Psychology Chapter 5, 6, 7 Textbook PDF

Chapter 5 Nervous system CNS – the brain and spinal cord PNS – everything besides the brain and spinal cord Somatic – Controls all voluntary movement Autonomic – doesn’t require your conscious controls Sympathetic – fight or flight system A-Sympathetic -br...

Chapter 5 Nervous system CNS – the brain and spinal cord PNS – everything besides the brain and spinal cord Somatic – Controls all voluntary movement Autonomic – doesn’t require your conscious controls Sympathetic – fight or flight system A-Sympathetic -brings you back to a calm state Understanding the brain Frank Gall and Phrenology (early 1800) Phrenology- connecting the function of the brain to thought behaviour and personality Separated the brain into regions and each one of those regions would be responsible for a person's personality – the larger the region the more influential that region will be Divisions of the brain Temporal lobe – Auditory processing, language and memory, taste and smell Frontal lobe – planning, organizing and impulse control Partial lobe – touch and spatial awareness Occipital lobe – visual processing Cerebellum – motor coordination Approx 100 billion neurons in health adult brain Surface features of the brain Gyrus – bumps on the brain Sulcus – a indentation Fissure – a deep sulcus Cerebral hemispheres Connected by the corpus callosum Sends info back and forth from both hemispheres Orientation of the brain Anatomical Orientation Meninges Cerebrospinal Fluid Cushions the central nervous system from ally movement Helps with waste removal Blood circulation in the brain Allows nutrients in the blood stream find their way into brain cells Most important nutrient is oxygen it is vital for the function of neurons Disruption to blood flow can result in two different types of stroke Ischemic stroke – A blockage or an area in the brain that isn't receiving blood flow Hemorrhagic stroke- A bleed in the brain ex. Ruptured blood vessels Techniques of studying the brain Histological – the brain is sectioned and sliced postmortem and neuronal loss is examined PET scanning – identifies areas of the brain that are calling more blood flow Functional magnetic imaging (fMRI) – Changes in the oxygen content of the blood alter its magnetic properties Near-Infrared Spectroscopy – light is Shaun into the brain through the skull. Identifies parts of the brain that are active in an activity. Static Imaging Technique Computerized tomography (CT scan) – X-ray beam passed through the brain at man different angles to create many different images (use to find lesions, bleeds) Magnetic Resonance Imaging (MRI) – more detailed than an CT and can identify specific brain tissue  Diffusion Tensor imaging (DTI) – identifies any disruptions n the pathways in the brain Measuring electrical activity in the brain Electroencephalography (EEG) – Studies electrical activity in the brain in the form of wave patterns (ex. Sleep) Deep brain stimulation – Electrodes implanted deep in the brain stimulate a targeted area with a low-voltage electrical current to facilitate behaviour. (Used for Parkinson’s, epilepsy and other brain disorders. Complex vs. Basic Behaviours Forebrain (cerebral cortex) – outer part of the brain. Responsible for most complex behaviours Brain stem – Source of much of our unconscious behaviours that are critical for survival Medulla – responsible for heart rhythm and breathing Reticular formation – responsible for sleep and waking up Pons- helps with transitioning between the different stages of sleep Hypothalamus – Responsible for the release of hormones and maintaining constant temperature in your body Thalamus – receives and relays many signals going to and from the brain Amygdala – regulates emotional responses Hippocampus – learning and memory. Transitions experience in the moment to long term memories Basal Ganglia – refining movement and also contains the reward centre Development of the forebrain Human brain retains the most of the basic features of the other less complex mammalian brains (brain stem, midbrain, forebrain) Human brain contains more neurons and connections than the forebrains of other animals The smallest unit of brain function Debate in early 1900s Camillo Golgi – The smallest unit of brain function were nerve fibers and the connection between them allowed higher level functioning  Santiago Ramony Cajal – Brain function can go down to the cellular level, individual neurons. Neurons Neurons send either electrical signals or chemical signals Electrical signals – helps you experience the world Dendrites – Receive signals from other neurons Myelin sheath – allows faster conduction of the electrical signal down the axon Neuron Types Sensory neurons – Simple. take in physical energy from the environment Motor Neurons – Most Robust. Send signals from the spinal cord and allow you to move different parts of your body. Pyramidal cells – Neurons contained in the brain. Populate the cerebral cortex Purkinje cells – Only located in the cerebellum. Interneurons – pass signals between neurons. Only located in the nervous systems. Neurons and Glial cells Support cells Astrocytes – extra nutrients from the blood stream to help with the function of neurons. Protect the brain from rupturing from the blood vessels Microglial cells – remove waste and debris from nearby brain function. Also help immune responses Ependymal cells – Produce the cerebral spinal fluid. Abnormalities in spinal fluid ex. Meningitis or hydrocephalous Oligodendrocytes – form the myelin of neurons within the central nervous system Schwann cells – form the myelin of neurons within the peripheral nervous system Electrical signaling between neurons Excitation and Inhibition - A neuron can receive thousands of electrical signals every second - Action potentials are electrical impulses used to signal other neurons Purpose of action potentials - Action potentials allow us to experience the world from sensation to higher order perception  - Ex. Sound and language Neurotransmitters - Neurons are constantly producing neurotransmitters - They are stored in presynaptic vesicles - When the action potential reaches the axon terminal it causes NT release in the synapse - NT is received by receptors on postsynaptic neuron - Presynaptic neuron – generates the action potentials - Postsynaptic neuron – receiving neuron - Reuptake – the neurotransmitter is sucked back up into the presynaptic neuron - Deactivation- enzymes break down the neurotransmitters and deactivate it - Diffusion- the neurotransmitter floats away from the synapse Drug action at synapses - Most psychoactive drugs exert their effects by influencing NT action at the synapse - Agonist – substance that ENHANCES the function of the neurotransmitter at a synapse - Antagonist – Substance that INHIBITS the function of neurotransmitter at a synapse Types of Neurotransmitters Acetylcholine (ACh) - Allows for activation and control of different muscles around the body. - major neurotransmitter involved in forming new memories Norepinephrine - Main neurotransmitter for the sympathetic nervous system – flight or flight response - Increase heart rate and increase blood flow Serotonin - Role in Altering mood and modulating mood - Allows us transition between the different stages of sleep Dopamine - Two main pathways in the brain - Reward pathway: Active when we engage in a rewarding behavior - Movement pathway: Modulates movement within the body Amino acid neurotransmitters - GABA: Involved with the parasympathetic nervous system (most inhibitory) - Glutamate: Most excitatory neurotransmitter  Endorphins - Act as the body’s natural pain relievers Chapter 6: Sensation and perception Sensation to perception: - Stimulus - sensory receptors - neural impulses –perception - Transduction – Physical energy in the environment being converted to a neural signal The eye - Cornea - focuses the image and protects the eye - Pupil – controls the amount of light that goes in the eye - Iris – muscles that allow the pupil to change size - Lens – focus a sharp image to the back of the eye - Retina – like a curved projection screen at the back of the eye - Blind spot – gap at the back of the eye, where the optic nerve connects to the retina - Fovea – part of the retina directly behind the centre of your field of view Problems of focus - Myopia – when things are further away they become for fuzzy - Hyperopia – objects that are close up are more out of focus The retina 1. Light enters the eye and travels to where the receptors are located (rods and cones) and convert it to a neural signal 2. Neural signal is passed onto the bipolar cells and the ganglion cells 3. Ganglion cells send the signal out of the eye along the optic nerve back toward the back of the brain Distribution of rods and cones - Rods allow us to detect motion within the visual field and see in dimly lit conditions - Cones provide high visual acuity and process color  Visual pathway - Two different optic nerve travelling from the left and right eye - Optic chiasm – where the signals of the optic nerve cross over - Signals travel to the thalamus and then to the to the visual cortex located in the occipital lobe Electromagnetic spectrum Seeing color - We see color because we have different sensitivity to different kinds of wavelengths - Physical energy in the environment does not have perceptual qualities – Light waves are not “colored” but wavelength determines perception of color Seeing Color Color reflectance - Most color we see is the result of light being reflected off an object Color warning signals - Animals use a lot of color warning signals so they can associate their colors with being dangerous Trichromatic vision - We are able to see colors due to the cones in our retina that respond to the specific wavelengths of light - We have 3 different types of cones. Each cone responds to a different range of wavelengths - Long: red and orange, medium: green, short: blue, purple and pink Dichromatism - The person only has 2 types of cones instead of 3 - red-green color deficiency is the most common type Opponent process - Opposing color channels processed by opponent neurons in visual cortex - With color afterimages you exhaust one end of the color channel, so you start seeing the other end Color vision - Trichromatic is in the retina - Opponent process in beyond the retina - Ratio of cone activity received and processed by opponent neurons  - Pattern of opponent neuron responses reveals the precise wavelength of light that produced it - Helps us notice the fine discrimination between two shades Complex visual perception - two approaches 1. Perception results from the sum of “sensations” 2. Gestalt approach: perception starts from the whole (illusory contours) Gestalt principles - Simplicity - Similarity - Continuity - proximity - Figure-ground segregation Perceiving depth - Binocular depth cues (results from binocular disparity): an image that enters our left eye is slightly different than our right eye - Stereoscopes and 3d movies - A 1960 study tested the ability of infants to detect a large change in height - Visual cliff – as babies develop they learn differences in height and depth perception - Monocular depth cues – don't require the interaction between both eyes. Is used to perceive depth from a 2d image - Relative height- we use relative height of images in the scene to determine how far away they are - Familiar size – having a perception of how big an object is in real life Size constancy - illusions in size constancy – using depth cues to create an illusion - The ames room – other visual illusion rely on restricted veiwing angle and manipulation of depth cues Sound - Travels in waves - The higher the amplitude the louder the sound is - Frequency is the number of wave cycles per second Hearing  - To hear sound the sound waves must travel into your ear and be converted into a neural signal and then transmitted to your brain - Pinna – exposed part of the ear - Tympanic membrane – eardrum - Cochlea – contains the receptors for sound Cochlea: basilar membrane - Responds to the sound waves and them transmits those fibers to nerve fibers - The apex of the membrane is tuned for low frequency sounds and the base is tuned for high frequency sounds Perception of sound - For a sound to be perceived it must travel to the brain - There is a specific part of the thalamus that is devoted to processing auditory signals Hearing problems - Conductive – disruption of the sound signal within the ear - Sensorineural – a problem with the neural processing of the sound waves Cochlear implant - Transmits neural signals within the cochlea that are no longer being transmitted on their own Taste - We taste food due to the chemical contents of the food reacting with taste receptors within our mouths - Each taste bud contains multiple receptors - The bumps on our tongues show where taste buds are located Taste sensitivity - Supertaster: have more taste buds than the average person (more sensitive to bitter foods)  - Non-taster: have fewer taste buds than the rest of the population Olfaction - Extract chemicals from the air into our noses and then the chemicals are converted by the receptors within the nasal cavity into a neural signal - Neural signals travel to the olfactory bulb then to the brain - Orbitofrontal cortex – the area of the brain that decides whether a odour is pleasant or not - Amygdala – allows us to have an emotional reaction to the smell Perceiving touch - Mechanoreceptors (receptors in our skin) are receptive to temperature and pressure changes against the skin - Cranial and spinal nerves carry signal to the brain - Somatosensory cortex – contains a map of the body and responds to different areas of the body Pain - Nociceptors – allow us to detect when a touch signal is harmful - Fast fiber pain – reserved for sharp pain - Slow fiber pain – transmits lingering pain Gate control method - Pain signals can be influenced by a person cognitive state - Pain signals travel to the brain via the spinal cord - Additional signals influence pain signals - Can act to open or close a “gate” - Open gate causes more pain, and closed gate means less pain - Ex. Placebo effect, meditation, acupuncture Chapter 7: States of consciousness Attentional system - Filters out sensory experiences that are not important Donald Broadbent - Filter theory: Filter only allows certain information through for further processing - If you are listening to something and there is another sound in the background, you may not process what the other sound is but you will be aware of its physical quality and its pitch. You will not be aware of anything meaningful  - Cocktail party effect: you are having a conversation with someone and you hear your name in someone else's conversation. This breaks the laws of the filter theory. Attenuation theory - Developed by Ann Treisman (1967) - The meaningful aspects of an unintended message are weakened Subliminal advertising - We can focus on something and then hidden messages are allowed to exist and get through our attentional system - Ex. Ad telling ppl to drink coca cola and people went and bought more without being consciously aware of how the ad affected them - The effect subliminal advertising has a small effect on peoples consumer choices Implicit priming - View a list of words with no explicit instruction to remember the words - Later given a word stem completion task - Since the person has prior experience of the word they remember it at an unconscious level Inattentional blindness - We attend to what we expect to see (filling in the blanks) - Unexpected events go unnoticed Divided attention - Multitasking - The effect of talking on driving ability - Reading while listening to music. Music with lyrics makes in harder to read Cerebral lateralization - Some tasks are more highly dependent on processing in one hemisphere as opposed to the other - Language production and comprehension is heavily collateralised to the left hemisphere in most people - When a person Is trying to focus on two language related tasks, they can interfere with each other being they are being processed in the same part of the brain - Most of our experiences involve the communication between the two hemispheres. The communication occurs in the corpus callosum Split brain surgery  - The complete severing of the corpus callosum - Separates the two hemispheres - Used to help people with seizures Spatial attention: line bisection task - How we process the space around us, usually at an unconscious level - Line bisection task: a person is presented with a series of lines one at a time and then have to determine where the middle and draw a line through it. Majority of a persons guesses will be more to the left - We have a left side bias for our attention to space Spatial neglect - Parietal lobe controls spatial attention - People that have suffered a stroke find it difficult to comprehend the left side of an image - Cancellation task Ventral and dorsal pathways - Ventral pathway goes to the temporal lobe: helps us identify objects (what) - Dorsal pathway goes to the parietal lobe: helps us interact with objects (where, how) - The visual illusions of the two lines uses the ventral pathway What is consciousness? - All conscious experiences are associated with brain activity - Variation in consciousness occur naturally or they can be manipulated The global workplace model Altered states of consciousness - Traumatic brain injury (TBI) - Effects range from mild to severe - Determining consciousness depends on degree of both arousal and awareness - Arousal: a person is awake - Awareness: how aware a person is  Unresponsive wakefulness syndrome - Terri Schiavo - Results from extensive brain damage - Formerly known as persistent vegetative state Locked in syndrome - As a psychological state has been compared to being buried alive - Full conscious awareness Altered states of consciousness - Hypnosis: a state between sleep and wakefulness in which a person becomes highly suggestable - Neo dissociation theory: a legitimate state of hypnosis a person can enter - Sociocognitive theory: a person in a hypnotic state is fully aware of what is happening, but they are behaving in a way they think a hypnotized would act - Concentrative meditation: focus on one mental image - Mindfulness: a person lets their thoughts flow freely but does not react Circadian rhythm - 4-hour clock - A portion of visual signals from the eyes travel to hypothalamus  - Allows light to influence the rhythmic activity of the suprachiasmatic nucleus (SCN) - Signals from the SCN project to the pineal gland to influences production of the hormone melatonin (sleep hormone) Measuring sleep - Electroencephalogram (EEG): measures brain wave activity - Electromyogram (EMG): measures changes in muscle tone - Electrooculogram (EOG): measures eye movements Stages of sleep - REM sleep: most conscious stage of sleep. REM sleep cannot be reached until at least 2 hours into the sleep cycle. The brain is very active and the eyes are fluttering underneath the eye lids. - Non-REM sleep: deep sleep. Lasts longer than REM sleep - Effect of depriving people of REM sleep: the next sleep the person has they will enter REM sleep earlier than they usually would (REM rebound) Brain activation during REM sleep - Brain regions linked to motivation, emotion and vision - Inhibition of prefrontal cortex - Atonia: A lack of muscle tone in the body Disorders of sleep - Sleepwalking - Night terror - Onset insomnia: inability to sleep from the beginning of the night - Maintenance insomnia: inability to stay asleep - Terminal insomnia: inability to fall asleep after waking up in the middle of the night - Narcolepsy: a person falls asleep at inappropriate times - Cataplexy: loss of muscle control - Dysfunction of Orexin neurons in the hypothalamus Neural basis of waking up - Reticular activating system (RAS): allow a person to be consciously awake - Mixture of nuclei and fibers in the brainstem - In some situations, signals can travel to the forebrain before the spinal cord so then a person is consciously aware they are awake Drugs and consciousness - Drugs alter conscious awareness through their effects on neurotransmitters Antianxiety and sedatives - Engage GABA receptors - Benzodiazepines: minor tranquilizers, anti-anxiety - Barbiturates and alcohol: produce sedation and can induce sleep Stimulant: MDMA - Slow to act but lasts long up to 4 hours - Sense of euphoria and heightened awareness - Acts serotonin, dopamine and norepinephrine Opioid analgesics - Used as painkillers - All opioids are potently addictive since effects often very pleasurable - Natural source of opioids: derived from seeds of opium poppies. Used for thousands of years Opioid Analgesics - Morphine - Named after “Morpheus” the Greek God of dreams - Synthesized from the active ingredient found in opium in early 1800’s - Heroin - Was used as a cough reliever - First synthesized from morphine in late 1800’s - Heroin: very potent pain reliever but highly addictive. Can cause respiratory failure - Fentanyl: analgesic potency about 80 times that of morphine Hallucinogens - Alter sensory perception and produce vivid hallucinations - LSD discovered by Swiss chemist Albert Hofmann - Tested it on himself and his colleagues in 1943 - Experiences vary greatly between users- from euphoric and frightening  - Addiction rates and neurotoxicity: not as bad as people thought - During 1950’s and 60’s clinical trials of LSD in Saskatchewan - May be beneficial in palliative care Chap 7 textbook - implicit associations test, or IAT. This research method uses computers to assess people’s reaction times to various stimuli and is a very difficult test to fake because it records automatic reactions that occur in milliseconds - Mindfulness is a state of higher consciousness that includes an awareness of the thoughts passing through one’s head. - Flexible Correction Model people who are aware that their thoughts or behavior are being influenced by an undue, outside source, can correct their attitude against the bias. - Hypnosis: can be explained by dissociation - Trance states: similar to hypnosis except the person has less control over their voluntary movements. Ex. A person getting “possessed” in a religious ceremony Sleep: Stage 1 (called NREM 1, or N1) is the “falling asleep” stage and is marked by theta waves. Stage 2 (called NREM 2, or N2) is considered a light sleep. Here, there are occasional “sleep spindles,” or very high intensity brain waves. These are thought to be associated with the processing of memories. NREM 2 makes up about 55% of all sleep. Stage 3 (called NREM 3, or N3) makes up between 20-25% of all sleep and is marked by greater muscle relaxation and the appearance of delta waves. Finally, REM sleep is marked by rapid eye movement (REM). Interestingly, this stage—in terms of brain activity—is similar to wakefulness. That is, the brain waves occur less intensely than in other stages of sleep. REM sleep accounts for about 20% of all sleep and is associated with dreaming.