Textbook Notes (368,356)
Canada (161,820)
Psychology (4,892)
Psychology 1000 (1,620)
Dr.Mike (707)
Chapter 5-8

Chapter 5-8 Notes.docx

23 Pages
155 Views
Unlock Document

Department
Psychology
Course
Psychology 1000
Professor
Dr.Mike
Semester
Fall

Description
Chapter 5 Reading Notes 10/26/2011 6:36:00 AM  Synesthesia: ‘mixing of the senses’  may experience sound as colors or tastes and touch sensations o Women more likely to be synaesthetes than men  Sensory receptors must translate stimuli information into nerve impulses for body to understand  process of transduction  Special neurons called feature detectors break down and analyze specific features of stimuli  Binding problem: how do we bind all of our perceptions into one complete whole while keeping its sensory elements separate?  Sensation: stimulus-detecting process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to brain  Perception: making ‘sense’ of what our senses tell us  active process od organizing stimulus input and giving it meaning  Transduction: process whereby characteristics of a stimulus are converted into nerve impulses  Psychophysics: studies relation between physical characteristics of stimuli and sensory capabilities o Absolute limit of sensitivity (ex: what’s the softest sound or weakest salt solution tat humans can detect?) o Differences between stimuli (ex: what is the smallest difference in brightness we can detect?)   Stimuli Detection: The Absolute Threshold  Absolute threshold: lowest intensity at which a stimulus can be detected correctly 50% of the time o The lower the absolute threshold, the greater the sensitivity o No fixed absolute threshold, instead there is a range o Decision criterion: a standard of how certain a person must be that a stimulus is present before they can say they detect it  Can change depending on fatigue, expectation and potential significance of stimulus o Signal Detection Theory: concerned with factors that influence sensory judgments  The Difference Threshold  Difference Threshold: the small difference between two stimuli that people can perceive 50% of the time  also called JND (just noticeable difference)  Weber’s Law: the difference threshold, or JND, directly proportional to the magnitude of the stimulus with which the comparison is being made o Can be expressed as a Weber fraction  the smaller the fraction, the greater the sensitivity  Sensory Adaptation: sensory neurons engineered to respond to a constant stimulus by decreasing their activity, this diminishing of sensitivity referred to as sensory adaptation/habituation Sensory Systems  Vision  Cornea: a transparent protective structure at front of the eye, light waves enter the eye through this  Pupil: adjustable opening that can dilate or constrict to control amount of light that enters the eye o Pupil’s size controlled by muscles in the iris which surrounds pupil  Lens: elastic structure that becomes thinner to focus on distant objects and thicker to focus on nearby objects  Retina: multi-layered tissue at rear of fluid-filled eyeball o Myopia (nearsightedness)  lens focuses on visual image in front of retina, resulting in blurred images for faraway objects  Can occur because eyeball is longer than normal o Hyperopia (farsightedness)  lens doesn’t thicken enough so image focused on point behind retina  Aging process causes eyes to become shorter, resulting in hyperopia and older people needing reading glasses  Retina is actually extension of brain, contains 2 types of light-sensitive receptors o Rods: primarily black and white brightness receptors (function best in dimlight)  500 times more sensitive to light than are cones o Cones: color receptors, function best in bright illumination o Fovea: small area in centre of retina that contains only cones  Bipolar Cells: have synaptic connections with roads and cones o Bipolar cells synapse with layer of ganglion cells, whose axons are collected into a bundle to form optic nerve  visual acuity: ability to see fine detail o greatest when visual image projects directly onto fovea  Photopigments: rods and cones translate light waves into nerve impulses through action of protein molecules  Dark Adaptation: progressive improvement in brightness sensitivity that occurs over time under conditions of low illumination o After absorbing light, photoreceptor is depleted of its pigment molecules for a period of time o During process of dark adaptation, photopigment molecules are regenerated and receptor’s sensitivity increases  Trichromatic Theory: three types of color receptors in retina o Though all cones can be stimulated by most wavelengths, individual cones most sensitive to wavelengths corresponding to red, green or blue o If all three cones equally activated, pure white color is perceived  Problems with trichromatic theory o Yellow isn’t produced from red and green  red-green colorblind people can still see yellow o Afterimage: image of different color appears after color stimulus has been viewed steadily and then withdrawn  Opponent-Process Theory: each of three wavelengths responds to two different wavelengths o Red or green, blue or yellow, black or white  Dual-Process Theory o Combines trichromatic and opponent-process theories for color transduction process o Certain ganglion cells in retina respond in opponent-process fashion by altering their rate of firing  Trichromat: person sensitive to all three color systems  Dichromat: person who is color blind in on of the systems (red-green or blue-yellow)  Monochromat: person only sensitive to black-white system Process of Combining Messages from Photoreceptors to Perception of Visual Scene  From retina, optic nerve sends impluses to visual relay station in thalamus  From thalamus, input routed to various parts of cortex, especially primary visual cortex (in occipital lobe)  Feature detectors: groups of neurons within primary visual cortex organized to receive and integrate nerve impulses from retina o Fire selectively in response to stimuli that have specific characteristics  From primary visual cortex, input goes to visual association cortex where we ‘recognize what it is’ Audition  Sound is actually pressure waves in air, water, or some other conducting medium  Frequency: number of sound waves, or cycles, per second o Hertz (Hz): technical measure of cycles per second  higher frequency = higher perceived pitch  Amplitude: vertical size of the soundwaves (amount of compression and expansion of molecules in conducting medium)  measures perceived loudness o Decibels (db): measure of psychical pressure that occurs at eardrum  Sound waves travel to auditory canal leading to eardrum (movable membrane that vibrates in response to soundwaves)  Beyond eardrum is middle ear (cavity housing 3 tiniest bones) o Hammer (malleus) o Anvil (incus) o Stirrup (stapes) o Vibrating activity of these bones amplifies soundwaves more than 30 times  Cochlea: in inner ear; coiled snail-shaped tube filled with fluid and contains basilar membrane  Basilar membrane: sheet of tissue that runs length of cochlea  Organ of Corti: on basilar membrane; contains 16000 tiny hair cells which are sound receptors o Hair cells synapse with neurons of auditory nerve, which then sends impulses in thalamus to auditory cortex (temporal lobe)  Soundwave strikes eardrum  pressure created by 3 bones sets fluid inside cochlea into motion o Fluid waves cause bending of hair cells in organ of corti o Bending of hair cells triggers release of neurotransmitter substance Coding of Pitch and Loudness  Loudness  high-amplitude sound waves cause hair cells to bend more o Higher rate of neuron firing within auditory nerve o Some neurons have higher thresholds so fire only when intense sound o Loudness coded in terms of…  rate of firing in axons of auditory nerve  which specific hair cells are sending messages  Pitch  one coding process for frequencies below 1000 Hz and another one for above  Frequency Theory: nerve impulses sent to brain match frequency of sound waves o 30 Hz sound wave = sends 30 volleys of nerve impulses per second to brain o Major flaw: neurons limited in their rate of firing so cannot produce high enough frequencies of firing to match wave frequencies above 1000 Hz  George von Bekesy  Place theory: specific point on cochlea where fluid waves peak and most strongly bend hair cells serves as frequency coding cue o Tonal frequency ‘map’ that corresponds to specific areas of cochlea o High frequency sounds  abrupt wave that peaked close to oval window o Low frequency sounds  slower fluid wave that peaks further down cochlear canal Sound Localization and Hearing Loss  Nervous system uses info concerning time and intensity differences of sounds arriving in both ears to locate source of sounds in space  Sounds arrives first & loudest in ear closest to the sound  Sound directly in front of us  sound waves reach both ears at same time  Conduction deafness: caused by problems in mechanical system that transmits sound waves to cochlea o Ex: punctures eardrum, loss of function in tiny bones of middle ear o Can use a hearing aid  Nerve Deafness: caused by damaged receptors within inner ear or damage to auditory nerve o Hearing aid won’t help o Caused by aging, disease, exposure to loud sounds Gustation (taste) and olfaction (smell) are chemical senses  respond to chemical molecules rather than energy  Sense of taste responds to 4 qualities  sweet, sour, salty and bitter  Taste buds: chemical receptors concentrated along edges and back surface of tongue  Receptors for smell are long cells that project through lining of upper part of nasal cavity and into mucous membrane  Olfactory bulb: forebrain structure above nasal cavity; olfactory receptors that fire send their input here  Pheromones: chemical signals found in natural body scents Tactile Senses  Touch  sensitivity to extreme temperatures and pain, allows us to have orgasms, etc  4 tactile sensations o pressure (touch) o pain o warmth o cold  primary receptors for pain and temperature are free nerve endings  simple nerve cells beneath skin’s surface  skin receptors send input to somatosensory cortex in brain  phantom limb  amputees experience vivid sensations coming from missing limbs o irritation of nerves that used to originate in limb fools brain into interpreting resulting nerve impulses as real sensations Pain  pain receptors in all body tissues except brain, bones, hair, nails and nonliving parts of teeth  cerebral processing of pain occurs faster than other kinds of tactile stimuli  some tracts in thalamus direct nerve impulses to limbic system, which is involved in motivation and emotion o control emotional component of pain  suffering  both painful sensations and negative emotional response  Gate Control Theory: experience of pain results from opening and closing of gating mechanisms in nervous system o Helps explain why pain is psychological and physical  Endorphins stop pain by inhibiting release of neurotransmitters involved in synaptic transmission of pain impulses Body Senses  Kinesthesis: provides us with feedback about muscles and joints’ positions and movements  Vestibular sense: sense of body orientation or equilibrium o Receptors located in vestibular apparatus of inner ear  canals filled with fluid with hairlike structures as receptors Perception: Creation of Experience  Bottom-up processing: system takes in individual elements of experience and combines them into unified perception o Ex: visual system as you read  Top-down processing: sensory information interpreted in light of existing knowledge, concepts, ideas, and expectations  Attention involves 2 processes of selection o 1. Focusing on certain stimuli o 2. Filtering out other incoming information  inattentional blindness: refers to failure of unattended stimuli to register in consciousness Gestalt Principles of Perpetual Organization  the wholes we perceive are more (and often different from) the sum of their parts  figure-ground relations o we tend to organize stimuli into central/foreground figure and a background  people group and interpret stimuli according to 4 Gestalt laws of perceptual organization  similarity, proximity, closure and continuity o law of similarity: when parts of a configuration are perceived as similar, they will be perceived as belonging together o law of proximity: elements that are near one another are likely to be perceived as part of the same configuration o law of closure: tend to close open edges of a figure or fill in gaps in incomplete figure so identification of form is more compete than what’s actually there) o law of continuity: people link individual elements together so that they form continuous line/pattern that makes sense  Perceptual schema: mental representation or image to compare a stimulus with (to ‘recognize it’)  Perceptual constancies: allow us to recognize familiar stimuli under varying conditions o Shape constancy: allows us to recognize people ad other objects from different angles o Brightness constancy: relative brightness of objects remains same under different conditions of illumination (ex: full sunlight or shade) o Size constancy: perception that size of objects remains relatively constant even though images on our retina change in size with distance Monocular Depth Cues  Light and shadow  Linear perspective: parallel lines converge (angle towards each other) as they recede into distance  Interposition: objects closer to us may cut off part of our view of more distant objects  Height in the horizontal plane  Texture  Clarity  Relative size  Motion parallax: if we are moving, objects nearby appear to move faster in opposite direction Binocular Disparity: each eye sees a slightly different image Convergence: produced by feedback form muscles that turn your eyes inward to view a near object Chapter 6 Reading Notes 10/26/2011 6:36:00 AM  Consciousness: moment-to-moment awareness of ourselves and our environment o Subjective and private  other people don’t know your reality o Dynamic (ever-changing) o Self-reflective and central to our sense of self o Intimately connected with process of selective attention  Freud said mind consists of three levels of awareness o Conscious mind: contains thoughts, perceptions and other mental events of which are currently aware of o Preconscious: outside current awareness, but can be easily recalled o unconscious: can’t be brought into conscious awareness under ordinary circumstances  controlled (effortful) processing: voluntary use of attention and conscious effort  automatic processing: can be performed with little or no conscious effort o happens with routine actions and well-learned tasks  divided attention: ability ot perform more than one activity at the same time  circadian rhythms: biological cycles within the body that occur on an approximately 24-hour cycle o regulated by suprachiasmatic nuclei (SCN)  located in thalamus o SCN reduces melatonin secretions during day and increases it during night  melatonin: hormone that has relaxing effect on body  seasonal affective disorder (SAD): cyclical tendency to become psychologically depressed during certain months of year  rotating shiftwork: forward rotating clock schedule that changes work shifts by extending a worker’s ‘waking day’ rather than compressing it Stages of Sleep  beta waves: a brain wave pattern of 15-30 cycles per second that is characteristic of humans who are in an alert waking stage  alpha waves: brain wave patters of 8-12 cycles per second that is characteristic of humans in a relaxed waking state  stage 1 o brain wave patterns become more irregular, theta waves at 3.5-7.5 cycles per second begin o can be easily awakened  stage 2 o sleep spindles (periodic one-to-two second burst of rapid brain activity) begin o muscles more relaxed, breathing and heart rate are slower o harder to wake up  stage 3 o delta waves: 0.5-2 cycles per second o keep occurring more often  stage 4 o body relaxed, activity in various brain parts has decreased  slow-wave sleep: stages 3 and 4  REM sleep Why do We Sleep?  Restoration model: sleep recharges our rundown bodies and allows us to recover from physical and mental fatigue  what gets restored in our bodies  adenosine o adenosine produced as cells consume fuel, more adenosine signals body to slow down and promotes sleep  evolutionary/circadian sleep models: sleep’s main purpose is to increase a species’ chances of survival in relation to its environmental demands  REM-rebound effect: tendency to increase amount of REM sleep after being deprived of it Sleep Disorders  Insomnia: chronic difficulty in falling asleep, staying asleep, or experiencing restful sleep o Most common sleep disorder; 10-40% of population o Pseudoinsomniacs: complain of insomnia but sleep normally when examined in lab  Narcolepsy: extreme daytime sleepiness, and sudden uncontrollable sleep attack lasting from 1 minute - 1 hour
More Less

Related notes for Psychology 1000

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit