain reflects bottom-up sensations and top-down cognition Pain is a biopsychosocial event - this helps us better understand and cope with it Biological Influences pain is a physical event produced by your senses No one type of stimulus triggers pain the way light triggers vision No specialized receptors process pain signals the way your retina receptors react to light rays Nociceptors: sensory receptors detect hurtful temperatures, pressure, or chemicals; located in your skin, muscles, and organs Experience of pain depends on genes & physical characteristics No pain theory can explain all available findings Gate-control theory: the spinal cord contains a neurological “gate” that controls the transmission of pain messages to the brain Small spinal cord nerve fibers conduct most pain signals Injured tissue: small fibers activate and open the gate Pain signals can travel to your brain Large-fiber activity & brain-to-spinal cord messages, can close the gate, blocking pain signals Chronic pain is also a treatment Phantom limb sensations create pain after a limb amputation Without sensory input, the brain may misinterpret and amplify spontaneous but irrelevant central nervous system activity 7/10 feel pain or movement in nonexistent limbs Tinnitus: the phantom sound of ringing in the ears that’s accompanied by auditory brain activity We feel, see, hear, taste, and smell with our brain, which can sense even without functioning senses Psychological Influences one powerful influence on our perception of pain is the attention we focus on it We edit our memories of pain by its peak & the end Social-cultural Influences pain is a product of our attention, our expectations, and also our culture We perceive more pain when others seems to be experiencing pain - the pain is mainly in the brain Pain can be cured by drugs, surgery, acupuncture, electrical stimulation, massage, exercise, hypnosis, training, meditation, and thought distraction Endorphins are a natural painkiller Mutated gene: disrupts pain circuit neurotransmission Placebos: can help dampen the central nervous system’s attention and responses to painful experiences - mimicking painkillers One experiment: 2 groups were giving a fake pill or pretend acupuncture

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