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Department
Psychology
Course
PSYA01H3
Professor
Steve Joordens
Semester
Fall

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9.12.12 PSYCHOLOGY CHAPTER 1: THE EVOLUTOPM OF A SCIENCE Psychology – scientific study of the mind and behaviour  Mind: private inner experience; consciousness that made perceptions, thoughts, memories & feelings  Behaviour: observable actions of human beings & animals What are the bases of perceptions, thoughts, memories and feelings or our subjective sense of self?  Electrical and chemical activities of our brains - fMRI (functional magnetic resonance imaging) allowed scientists to ‘scan’ brain to view which parts are active due to certain stimulus (learning, seeing …etc) - i.e. professional pianist has less brain activity than a novice due to the brain’s memorization of the keys (efficiency) What does the mind usually allow us to function effectively in the world?  If we want to understand how something works, we need to know what it is working for. “thinking is doing” i.e. acquiring good, shelter and mates (adaptive) Perception: recognition of families, see predators before they see us, avoid oncoming traffic Language: organize thoughts and communicate, forming social groups, cooperate Memory: avoid solving same problems over again; what we are doing, why  Given adaptiveness of psychological processes; people with deficiencies with processes often have harder time  Emotions are adaptive because they function as signals that tell us when we are putting selves in harm’s way Why does the mind occasionally function so ineffectively in the world?  Like all machines, the mind often trades accuracy for speed and versatility; we all make mistakes  Human brains can go on ‘auto-pilot’ - William James found this intriguing; the mind’s mistakes (instructive)  began studying it for psychology - We learn from taking things apart; understanding lapses, errors, mistakes; puzzling nature of human behaviour provides point of understanding normal operation of mental life and behaviour Psychology’s Roots: Path to a Scientific Mind • Plato (428 BC – 347 BC); argued nativism (philosophical view that certain kinds of knowledge are innate/inborn) o i.e. children learning that sounds make words and sentence • Aristole (384 BC – 322 BC); believed child’s mind is a blank slate o Philosophical empiricism: all knowledge acquired through experience o Argument of ‘nature’ vs ‘nuture’ • Rene Descartes (1596-1650) – body and mind fundamentally different; body = material substance, mind = soul o Dualism; mental activity reconciled/coordinated with physical behaviour o mind influences body via pineal gland • Thomas Hobbs (1588-1679) – mind and body not different; mind is what brain does • Franz Joseph Gall (1758-1828) – brains and mind linked; by size o Mental ability increases with larger brain size, decreases with damage to brain o Phrenology: specific mental abilities and characteristics; memory to capacity for happiness located on regions of brain o i.e. hippocampus  memory, amygdala  fear o asserted size of bumps on skull reflected size of brain regions underneath; can tell if person is friendly, cautions … etc  proven wrong eventually  strong claims, weak evidence 1 • Pierre Flourens (1794 – 1867) – surgically removed parts of brains on animals to discover actions/movements differed from those with intact brains • Johannes Muller (1801-1858) Doctrine of Specific Nerve Energies o Modulers; cut up human bodies and used wires to imitate movement (electricity); which part of the body would move • Paul Broca (1824 – 80) – worked with brain-damaged patient (part of the brain) discovered patient understood instructions but could not communicate words (only through gestures)  brain & mind closely linked • Broca & Flourens  first to demonstrate mind is grounded on material substance (brain) • Hermann von Helmholtz (1821-1894) – spead of responses; trained particiants to respond via stimulus (sensory input from environment) to parts of leg; recorded reaction time (amount of time taken to responds to stimulus) o Participants took longer to respond on toes than on thigh; distance of nerves sending signal to brain • Wilhelm Wundt (1832-1920) o first to open lab exclusively for psychology o development of Structuralism (analysis of basic elements that constitute the mind)  tried to understand association of described feelings to structure of consciousness o Wanted to study consciousness (person subjective experience of the world and the mind)  Studied it via Introspection (subjective observation of one’s own experience)  Students presented with stimulus (colour/sound) and report introspections  Introspections of ‘raw’ sensory experience (i.e. brightness, loudness)  Used reaction time to examine distinction b/w perception and interpretation of stimulus • Edward Titchener (1867 – 1927) – studied with Wundt for 2 years ( brought to US) o Wundt emphasized relationship b/w elements of consciousness, Titchener focused on identifying basic elements themselves  STRUCTURALIST APPROACH FADED; DUE TO INTROSPECTIVE METHOD; didn’t feel like science • William James agreed with Wundt on some points (importance of focusing on immediate experience & introspection) but disagreed Wundt’s claim on consciousness broken down into separate elements o Functionalism: study of the purpose mental processes serve in enabling people to adapt to environment o set out to understand functions mental processes served o consciousness must serve important biological function • Charles Darwin (1809-1882) o Father of Natural Selection (feature of organism to help it survive; environment adaption  pass to offspring; changes in genetics) • G. Stanley Hall (1844-1924) o established first research laboratory, journal and professional organization devoted to psychology CLINICAL PSYCHOLOGY – SIGMUND FREUD Hysteria: temporary loss of cognitive or motor functions, result of emotionally upsetting experience 2  Jean-Martin Charcot (1825-93) and Pierre Janet (1859-1947) reported these cases  Patients become blind, paralyzed or lost memories (w/o physical cause of problems)  Under hypnosis; symptoms disappeared  William James believed it had important implications for understanding nature of mind  Task taken up by Sigmund Freud Psychoanalysis (bringing unconscious material into conscious awareness)– Sigmund Freud • Theorized patient’s problems may be caused by painful childhood experiences (couldn’t remember) • Unconscious: part of mind that operates outside of conscious awareness; influences thoughts, feelings & actions Psychoanalytic theory: Freud’s approach to understanding human behaviour via unconscious; mental process in feelings, thoughts and behaviour • Freud continued psychoanalytic movement; person’s early sexual desires & sexual experiences • Freud’s ideas less influential today due to the lack of scientific support • Abraham Maslow (1908-70) & Carl Rogers (1902-87) o Created Humanistic Psychology – approach to understanding human nature; positive potential o People more inherently disposed toward growth & reach full potential with help from friends Behaviourism: scientific study of objectively observed behaviour • John Broadus Watson (1878-1958) o Psychologists focused entirely on what people do rather than what they experience o Goal of scientific psychology (according to Watson): predict & control behaviour to benefit society o Influenced by Ivan Pavlov (1849-1936)  salvation of dogs w/ sound of bell response  Stimulus-response & reinforcement o Watson applied Pavlov’s techniques on human infants; “Little Albert” • B.F Skinner (1904-90) o Reinforcement: consequence of behaviour determine whether it will be more likely that behaviour will occur again  rat experiment “skinner box” o Skinners claims provoked outcry; our ‘free will’ is nothing but an illusion; we do based on reinforcement (past and present) o Understanding principles which behavior is generated used to increase social welfare (i.e. drink milk, quit smoking) Cognitive Revolution • Illusions: errors of perception, memories, judgement; subjective experience differs from reality Gestalt Psychology: trying to understand the laws underlying ability to acquire and maintain stable percepts in world  “Humanistic Psychology”  positive aspects of humanity (positive psychology) • Manipulation  picture representation (first thing to come into mind when looking at a picture due to unconscious feelings related to unidentifiable object)  Jean Piaget (1896-1980) perceptual and cognitive errors of children; development of human mind  Kurt Lewin (1890-1947) study of thought; predict person’s behaviour o Attempts to model mental life & insistence to study how people construe their worlds  EMERGENCE OF COMPUTER = COGNITIVE PSYCHOLOGY (study of mental processes, perception, thought, memory & reasoning) o Limited capacity to handle incoming info (7 pieces of info) o Noam Chomsky: language relies on mental rules to produce words and sentences  Behavioural Neuroscience: approach to psychology  inks to activities in nervous system & body processes  Cognitive Neuroscience: attempt to understand link b/w cognitive process & brain activity o Left Hemisphere: language, speech 3 Evolutionary Psychology (explains mind and behaviour in terms of adaptive value; natural selection) • Some ancestorial processes (biology) may be passed onto offsprings (natural selection) • i.e. “jealousy genes”  guard mates and aggress against rivals; reproduce ‘jealousy genes’ Social Psychology  causes and consequence of interpersonal behavior • people exists as part of network of other people; individuals influence and interact w/ one another • Kurt Lewin; motivated desire to address social issues and problems Cultural Psychology • Broader culture on individuals w/ similarities and differences among people in diff cultures • Absolutists; culture has little impact on psychological phenomena • Relativists; culture has powerful effect Psychology Chapter 2: Methods of Psychology Dogmatists: people cling onto their assumptions Empiricism: belief that accurate knowledge is acquired through observation Scientific Method: set of principles about appropriate relationship between ideas and evidence Theory: hypothetical explanation of a natural phenomenon  Rule of Parsimony: simplest one Hypothesis: falsifiable prediction made by a theory - i.e. bats navigate via sonic hearing; deaf bats navigate poorly = constant but not proof; due to chance that something will disprove this observation Empirical method: set of rules and techniques for observation - 3 things make it difficult to study people via observation 1. Complexity: human brain is very complicated 2. Variability: no two individuals are the same under the exact same circumstances 3. Reactivity; people do not act natural when under observation Measurement - We must always define the property we wish to measure and find a way to detect it Operational Definition: description of a property in concrete, measurable terms Measure: device that can detect condition to which operational definition refers Electromyogram (EMG): device that measures muscle contractions under surface of person’s skin i.e. wanting to measure happiness via frequency of smiles; EMG detects frequency Validity: extent of which measurement and a property are conceptually related (i.e. frequency of smile; people all over the world smile more when happy) Reliability: tendency for a measure to produce the same measurement whenever it is used to measure the same time (i.e. facial muscles produce precisely same electrical activity on two diff occasions) Power: ability of a measure to detect concrete conditions specified to operational definition Demand Characteristics: aspects of observational setting that cause people to behave as they think they should Naturalistic Observation: technique for fathering information by unobtrusively observing people in natural environment  not always viable solution due to demand characteristics Solution: Blind: purposely give opposing or different scenario to participants for natural behaviour to surface Double-Blind: experimenters and participants blind to ‘real’ purpose of study. Graph Representations (Description) Frequency distribution: Graphic representation of measurements arranged by the number of times each measurement was made Normal Distribution: mathematically defined frequency distribution in which most measurements are concentrated around the middle o Symmetrical; peak in the middle, trails off at both ends Descriptive statistics: brief summary statements; essential information from frequency distribution  Central tendency  value of measurements that tend to be near the center of frequency distribution 4 - Mode: most frequently observed measurement - Mean: average value of all the measurements - Median: ‘middle value’; 50% up 50% down  Variability  statements about location of measurements in frequency distribution - Range: largest measurement minus smallest measurement - Standard deviation: statistic that describe the average difference between measurements in frequency & mean distribution - M.A.D – the mean absolute deviation of each data point from the mean of the numbers (i.e. 1.2 vs 9.2) - Variance – average squared deviation of each data point from the mean 2 vs 111.3 5 Correlation: How can we tell if two variables are correlated? Patterns of variation in a series of measurements 1. Measure a pair of Variables: “values” that vary 2. Make a series of measurements rather than just making one 3. Discern a pattern in your series of measurements  synchronized ‘columns’ on table; pattern of covariation correlation (two variables are said to ‘be correlated’ when variables in the value of one variable are synchronized with variations in the value of the other (i.e. not insulted to insulted; varies from agreed to refuse) • We can use measurements to discover the relationships b/w variables • i.e. women who watch romantic shows = ‘less excited’ about their own relationships (negative correlation) • i.e. more spinach associated with more longetivity = positive correlation (two negatives = positive) • Correlation coefficient: measure of the direction and strength of a correlation o value increases via fixed about = perfect positive correlation r = 1 o value decreases via fixed amount = perfect negative correlation r = -1 rd o data scattered = uncorrelated r = 0 The 3 variable problem • no way to eliminated 3 variable issue o solution: manipulation must take place for lab assessment (control and experiment group) • Natural correlations: correlations we observe in the world around us (i.e. aggression and media violence) • Matched samples technique: participants in two groups are identical in terms of a 3 variable • Matched pairs technique: participants is identical via 3 variable • Experiment: involves contrasting ‘behaviour’ across two or more conditions that differ in the same way that should matter (i.e. affecting behaviour) according to some theory; establish casual relationship b/w variables • Independent variable: variable changed to create critical difference across the conditions; presence/absence of current • Dependent variable: reflects the ‘behaviour’ of interest i.e. aggression • Experimental group: participants who are treated a particular way • Control group: participants who are not treated in particular way • Self-selection: problem in which participants choose own groups or determination of which group via variables • Random assignment: participants placed in different groups randomly o Less than 5% chance of failure than differences in measurements across groups are assumed to have been caused via manipulation Drawing conclusions • Internal validity: characteristic of experiment that establishes causal relationship b/w variables o Confound: resent when some variable other than independent variable also varies across groups; cause-effect relations become ambiguous o Random assignment: helps us avoid confounds; large sample size results in groups & do not differ on variables we know we should care about & those we may not be thinking about (relevant) o Replications: subsequent experiments that found same results w/ diff sample of participants (slightly diff operation definitions) • External validity: property of experiment; variables operationally defined in normal, realistic way • Case method: study of an individual scientifically • Random sampling: choosing participants that ensure equality of chances for sample o Failure not always a problem; as long as somebody is doing it o Generalization of experiment result is important; new experiments that use same procedures on diff samples 6 o If results of study replicated in numerous non-random samples  confident that results would generalize to population at large o Similarity of sample & pop reasonable assumption PSYCHOLOGY CHAPTER 3 NEUROSCIENCE AND BEHAVIOUR Neurons; Origin of Behvaiour • Neurons: cells in nervous system; communicate with one another; information-processing tasks o Composed of cell body, dendrite, axon, myelin sheath (insulating layer of fatty material) & glial cells (support cells found in nervous system) o Synapse: gap between terminal branches of axon and dendrite; releases neurotransmitters to communicate with other neurons • Sensory Neurons: light, sound, touch, taste & smell; recives info from external world  relays to brain via spinal cord • Motor neurons: carry signals from spinal cord to muscles  produce movement • Interneurons: nervous system mostly composed of this; connects sensory, motor and other interneurons together o Carry info from sensory to nervous system; nervous system to motor neurons (simple tasks) • Purkinje cell: (brain) carries info from cerebellum to rest of the brain via spinal cord (many dendrites) • Hippocrampal pyramidal cell: (brain) found in cerebral cortex • Bipolar cells: (retinas in eye); single axon & single dendrite Action Potential: • Action potential: electric signal conducted along length of neuron’s axon to synapse o All or none: electric stimulation below the threshold fails to produce action potential whereas electric stimulation at or above threshold always produces action potential o Resting potential: K+ channels open; electric charge raised to threshold value; K+ channels close; thus Na+ channels opened  increased Na+ (positive) inside axon relative to that of outside • Refractory period: time following action potential during new action potential cannot be initiated o Balance must be restored; pumps move Na+ outside of axon and moves K+ inside axon (pump shuts off during A.P) • Nodes of Ranvier: spaces between myelin sheath on axon; charges ‘jump’ from node to node  salutatory conduction (helps speed flow of info down axon) Chemical signaling: transmission between neurons • Axons end in terminal buttons: knob like structures that branch out from axon; filled with tiny ‘vesicles’ of neurotransmitters (chem that transmit info across synapse to receiving neuron’s dendrites • Dendrites contain receptors: parts of cell mem that receives neurotransmitters and initiate or prevent new electric signal o Neurotransmitters bind to receptor sites of nearby dendrite on receiving neuron (postsynaptic neuron) o Neurotransmitters leave via 3 steps 1. Reuptake: reabsorbed by terminal buttons of presynaptic neuron’s axon 2. Neurotransmitters destroyed via enzymes in synapse in processed enzyme deactivation 3. Can bind to receptor sites called autoreceptors on presynaptic neurons; a. Detects how much of neurotransmitter released into synapse  signal neuron to stop releasing when excess is present  REFER TO TEXTBOOK PG 87 FOR DRUGS (Acetyecholine, Dopamine, Glutamate, Norepineprine, Sertonin, Endorphins) Drugs • Agonists: drugs that increase action of neurotransmitter 7 • Antagonists: drugs that block function of neurotransmitter 8 Nervous System: • Nervous system: interacting network of neurons that conveys electrochemical info throughout body o Central nervous system (CNS): part of nervous system composed of brain and spinal cord o Peripheral nervous system (PNS): connects to central nervous system of body’s organs and muscles  Somatic nervous system: controls voluntary movements of muscles  Autonomic nervous system: controls self-regulated action of internal organs and glands • Sympathetic: fight or flight; prepares body for action in threat • Parasympathetic: helps body return to normal resting state  Work hand in hand; parasympathetic help with erection, sympathetic = ejaculation • Spinal reflexes: simple pathways in the nervous system; rapidly generate muscle contractions The Brain • Higher levels = complex functions, lower levels = simpler functions Hindbrain  Area of brain coordinates information coming into and out of spinal cord • 3 anatomical structures: o Medulla: extension of spinal cord into skull; coordinates heart rate, circulation and respiration  Reticular formation: inside medulla; regulates sleep, wakefulness, arousal  Severing R.F = irreversible coma o Cerebellum: large structure of hindbrain controls fine motor skills “little brain” o Pons: structure that relays info from cerebellum to rest of brain “bridge” Midbrain • Sits on top of hindbrain • Tectum: orients organism in environment  receives stimulus input from eyes, ears, skin and moves organism in coordinated way toward stimulus • Tegnmentum: involved in movement and arousal  helps orient organism toward sensory stimuli • Midbrain is small but central location of neurotransmitters involve in arousal, mood and motivation Forebrain • Highest level lf brain; controls complex cognitive, emotional, sensory and motor functions • Cerebral cortex: outmost layer of brain, visible to the naked eye and divided into two hemisphere o 3 levels of organization o (1) Most complex aspects of perception, emotion, movement and thought; smooth surfaces of cortex (raised) gyri and indentations/fissures sulci (both represent triumph of evolution; fitting more info in folds) o Each hemisphere controls opposite side of body (contralateral control) o (2)Corpus callosum: connects large area of cerebral cortex o each side of the brain; supports communication of info across hemispheres o Occipital lobe: process of visual info; lower part of temporal  Scitoma: damage to occipital lobe produces hole in a person’s visual field (primary)  Association cortex; providing interface b/w visual input and memory; categorize visual images  Agnosia: damage to association cortex; inability to name common objects o Parietal lobe: front of occipital lobe; processes info of touch; contains  somatosensory cortex represents skin areas on contralateral surface of body  Motor cortex  parallel to somatosensory cortex  initiates voluntary movements; sends msgs to basal ganglia, cerebellum and spinal cord o Temporal lobe: responsible for hearing and language  Primary auditory cortex: inside temporal lobe; analogous to somatosensory cortex in parietal lobe and primary visual areas of occipital love; receives sensory info from ears based on frequencies of sound 9  Secondary areas of temporal lobe process info into meaningful units (speech/words) o Frontal Lobe: specialized areas for movement, abstract thinking, planning, memory and judgement  Contains motor cortex & allows for imagination o (3) association areas: composed of neurons that help provide sense and meaning to information registered in the cortex  i.e. neurons in primary visual cortex highly specialized; detect features of environment that are in horizontal orientation; movement and human vs nonhuman forms • Subcortical structures: areas of forebrain housed under cerebral cortex near center of brain (thalamus, hypothalamus, pituitary gland, amygdala, and hippocampus) o Thalamus: relays and filters info from senses and transmits info to cerebral cortex  Actively filters sensory info; more weight to some inputs and less to others; close pathways during sleep o Hypothalamus: regulates body temperature, hunger, thirst and sexual behaviour  Lesions to some areas of hypothalamus = overeating or not eating at all o Pituitary gland: ‘master gland’; body’s hormone-producing system; releases hormones that direct functions of many other glands in the body (Endocrine glands)  hormones like neurostransmitters  i.e. oxytocin for breast milk reduction; also involved in response to stress • Limbic System: group of forebrain structures including hypothalamus, amygdala, and hippocampus  motivation, emotion, learning and memory o Hippocampus: critical for creating new memories; integrating them into a network of knowledge so they can be stored indefinitely in other parts of cerebral cortex  Patients with damage to hippocampus can only keep awareness of new info for a few seconds; once distracted  cannot recall anything o Amygdala: located at tip of each horn of hippocampus; central role in emotional processes, particularly formation of emotional memories  Also attaches significance to previously neutral events associated with fear, punishment/reward • Basal Ganglia: set of subcortical structures that directs intentional movements o Receive input from cerebral cortex; sends outputs to motor centers in brain stem o Undersupply of dopamine then affects striatum in basal ganglia  leads to Parkinson’s disease behaviour Brain Plasticity: • The ability to be molded; i.e. lose finger in accident; somatosensory cortex becomes responsive to stimulation of the fingers adjacent to missing finger • Functions that were assigned to certain areas of the brain may be capable of being reassigned to other areas of the brain to accommodate changing input from the environment 10 PSYCHOLOGY CHAPTER 4 – SENSATION AND PERCEPTION Synesthesia: perceptual experience of one sense that is evoked by another sense (seeing colour of musical notes Senses Encode information our Brains perceive • Sensation: simple stimulation of a sense organ o Light, sound, pressure, odor, taste as parts of your body interact with the physical world • Perception: brain level; organization, identification and interpretation of a sensation in order to form a mental representation • Our 5 senses: vision, hearing, touch, taste, smell • Transduction: when many sensors in body convert physical signals from the environment into encoded neural signals send to CNS (Translating physical properties of the outside world into neural signals) • operationalize perceptions; finding a reliable way to measure it th o Psychophysics: (19 cent) methods of measuring strength of stimulus and observer’s sensitivity to stimulus Measuring thresholds • Absolute threshold: minimal intensity needed to just barely detect a stimulus o People tend to be more sensitive to range of tones corresponding to human conversation • Just noticeable difference (JND): minimal change in a stimulus that can be barely detected o Humans are very good at detecting slight changes i.e. infant’s cry for different requirements • Weber’s law: the JND of stimulus is constant proportion despite variations in intensity o When calculating difference threshold; proportion between stimuli Is important i.e. noticeable difference of 1-ounce package compared to 2-ounce package then a 20lb compared to 20.1lb Signal Detection • Absolute threshold is operationalized as perceiving the stimulus 50% of the time; other 50% go undetected • Signal Detection Theory: observation that the response to a stimulus depends both on a person’s sensitivity to the stimulus in the presence of noise and on a person’s response criterion (measure perceptual sensitivity) o Signal detection theory allows researchers to quantify an observer’s response in presence of noise • Sensory adaption: sensitivity to prolonged stimulation tends to decline over time as organism adapts to current conditions o Our perceptual systems emphasize change in responding to sensory events Vision: Eyes & brain covert light waves to Neural Signals • Visual acuity: ability to see fine detail; 20/20 vision on Snellen chart; Hermann Snellen (1834-1908)  the smallest line of letters that a typical person can read from a distance of 20 feet • Sensing light falls under 3 properties of light waves o Length of light wave; determines hue (colour) o Intensity or amplitude of light wave; how high the peaks are determine brightness of light o Purity number of distinct wavelengths that make up life; saturation or richness of colours The Eye • Iris: colour part of the eye; muscle that controls the size of pupil • Pupil: black part of the eye; allows light into the eyeball • Sclera: white part of the eye; tough membrane that serves as protection 11 • Cornea: fluid filled outer coating of the eye; provides moisture and nutrients • Lens: focuses the incoming light onto retina; flexible and slight alterations in it can alter the focus of it; process called accommodation (squinting  bending your lens)  process which eye maintains clear image on retina • Aqueous Humor: fluid nourishes front of the eye • Vitreous Humor: fluid nourishes and supports inner part of the eye • Retina: surface that the image lands on; inner coating is retina  transmit the light signal (focused or not) into a neural signal (light-sensitive tissue lining the back of eyeball) • Photoreceptors: where transduction happens; lights strike back of the eye stimulating photoreceptor cells (rods or cones)  transduce light into neural impuses o Rods: not responsive to colour; but responsive to dim light; low light situations for night vision o Cones: sensitive to colour (red, green, and blue)  detailed image; high light, detailed imaging  Bleaching process begins when colour (R, G, B) touches the cone; percepting the colour (bleaching the cone when colour touches them)  brain thus receives wavelengths and produces image o Transduction is done via bleaching process in which the photo-pigments are split causing action potential o Fovea: area of retina where vision is clearest and no rods at all  Absence of rods in fovea decreases sharpness of vision in reduced light but can be overcome  120 mil rods, 6mil cones o Peripheral vision aren’t so clear due to the difficulty of the light from peripheral to land on fovea • Retina is thick with cells; Bi-Polar Cells: sharpen and refine imagines; accentuate image from different signals (rods/cones) o Collects neural signals from rods and cones and transmit them to outmost layer of retina; the Retinal ganglion cells o Signal from photoreceptors passed onto bi-polar cells; reprocess signal to emphasize edges and contours’ o Photoreceptors associated with spatially close parts of retina rd • Ganglion Cells: 3 & final cell in retina pre-processing of visual information o organize signals and send them to the brain o RGC axons (1.5mil) forms optic nerve; leaves eye through role in retina (doesn’t contain any rods or cones)  blind spot: no sensation on retina due to area containing no rods or cones; no mechanism to sense light o 2 types; red/green, blue/yellow o Each cell represents opponent process system  i.e. red/green cells; resting behaviour of cell is to produce mid-level rate of responding  rate increases when red is present, decreases when green is present  yellow/blue increases when both red and green are present (yellow?) decreases when blue is present • receptive field: region of sensory surface; when stimulated causes a change in firing rate of neuron o particular RGC will respond to light falling anywhere within small patch; receptive field • most receptive fields contain central excitatory zone surrounded by inhibitory zone (on-center cell) or central inhibitory zone surrounded by excitatory zone (off-centre cell) • trichromatic colour representation: pattern of responding across the three types of cones provides a unique code for each color. o 3 basic colours: red, blue and green create the hues of all the colours in which we perceive o Each concentration of the colour allows the cones to fire at a faster rate in the presence to produce a ‘louder’ or ‘brighter’ colour (standing out) i.e. contrasting colours • Color-opponent system: pairs of visual neurons work in opposition 12 o Red-sensitive cells against green-sensitive and blue-sensitive against yellow-sensitive  Red-green cells excited (increase firing rates) in response to red wavelengths and inhibit (decrease firing rates) in presence of green wavelengths ; blue-yellow increase firing rates to blue wave lengths and decreases to yellow (colour pairs are linked to each other as opposites) o Aftereffects: when colour has been strongly concentrated (fatigued) over time = imbalance of inputs to color-opponent neurons beginning with retinal ganglion cells;; weakened signal from colour leads to overall response that emphasizes opposing colour. Visual Brain • Half of the axons in optic nerve that leave each eye come from retinal ganglion cells that code information in the right visual field; and vice versa • Optic nerve travels from each eye to the lateral geniculate nucleus (LGN) o Thalamus receives inputs from all the senses except smell; visual signal travels to the back of brain; called area VI: part of the occipital love that contains primary visual cortex • Ventral “below” stream travels cross occipital lobe into lower levels of temporal lobes and includes brain areas that represent an object’s shape and identity  ‘the what pathway’ • Dorsal “above” stream travels up from occipital lobe to parietal lobes; connecting with brain areas that identify the location and motion of object;  ‘where it is’ • Visual-form agnosia: inability to recognize objects by sight o D.F patient with damage to large region of lateral occipital; can no longer recognize objects by sight, but touch sense was normal o She could accurately guide her actions by sight o Other patients with brain damage to the parietal section of the dorsal stream have difficulty using vision to guide their reaching and grasping movement; condition termed optic ataxia 13 PSYCHOLOGY – CHAPTER 5: CONSCIOUSNESS Consciousness: person’s subjective experience of the world and the mind - ‘being awake’ and experience (including dreams)  private to one’s self Consciousness & Unconsciousness: Mind’s eyes open & closed • Nature of consciousness (what it is that can be seen in mental theater) & unconscious mind (what is not visible to the mind’s eye) Mysteries of Consciousness • Phenomenology: how things seem to the conscious person • two problems: (1) Problem of Other Minds: fundamental difficulty we have in perceiving the consciousness of others o no clear distinction on whether or not participants are saying or actually feeling it, compared to the unconscious’ raw sensory experiences o Philosopher’s “zombie” refers to people who can talk and react to experiences but have no inner experience at all o Every person’s mind is different, what we perceive can be different but named the same thing (i.e. seeing red colour could be blue to another but called ‘red’) o People judge according to the capacity for experience (ability to feel ain pleasure, hunger, consciousness, anger or fear) and the capacity for agency (ability for self-control, planning, memory or thought) • Body/Mind Problem: issue of how the mind is related to the brain and body o Rene Descartes proposed that the human body is a machine made of physical matter but the human mind and soul are separate entity made of ‘thinking substance’  Mind has effect on body due to pineal gland (endocrine gland)  In contrast; the mind is connected to everything “the mind is what the brain does” o Our mind is constantly flowing and changing in terms of thought as human beings can only hold so much information at a time • Nature of consciousness • Four Basic Properties: (1) intentionality – the quality of being directed toward an object o Conscious attention is limited: 3 properties of consciousness  (2)Unity – or resistance to division (trying to attend to more than 1 thing at a time) i.e. studying and watching TV at the same time  (3)Selectivity – capacity to include some objects but not others. Dichotic listening: people wearing headphones are presented with different messages in each ear – consciousness filters out some information but can notice if voice tone changes; tuning in  Cocktail party phenomenon: people tune in one message even while filtering out others nearby  (4)Transience – tendency to change; William James “Consciousness… does not appear to itself chopped up in bits.’ – constantly flowing and changing • Levels of consciousness o Min  full  self-consciousness o Minimal consciousness: low-level kind of sensory awareness and responsiveness that occurs when the mind inputs sensations and may output behavior (i.e. somebody pokes you in your sleep and you turn over) o Full consciousness: consciousness in which you know you are able to report mental state (i.e. feeling suns ray on your face in the morning during a spring day – being aware) o Self-consciousness: person’s attention is drawn to the self as an object (i.e. noticing you are reading a book and the pimple on your nose) – being the focused attention in a group  Brings out the tendency to evaluate oneself 14  In experiment where red dye placed on chimp’s eyebrow  chimp recognized itself has having a red dot and tried to wipe it away  thus chimp realizes reflection in mirror is itself  Human (18months +), chimp, orangutan, elephants and possibly dolphins recognize self-mirror images • Conscious Contents o Experience sampling technique – people asked to report their conscious experiences at particular times o Skin conductance level (SCL)  placed on finger tips; detects when it gets moist (thinking of distress)  Some people can do certain tasks in default network which they can day dream while doing (due to knowing how to do it so well) o Mental control: the attempt to change conscious states of mind  i.e. “what if I don’t get a decent job when I graduate?”  troubled worry o thought suppression: conscious avoidance of a thought  the more you try to suppress a thought the more likely it is to return  rebound effect of thought suppression: the tendency of a thought to return to consciousness with greater frequency following suppression  ironic processes of mental control: ironic errors occur because the mental process that monitors errors can itself produce them (i.e. trying to not think about white bear; mind searches for it • The unconscious mind o The actual process of thinking is not conscious at all (i.e. knowing the answer to 4+5 = 9 without having to calculate mentally  unconscious already knew the answer) • Freudian Unconscious o Dynamic unconscious: an active system encompassing a lifetime of hidden memories, the person’s deepest instincts and desires and the person’s inner struggle to control these forces.  i.e. hidden sexual thought of one’s parent; thoughts kept secret from others & not acknowledged themselves o repression: mental process that removes unacceptable thoughts and memories from consciousness & keeps them unconscious  evidence of this is errors within the speech & lapses called “Freudian slips” i.e. forgetting the name of somebody you dislike or Obama’s slipped saying “My Muslim faith” when he’s part of the united Church of Christ • Modern view of the Cognitive Unconsciousness o Cognitive unconscious: all mental processes that are not experienced by a person but that give rise to the person’s thoughts, choices, emotions & behavior o Subliminal perception: thought or behavior is influenced by stimuli that a person cannot consciously report perceiving  Person’s thought/behavior changes when exposed to information outside of consciousness o Words flashed for 16ms is unconsciously perceived o Subliminal messaging can be seen in surveys of those who were afraid of ‘aging’ without actual exposure to “getting old” they were simply shown words associated with getting old = they walked more slowly after (as they think getting old = walking slowly) o Unconscious mind seem better able than conscious minds to sort out the complex information & arrive at best choice Sleep & Dreaming: Good Night, Mind - Altered state of consciousness: A form of experience that departs significantly from the normal subjective experience of the world and the mind - Presleep consciousness: hypnagogic state  you can experience hypnic jerk (feeling of falling) 15 - Postlseep consciousness: hypnopompic state - Sleep cycle  circadian rhythm: naturally occurring 24-hr cycle o People live in a 25.1 hr rest-activity cycle in our 24hr day o During waking; changes involve alternation b/w high frequency activity (beta waves) during alertness and lower-frequency activity (alpha waves) during relaxation - 5 sleep stages:
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