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Psychology 260: Sensation and perception Psychology 735: Psychology of perception Spring 2017 Review sheet for Final Exam (Thursday, May 25, 11am-1pm)

Material covered: Answers to all of the questions below, as found in all lectures and Goldstein, Chapters 1-15 (excluding 13), and clinical aspects of vision and hearing chapter (from older edition of Goldstein) If you can answer ALL of these questions, you should do well on the final. If it’s not on this list, it won’t be on the exam: General sensory systems What is the process in which environmental stimuli are converted to electrical signals? Transduction What is the stimulus for each of the following sensory systems? Vision =light Audition = sound waves Cutaneous senses = tactile stimuli, anything on skin Olfaction/Taste = chemical molecules What are the names and functions of the following different parts of the neuron? Cell body Dendrites Axons / axon terminals Synapses Neuron brain is cell body – helps keep the neuron alive/ metabolized Dendrites – finger like structures - that’s where signals from other neurons are received. Function is to receive signals from the other cells. Axon – two leg structure – highway along which signal travels to get passed on to other neurons. Bunch of axons together, form a nerve. A nerve is a bundle of axons together. Axon terminals – are at the end of traveling and they come in contact with other neurons and get passed on afterwards. The function of the synapse is to transfer electric activity (information) from one cell to another. The transfer can be from nerve to nerve (neuro-neuro), or nerve to muscle (neuro-myo). The cell body connects to the dendrites, which bring information to the neuron, and the axon, which sends information to other neurons. What is the difference between all of the following terms?

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Action potential = wats generated when neuron is activated, increase and decrease Resting potential = records electrode. Pretty much flat on graph so not moving Refractory period = limits how many action potentials are generated over time – the atom needs a break after generating action potential Spontaneous activity = action potentials are Generated even when neuron is not activate/activated by a stimulus – baseline activity Propagated responses = action potentials travel down the whole of the axon without decreasing in magnitude. Or reducing in strength What are the differences between the two main portions of the brain? Cerebral cortex (grey matter) = outermost layer. Part of the brain that contains mostly cell bodies. Some axons but mostly dendrites, axon terminals, structures that are close to the cell body White matter = axons are contained there = the highways along which signals travel. Signals are generated and pass through white matter areas of the cortex For the following sensory systems, in what lobe of the brain is the primary receiving area located? First cortical areas to receive signals from the receptors Vision = V1 = occipital lobe Auditory = A1 temporal lobe Somatosensory = S1 = parietal lobe Olfaction = temporal lobe Ol f act i oni st heonl ysens or ys y st em t hati snotr out edt hr ought het hal amus. Signals travel along axons. Axons = highways What sensory system are the following receptors associated with, and what stimulus activates them? Sensors: Rods/cones = visual system Hair cells = auditory system (also vestibular system) Merkel disks = cutaneous system Meissner corpuscles = cutaneous system Ruffini endings = cutaneous system Pacinian corpuscles = cutaneous system I think its called the cutaneous system Nociceptors Olfactory receptors = chemical Taste cells/receptors = chemical Through which area of the brain do signals initiating from visual, auditory, and cutaneous receptors pass before traveling to cortex? Thalamus - common area in sensory system processing

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Vision and the visual system Cornea = lasic. Outermost part. Does most of the focusing bc its more curved. Lens – inside the eye, behind the pupil. Has muscles attached to it, has automatic focusing power accommodation - automatic focusing power. When you focus on close things your lens immediately accommodates. lens changes compared to far and close focus on things Photoreceptors: located in the retina. respond to small spots of light; brighter lights induce greater responses (simplistic like light meters How are the rods and cones distributed across the retina? We have more cones than rods Where are there both rods and cones? Peripheral retina. Everywhere but phobea you have rods and cones. Where are there no rods? Phobea (tiny place) Where are there no receptors? Blind spot Why are we not aware of the blind spot? Located in the periphery Not consciously “looking” for it Brain perceptually “fills in” the area How do the rods and cones differ in everything Distribution • Fovea (cones only), Periphery (rods and cones) • More rods than cones (20:1) Sensitivity to light • At maximal sensitivity, rods are more sensitive than cones • Cones reach maximal sensitivity (regenerate visual pigment) faster than rods In brightly illuminated conditions Cones control your vision: Fovea and periphery Fine details, but not very sensitive to light Most sensitive to greenish-yellowish light In minimally illuminated conditions Rods control your vision: Periphery only (outnumber cones 20:1) Very sensitive to light, but not to fine detail Most sensitive to bluish light More Sensitivity to light (convergence)? Rods, and they have more convergence process more light Ability to convey fine details? cones Ability to convey color? Cones, bc we have 3 different types. (Rods we only have one type) Convergence: 3

More than one neuron synapses onto another neuron Higher convergence à higher sensitivity Less convergence à greater visual acuity (ability to see detail) Convergence influences neural circuits Networks of interconnected neurons Focusing components of the eye: Light enters the eye through the Cornea and lens. Pupils, retina. Retina: contains the photoreceptors: rods and cones Which can change in focusing power automatically? What is the name of this process? Lens changes automatically. Called Accommodation Which does most of the focusing of light rays entering the eye? Cones Which structure is sculpted during LASIK? Cornea Lateral inhibition = lateral sending of signals across the retina Lateral inhibition cannot explain Benary’s Cross or White’s Illusion What is the simultaneous contrast illusion, and how does lateral inhibition explain this illusion? 2 grey squares one surrounded by white one by black The grey square surrounded by white excites a lot of surrounding receptors and those surrounding receptors inhibit the response towards the center so the grey square is darker = inhibition Surrounded by white is darker = more inhibition General ordering of signals through the visual system as they go up the highway : Initiated in the rods and cones in the retina -> LGN thalamus-> V1 cortex -> higher areas like V4 (good for color)/MT (good for motion) & IT (the face area) How are the following neurons in V1 different from one another and how are they similar? (what important visual characteristic do they ALL respond to?) V1 is first place neurons are coated and they respond to angles of orientation (and location) Before V1 in LGN and retina, they respond mostly to light or dark In V1 there are 3 classes of neurons. All these 3 respond/code to orientation/angles: Simple cells = picky about location . don’t really respond to movement Complex cells = respond to movement Hypercomplex (end-stopped) cells = respond to movement What is cortical magnification in the visual system? Stimulus that is viewed in your central vision activates many neurons in v1 The same stimulus viewed in your peripheral vision, activates much fewer neurons in V1. If you are looking at two identical stimuli, one in the fovea, and one in the periphery, how does the amount of V1 cortical tissue devoted to processing the two compare and why (know factors)? So if you have 2 stimuli that are the same size, one you are looking straight at and one is in your peripheral vision, the one in your central vision is gonna activate more V1. Factors that contribute to that = there’s a slide about this – look at it. FACTORS: 4

Photoreceptors Density Ganglion cells Convergence Cortical cells No convergence Uniform density Case experiment: In the patient with visual form agnosia resulting from damage to her temporal pathway, what specific perceptual task is she able to do and what is she unable to do? Card posting Rotating the card to match orientation task or she was actually posting a card into a slot In monkeys, what perceptual deficits result from damage to each of the following pathways? (know the names of the tasks that they can and can’t do) Different parts of the brain were removed – what were the consequences? Moneky experiment =object identification vs object location task extra-striate pathways: Ventral (temporal) pathway Dorsal (parietal) pathway Dorsal = top of the brain. info about where something is / how to interact with it Ventral pathway = travels down the under side of the brain – info about what something is Different areas in ventral and dorsal pathways: V1: the signals travel to pathways to dorsal pathways. in the ventral pathway, codes color WHAT pathway IT FFA: also in ventral pathway. Respond to complex objects and faces WHAT pathway What are each of the following cortical areas specialized for? MT (damage results in motion agnosia – what are symptoms?) WHERE pathway. Signal directions of motion. Responds best to motion, not color V4 responds best to color, not motion IT/FFA (damage results in prosopagnosia – what are symptoms?) (humans only): inability to recognize familiar faces resulting from damage to FFA MST responds to patterns of optic flow = important for understanding where something is, how to interact with it, navigating through the environment What is perceptual organization (broken down into grouping & segregation)? What do grouping and segregation enable your visual system to do in the dog example = dalmation discussed in class? Separating dog from background AND grouping it together to know it’s a dog. You group the dots corresponding to the dalmation to the form of the dalmation , but you are also separating the dog from the background = grouping and segregation Grouping: How individual features/parts combined to yield percepts of whole objects Process of grouping small elements into whole objects. 5

Gestalt organizing principles explain how we do this Segregation: How areas or objects are separated from one another and from the background If you vary a color in each of the following dimensions, how does the color change? (be familiar with examples) Dimensions of color: Hue wavelength Saturation how much grey or white pastel Intensity (Value) how bright or how dark something is Light pink and rainbow red differ in saturation 3 dimensions of color- you need all three to find color 1. Hue- “color” associated with the wavelength of light. Hue is changing around the dimension. (color naming, using: red, yellow, green, blue = pure/unique colors) 2. Saturation- vividness or death of a color ex: rainbow red is very saturated Saturation is radially varies- least saturated in the center (how DEEP) vividness/depth, amount of white/grey e.g. pink vs. rainbow red 3. Intensity- Value- brightness of the color- how dark or bright it is. Value goes from the bottom(black ) to very BRIGHT more up . brightness e.g. dark (dim) vs. bright red For the following color deficiencies, how many receptor types are present, what receptor types are missing, and how is each deficiency diagnosed using the color matching test? Color matching is a technique used to diagnose color deficiencies. Correspond to how many cone classes are missing Monochromats 1 type of cone , can color match 1 wavelength in comparison Dichromats 2 types of cones, can do color match with 2 wavelengths in comparison Protanopes – missing L cone Deuteranopes missing M cone Tritanopes missing S cone Anomalous trichromats – have all 3 What is color constancy? (be familiar with examples) = ability to judge color is unchanged by the color of the light Banana looks like a banana under fluorescent light and even if you take it to another side where light is more red And the black blue white gold dress is another example of this What are color afterimages, and simultaneous color contrast? Coupling with red and green, blue and yellow. If you stare at something that’s red and then you look at something that’s white itll tend to look green and vise versa Same as when you surround grey with red it tends to look green 6

Adapt to red, white looks green (and vice versa). Adapt to blue, white looks yellow (and vice versa). Depth Perception: 3 different classes of cues: How are the following three classes of cues to depth different from one another? Oculomotor (convergence, accommodation) related to the movement and position of the eyes. Convergence and accommodation provide information about how far something is from you Binocular (binocular disparity) = theres a lot of these. Difference between the 2 images projected to the 2 different eyes Monocular = they are called monocular cues because you only need one eye (know only occlusion =when something occludes object that’s perceived to be closer , relative height= look at base of the object how high it is in the picture tells you how far away it is , atmospheric perspective = landscapes, farther away objects look hazier , perspective convergence= railroad track. Parallel lines in the world converge in the pictures as increasing distance. Lines fo the railroad look like it converges and the more convergence there is the farther away things look

What do the results of the Holway-Boring experiment tell us about size perception? More info you have about depth, more you can tell the size of the object . in the experiment, their ability to judge the size of the object decreased as they decreased the depth information. Extreme case: moon size is hard to judge bc you don’t have depth information Eclipse: moon and sun look like theyre the same size even though they are not What are the components of the size-distance scaling equation (S = RxD) and how does this equation accounts for these illusions? (remember: what is real and what is perceived?) S = perceived size R= retinal size = actual size of the image on the retina D= actual perceived depth In the illusions, S is always different for 2 things – you are trying to explain why is the perceived size different when they are actually the same. Theres gonna be something different about either R or D. Ames Room = 2 diff ppl look diff size even though they are exactly the same R= different- small on the left and big on the right D= looks like theyre standing the same S= large on the right and small on the left Moon illusion = moon looks big on horizon, but looks smaller up in the sky even though really bigger on sky R= the same

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D= larger on the bottom because there are things you can compare it to and smaller on top because theres nothing to compare it to and tends to look closer S= bigger on the horizon and smaller above R and d are different here What are the differences between the following different kinds of motion? The smooth motion you perceive in movies is a classic example of which of these? Real motion = object rlly moving Apparent motion = perception of motion, but theres no real motion. Example: movies . really still frames but u think moving Structure from motion (e.g. biological motion) = perception of movement of 3 dimensional object when you are looing at 2 dimensional movie . examples: biological motion – looking at dots on flat screen, they are moving and the depth/3 dimensionality of that movement jumps out at you. Another example= rotating of the shadow of rotating cube-looking at it on flat screen but you u think its moving bc its 3 d What is optic flow, and what do blind walking experiments tell us about the use of optic flow? = objects move by you when you navigate through an otherwise stationary environment. Star feild example = pattern of motion that stuff follow when in the direction you are navigating. Blind walking experiment: subjects see a target, they are blindfolded and asked to walk to it. they do it pretty well so this says you don’t need optic flow to navigate short distances What do results from experiments done in swinging rooms they tell us about visual information and balance? Stimulates self movement = you think youre moving bc room is moving , you perceive self movement Swinging rooms experiment: stimulates self movement – walls and ceiling swing to stimulate movement of you moving through the stationary environment. it says that Your sense of balance is very linked to your vision. When you see things that show you moving, you get a strong sense of actual self movement . they stayed stationary bc floor is stationary but felt like they were moving Clinical aspects of vision: focusing problems -nearsightedness : light is focused too strongly . far point is very close. - far sightedness : light is not focused strongly enough so the lenses have to take care of the difference Presbyopia (near point) =type of far sightedness Astigmatism = Misshapen cornea (not spherical, normally elongated); some orientations are clear, others are blurred. Prescription includes axis/axes of blur and diopters. Without correction, what do people with the following focusing problems perceive (specifically what things appear blurred)? Also, for each condition, how do the cornea and/or lens differ from those of someone with no focusing problems? Myopia = near sightedness. Far point. Far things get blurred. cornea/lens bend light rays 8

too much far point = the farthest distance. You start close and see and things get blurrier and blurrier and that’s your far point ) linked to prescription of your glasses. Inverse relationship between your prescription number and your far point. LASIK = flatten cornea Hyperopia = far sightedness = near point: start with far objects and closer things start to go blurry at a certain point. LASIK = curve cornea increase curvature Far things in focus, close things blurred cornea/lens don’t bend light rays enough The more hyperopic you are, the farther your near point.

Presbyopia = type of far sightedness (near point) with age, lens hardens, muscles weaken leading to the inability to accommodate (focus on close objects); a form of hyperopia (close things are blurred). NEAR POINT: : closest distance at which objects are still in focus FAR POINT: : farthest distance at which objects are in focus without correction. (Farther objects will appear blurred.) The more myopic you are, the closer your far point.

For someone with myopia, given the numbers of diopters required to correct their vision, how do you compute the person’s far point, and vice versa? Equation for finding prescription number based on your far point for nearsightedness: 1/ small number = large number that’s the prescription for your glasses For myopia and hyperopia, what is done in LASIK to correct your vision? Flattens cornea vs Creates curvature on cornea How do you determine whether a person is considered legally blind or not? = tunnel vision OR legal blindness – 20/200 or worse in the better eye or have tunnel vision. The larger the denominator, the worse your vision is. 20 = The distance in feet at which an object needs to be brought to be seen clearly by you, with the focusing problem 200 = The distance in feet at which an object is seen clearly for someone with no focusing problems

Sound and the auditory system

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Hearing and balance: Pure Tone = the simplest type of sounds Sound wave that has shape to it, if you graph sound pressure vs time If you plot that it looks like a sound wave For a pure tone, how are variations in the following perceived? 2 parameters of a pure tone: Frequency = pitch. The higher the frequency the higher the pitch Amplitude = loudness = greater the amplitude, louder the sound What does the audibility (threshold of hearing) curve tell us about o...