THE BRAIN and its functions
a s e r ie s o f g u i d e s for g e n e ra l p s y c ho l o g y
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Anatomy of the Ner vous System, Anatomy of the Senses, and Psychological Disorders
Anatomy of the Nervous System
Neurons are Nerve Cells. Bipolar (interneuron)
Unipolar (sensory neuron)
Multipolar (motor neuron)
Pyromidal cell
Sensory (afferent) neurons: carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord.
Motor (efferent) neurons: carry outgoing information from the brain and spinal cord to the muscles and glands.
Interneurons: within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.
Soma (cell body): cell’s life support center; contains nucleus, DNA, mitichondria, ribosomes, etc.
Dendrites: branch like, recieve messages from other cells.
Axon: carries elecrical implusles from cell body.
Myelin Sheath: speeds up transmission of messages; fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.
Multiple Sclerosis: a chronic, typically progressive disease involving damage to the myelin sheath of the nerve cells in the brain and spinal cord. Results in lack of muscle control.
Neurons transmit signals when stimulated by sensory input or triggered be neighboring neurons.
Dendrites pick up signal and activate action potential (a neural impulse; a brief electrical charge hat travels down an axon.) Contact points betwen neurons are synapses. Synapses do not touch neighboring neuron. This is called a synaptic gap.
Neurotransmitters: chemical
messengers jump gap to receptor sites. Neurotransmitters excite or trigger the next neuron, then “pop” out and reuptake (a neurotransmitters reabsorption by the sending neuron. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the recieving neuron, thereby influencing whether that neuron will generate a neural impulse. This causes motions and emotions.
Endorphins: natural opiate-like neurotransmitters linked to pain control and pleasure.
Ovesupply with opiate drugs can suppress the body’s natural endorphin supply.
Excitatory neurotransmitters:
Inhibitory neurotransmitters:
Norepinephrine: helps control alertness and
GABA: Gamma-aminobutyric acid;
arousal; undersupply can depress mood.
undersupply linked to seizures, tremors, Glutamate: major excitatory neurotransmitter; and insomnia. involved in memory; oversupply can Seratonin: mood, hunger, sleep, arousal; low overstimulate the brain, producing amounts linked to depression. migraines or seizures.
These neurotransmitters can excite or inhibit: Acetylcholine (ACh): enables muscle action, learning, memory. Dopamine: influences movement, learning, attention, emotion. Alzheimers: progressive neurological deterioration that can occur in middle or old age, due to generalized deterioration of the brain (deterioration of ACh-producing neurons.)
Schizophrenia: a long-term psychiatric disorder of a type involving a breakdown in the
relation between thought, emotion, and behavior. Excessive amounts of dopamine are linked to schizophenia, and addictive and impulsive behaviors An undersupply of Dopamine is likned to tremors and decreaed mobility in
Parkinson’s disease.
The endocrine system: the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream. Endocrine system Postal service
Neurotransmitters Email
Hormones: chemical messengers that are manufactured by the
endocrine glands, travel through the bloodstream, and affect other tissues; affect mood, arousal, circadian rhythm, regulate metabolism, monitor immunse system, signal growth, help sexual reproduction’ attraction, appetite, agression; hormones linger.
Glands of the Endocrine System Adrenal glands: produce adrenaline; inner part helps trigger fight or flight Pancreas: produces insulin gluragon; regulates levels of sugar in blood Thyroid: affects metabolism Parathyroids: help regulate level of calcium in blood Testes: produce testosterone Ovaries: produce estrogen Pituitary: rules all of the glands; produces growth hormone, helps stimulate
growth; produces oxytocin: trust and social bonding mastered by hypothalamus
Phrenologist Franz Joseph Gall Phrenology: the detailed study of the shape and size of the
cranium, as a supposed indication of character and mental abilities.
Phrenology was dismissed as a psuedoscience.
Psychologist just beginning to realize the brain was the source of self, not the heart or soul. Phrenology did lead to an important discovery: different parts of the brain control specific aspects of our behavior.
Brain function is localized.
The nervous system: the body’s speedy, electrochemical
communication network, consisting of all the nerve cells of the peripheral and central nervous systems. Central Nervous System (CNS): brain and spinal cord; makes decisions; command center. Peripheral Nervous System: connects CNS to the rest of the body; sensory and motor neurons that gather information and report back to CNS. Nerves: bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs.
Case Study: Phineas Gage Phineas Gage was using a tamping iron to pack gunpowder into a rock. A spark ignited the gunpowder, shooting the rod up through his left cheek and out the top of his skull, leaving his frontal lobes damaged. Gage was immediately able to sit up and speak, and after his wound healed, he returned to work. But having lost some of his neural tracts that enabled his frontal lobes to control his emotions, the affable, soft-spoken man was now irritable, profane, and dishonest. This person, said his friends, was “no longer Gage.� His mental abilities and memories were unharmed, but his personality was not.
True or False? We only use 10% of our brain. False. Nearly every region of the brain lights up during even simple tasks like walking and talking.
Our new brain systems are built on old brain systems. The “Old Brain� Brain stem: most ancient and central core of the brain. Medula: automatically controls (beating heart, breathing lungs.) Pons: helps coordinate several other automatic functions. Thalamus: takes in sensory information related to seeing, hearing, touching, and tasting.
Reticular formation: network inside the brainstem essential for arousal. Cerebellum: responsible for non-verbal learning and memory, the perception of time, and modulating emotions.
The Limbic System
Limbic system: border region seperating new vs. old brain. Amygdala: two lima-bean-sized clusters of neurons involved in memory consolidation and emotion.
Hippocampus: central to learning and memory. Hypothalamus: regulates body temperature, circadian rhythms, and hunger; helps govern the endocrine system.
The two hemispheres of your cerebrum make up about 85% of your brain weight, and oversee your ability to think, speak, and percieve.
Four lobes of the brain all seperated by fissures. Frontal lobe: speaking, planning, judging, abstract thinking, personality aspects Parietal lobe: sense of touch, body position Occipital lobe: information related to sight Temporal lobe: comprehension, sound, speech Motor cortex (rear of frontal lobe): controls voluntary movements, sends messages from brain out to body.
Somatosensory cortex: processes incoming sensations. Association areas: interpereting and integrating sensory input and linking with memories; found in all four lobes.
The mind is what the brain does.
Anatomy of the Senses
Sensation is the bottom-up process by which our senses, like vision, hearing, and smell, receive and relay outside stimuli.
Perception is the top-down way our brains organize and interpret that information and put it into context.
Absolute threshold of sensation: the minimum stimulation
needed to register a particular stimulus fifty percent of the time.
Weber’s Law: we percieve differences on a logorithmic, not a linear scale.
Light moves in waves.
Short wavelength = higher frequency, higher energy (blue light)
Longer wavelengths = lower frequency, lower energy (red light)
Smaller amplitude = duller colors
Rods and cones
Greater amplitude = brighter colors
Rods: see in grayscale, used in peripheral and low-light Cones: see fine details and color, well-lit conditions
Young-Helmholtz Trichromatic theory: the retina houses three color specific receptor cones (red, green, and blue.)
Opponent- Process theory:
we see color through proceses that work against each other (some receptor cells stimulated by red, inhibited by green, etc.)
Light > cornea > pupil > lens > retina > receptor cells > bipolar cells > ganglion cells + optic nerve > thalamus > visual cortex
Sound, like light, also moves in waves. Sound is measured in decibels.
The outer ear collects soundwaves and funnels through ear canal to the middle ear causing the eardrum to vibrate, sound waves are amplified by ossicle bones (stirrup, hammer, anvil anvil), the vibrations travel to the inner ear to the cochlea causing 16,000+ hair cells to bend, nerve fibers convert energy to electrical impulses, which go up auditory nerve to auditory cortex.
Taste buds contain a taste pore, a supporting cell to the Basal cell, and a Gustatory receptor cell. These determine between 5 distinct tastes, and combination thereof.
Salty
Sweet
Sour
Bitter
Umami (savory)
Sensory interaction: principle that one sense can influence the others. Synesthesia: the production of a sense impression relating to one sense or part of the body by stimulation of another sense or part of the body.
There are three theories regarding synesthesia: Theory 1: the rogue development of new neural connections may overide normal boundaries that typically seperate the sense.
Theory 2: all babies are born with synesthesia and experience mixed senses until the brain matures and creates seperate sense chanels, unless they don’t.
Theory 3: neurotransmitters associated with one function turn up in a different part of the brain.
Taste and smell are chemical senses. Airborne molecules travel up the nose, reach 5-10 million receptor cells at the top of each nasal cavity.
Receptor cells
Olefactory bulb
Primary smell cortex
Limbic system
Odor receptors can come together in different combinations to communicate unique smells. How we feel about a smell, and our perception of it, is often tangled up in our experiences with that scent.
Sense of touch is a combination of 4 distinct skin sensations: pressure, warmth, cold, pain.
Kinesthesis: the way your body senses its own movement and positioning.
Your vestibular sense monitors your heads position and your balance; ruled by semi-circular canals and fluid filled vestibular sacs that connect canals to cochlea.
Perception is heavily biased by expectations, experiences, moods, cultural norms. Perception is the process that allows us to make meaning out of our senses and experience the world around us.
Perceptual set: the psychological factors that determine how you perceive your environment: expectaions, context, culture, emotions.
Form perception Figure-ground relationship: the organization of the
visual field into objects (figures) that stand out from their surroundings (ground).
Proximity: we group nearby figures together. Continuity: we perceive smooth, continuous patterns
Proximity
rather than discontinuous ones.
Closure: we fill in gaps tp create a complete, whole object. Depth perception: the ability to see objects in 3D although images that strike the retina are 2D.
Binocular cues: depth cues, such as retinal disparity, that depend on the use of two eyes.
Continuity
Monocular cues: depth cues, such as interposition
and linear perspective, available to either eye alone; relative size and eight, linear perspective, texture gradient, interposition.
Motion perception: shrinking objects are retreating, and enlarging objects are approaching.
Closure
Your brain constructs your perceptions.
States of Consciousness
Consciousness is loosely defined as our awareness of ourselves and our environment. Cognitive neuroscience: the study of how brain activity is linked
with our mental processes (thinking, perception, memory, language).
Structural imaging: shows brain’s anatomy and is useful for identifying tumors, diseases, injuries.
Functional imaging: shows electromagnetic or metabolic activity in brain, like bloodflow, to show correlations between specific mental functions and activity in particular brain areas.
Dual processing: the principle that information is simultaneously processed on seperate conscious and non-conscious tracks.
Selective attention: the focusing of conscious awareness on a particular stimulus or group of stimuli.
Change blindness: psychological phenomenon in which we fail to notice changes in our environment.
Sleep is another state of consciousness.
Sleep: a periodic, natural, reversible and near total loss of consciousness.
Sleep is neccesary for recuperation, growth (pituitary releases growth hormones), mental function (improving memory, time for processing, boosting creativity.)
Electroencephalograph (EEG): machine that measures the brain’s electrical activity.
Rapid eye movement (REM): a recurring sleep stage during which vivid dreams commonsly occur.
Four Stages of Sleep N REM-1: Lightest sleep, expereince hypnagogic sensations (falling) N REM-2: Experience sleep spindles, rapid brain wave activity N REM-3: Delta waves, experience most restful, deepest sleep REM: Muscles are paralyzed, brain is more active than in relaxed wakefulness, expereince vivid visual dreams.
The Sleep cycle repeats roughly every 90 minutes.
During the day, the adrenal gland releases cortisol. When falling asleep, the pineal gland releases melatonin: the brain is relaxed, but still awake; alpha waves occur in brain.
Sleep deprivation: immune system depression, slow reaction time, predictor for depression, weight gain. Insomnia: recurring problems in falling or staying asleep. Narcolepsy: a sleep disorder characterized (sometimes) by uncontrollable sleep attacks; difficiency in hypocretin: neurotransmitter that helps keep you awake.
Sleep apnea: sleep disorder that causes the sleeper to temporarily stop breathing.
REM sleep disorder: associated with dopamine difficiency. Night terrors: increased heart and breathing rates, screaming and thrashing, not remembered upon waking. Most common in children under7, may be spurred by stress, fatigue, sleep deprivation, sleeping in unfamiliar surroundings; occurs during NREM-3. Night terrors are NOT the same as nightmares. Nightmares are bad dreams that occur during REM and are typically remembered upon waking.
Theories on why we dream: Information processing theory: our dreams help us sort out and process the day’s events and fix them into our memories.
Physiological function theory: dreaming may promote neural development and preserve neural pathways y providing the brain with stimulation.
Cognitive development theory: Dreams are part of our cognitive development, they draw on our knowledge and understanding of the world, mimicking reality.
Neural activities model theory: REM triggers neural activity, and dreams are accidental side-effects.
Altered States Hypnosis: a calm, trance-like state during which you tend to have, heightened concentration and focus, and in which you’re typically more open to suggestion.
Dissociation: a special dual processing state of “split consciousness.”
Tolerance: the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect.
Neuroadaptation: brain chemistry adapting to offset the drug’s effect.
Psychoactive drugs
Psychoactive drugs: chemical substances that alter your mood and perception; mimick functions of neurotransmitters; expectation of what substance might do (placebo.)
Depressants: mellow, slow body function, suppress neural activity;
Disinhibitor: impairs your judgement areas, while reducing your self-awareness and self-control; Alcohol, tranquilizers, opiates
Stimulants: speed up body functions, excite neural activiy, spike self-confidence, mood changes; Aggitated depressive crash;
Caffeine, nicotine, amphetamines (meth, ectasy, cocaine); cocaine blocks reuptake of dopamine, seratonin, and norepinephrine; meth triggers release of dopamine
Hallucinogens: distort perceptions, evoke sensory images; Plants, fungus, synthetic (LSD)
Neurological disturbances can also spur hallucinations.
We are far less aware of what’s going on around us than we think we are.
Psychological Disorders and Treatments
Psychological disorders are deviant, distressful, and dysfunctional patterns of thoughts, feelings, or behaviors. Deviant: thoughts and behavior that are different from most of the
rest of your cultural context. “Deviant” behaviors change across multiple cultures.
Distress: a subjective feeling that something is really wrong. Dysfuntion: when a person’s ability to work and live is clearly, often measurably impaired.
The medical model says that psychological disorders have physiological causes that can be diagnosed on the basis of symptoms, treated, and sometimes cured.
Biopsychological approach: holistic perspective; takes into
account psychological influences (stress, trauma, learned helplessness) and biological influences (evolution, individual genes, brain structure and chemistry) and social-cultural influences (roles, expectations, definitions of normality and disorder.)
American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5)
Houses all psycholigical disorders, designed to be a work in progress, forever.
Anxiety disorders are characterized not only by distressing, persistent anxiety but also aften by the dysfunctional behaviors that reduce that anxiety. Obsessive-Compulsive disorder (OCD): characterized by unwanted repetitive thoughts, which become obsessions, which are sometimes accompanied by actions, which become compulsions.
Generalized anxiety dirorderr (GAD): continually tense and apprehensive, experiencing unfocused, negative, and out-of-control feelings.
Panic disorder: sudden episodes of intense dread or sudden fear that come
without warning, affects about 1 in 75 people, most often teens and young adults. Panic attacts are brief, well-defined and sometimes severe bouts of elevated anxiety. Characterized by chest pains, racing heartbeat, difficulty breathing. A common trigger for panic disorder is simply the fear of having another panic attack.
Social anxiety disorder: characterized by anxiety related to interacting or being seen by others.
Phobias: persistent, irrational fears of specific objects, activities, or situations; leads to avoidance behavior.
Learning perspective: suggests coonditioning, observational learning, and cognition best explain the source of anxiety.
Biological perspective: natural selection. Moods are emotional states that are even more subjective and harded to define than emotions themselves. Moods are long-term emotional states rather than discreet, fleeting feelings.
Mood Disorders
Mood disorders: characterized by emotional extremes and challenges in
regulation mood (tend to be longer-term disturbances.) Includes depressive disorders (prolonged hopelessness and lethargy) and bipolar disorders (involve alternating between depression and mania.)
Bipolar disorder: a mood disorder in which a person alternates between the hopelessness and lethargy of depression and the overexcited state of mania (formerly called manic-depressive disorder.)
Depression: diagnosed when a patient has experienced at least five symptoms of depression
for more than two weeks. Symptoms include: depressed mood, significant weight or appetite loss or gain, too much or too little sleep, decreased interest in activities, feeling worthless lethargic or fatigued, difficulty concentrating or making decisions, recurrent thoughts or death or suicide.
Mania: a mood disorder marked by a hyperactive, wildly optimistic state.
The cause of mood disorders is often a combination of biological, genetic, psychological, and environmental factors. Norepinephrine is severly lacking in depressed brains, but “off-the-charts” in manic brains. Drugs that seek to reduce mania do so by reducing norepinephrine levels. Low serotonin levels correlate with depressive states. Exercise is often recommended to combat depression, as it increases serotonin levels. Medications designed to treat depression do so by raising serotonin or noepinephrine levels.
Schizophrenia Schizophrenia Spectrum Disorders: characterized by disorganized thinking; emotions
and behaviors that are often incongruent with their situations; and disturbed perceptions, including delusions and hallucinations; a chronic condition that usually surfaces for men in their early to mid-20s, and for women in their late 20s. Characterized by: loss of contact with reality, psychotic symptoms, disorganized thinking and speech, breakdown in selective attention, delusions or false beliefs not based in reality, naratives of persecution and paranoia, perceptual disturbances and hallucinations (auditory hallucinations are the most common form), disorganized, abnormal and incongruent behavior and emotions. Positive symptoms: add something to the experience of a patient; ex. hallucinations. Negative symptoms: subtract from normal behavior; ex. lack of emotion. Disorganized symptoms: jumbles of thought or speech, problems with attention. The brain has extra receptors for dopamine; overly responsive dopamine systems might magnify brain activity, creating positive symptoms. Dopamine blocking drugs are often used as antipsychotic medication. Unusually high activity in thalamus (filtering incoming sensory signals) when hallucinating. Over-activity in the amygdala (fear processing) in patients with paranoia.
Diathesis-Stress Model: a combination of biological and genetic vulnerabilities–diathesis–and environmental stressors–stress–that both contribute to the onset of schizophrenia.
Dissociative Disorders Dissociative disorder: disorders in which conscious awareness becomes separated (dissociated) from previous memories, thoughts, and feelings.
Dissociative amnesia: when a person may block out specific information or have no memory of a particular event.
Dissociative Fugue: during which a person may suddenly just set out on a journey for hours or months, and travel around with no awareness of their identity.
Dissociative Identity Disorder: when a person exhibits more than on distinct and alternating personality.
Trauma and Addiction Post-traumatic Stress Disorder (PTSD): a psychological disorder generated by either
witnessing or experiencing a traumatic event. When trauma manifests as nightmares, flashbacks, avoidance, fear, guilt, anxiety, rage, or insomnia and begins to interfere with your ability to function, it can be PTSD. Symptoms: Re-living the event, avoiding situations you associate with the event, excessive physiological arousal, negative changes in emotions and beliefs.
Post-traumatic growth: the positive psychological changes resulting from the struggle with challenging circumstances and life crises.
Addiction/Dependence: compulsive, excessive, and difficult-to-control substance use
or other, initially pleasurable behavior that begins to interfere with ordinary life, work, health, or relationships. Physical dependence: a physiological need for a drug, that reveals itself through unpleasant withdrawal symptoms if the use stops or reduces. Psychological dependence: a psychological need to use a drug, or complete an activity to relieve negative emotions.
Eating and Body Dysmorphic Disorders Anorexia Nervosa: an eating disorder in which a person (usually an adolescent female) maintains a starvation diet despite being significantly (15 percent or more) underweight. Two subtypes of the disorder: First involves restriction: usually consists of an extremely low-calorie diet, excessive exercise, or purging, like vomiting or use of laxatives. Second involves binge/purge: episodes of binge eating, combined with the restriction behavior. Symptoms of Anorexia include: abnormally slow heart rate, loss of bone density, fatigue, muscle, weakness, hair loss, severe dehydration, and extremely low body mass index.
Bulimia Nervosa: an eating disorder in which a person alternates binge eating (usually of
high-calorie foods) with purging (by vomiting or laxative use), or fasting. Symptoms include: irregular heartbeat, inflammation of mouth and esophagus, tooth decay/ staining, irregular bowel movements, peptic ulsers, and pancreatitis.
Binge-eating disorder: significant binge-eating, followed by emotional distress, feelings of lack of control, disgust, or guilt, but without purging or fasting.
Body Dysmorphic Disorder: a psychological illness that centers on a person’s obsession with physical flaws- either minor or imagined. A growing understanding of body dysmorphia suggests that it shares some traits with obsessive-compulsive disorder: excessive exercise, obsessive grooming, extreme cosmetic procedures, critical and unsatisfied with appearance, fears of deformity, anxiety and depression, avoiding social situations, fear of being judged.
So far, all of the psychological disorders discussed have been considered ego-dystonic, meaning those who have them are aware they have a problem and tend to be distressed by their symptoms. This next group of disorders are considered to be ego-syntonic, meaning that the person experiencing them doesn’t necessarily think they have a problem.
Personality Disorders Personality disorders: psychological disorders marked by inflexible disruptive, and enduring behavior patterns that impair social and other functioning–whether the sufferer recognizes that or not.
The DSM-V contains ten distinct personality disorder diagnoses, grouped into three clusters.
Cluster A: “odd” or “eccentric” characteristics
Paranoid personality disorder: distrusting of others, guarded, suspicious. Schizoid personality disorder: aloof, indifferent, no interest in relationships, few emotional responses.
Schizotypal personality disorder: severe social anxiety, thought disorder, paranoid ideation, derealization, transient psychosis and often unconventional beliefs.
Cluster B: “dramatic,” “emotional ” or “impulsive” characteristics Antisocial personality disorder: a personality disorder in which a person (usually men) exhibits a lack of conscience for wrongdoing, even toward friends and family members.
Borderline personality disorder: a complicated set of learned behaviors and emotional
responses to traumatic or neglectful environments, particularly in childhood. learned to use dysfunctional ways to get basic psychological needs met; outbursts of rage, self-injury behaviors.
Histrionic personality disorder: “acting a part,” atention-seeking, dramatic & dangerous risk-takers.
Narcissistic personality disorder: selfish, grandiose sense of self-importance & entitlement.
Cluster C: “anxious,” “fearful,” or “avoidant” characteristics Avoidant personality disorder: avoidant, lack of confidence. Dependent personality disorder: excessive need to be taken care of, fear of abandonment. Obsessive-Compulsive personality disorder: preoccupation with orderliness, perfectionism, and mental and interpersonal control, at the expense of flexibility, openness, and efficiency. Researchers argue that some conditions overlap with each other so much that they can be impossible to distinguish. Because of this, the most commonly diagnosed personality disorder is
Personality Disorder not otherwise Specified (PDNOS.)
There are two approaches that will be discussed that are used to treat psychological disorders. Psychotherapy and Biomedical approaches.
Psychotherapy
Psychotherapy: involves a therapist using a range of techniques to help a patient overcome troubles, gain insight, and achieve personal growth.
Psychodynamic approach: helped patients access repressed feelings and memories and un-
conscious thoughts by free association and dream analysis with interpretations from the therapist until patient gained some self-insight.
Existential-Humanistic approach: emphasized people’s inherent capacity formaking rational choices, achieving self-acceptance, and attaining their maximum potential.
Behavioral approach: therapy that aims to change behavior in order to change emotions and moods.
Counterconditioning: a behavior therapy procedure that uses classical conditioning to evoke
new responses to stimuli that are triggering unwanted behaviors. Aversive Conditioning: involves pairing an unpleasant stimulus with the targeted behavior. Exposure therapies: treat anxiety by having a person face their fears by exposing them to real or imagined situations that they typically avoid. Systematic Desensitization: a type of exposure therapy that associates a relaxed state of mind with gradually increasing anxiety-inducing stimuli.
Cognitive approach: helps patients understand that changing what we say to ourselves is a very effective way to cope with our anxieties and modify our behavior. excessive need to be taken care of, fear of abandonment
Effectiveness: whether or not a given therapy works in a “real world setting.” Efficacy: whether a therapy works better than some other, comparable intervention, or a control.
Biomedical
Biomedical therapies: aim to physiologically change the brain’s electrochemical state with psychotropic drugs, magnetic impulses, or even electrical currents and surgery.
Pharmacotherapy is the most widely used. Antipsychotics: used to treat schizophrenia, and other types of severe thought disorders; most alter the effects of dopamine in the brain by blocking the neurotransmitter’s receptor sites and its uptake. Anxiolytics: work by depressing activity in the central nervous system. Antidepressants: treat depression, but also a number of anxiety disorders; mainly altering availability of serotonin and norepinephrine in the brain (SSRIs.) Mood stabilizers: effective in smoothing out the highs and the lows of bipolar disorder.
Electroconvulsive therapy (ECT): involves sending a brief
electrical current through the brain on an anesthetized patient.
Theories on why ECT is effecive: Theory 1: The resulting seizure beneficially alters neurotransmitter activity in areas of the brain associated with moods and emotion.
Theory 2: The electrical impulses modify stress hormone activity in the brain. Theory 3: ECT may re-activate previously dormant or supressed neurons, or possibly stimulate the groth of new ones in key brain regions.
Repetitive Transcranial Magnetic Stimulation (rTMS): involves the painless application of repeated electromagnetic pulses.
Deep Brain Stimulation (DBS): calls for syrgically implanting a sort of “brain pacemaker� that sends out electrical impulses to specific parts of the brain.
This book was created by Kira Stoy for a Senior Digital Design Course at the University of West Florida.