Psychology Concise Notes PDF

Proprioception and Kinaesthesia How can you walk in a pitch black room? You rely on your sense of balance/position --proprioception. \- Tiny little sensors located in our muscles that goes up to spinal cord and to the brain. It's sensitive to stretching. \- Sensors contract with muscles -- so we'...

Proprioception and Kinaesthesia How can you walk in a pitch black room? You rely on your sense of balance/position --proprioception. \- Tiny little sensors located in our muscles that goes up to spinal cord and to the brain. It's sensitive to stretching. \- Sensors contract with muscles -- so we're able to tell how contracted or relaxed every muscle in our body is. Kinaesthesia is talking about movement of the body. Proprioception was cognitive awareness of body in space. Kinaesthesia is more behavioural. Kinaesthesia does not include sense of balance, while proprioception does. Pain and Temperature \- Pain = nociception, temp = thermoception \- In order for us to sense temperature, we rely on the TrypV1 receptor. Interestingly, this receptor is also sensitive to pain. · There are thousands of these in membranes. Heat causes a conformational change in the protein. · When cell is poked, thousands of cells are broken up, and releases different molecules that bind to TrypV1 receptor. Causes change in conformational change, which activates the cell and sends signal to brain. \- 3 types of fibres -- fast, medium, slow. · A-beta fibres - Fast ones are thick and covered in myelin (less resistance, high conductance) · A-delta fibres --- smaller diameter, less myelin. · C fibres - small diameter, unmyelinated (lingering sense of pain). Pain also changes conformation of receptors -- capsaicin binds the TrypV1 receptor in your tongue, and triggers the same response. Taste and Smell Olfaction -- Structure and Function \- When you have a cold, you aren't able to taste things very well. · When you eat, molecules travel up back of throat and some go into back of your nose. So you're using your sense of smell in conjunction with taste. · If your smell is knocked out, you can't taste things as well. Smell is also known as olfaction \- Area in nostril called the olfactory epithelium. Separating the olfactory epithelium from the brain is the cribriform plate. Above the plate is an extension from the brain -- olfactory bulb -- a bundle of nerves that sends little projections through cribriform plate into the olfactory epithelium, which branch off. · At end of each connection are receptors, each sensitive to 1 type of molecule. · Molecule travels into nose, binds one of receptors on nerve endings. \- Zoom in on olfactory bulb · Imagine there's olfactory cell sending projection to olfactory bulb. There are thousands of types of epithelial cells, each with dif receptor. Say this one is sensitive to benzene rings. · When it binds to receptor, triggers events that cause cell to fire. AP will end up in olfactory bulb. All cells sensitive to benzene will fire to one olfactory bulb -- called a glomerulus. · They then synapse on another cell known as a mitral/tufted cell that projects to the brain. \- The molecule binds to the GPCR receptor, G-protein dissociates and causes a cascade of events inside the cell. Binds to ion channel, which opens and triggers an AP. Pheromones Why do dogs pee on fire hydrant? There are molecules released in the urine, which can be sensed by other animals through the nose -- pheromones. \- Cause some sort of response in animal smelling them. \- Pheromone is a chemical signal released by 1 member of the species and sensed by another species to trigger an innate response. \- Really important in animals, particularly insects -- linked to mating, fighting, and communication. Specialized part of olfactory epithelium in animals -- the accessory olfactory epithelium. It sends projections to the accessory olfactory bulb. \- Within the accessory olfactory epithelium, you have the vomeronasal system. \- In vomeronasal system, there are basal cells and apical cells. They have receptors at tips. \- Triangle will come in and activate receptor on basal cell here. Basal cell sends axon through accessory olfactory bulb to glomerulus, which eventually goes to the amygdala. · Amygdala is involved with emotion, aggression, mating etc. \- Humans have vomeronasal organ, but no accessory olfactory bulb. Gustation -- Structure and Function \- We have 5 main tastes, localized on the tongue -- bitter, salty, sweet, sour, and umami (ability to taste glutamate). \- Taste buds are concentrated anteriorly on the tongue. Taste buds can be fungiform (anterior), foliate (side), and circumvallate (back). · In each taste bud are the 5 receptor cells that can detect each taste. Each taste can be detected anywhere on the tongue. · Mostly on anterior part of tongue. \- Each receptor has an axon, which all remain separate to the brain. And they all synapse on dif parts of the gustatory cortex. Known as the labelled lines model. · Ex. Glucose hits tongue, activates sweet cell (because it has sweet sensitive receptors), triggers cascade of events so cell depolarizes, and travels down axon to the brain. · Glucose binds GPCR, conformational change, G-protein dissociates, opens ion channels, cause cell to depolarize and fire an AP \- Sweet, umami, and bitter cells GPCR receptors. \- Sour and salty rely on ion channels. They bind to receptor directly, ex. NaCl binds to receptor and causes ion channel to open, and + ions outside flow in. Cell depolarizes and fires an AP. \- What happens if we put salty receptor inside a sweet cell? Receptors in membrane bind to glucose. But let's insert a salty receptor. Since axon from cell leads to brain, if NaCl comes in, it activates the receptor, + ions go inside, sweet cell depolarizes and fires AP, and brain interprets it as a sweet signal. Sleep and Consciousness States of Consciousness \- Consciousness is awareness of our self and environment -- dif levels of awareness can be induced by external factors such as drugs or internal mental efforts. Range from alertness to sleep. \- Alertness -- you're awake \- Daydreaming- feel more relaxed, not as focussed. Can also be light meditation (self-induced) \- Drowsiness - just before falling asleep/after waking up. Can also be self-induced in deep meditation. \- Sleep -- not aware of world around you.4 main types (Each type oscillates at dif frequency) · Beta (13-30Hz) -- associated with awake/concentration. Increased stress, anxiety, restlessness. Constant alertness. · Alpha waves (8-13 Hz) -- in daydreaming. Disappear in drowsiness but reappear in deep sleep. During relaxation. · Theta waves (7 Hz) -- Drowsiness, right after you fall asleep. · Delta waves (0.5-3 Hz) - Deep sleep or coma. · EEGs can measure brainwaves Sleep Stages and Circadian Rhythms Your brain goes through distinct brain patterns during sleep. 4 main stages that occur in 90 min cycles \- (Order is from N1 -\> N2 -\> N3 -\> N2 -\> REM - Order within cycle goes How long each stage lasts depends on how long you've been asleep and your age) First is non-rapid eye movement sleep (non-REM) -- N1, N2, N3 \- N1 (Stage 1)-- Dominated by theta waves. Strange sensations -- hypnagonic hallucinations, hearing or seeing things that aren't there. · Ex. Seeing flash of light, or someone calling your name, doorbell, etc. Or the Tetris effect -- if you play Tetris right before bed, you might see blocks. Also a feeling of falling -- hypnic jerks. Theta waves. \- N2 (Stage 2) -- deeper stage of sleep. People in N2 are harder to awaken. We see more theta waves, as well as sleep spindles and K-complexes. · Sleep spindles help inhibit certain perceptions so we maintain a tranquil state during sleep. Sleep spindles in some parts of brain associated with ability to sleep through loud noises. · K-complexes supress cortical arousal and keep you asleep. Also help sleep-based memory consolidation. Even though they occur naturally, you can also make them occur by touching someone sleeping. \- N3 (Stage 3) -- slow wave sleep. Characterized by delta waves. Where walking/talking in sleep happens. REM (rapid-eye movement) stage. Most of your other muscles are paralyzed. Most dreaming occurs during REM sleep, so paralysation inhibits actions. Most important for memory consolidation. \- Combination of alpha, beta, and desynchronous waves, similar to beta waves seen when awake. · Sometimes called paradoxical sleep, because brain is active and awake but body prevents it from doing anything. · Waking up during REM sleep prevents memory formation of the dream. Circadian Rhythms -- why you get sleepy in afternoon. They're our regular body rhythms across 24-hour period. Controlled by melatonin, produced in the pineal gland. \- Control our body temperature, sleep cycle, etc. \- Daylight is big queue, even artificial light. \- Also change as you age -- younger people are night owls, but older people go to bed early. Dreaming \- Everybody dreams during REM sleep. Can tell someone is dreaming because eyes are moving rapidly under eyelids, and brainwaves look like they are completely awake. \- Activity in prefrontal cortex during REM sleep is decreased -- part responsible for logic. Why things in our things that defy logic don't seem weird. Sigmund Freud \- Dreams are our unconscious thoughts and desires that need to be interpreted. Little scientific support. Evolutionary biology \- Threat simulation, to prepare for real world. \- Problem solving \- No purpose Other \- Maintain brain flexibility \- Consolidate thoughts to long-term memory, and cleaning up thoughts. People who learn + sleep retain more than those who do not sleep. But role of REM is unclear. \- Preserve and developing neural pathways. Because infants constantly developing new neural networks spend most of time in REM sleep. Dream Theories -- Freud and Activation Synthesis Hypothesis Do our dreams have a meaning? Sigmund Freud's theory of dreams says dreams represent our unconscious feelings/thoughts. Like an iceberg. \- 1. What happens? Manifest content (Ex. Monster chasing you) \- 2. What is hidden meaning? Latent content (Ex. Job pushing you out) · Can help us resolve and identify hidden conflict. Activation Synthesis Hypothesis \- Brain gets a lot of neural impulses in brainstem, which is sometimes interpreted by the frontal cortex. \- Brainstem = activation, and cortex = synthesis. \- Our brain is simply trying to find meaning from random brain activity. Therefore might not have meaning. Sleep Disorders People with sleep deprivation might be more irritable and have poorer memory. Could be dangerous when it comes to flying airplanes or driving cars. \- Also more susceptible to obesity -- body makes more cortisol, and the hunger hormone. \- Can also increase your risk for depression. REM sleep helps brain process emotional experiences, which can help protect against depression (not certain). · How much is enough sleep? 7-8 hours for adults. Varies with age and individual. Babies need a lot more. More serious form -- insomnia (persistent trouble falling asleep or staying asleep). Various medications but taking them too long leads to dependence and tolerance. Other end of spectrum is narcolepsy -- can't help themselves from falling asleep. Various fits of sleepiness, going into REM sleep. Can occur any time. 1 in 2000. \- Indications it's genetic, and linked to absence of alertness neurotransmitter. Sleep apnea -- 1 in 20 people. People with it are often unaware. Stop breathing while sleeping -- body realizes you're not getting enough oxygen, wake up just long enough to gasp for air and fall back asleep without realizing. Can happen 100x/night! \- Don't get enough N3 (slow-wave) sleep. \- Snoring is an indication, or fatigue in morning. Sleepwalking/sleep talking -- mostly genetic, occur during N3 and are harmless. Occur more often in children (have more N3). Breathing-Related Sleep Disorders \- Sleeping problems can arise from brain, airways, or lungs/chest wall. \- Obstruction to airways causes problems breathing at night · Air going into nose/mouth reaches the lungs. Tissues around neck may block this airflow -- snoring/gasping/pauses in breathing. Called an apnea (absence of airflow). · Called obstructive sleep apnea, very common and gets worse as people get older. · People are tired/sleepy and unrefreshed when they wake up. 5+ apneas an hour (measured by polysomnography) \- In the brain, called central sleep apnea. Presence of apneas without obstruction. Problem with the control system for ventilation. · Cheyne-Stokes breathing (period of oscillations, then flat, etc.) pattern in polysomnography \- In lungs or chest wall, hyperventilation can occur (high pCO2, low pO2). Caused by medication/obesity. Chronically elevated pCO2 can lead to right-sided heart failure. Hypnosis and Meditation Hypnotism usually involves getting person to relax and focus on breathing, and they become more susceptible to suggestion in this state -- but only if they want to. More alpha waves in this stage -- an awake but relaxed state. \- Some use hypnosis to retrieve memories, very dangerous because memories are malleable. Can create false memories. \- 2 theories for how it works: · Dissociation Theory - hypnotism is an extreme form of divided consciousness · Social Influence Theory - people do and report what's expected of them, like actors caught up in their roles \- Refocused attention, so sometimes it's used to treat pain. Reduced activity in areas that process sensory input. Although it doesn't block it out, it might inhibit attention Meditation -- training people to self-regulate their attention and awareness. Can be guided and focused on something in particular, like breathing, but meditation can also be unfocussed -- mind wanders freely. \- More alpha waves than normal relaxation in light meditation. \- In deep meditation have increased theta waves in brain. · In people who regularly go to deep meditation, increased activity in prefrontal cortex, right hippocampus, and right anterior insula -- increased attention control (goal of meditation). \- Can be helpful for people with ADHD, or in aging. Drug Dependence Psychoactive Drugs Depressants and Opiates Depressants are drugs that lower your body's basic functions and neural activity, ex. Heart rate, reaction time, etc. The most popular depressant is alcohol. · Think more slowly, disrupt REM sleep (and form memories), removes your inhibitions \- Barbiturates -- used to induce sleep or reduce anxiety. Depress your CNS. · Side effects are reduced memory, judgement and concentration, with alcohol can lead to death (most drugs w/ alcohol are bad) \- Benzodiazepines are the most commonly prescribed suppressant. Sleep aids or anti-anxiety · Enhance your brain's response to GABA. They open up GABA-activated chloride channels in your neurons, and make neurons more negatively charged. · 3 types: short, intermediate, and long-acting. Short and intermediate are usually for sleep, while long acting are for anxiety.