AP Psychology Unit 6: Sensation and Perception --> Chapter 14

The Skin Senses (Touch)

**********FOURTH TYPE OF SENSATION Unlike vision, hearing, and taste, skin senses use no specialized receptor cells other than neurons --> receptors are neuron dendrites But, dendrites modified, altering whey they transduce physical energy Distributed unevenly +I.e face more sensitivee than back b/c receptors denser Tried to link diff receptors to diff sensations with limited success ****MUST KNOW SKIN RECEPTORS WITH DIAGRAM**** Free Nerve Endings (Pain) **********Free Nerve Endings umbrella or just pain?????????? Merkel's Disks (light touch) Meissner's Corpuscle (touch) Ruffini Endings (heat) Kraus' Bulb (cold) Fat Pacinian Corpuscle (pressure) TOUCH = PRESSURE, TEMPERATURE, PAIN *Pressure* *Stim is force causing displacement of skin *Quick sens ad (if not, pain) *Face and fingers most sensitive, back and legs least *Temperature* *Imp for survival *Certain very localized areas sense to cold but not warm and vice versa *Consistent with idea that different *free nerve endings*: specialized dendrite endings respond to hot or cold *More rapid response as temp decreases or increases *Detectors for cold closer to surface +May explain initial cold under hot **Paradoxical cold*: stimulation of cold areas with hot stimulus *Chems can produce hot or cold *PAIN* OVERVIEW *1/3 OF AMERICAN adults some chronic *NECESSARY --> WARNING +*Congenital Pain Insensitivity*: do not have pain sensations -Genetic mutation that stops non-expression of sodium channels in pain transmitting neurons, so stops neural signlaingin b/c needs influx of sodium for action potential -Injuries *Little known about cause or relief --> many reasons, one is b/c no one stimulus for pain *Theories of Production of pain +Overstimulation of any receptors or +Damaged tissue release chemicals that stimulate free-nerve endings in skin, which transduce chemical energy to neural signals that carry pain message to brain --> prostaglandins, bradykinin, and substance P (for pain protein) *Ransmission +Nerve fibers transmit pain signals from injury to spinal cord --> then, brain +Rapid myelinated bibers convey localized sharp pain (only one if short pain) +Slower unmylatnated fibers convey more spread burning, searing, throbbing or aching (if longer) *GATE CONTROL THEORY OF PAIN*: neural gates in spinal cord allow passage of pain signals to brain; these gates may be closed by simluataneous firing of ninepin nerve fibers, so that pain is not perceived +Melzack and Wall in 1965 +So, competition +Ev inconsistent, and not all propositions upheld, but major tenets ESP THAT PAIN IS SENSORY AND PERCEPTUAL PHENOMENON (SEE BIOPSYCHOSOCIAL) supported +Expalins some phenomiena -Pain relief by stimulating certain areas of spinal cord (maybe close gates) -No pain under high stress and intense emotions, which could create competing stimuli that overload neural circuits and block pain paths +Small and large nerve gibers?????????? NEUROTRANSMITTERS, BRAIN, AND PAIN *NEUROPEPTIDES +*Substance P*: peptide neurotransmitter that single spain from peripheral nerve fibers to spinal cord -Throughout midbrain, pons, and medulla and spinal cord; in spinal cord, it is nt that released by nociceptor to transmit pain single to spinal cord +*Endorphins*: class of (neuropeptide) neurotransmitter substances that function to inhibit transmisison of pain info; morphine and other opiates act by facilitating endorphin transmission; painkilling (analgesic) **Nociceptor*: sensory receptor speicalizedin transmitting pain signals to spinal cord *Periaqueductal Gray Area (PAG): region of BRAIN STEM that controls pain signals sent to higher brain centers, which receives signals from endorphin-containing neurons for pain analgesia **********PAG ONLY INHIBITS?????????? *TRANSMISSION +Sensory neurons transmit pain signals to spinal cord by exciting afferent neurons (**********HOW MANY? PERIPHERAL ONE LONG? ALL ONE LONG??????????) that rise to brainstem and thalamus +These afferent neurons release endorphins in PAG, which along with other neurons excite descending neurons that release SEROTONIN at original synapse in spinal cord, inhibiting pain signaling neuron ***So serotonin imp in inhibiting pain; so, SSRI for pain ***MUST KNOW PAIN IN BRAIN W/ PAG AND OTHERS********** Pain -+-> Dorsal horn of spinal cord ----------Branch for thalamus to higher centers----->PAG: endorphin (+??????????) and GABA (-) neuron's interact to release serotonin in spinal cord and inhibit pain --->PNucleus Raphe Magnus: Serotonin (+??????????) --Dotted branch to higher centers------>Dorsolateral funicular of spinal cord - (-) -> back to pain in dorsal horn of spinal cord? BIOPSYCHOSOCIAL FOR PAIN *GATE CONTROL THEORY OF PAIN*: -->ESP THAT PAIN IS SENSORY AND PERCEPTUAL PHENOMENON (SEE BIOPSYCHOSOCIAL) *Ind diffs in perceiving pain = social influence on pain *Pain not merely physical, as proposed by Renes Descartes; pain created by brain *Hyperalgesia*: ***FROM WIKIPEDIA --> increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves. *Phantom limb*: ***FROM WIKIPEDIA --> is the sensation that an amputated or missing limb is still attached. Approximately 60 to 80% of individuals with an amputation experience phantom sensations in their amputated limb, and the majority of the sensations are painful

Perception: Overview and Key Review

***Before, all sensation; perched diff processes --> brains give meaning by SELECTING, ORDERING, SYNTHESIZING, AND INTERPRETING!!!!!!!!!! IMP PSYCH CONCEPTS <-- WHY intuition fails and are imp concepts to know in general for psychology HINDSIGHT BIAS *The "I-knew-it-all-along" phenomenon +Looking back at answer, we often feel that already knew it and should have seen it +49ers --> John Brigham -Group 2 to predicty --> 81% said Dopphins win -Week after, asked group 3 (same demographic) what they predicted before, and 58% said 49ers -B/c... | OVERCONFIDENCE +tend to think we know more than we actually do -So, have to test in psychology -Think we can complete anagrams/our assignments in less time that we actually can CONFIRMATION BIAS +Not only overstimate knowledge, but also tend to pay attention to events that vconfirmt their beliefs and ignore evidence that contradicts those same beliefs COGNITIVE CAPTURE --> what grapes our attention/thinking; focus of our attention ***Whatever fills attention grabs fully, so whatever our con capture is on is only thing we can focus on/do w/ awareness +Hand free phone --> Either, but must apply cc, sa, AP, and CP; driving moves btw AP and CP so where is con cant w/ hands free phone SELECTIVE ATTENTION +Same as CC +Stoop Effect -1st (word) faster than 2nd (color) b/c reading is AP; 2nd requires you to overdid AP, so it takes more time -Neutral (word and color [2 stim] differ) object and congruent (same) object -Takes en to turn off AP; 2 is CP that overrides AP (b//c need to move selective attention away from AP), so takes even more effort -Concussion --> time for 2 up Roarshark Test GESTALT PSYCH Sensation = hardware; sensory input Perception = interp sensation CHANGE BLINDNESS --> not noticing change b/c not paying atteniton to it +Exp w/ changing people giving forms --> 75% didn't notice change in person +Form of inattention blindness, where 75% of direciton giving or form writing inds did not notice change in ind asking for directions or form INATTENTION BLINDNESS --> inability to see/notice something to which one is not paying attention +Ex: gorilla and passing exp --> most don't (and aren't supposed to) see gorilla b/c focused on passing ***Change, innatention, and choice blindness all distinct but related CHOICE BLINDNESS --> MAKE CHOICES W/O INITIALLY NOTCIING DETAILS/REASONS FOR THEM +Ex: people choose one image tey think is more attractive, given other w/o known thru deception/slight of hand, still justify picking the image even though they didn't pick it COCKTAIL-PARTY PHENOMENON --> ability to focus one's listening attention on a single talker among mix of converstatoins and backgournd noises, ignoring other conversatoins +Certain trigger, however, can take our atteniton away and cause us to miss somerhign +I.e. NAME What does it all mean? --> what we notice goes a long way to what we encode, and poetnioally the way we "think" about something -- which goes a long way

Structure and Function of the Ear and Steps of Audtion

***MUST*** MEMORIZE STRUCTURES OF EAR AND THEIR LOCATION AND FUNCTION **********Are inner, outer, middle ear umbrella terms?????????? **********Diff in functor of ossicles and middle ear? (Below lists all structs, and they are in order in which steps of audition occur in them) OUTER EAR Pinna (outer ear) Auditory Canal Tympanic Membrane (Eardrum) = Bridge to Middle Ear MIDDLE EAR Ossicles +Hammer (Malleus) +Anvil (Incus) +Stirrups (Stapes) Middle Ear Eustacian Tube (Not involved in audition, but involved in pressure??????????) INNER EAR **********OTHER STRUCTS??????????? OR SYNONYMOUS WITH COCHLEA?????????? Semicircular Canals?????????? Cochlea (Inner Ear) +Oval Window +Vestibular Canal +Cochlear Duct +Basilar Membrane -Organ of Corti --Tectoral [Tectorial??????????] Membrane --Cilia --Auditory Hair Cells +Tympanic Canal +Round Window Auditory Nerve [Inner??????????] *Steps of Audition* OUTER EAR 1. *Pinnas*: odd-shaped, flesh covered cartilage that protrudes from sides of head --> collects and funnels sound down *auditory canal* 2. Sound waves, at end of auditory canal, strike *tympanic membrane*: membrane stretched across end of auditory acanal that vibrates in response to sound waves which is aka the eardrum +Opening to middle ear 3. Connected to tympanic membrane are *ossicles*: set of three tiy linked bones (the malleus, incus, and stapes) in middle ear that receives a sound stimulus from the tympanic membrane and transfers it to the oval window of the inner ear +Series of vibrations; system of levers that transfer and amplify (or dampen) intensity of a sound stimulus +Malleus -- Incus --> Stapes 4. Stapes pounds against *oval window*: flexible opening to vestibular canal of inner ear --> transmits sound energy to *cochlea*: coiled, fluid-filled chamber in inner ear with two flexicble surfaces: oval iwindow and round window (flexible, elastic material) at end of tympanic membrane +Rest of cochlear wall is bone, but the two flexible spots allow pressure waves to be generated that start at oval window thru vestibular canal then tympanic canal to round window +Stapes cause movement of oval window and complementary movement of round window --> mech displacements translate into pressure waves 5. Pressure waves cause ripples in *basilar membrane*: membrane in cochlea of inner ear that vibrates in response to pressure waves, causing auditory hair cells on the adjoining organ of Corti to release neurotransmitters that activate neurons of the auditory nerve (explained in following steps) 6. Ripples in basilar membrane influence *Organ of Corti*: structure in inner ear located directly above basilar membrane, consisting of specialized neurons audditory hair cells (NEURON TYPE??????????) that terminate in cilia and a tectoral membrane +Rippling of Basilar membrane cause cilia to move against relatively stationary sectoral membrane, bending +Bending of cilia causes hair cells to release neurotransmitters 7. Nts from auditory hair cells activate *auditory nerve*, which transmits messages to *auditory cortex* in brain **********STEPS 6 AND 7 ARE TRANSDUCTION (I think but am not sure)!!!!!!!!!!?

The Chemical Senses

***More on vision and audition, but others just as imp ***All vital to ability to funct, including pain, which you *MUST* know!!!!!!!!! *B/c stimulus is chemical sub (mol) from env *Humans rely more on vision and audition, but these imp +I.e. danger; low calorie/toxic = bitter, high calorie = sweet, most flavorful and desirable *Gustation*: the sense of taste, which, like olfaction, is activated by chemical senses in the environment *Diff regions most sensitive to basic tastes +Bitter --> back +Sour ==> sides +Salt --> tip and forward portion of each side +Sweet --> tip +Umami (meaty, savory)--> all ***Regions reflect zones of greatest sensitivity; taste receptors NOT flavor specific in these regions but rather respond some to all taste qualities *THEORIES OF HOW WE DIFFERENTIATE TASTES *Labeled-line theory*: neurons called labeled-lines dedicated to specific taste qualities and make contributions that lead to diff tastes +But, does not explain recent electrophysiological data or complexity *Across-fiber pattern theory*: neurons do not code particular taste quality but rather cooperate to make unique firing pattern "fingerprint" for each taste *SENSING TASTE +*Papillae*: bumps on tongue containing many *taste buds*: contain many receptor cells called *microvilli* +Coated by saliva +Microvilli are hair like projections that are stimulated by chess dissolved in saliva, trandsucing chemical energy to neural single transmitted to medulla, thalamus, and gustatory cotex *More +Imp to survival of some species +Pref for calorie-rich foods mediated by release of dopamine in meslolimbic system -Makes carbs and fats more valuable and memorable -Dopamine also realesed when calorie rich/palatable foods reach stomach -Led ancestors to right diet, but now obesity *Olfaction*: sense of smell, which, like taste, is actiaved by chemical substances in the environment ***MUST KNOW STRUCTURE OF OLFACTORY SYSTEM Nasal Cavity Olfactory Mucosa +Cilia +Receptor Cells +Olfactory Bulb +Nerve Fibers +Olfactory Tract Olfactory Tubercle Olfacotry Tract Amygdala Pharynx? *SENSING SMELL +Odor molds enter through nostril or back of oral cavity to *nasal cavity* +In *olfactory mucosa*: mucus memo of nasal cavity, receptor cells with tiny hair-like cilia extending outward catch molds +Not exactly sure how chem energy --> neural signals; but, one theory -Cilia specialized to accomodate odor of diff shapes -So, molcs have diff odors b/c shape (supported0 -*olfacotry binding protein*: transports and binds molcs to receptor cells -Then, neural firing to *olfactory bulb* and *olfactory nerve* to higher brain centers in amygdala and olfactory cortex ****SMELL ONLY SENSE THAT DOES NOT GO THROUGH THALAMUS*** *HOW DIFFERENTIATE? +NO primary odors +**********Olfactory receptors do not fire to specific odor compounds?????????? But I thought specialized for shape?????????? +Neural patterns of receptors with broad range of senstiivties to diff molcs/odors **Phermones*: odors that attract sezxual interest +I.e. perfume says +Many animals, many functs --> ident offspring, territories, dominance, alarm, locate food, aggregate social animals +Mammals --> Vomeronasal organs (VNO) +Humans have VNO but not other neuronal elements +Ev for humans --> INCONSISTENT -Ev for Identify infants -Ev for male steroid reducing nervousness and tension and other autonomic changes when directly to female VNO -Ev for humans detergent pheromone thru olfactory system, not VNO -No confirmation if pheromones or other olfactory systems can stimulate sexual drive in humans *More +Humans do not depend on smell to identify like animals +Used to sell b/c can recall mems and associated emotions

Visual Illuisons

***PERCEPTIONS DIFF THAN PROPS OF PHYSICAL STIM --> DUE TO PROCESSING OF NERVOUS SYSTEM/TRANDUCIOTN + PERCEPTUAL ORGANIZATION ***So, stim can produce perceptual ambiguity based on this diffs --> *ILLUSIONS*: false or inaccurate perception that differs from the actual physical state of the perceived object +Imp b/c insight into normal perception, not b/c error +Here, discuss ones related to spatial perception *AMES ROOM* +People walking appear to change size +B/c of CONFLICTING ENVIRONMENTAL CUES -Tricked into normal rectangular room, but actually trapezoidal --I.e. windows resized -Floor uneven -Thus, changes relate btw people and env that we normally see --> since we have not seen this arrangement, perched constancy causes us to perceive [we are used to things looking a certain way to indicate certain distance --> altering that leads us to perceive diff distance?] -Persists (diminished) after leaving viewing point and moving thru room -B/c depth cues not apparent to viewer *Müller-Lyer Illusion* --> <--> looks shorter than >--<, but equal length +Why? --> Debated -First --> angles draw eyes into space or center -Doubted b/c study --> held head still, flashed parts to diff eyes, still thought one longer; SO, NOT MOVEMENT OF EYES ***Most likely = R.L. Gregory --> SIZE CONSTANCY +Angled lines are LINEAR PERSPECTIVE CUES -Inward, closer, smaller +Supported by eve that Müller-Lyer illusion weak or absent in culture with little exposure to angles +See figures in text *Moon Illusion* --> moon appears larger when low on horizon even though same image on retina +B/c of SIZE CONSTANCY (+HEIGHT ON A PLAIN??????????) -Moon appears farther away when lower b/c of visual cues for distance such as overlap and relative size not present when high overhead --So, underestimate distance -So, since moon same size low or high, seems larger when lower b/c seems farther when lower **********MOON ILLUSION?????????? --> SINCE RETINAL IMAGE SHOULD GROW SMALLER AS MOON MOVES TOWARD HORIZON (SINCE PERCEIVED AS MOVING FARTHER AWAY) BUT RETINAL IMAGE STAYS THE SAME, IT APPEARS LARGER B/C FOR IT TO PRODUCE SAME SIZE RETINAL IMAGE BUT BE FARTHER AWAY, MUST BE LARGER!!!!!!!!!! *Ponzo Illusion* --> covering lines rep distance; "farther" line appears longer b/c we perceive object that is farther away but in same visual angle as closer object as longer, but in reality they are same length *Poggendorff Illusion* --> lines appear to pass, but actually join +B/c of SHAPE CONSTANCY --> associate w/ something we have experienced that influences perception -I.e. overturned chair, never meet *Steroegrams* +B/c of BINOCULAR VISION and INHIBITION OF OCULAR CONVERGENCE INHIBT OF OC CONV -When convergence inhibited (proper convergence (often behind)) --> 3D +Sim to steroscope --> two 2D images from slightly diff perspectives to each eye; brain creates 3D BINOCULAR VISION -When eyes diverge and focus on point further, binocular disparity produces illusion of 3D

Audition Overview

*AUDITION*: act or sense of hearing *Views of deaf culture advocates on cochlear implants *Become deaf, often experience stress and isolation *Ears less info than eyes, but convey communication that is extremely imp to life ***All depends on frequency and amplitude

Intro

Humans and animals and diff species of animals have diff sensory worlds and perceive diff *This chapter +Sensory processes that bring info about env and neural activity that gives info meaning +Physiological and psychological +Sens and Percep infl beh --> beh limited by and defines organism's perceptual abilities

Spatial Perception

OVERVIEW *Vision --> rep spatial arrangement *Need to recognize objects from diff depths/distances and diff perspectives *Following answers how we see 3D (given 2D image on retina) and how we perceive depth/distance **********EXPLAINS 3D TOO?????????? DEPTH VS DISTANCE?????????? DEPTH DEPENDS ON PERCEPTUAL CUES *Binocular Cues*: visual cues for depth or distance, such as binocular disparity and convergence, that depend on both eyes working together +*Binocular (Retinal) Disparity: differnece in the retinal image of an object as seen from each eye, due to the difference in viewing angles, that provides an important binocular cue for depth -B/c eyes apart -Perhaps most accurate -I.e. alternately close eye --> shift -Normally, brain fuses two images from each eye into 3D; analyzes diffs to determine distance -Greater for closer objects b/c diff in angle of two eyes larger -Binocular disparity improessive; minimum is 1 micron -*Stereograms*: image that is able to convey the expereience of depth perception using binocular cues; 2D converts to 3D as eyes diverge and brain tricked --Slight diff in vertical reparations of pattern creates illusion of depth +*Convergence*: binocular distance cue based on the fact that the two eyes must converge or rotate toward the inside to perceive objects closer than about 25 feet (the closer the object, the more rotation is necessary, and the more muscle tension created) -So, muscular feedback from covering eyes imp cue for distance within 25 ft *Monocular Cues*: distance cues such as linear perspective and height on a plane that can be used with just one eye +*Height on a plane (elevation)*: important moocular depth cue based on fact that objects that are highest on one's plane of view appear to be farthest away -Farther, have to lift gaze more +*Overlap (interposition)*: important monocular distance cue based on fact at objects close to us tend to block out parts of objects that are father away +*Linear Perspective*: important monocular distance cue based on fact that parallel lines converge when stretched into distance +*Relative Size*: monocular distance cue based on fact that objects of the same size appear to be smaller the farther they are from the viewer -If already know how large +*Texture gradients*: monocular distance cue based on the fact that textured surfaces (such as a grassy lawn) appear to be smoother, denser, and less textured when they are far for the viewer than when they are close -Perceived change in texture of surfaces as they extend -Textured surface; elements closer seem farther apart or less dense **********ELEMENTS = PARTS OF TEXTURE?! +*Aerial (Atmospheric) Perspective*: monocular distance cue based on fact that distant objects tend to appear more fuzzy and less clear than those close to the viewer due to dust and haze -Can cause error in distance judgement, esp if accustomed to smog in urban -Farther away seems fuzzier b/c smog, dust, and haze reduce clarity as distance increases +*Relative Motion (Motion Parallax)*: monocular distance cue based on the fact that moving objects appear to move a greater distance when they are lost to the viewer than when they are faraway -I.e. moving car *Above assumes spatial perceptual cognitive processing necessary --> need spatial cues to draw on past experience and cognitive processing for spacial rep such a depth OPPOSITE TO THIS CONCEPT = NO COGNITIVE PROCESSING --> GIBSON *Gibson's Theory of Direct Perception*: theory of perception that argue that all information necessary for perception is available to the sensory system and no cognitive processing is necessary to complete the perceptual process +All visual info necessary for spatial representation availabel in environemnt +*Direct perception*: interpretation of sensory information directly by brain as opposed to perceptual interpretation resulting from cognitive processing; NOT COGNITION +Asserts *Invariants*: sensory info from env that is constant form one experience oto the next (for example, texture is invariant because it is always ifener at close distances than is at further distances) -Rep depth or distance w/o addition cogn -I.e. texture gradients; motion parallax +Not all agree -Ev for not just pick up spatial info but process -More research needed DEPTH PERCEPTION --> many enhance b experience, but AT LEAST SOME INNATE (in at least some species) *Visual Cliff*: device that produces the illusions of a cliff, allowing researchers to test the ability of animals to perceive and respond to depth cues +Eleanor Gibson and Richard Walk +Glass; half with checkerboard just under, half with checkerboard 3.5 feet below +Infants of many species that can walk immediately refused to cross, suggesting depth perception innate in these species +Ev that this based on motion parallax --> dominant cue for depth in most animals +HUMANS -Could not be tested until crawl (about 6 months) -Most would not spontaneously crawl to deep -But, some, esp. young, could be enticed to crawl -Contested --Some say learned before test ---Others say innate that emerges at about 6 months when need ***CONCLUSION --> INNATE IN MANY SPECIES OF ANIMALS; EITHER INNATE OR LEARNED VERY EARLY IN HUMANS *PERCEPTUAL CONSTANCY*: The fact that objects are normally perceived to be constant in size, color or brightness, and shape, despite the fact that their retinal images change according to different conditions +*Size Constancy*: one form of perceptual constancy, in which retinal image of an object becomes smaller as the object recedes into the distance (or larger as it approaches)-the viewer adjusts for this change and perceives the object to be constant in size -I.e. boat --> PERCEPTION ADJUSTS AUTOMATICALLY; man -A.H. Holway and Edwin Boring --> accurate judgements of circle size with more distance cues; as distance cues removed, perception relied more on size of retinal image (perceptions of size increased as closer) ***SO, APPARENT RETINAL SIZE IS IMP CUE FOR SIZE CONSTANCY!!!!!!!!!! *Brightness constancy*: element of perceptual constancy perceiving objects that wee see at night or in poor lighting to be the same brightness as they appear during the day + *Color Constancy*: element of perceptual constancy perceiving objects that we see in the dark to be the same color as they appear during the day even though their retinal images change ***Perceive these as same under diff illumination *Shape Constancy*: element of perceptual constancy perceiving objects as maintaining the same shape even though their retinal images change when we view them from different angles +I.e. door *SUMMARY +Percieve dynamic env as essentially table with constant stim props even though visual system receives constant change --> *FACTORS IN THIS* -OBJECT FAMILIARITY--> experience infl perception of obj as changes -Still, perceptual constancies early in human and other animals --> some may be innate

What Do We Perceive? What Influences Perception? Measure Sensation and Perception?

Why are we are of some sensations and not others? --> *Psychophysics* study of the relationship btw the physical aspects of external stimuli and our own perceptions of these stimuli; (CLASS) branch of psychology that deals with relations between stimulus magnitudes, stimulus differences, and corresponding sensory processes +Subsets (att, etc.) deal w/ infl on PERCEP (b/c sensation there even if we do not perceive it) +Psychological world simpler than physical because sense organs do not inform brain about all events that take place Physical World --> Psychological World Light --> Brightness Sound --> Volume Etc. MEASURE... Sensory *Thresholds*: minimum level of intensity or strength of a stimulus that is sufficient to activate a sensory process (for instance, the minimum number of molecules that must be present in the air for us to smell a substance) +So, one reason why only respond to some stimuli is limits of our senses +*Absolute threshold:* minimum physical intensity of a stimulus can be perceived by an observer 50 percent of the time **********IS ABSOLUTE THRESHOLD FOR SOUND PITCH OR LOUDNESS?????????? PITCH? -Measure by determining intensity when detect 50% of time -I.e. First notice but not sure **********Always not sure?????????? -Average --> diff from person to person and only for ideal lab conditions -Figure 4.1: Some Absolute Thresholds SIGHT --> Candle flame seen from a distance of 27 km (17 miles) TOUCH --> wing of bee falling on cheek from distance of 1 cm (0.39 inch) TASTE --> one teaspoon of sugar dissolved in 2 gallons of distilled water (1 part in 2000) SMELL --> one drop of perfume in a three-room house (1 part in 500,000) HEARING --> ticking of a watch in a room 6 meters (20 feet) away -ANtything but absolute jssince "momentary" threshold changes from moment to moment; Joseph Jastrow speculated that lapses of attention, slight fatigue, and other psychological changes could cause fluctuations in absolute thresholds ***But, not always true b/c of SDT! +*Subliminal threshold*L: stim below absolute threshold for conscious awareness ***SEE GRAPH of stim intensity vs % detect -I.e. brightness --> lumens +*Difference threshold*: minimum difference in intensity that we can distinguish btw two stimuli 50 percent of the time, aka just noticeable difference (jnd) -I.e. can now distinguish **********∆ or lowest noticeable? ∆ I think but am not sure?! -Why 50%? --> B/c perception of stim changes as stim intensity increases -So, experiments to test thresholds do several tests with diff intensities in random order and plot percent correct responses against tim intensity; above 50% is better than chance; below 50% is poorer than chance performance -*Weber's Law*: one of major principles of sensation, based on fact that for various stimulus intensities, the difference threshold tends to be a constant fraction of the stimulus - as the strength of the original stimulus increases, magnitude of change must also increase in order for a just noticeable difference to be perceived; jnd by minimum constant %, NOT amount --I.e. light, 8%; weight; tone --BUT, NOT ALWAYS TRUE B/C OF SDT --SEE GRAPH IN NOTES --PERCEPTION of stim alway relative to background level or its context (intensity, etc.) --Weber's experiment --> found ind always constant fraction of original stim intensity --∆I = kI wehre ∆I is change in stim intensity necessary for ind, I is initial stim intensity, and k is Weber's constant --Weber's constant is ratio of stimulus intensity for a ind (∆I/I = k) --> same for each dimension of sensation (diff I/intensity) but change for diff stimulus dimensions (diff stimuli) --K = deltaI/I ---I.e. light --> 8%; weight; to *Attention*: psychological seletion mechanism that determines which stimuli an organism responds to or perceives +Not aware of all stimuli even though we are biologically capable of responding to them --> attention does not block psychical and biological response but rather increase or decreases psychological PERCEPTION of these events +Some stimuli catch attention more/interfere (i.e. name); chars later *Sensory Adaption*: in PERCEPTION, the decrease in the response of sensory receptors to stimuli when exposed to continual, unchanging stimulation +I.e. forget about clothes +Very imp; some people w/ schizophrenia/autism don't have it, and it can be problematic +Some quicker than others (i.e smell first), but all (including sight) -Visual adaption much more difficult to detect b/c *saccadic movements*: rapid scanning movements of the eye (rapidly chaining location of stimulus within the eye) +PERCEPTION DEPENDENT ON STIMULUS CHANGE +I.e. hands in lukewarm water +Pain sadapts slowly and usually only to slight degree; may adapt to mild pain but may never adapt to extremely painful stimuli -I.e. hot water experiment Other variables influencing what we do or do not PERCEIVE --> *Signal Detection Theory*: theory that says our ability to detect a sensory stimulus (signal) depends not only on the intensity of the signal but also on varibeles such as distractions and motivation; (CLASS) predicts how and when we detect presence of faint stim (singal) amid background nosise (other stim) [not just siganl but other factors --> deals w/ other factors] *Assumes no absolute threshold *Says deteciton deps on many factors such as... +Fatigue +Intensity +Expectations +Experience/learning +Psycholgical state +NOise and distratcitng factors ***Response criterion --> ROC (see below) +Etc. *Started as attempt to set how people distinguish target stimuli from background of random noise **Noise*: any kind of distracting and irrelevant stimuli +Stronger, harder to detect +Internal: ongoing, variable, random firings of neurons -Sens inputs occur against variable background, level of which affects ability to detect signal +Extneral: other distracting factors in the outside evironment +Other --> expectations about when or where stimuli might occur; *Response Criterion*: particular criterion you set for how sure you must be before reporting a signal has been detected --> significant role in PERCEPTION -I.e. VW Bug Game -Receiver Operating Characteristic (ROC) Curve --> See Fibure 4-4; probability of hit and false alarm on each axis --4 otpoins: false alarm; correct rejection; hits; misses --Below diagonal = stim intensities below threshold; above diagonal = stim intensities above threshold --A = no penalties for false alarms; perception quite good --B = penalties for false alarms and extra incentive change perception --C= below threshold (undetectable) --*Response bias*: inoculation or tendency to respond in a certain way ---I.e. Scud missiles *SDT says no absolute threshold b/c stimulus reps not only on stim strength but also on noise and spcyolgica variable such as expectation and response bias *Demonstrates that detecting and resounding to sit more compelex than phsycial energy --> sensory process *Applications --> techs for sens det = breaks, exercise, "real targets," performance in form of feedback ***This deals with principles of all senses; now, unique props of each

Auditory Localization

*Ability to Locate Origins of Sounds by Differences fro ear to ear in variables such as intensity (since large object like human head does not transmit high-frequency sounds as well, so sound shadow b/c sound wave lessens in intensity by time it goes around he'd to other ear) and time the sound arrives at each ear (give that sound waves travel at relatively slow rate of bout 1,100 ft/sec in air) *Brain Structs Key to Spatial Loc of Sound = Occipital Lobe and Parietal Lobe* +Ev --> magnetic stimulation as "virtual lesions" +Righ occipital cotex rereceivs sound info before parietal lobe -When right occipital inhibited 50 sec after sound, aud loc disrupted; similar, but delayed by fifty sec, inhibiting par lobe disrupts aud loc ***So, 50 msec dealy in processing by parietal lobe seems essential to normal sound loc **********2 x 50 msec??????????

Synesthesia

*CONDITION IN WHICH ONE TYPE OF SENSORY STIMULATION EVOKES THE SENSATION OF ANOTHER AS WHEN, FOR EXAMPLE, HEARING A SOUND PRODUCES VISUALIZATION OF A COLOR* **********Particular stim ALWAYS to particular sensation (i.e certain color for certain note ALWAYS)?????????? +Sensations in one mode cause perceptions in other +Long known (Francis Galton 1880) +Believed cause is cross wring between cortical brain centers for sensory processing -I.e. colors and numbers --> black numbers activate both color and number (unusual; test) +In families, so possibly genetic +About 50 distinct types +1:200 people +For some, stim with strong emotion more likely to cause synesthetic experience

Dark and Light Adaptation

*Dark Adaptation*: Process by which an organism's vision gradually becomes more sensitive to minimal levels of light due to a chemical change in the rods and cones of the retina +Rods --> 30 mins (more extensive +Cones --> 10 mins +In poor lighting, eye most responsive to 550-650 nm range, which corresponds to yellow-green +Apps: avoid exposure to white light, use red to enhance night vision: night vision goggles capture light and intensify it with special power, transit light to phot cathode screen, which illuminates phosphorescent screen monochrome green by emitting electrons *Light Adaptation*: processs by which an organism's vision adjusts to bright lighting, due to a chemical change within the rods and cones of the retina +Much faster, but brief light after dark-adapted does not reverse process entirely

Neural Processing of Vision (Step 4)

*Lateral Geniculate Nucleus*: region in thalamus where optic nerve hits thalamus; information from two optic nerves of two eyes converge here (HOW?????????? [Figure 4-9] +Two LGN combine info from left and right hemispheres before sending to cortex +Thalamus = relay station *Sent to visual cortex in right and left Hemispheres; how does brain translate neural signals into vision? +David Hubel and Thorsten Wiesel --> expm with electrods in vis costs of cats; diff cortical cells respond to specific stimuli (size, shape, or movement) --> *Feature detectors*: specialize nerve cells in brain that respond to specific features of stimulus such as shape, angle, movement, dot, edge, contour, shape +How does brain integrate all these signals into one image? -"Dot-Detection"?????????? --Visual info enters as dots, edges, countours, movement, and shapes --Brain analyzes pattern -*Lateral Inhibition(?)*: inhibietory interaction btw neighboring areas of retina that enhances perception of particular patterns and shpaes and counters and edges by heightening ctonrast btw light and dark borders --I.e. Mach bands -Parallele Processing??????????

Structure and Function of the Eye (Steps 1-3)

*MUST See and Memorize Diagram of Eye!!!!!!!!!!* **********MUST know extra structures? Cornea Pupil Acqueous Humor Iris Lens Ciliary Body Vitreous Humor Blood Vessels Sclera Choroid Retina -Pigment Epithelium -Rod -Cone -Amacrine Cell -Bipolar Cell -Ganglion Cell -Horizontal Cell -Retinal Surface -Fovea Optic Disk (Blind Spot) Optic Nerve Optic Chiasm *Eye receives light stimulus *Two main components --> Image-Focusing (Main = cornea, lens, iris, and pupil) and Image-Recording/Retina *IMAGE FOCUSING* 1. Light passes thru cornea: thin, transparent membrane that bends or reflacts light waves to bring them into sharper focus on retina 2. Light passes thru aqueous humor: water fluid that nourishes cornea 3. Light passes thru pupil: small opening in iris: pigmented set of muscles that constrict or expand to dilate or constrict pupil to control amount of light that can enter +Iris pigment dets eye color (high = brown, low = blue) 4. Light enters lens: oblaong elastic structure that further reacts and focuses light be a into an image projected onto retina +*Accomodation*: in vision, the focusing process sin which lens adjust its shape, depending on distance btw eye and object viewed, in order to project a clear image consistently onto retina -Flatten or round -Grow old, lens grows rigid, less accommadation, sight probs -Abnormal functioning of lens leads to... --Nearsighted: see distinctly only for short distance --Farsighted: see distant objects find but cannot see near objects in focus 5. Light passes thru vitreous humor: clear fluid supplying nutrients to interior of eye 6. Light hits retina *IMAGE-RECORDING = Retina: thin membrane at back of eye containing photoreceptors called rods and cones, which functions to record images **********INCLUDES ALL LAYERS?????????? ***NOTE LIGHT MOVES TO BACK FIRST, THEN INFO TRANSFERRED TO SURFACE AND TO BRAIN! 1. Light passes thru several layers of neurons to primary photoreceptor cells --> rods and cones +*Pigment epithelium*: backlist part of eye with pigment to absorb (or reflect) light not absorbed by receptor cells -Dark in humans to not distort vision -But, night animals rely on SENSITIVITY (ability to detect light) over ACUITY (ability to focus light finely), so have light pigment epithelium that reflects light to be absorbed on second pass -Light reflected by it can be seen (due to more light than can be absorbed by eye in humans) --> i.e. deer in headlights, red eye +20 rods to 1 cone +Rods: photoreceptor cells distributed across inner layer of retina that are important in peripheral vision and seeing in dim light -So, sailing at dusk --> look to right/side +*Cones*: photoreceptor cells distributed across inner layer of retina that play an important role in perception of color +Each distributed in orderly fahion on membrane --> most cones in center in *fovea*; rods concentrated around edges of fovea and elsewhere (no rod sin fovea and relatively few cones outside of fovea -So, focus image on fovea -Cones less sensitive than rods, so no color in dark -Rods extremely sensitive, so allow us to see in dim light -Peripheral vision relies on rods +Contain *Photopigments*: respond to light; CHEMICAL RESPONSE TRANSDUCES LIGHT ENERGY TO NEURAL IMPULSE 2. Neural signal passed to *bipolar cells* (type of neuron?) 3. Passed to *gaglion cells* (type of neuron?); axons of ganglion cells travel across inner SURFACE (??????????) of retina and converge to form *optic nerve*: transmits visual messages to brain *Optic Disk*: spot where optic nerve exits eye +BLIND SPOT b/c no photoreceptor cells +Usually don't notice b/c eyes constantly moving and b/c image in blind spot of one eye focused by other eye *Horizontal Cells* and *Amacrine Cells*: transmit signals laterally across retina, allowing interactions btw adjacent photoreceptor, bipolar, and ganglion cells; do NOT transmit visual info to brain --> LATERAL INHIBITION - enhances perception of images by turning off neighboring photoreceptors

Vision Overview

*Most imp sense +Awareness of surrounding env +Change location and actions +Deprivation of vision --> adjustment difficult +***Greater portion of brains devoted to vision than any other sense *4 Steps 1. Light gathered into Eye 2. Light channeled to back 3. Neural cicrucits transmit signals from eey to brain --> Transduction 4. Visual centers in brain interp those messages *3 Parts ***Eyes: capture and respond to light en ***Neural circuits: transmit signals from eye to brain ***Visual centers: interp messages in brain *PHASES* 1. All outside 2. Focusing ****DIAGRAM**** ***NEED spot b/c / WHY blind spot is b/c need spot for optic nerve, but no rods and cones there +oNLY COMES INTO PLAY IF STARE AT DOT (LIKE SPLIT BRAIN) ***Saccadic momenten 3. Transucitn ****DIAGRAM**** +In retina (Rods/Cones --> Bipolar --> Ganglion --> Optic Nerve --Optic chiasm--> LGN in thal --> cerebral cotexes [visual cortex in occipital] 4. Brain (visual cortex) +*FEATURE DETECTORS* -- diff ones process idff aspects of vision -IN vic dort -Bottom-up -Scanning -Fidd for lines, motion, curves -MUST know scientists who discovered this!!!!!!!!!!! --> David Hubel and thorsten Wiesel -Then, assoc areas do naming/interpreting (top-down) +****PARALLEL PROCESSING**** --> features processed/brought together AT THE SAME TIME!

Perceptual Organization

*Perceptual Organization*: process by which we structure elementary sensations (such as the sight of lines, brightness, and points) into the objects we perceive *Key = Gestalt: PERCEPTION OF PATTERNS MORE THAN SUM OF SENSATIONS +Max Wertheimer, Kurt Koffka, and Wolfgang Köhler +*Gestalts*: whole patterns that are influenced by principles determining how people organize sensations PRINCIPLES OF PERCEPTUAL ORGANIZATION Figure-Ground *Figure*: in perception, the part of an image on which we focus our attention *Ground*: in perception, background against which the figure that we focus on stands ***AMBIGUOUS --> depends on which you choose ***SO, SENSATION ALWAYS SAME, BUT PERCEPTION VARIES ***Applies to all senses, not just vision (i.e. music) ***ONE MUST BE FIGURE, ONE MUST BE GROUND; CAN'T FOCUS ON BOTH *Perceptual Grouping*: Tendency to organize patterns of stimuli into larger units according to proximity, similarity, and good continuation +*Proximity*: perceptual grouping principle whereby, all else being equal, we tend to organize perceptions by grouping elements that are the nearest to each other +*Similarity*: in perception, the principle that we tend to group elements that are similar to each other +*Good Continuation*: perceptual grouping principle that we are more likely to perceive stimuli as a whole or single group if they flow smoothly into one another than if they are discontinuous +*Closure*: perceptual organizing principle that we tend to perceive incomplete figures as complete -I.e. not present triangle

Perceptual Sets

*Perceptual Set*: Tendency to see, ehar, smell, fell, or taste what we expect or what is consistent with our preconceived notions **********BIOPSYCHOSOCIAL APPROACH?????????? +Subjective influences on perception +i.e. see figure in text; PERCEPTION (of drawings) DEPENDS ON PREVIOUS EXPERIENCE + One key = MOTIVATION --> impact on perception by establishing perceptual sets -I.e. hungry, misread signs +Key type = *SELECTIVE PERCEPTION*: a form of perceptual set; the tendency to perceive stimuli that are consistent with exception and to ignore those that are inconsistent **********SAME AS CONFIRMATION BIAS??????????? -IF BELEIVE, THINK THAT -INFL BEH

Theories of Audition (of Pitch Discrimination [ONLY??????????])

*Place Theory of Pitch Dicrimination*: theory that we discriminate different pitches because sound waves of different frequencies displace different regions on cochlea's basilar membrane +Georg von Békésky +Diff hairs vibrate in cochlea when sense diff pitches --> same vibrate at high pitches, some at low +Ev --> exams with guineag pigs; diff pitch, diff regions of basilar membrane with greatest response +High pitch, close to oval window; intermediate is farther along +Prob --> does not explain how we discriminate tonal differences btw tones that/with frequencies that differ very slightly since these produce almost identical displacement in basilar membrane +Prob --> Displacment of basilar membrane by tones below 4,000 Hz indistinguishable, so below 4,000 HZ, Place theory doesn't hod --> Solution = frequency theory *Frequency Theory of Pitch Discrimination*: theory that perception of low tones depends on frequency with which auditory hair cells in inner ear's Organ of Corti tigger firing of neurons in the auditioory nerve +**********Hairs in our ear vibrate at diff rates = diff pitches?????????? +All hairs vibrate but at diff speeds +Low frequency perception det'd by frequency of nerve impulies traveling up auditory nerve +Ev shows fibers in auditory nerve do fire in rhytmym with low-frequency tones (i.e. 262 and 262) +PROB --> singly auditory neurons can only fire up to 1,000 times per second, but place fails below 4,000 Hz, so what about 1,000 to 4,000 Hz) --> SOLUTION = *Volley Theory*: related to frequency theory of pitch discrimintation , which postulates that since single audityory neurons cannot fire rapidly enough to enable us to perceive tones in 1,000 to 4,000 HZ range, pitch perception is made p[ossible by groups of interrelated neurons firing in concert (in a staggered fashion) -If neural messages appropriately integrated *Summ: Combo --> PItch deps on Place and Frequency* +Place explains above 4,000 HZ +Frequeency with volley principle explains lower (below 4,000 Hz) frequencies ***MECURE EFFECT OVERRIDES VISUAL CAPTURE!!!!!!!!!! ***From GOOGLE --> *Sensory interaction* refers to the interaction of the senses to each other and how they influence each other +*McGurk Effect: ***FROM WIKIPEDIA --> The McGurk effect is a perceptual phenomenon that demonstrates an interaction between hearing and vision in speech perception. The illusion occurs when the auditory component of one sound is paired with the visual component of another sound, leading to the perception of a third sound.

Attention and Perception

*Selective Attention*: the process of focusing on one or a few timely of particular significance while ignoring others ***Attention key to detection +Percep change moment to moment -I.e. Necker Cube ***COCKTAIL PARTY EFFECT = form of selective attention +Sounds, for SDT, are noise, so external +Like sense mem --> almost inverting coming in, but have to pay attention to notice/STM/prefonrtal cortex/conscious awareness +We never attend equally to all stim; some focused, others fade into background +ENHANCES perception (b/c otherwise overload) +*Inattentional blindness*: the failure to see one aspect of a visual scene due to selective attention to another aspect of the scene -I.e. gorilla; magicians -Many other eps with salient stimuli *We control attention to some extent CHARS OF STIMULI THAT CAPTURE ATTENTION ALMOST AUTOMATICALLY *Complex Stimuli* +Difficult to process pull attention +More complex requires more effort to comprehend +*Inverse hypothesis*: more we focus on one category of stim, less we can respond to others; related to selective attention: more complex stim, less attention we can focus on any particular aspect of it **********INVERSE HYPOTHESIS?????????? DIFFICULT TO COMPREHEND PULL ATTENTION OR LESS ATTENTION TO FOCUS ON ANY PARTICULAR ASPECT OF MORE COMPLEX STIMULI?????????? ANY PARTICULAR ASPECT WHILE FOCUSING ON ANOTHER?????????? *Sudden Change* +CAPTURES attention +Quantity or quality or background +B/c main char of sensory is respond to change *Contrast and Novelty* +CAPTURES attention *Stimulus Intensithy* +VARY intensity CAPTURES attention (sudden increase or decrease) +I.e. tv adds; whisper *Repetition* +CAPTURES attention *Sign Stimuli*: stimuli that naturally elicit a change in motivational state and behavior +Fear, hunger, or sexual +Evolution +More imp in lower animals, but humans too +I.e. yawning

Chapter Summ

*Sensation --> physical env transduced to neural activity; neural activity interpreted as vision, auction, gustation, olfaction, or skin sense (or body sense?) *Perceptoin --> brain organizes info into reps of env w/ perched org +Exs +How conflicting processes lead to illusions (i.e. shape constancy and distance cues??????????) ***EXPEREINCES INLFUENCY ORGANIZATIONAL PROCESSES OF PERCEPTION, BUT MUCH OF PERCEPTUAL ORGANIZATION APPEARS TO BE INNATE OR DEFINED VERY EARLY IN DEVELOPMENT!!!!!!!!!!

Principles of Sensation and Perception

*Stimulus*: some type of physical energy such as a sound or a flash of light, to which we can respond +Produce physical change in sensory receptor cells, which transmit info to brain, which interprets info *Sensation*: basic, immediate experiences that a stimulus such as a sound elects in a sense organ such as the ear; physcial experiences of stimuli +Window to world +Realtively same for everyone +Everyone ahs same abs threholsd according to Weber (biut, motiv etc, do matter, response criterion = consequences; so not always true as SDT says) +5 Major Senses: vision --> photoreceptor, photons, visible light +hearing--> organ of corti (hari cells), vibratoins +smell--> +chemoreceptor, chemical concentration; smel +taste --> chemoreceptor; chemical concentratoin; taste +Touch/the skin senses (pressure, temperature, and pain) --> mechanoreceptor; mechanical distortion; touch; ***sensory adaptation +OTHER RECEPTORS -Thermoreceptors - temp; warm, cold -Nociceptor -noxious; pain -Propioreceptor - body posiotn; muscle tone - joint positon, tendon force (kinesthesis) +Also, so called body senses to detect moment and position of body -Kinesthesis: sense of poison and movement of parts of body via position and emotion sensors all over body --Whicy part of brain? -Vestibular sense: sense of body movement and position, including sense of balance; monitors head's poison and movement --Gyroscopes in inner ear (semicircular canals and vestibular sacs) +*Bottom-up processing*: analysis that begins with sense receptors and works up to brain's integration of sensory information --Aka feature analysis --> use features of object itself to form perception/understanding of sensation ---Exs: light; distinguishing chari from stool; leters --Detectin via receptor cells --Transduction --Info senses --> thalamus (except smell) --> areas of brain --Infl by context --Transmission to brain *Perception*: process of interpreting, organizing, and often elaborating on sensations; psychological interpretations of those stimuli +Diff for people +Conf bias, etc. +Everything +Top-down processing: information processing guided by our experience and expectations --Experience, motivation, and expsections --Organization and interpretation --> behaviro, thoughts, and emotions +I.e. scrambled words --Perceive by filling gaps in what we sense --Based on own experiences and schemas --Focus of Gestalt Psych; PERCEPTOIN MORE THAN SUM OF PARTS --INFO PROCESSING GUIDED BY HIGHER LEVEL MENTAL PROCESSES AS WE CONSTRUCT PERCETPTIONS OBASD ON (PAST) experiences and schemas --HUge variety --Huge impact on resulting emotions/behaviors --Expectatoins influence perception (priming) +Gestalt's First (Greatest) Principle --> figure gound: first perception dets what we see as figure and what we see as background -Deps on attention -Figure-ground: figure is to what we pay atteniton; backgournd is what we don't pay attention to -First perceptual deciosn in regard to something is what we sese as figure and what we see as background +Gestalt Psych focused on how we GROUP objects together +Innately look at objects in groups, not isolated +Principles --> *PROXIMITY; SIMILARITY; CONTINUITY; CLOSURE (LIKE TOP DOWN PROCESSING; FILL IN GAPS IF RECOGNIZE)* +Selective Attention --> percepts about objs change from moment to moment; Necker cube; diff forms available to attention, but only can pay attention to one at time *Transduction*: process by which sensory organs transform mechanical (hearing and skin), chemical (smelling and tasting), or light (seeing) energy into electrochemical energy that is generated by neurons firing ***BRAIN CAN ONLY RESPOND TO ELECTROCHEMICAL EVENTS OF NEURONS, NOT PHYSICAL ENERGY, SO NEED THIS +Receptors change shape, initiation series that culminates in neural transmission to brain -I.e. photopigments in eyes +Sight = photoreceptors (rods and cones) to bipolar to ganglion cells +EAr = organ of corti hari cells *Distinguishing types based not on diffs in sense organs but on part of brain activated by sensory messages; brain distinguishes btw impulse types based on various cortexes (which it goes to and which does processing) +going to wrong area causes SYNESTHESIA +Ev --> synesthesia and brain surgery/stim SENS = stim en --> sens receptors --TRANSDUCTION-->Neural impulses --> PERCEP = Brain (vsual, auditory, ofactory areas) ***Ulstimately about asociotns +Tones key to perception BRAIN (clockwise) Frontal Lobe --> coords info from other areas and controls some beh +Prefrontal Cortex +Primary motor cortex --> skeletal muscle control +Motor assoc area (premotor cortex) Parietal Lobe --> ***Sensations; snesoryi infor rom skin, musculoskeletal system, viscera, and taste buds +Primary somatosensory cortex +Sensory association areas Occipital Lobe --> vision +Visual assoc area +Visual cortex Temporal aLobe --> Hearing; ***NOT LATERALIZED b/c so turn to correct side and aud loc Olfactory Cortex --> Smell Gustatory Cortex --> Taste ***Cortex --> break down; mechanics (put together) -I.e. visual cotex --> feature detectors cobmbine line and shapes ***Assoc --> interp and decide what it is; what assoc you've learned; PERCEPTIONS; learning +i.e. visual assoc --> call obj by name

Body Senses

*TERM USED TO DESCRIBE TWO INTERRELATED SENSORRY STYSTEMS OF KNESTHESIS AND EQUILIBRIUM* *Work together *Orientation of body in space, relative poison of body parts, and movement of any parts of body *Tasks not with others *Kinesthesis*: bodily sense that provides information about PERCEPTIONS of the location of various BODY PARTS in relation to other parts and bout the position of the body ins space +Thruout entire body +Special nerve endings in muscles, tendons, and joints that tell brain whether muscles stretched, contracted or relaxed +Cortex translates this into PERCEPTIONS about lots of body parts in relation to other parts +I.e. throw ball or stumble *Equilibrium*: sense of balance (POSITION OF HEAD; INNER EAR), localized within inner ear and domprising two sensory receptors: +*Semicircular canals*: three ring-shaped structures in inner ear (near cochlea) that provide info about body's equilibrium or balance ***MUST KNOW DIAGRAM! -Right angles to each other; all 3 dimensions of space -Endolymph fluid that fills them moves when head rotated -Bends hair cell; movement transduce to neural messages, telling if brain accelerating or deccelerating -Constant velocity, no motion detected -Viscosity changed by alcohol --> "spin" +*Vestibular sacs*: structure at junction of semicircular canals and cochlea of middle ear that provide info abobut head's position in space -Contain hair cells weighted with crystals of calcium carbonate -Tilt in head, graivity shifts cilia, triggering adjacent neurons -Works IN CONUCTION WITH SEMICIRCULAR CANALS to produce motion sickness --> caused by unusual vestibular stim when vestibular motion info does not match visual **********ALWAYS WORK TOGETHER OR JUST FOR THIS?????????? **********EQUILIBRIUM = VESTIBULAR SENSE?????????? **********VESTIB SENSE VS KINESTHESIS??????????

Biopsychosocial Approach to Sensation and Perception

*To TOUCH* Top-down influence on touch is illustrated by fact that a self-produced tickle produces less activation in the somatosensory cortex BIOPSYCHOSOCIAL FOR PAIN *GATE CONTROL THEORY OF PAIN*: -->ESP THAT PAIN IS SENSORY AND PERCEPTUAL PHENOMENON (SEE BIOPSYCHOSOCIAL) *Ind diffs in perceiving pain = social influence on pain *Pain not merely physical, as proposed by Renes Descartes; pain created by brain *Perceptual Set*: Tendency to see, ehar, smell, fell, or taste what we expect or what is consistent with our preconceived notions **********BIOPSYCHOSOCIAL APPROACH?????????? +Subjective influences on perception +i.e. see figure in text; PERCEPTION (of drawings) DEPENDS ON PREVIOUS EXPERIENCE + One key = MOTIVATION --> impact on perception by establishing perceptual sets -I.e. hungry, misread signs +Key type = *SELECTIVE PERCEPTION*: a form of perceptual set; the tendency to perceive stimuli that are consistent with exception and to ignore those that are inconsistent **********SAME AS CONFIRMATION BIAS??????????? -IF BELEIVE, THINK THAT -INFL BEH

Stimulus of Vision

LIGHT *We see b/c objects reflect light *Almost all matter made of charged, oscillating light that elicit many types of electromagnetic radian: type of radiation that travels in waves; including but not limited to light +*Wavelength*: how far radiation travels btw oscillations -Usually measured in nanometers *Electromagnetic Spectrrum +Visible light is only about 400-750 nm of spectrum +Not all orgs blind outside to other segments of spectrum ****VISUAL CAPTURE****: our most dominating sense; people rely most ehavlity on visual info, and visual dominates (over others) in a scene +i.e. ventriloquist *Props +*Brightness*: INTENSITY of light, measured by the number of photons or particles of electromagnetic radiation emitted by a light source -More intense light source, more photons, brighter light, HIGHER AMPLITUDE **********Brightness deps on # of photons, amplitude, but basically comes down to amplitude +*Hue*: COLOR PERCEIVED; color we PERCEIVE, determined partly by wavelength of light and partly by complex process by which an organism's visual system mixes wavelengths -I.e. purple and white +*Saturation*: proportion of colored or chromatic light to non-colored or non chromatic light, which determines how HOW COLORFUL LIGHT APPEARS -White = colorless; more white, less saturated

Hearing Loss

OVERVIEW *Most common *Many causes, but two types *Sensorineural Hearing Loss*: hearing loss caused by damage to either hair cellos inner ear or auditory nerve, which can be caused by a loud noise +Key ex --> *prebycusis*: gradual loss of sensitivity to high frequencies that occurs with aging -Ev --> high-frequency deafness begins surprisingly early -May be due at least in part to lessening of blood flow to inner ear, destroying some critical neural elements +Can be caused by permanent damage to sensitive inner ear structs due to excessively loud noise -Such loud noise often along with *tinnitus*: continuous ringing in ears -MAY ACCUMULATE --> steady loss -But, brief exposure to extremely loud sounds can do similar damage -I.e. rock concerts --> May have ringing in ears and may not notice b/c damage often minimal, but cumulative -Listening to loud music while young can permanently damage hair cells *Conduction Hearing Loss*: hearing loss caused by failure of outer and middle ear to conduct sound energy to the inner ear's receptors, sometimes because of an infection or buildup of earwax +Problem with sound and vibration on way to cochlea (NOT damage in cochlea) +Earwax easy to remedy +Ear infection can buildup so much pressure that eardrum ruptrues, impairing hearing _in children, ear infections cause increase in pressure because Eustachian tube not fully developed --> small tubes relieve +Common --> *ostoclerosis*: disease in which spongy substance around bad of stapes hardens -Replacing stapes with plastic sub can surgically repair -Often in young adults ***Conduction does not produce total deafness as often severe sensorineural does --> conduction **********easier to treat??????????? +B/c sound can be transmitted riectly thru bones of skull to inner ear -I.e. why recording of self sounds different +Hearing aids that amplify sound transition by bone conduction can reduce conduction hearing loss

Color Vision

OVERVIEW *Primates only mammals that see color *Dogs no, but maybe a little *Simpler animals yes for some *Overview of Color* *COLOR IS PSYCHOLOGICAL PHENOMENON OF BRAINS PERCEIVING LIGHT; COLOR NOT INHERIENT IN OBJECTS BUT RATHER IN LIGHT THEY REFLECT *PERCEPTOIN OF DIFF COLORS DEPS ON WHICH WAVELENGHTS ABSORBED AND REFLECTED --> COMBO OF WLS ALLOWS FOR MANY COLORS?????????? *Primary colors of pigments are red, blue and yellow; BUT PRIMARY COLORS OF LIGHT ARE RGB *So, humans able to see many colors formed from combo of 4 hues and two hueless colors **********So, ROYGBIV (primary red, yellow, and blue) for ink, RGB for light and vision!!!!!!!!!! *Subtractive Color Mixing*: color mixing process that occurs when pigments are mixed, so that when light falls on the colored object some wavlenghts are absorbed (or subtracted) and others are reflected +PIGMENTS (mix of): absorb, now reflection +Wavelength of light reflected gets hue we see, and some wls reflected and some absorbed +Takes place in object +Primary for this --> Red, yellow, blue *Additive Color Mixing*: color mixing that occurs when light s of different was simultaneously stimulate the retina, so that color perception depends on the adding or combining of these wavelengths +LIGHT (mix of); stim photoreceptors diff +Takes place in visual system +Primary for this --> RGB +I.e. TV = RGB monitors **********SO, HUMANS SEE IN *4 BASIC HUES* RED, YELLOW, BLUE, GREEN + *2 HUELESS COLORS* BLACK, WHITE THEORIES *Young-Hemholtz Thory (Trichromatic Theory of Color Vision)*: postulation that human eye contains three type so color receptors (for red, green, and blue) which form basis for our perception of all colors +Says brain perceives color from combining info from all three types +Supported b/c three types of cones with 3 diff photopigments found ---> respond best to 435, 540, and 565 nm (blue, green, and yellow-green [but still called blue S, green M, and red L by convention}), but respond some to others, and diff wls stim multiple, explaining how mixing colors of diff wls allows us to see many colors?!!!!!!!!!! +But, does not explain pair colorblindness or negative afterimages *Opponent-Process Theory of Color Vision*: theory that explains color vision based on six primary colors, which are grouped into three pairs;: red-green, blue-hello, black -white (receptors in eye are sensitive to specific pairs, and presence of one member of pair inhibits perception of other) +Inhibition explains why we never see i.e. bluish yellow +Explains color-blindness b/c pairs (red-green most common) +Explains negative afterimages: staring at image and then at white and seeing complements -One color receptor becomes fatigues, white light stims color pari equally, but overloaded component fatigued and only responds minimally, producing imbalance that leads to afterimage (in which you see color in pair) **********W/in one type of cone?????????? *Believe Combo* *Trichromatic at level of photoreceptors *Opponent-process at ganglion in retina, LGN, and opponent manor of red-green and blue-yellow in visual cortex (shown by fMRI) --> on neural path from photoreceptor cells to visual cortex

Sound: the Stimulus for Audition

SOUND = CHANGE IN AIR PRESSURE *Sound-producing objects vibrate, producing motion and rhythmic pressure changes in air *Alternately compresses and rarefies are *Travels in longitudinal waves *Compression and rarefaction bends eardrum in and out *Vibrations of eardrum thus act as first step in transducing sound energy to neural signals that carry auditory messages to brain *Props* *Loudness*: in hearing, intensity of a sound as measured by decibels (exponential, not linear unit [i.e. 30 db = 1,000 x 1 db]), which is determined by the amplitude of a sound wave +90 db = risk of hearing loss with prolonged exposure +130 db = threshold of pain *Pitch*: dimension of hearing that determines how high or low a sound is, measured in hertz,(Hz), which is determined by the frequency of a sound wave +High frequency, high pitch, shriller sound; low freq, low pitch, deep sound +Humans: range of 20 to 20,000 Hz; most sensitive from 100-3,500 Hz (human speech falls here) +Ranges diff for diff animals -Dogs and dolphins higher, birds rely on low for navigation ***Absolute threshold refers to smallest level of tone that can be detected by moral hearing when no other interfering sound present +I.e. levels that participants can detect ticking of clock ++Young children have lower absolute thresh b/c lowest and highest ranges ten to decrease with age +Quitetiest sound that childeren with normal hearing can detect is around 1,000 H **********Is absolute threshold for sound for pitch or loudness?????????? DISTINGUISHING DIFF SOUNDS OF SAME PITCH --> *Timbre*: quality of complex sound that is product of the combination of fundamental frequency and additional frequency components called overtones +B/c instruments don't produce pure tones, timbre allows us to distinguish bt same notes on diff instruments +Very few sounds are pure tones +Additional overtones alter wave (i.e. less uniform)??????????