BIOLOGICAL PSYCHOLOGY Everything psychological is ultimately physiological Biological
BIOLOGICAL PSYCHOLOGY Everything psychological is ultimately physiological.
Biological Psychology Origins: Phrenology: Franz Gall (Early 1800’s) He Was Right: • Mental processes found in parts of brain • Larger brains = more intelligent behavior But He Was So Wrong: • Phrenology: bumps on skull indicate mental abilities/character traits.
The Neuron: Basic Hardware Nerve cells specialized in communication Building blocks of the nervous system Receive, integrate, transmit info 86 billion
Anatomy of a Neuron Soma: Cell body – keeps cell alive Nucleus: Contains DNA and coordinates cellular activity Dendrites: receive information from other neurons and relay it to the cell body Axons: carries information to other neurons, muscles or glands. Can be very long – even up to one meter Myelin Sheath: insulating material (made of glial cells) that encases some axons Nodes of Ranvier: gap in myelin that facilitates transmission of nerve impulses Terminal Branches: forms junctions with other cells Terminal Buttons: contains synaptic vesicles that secrete chemicals called neurotransmitters
Multiple Sclerosis Immune system attacks myelin Impulses are transmitted more slowly People with MS have varying symptoms and incapacitation No cure right now, but stem cell transplantation shows promise
Glial Cells Support cells found in nervous system • 1: 1 ratio with neurons • • Supply nourishment, remove waste products, provide insulation
Types of Neurons
Synaptic Transmission Between Neurons • Area between one neuron’s axon terminal and another’s dendrites is the synapse. • When a neuron fires, it releases neurotransmitters, which cross the synaptic gap & bind to receptors on the receiving neuron (lock and key) • Excess neurotransmitters are reabsorbed by the terminal buttons of the sending neuron in a process called reuptake.
Neurotransmitters Acetylcholine (ACh) Associated Disorders: Alzheimer’s Disease • Contributes to regulation of attention, arousal, sleeping, dreaming, learning, and memory. • Botox blocks ACh receptors; black widow bite causes release of Ach. • People who take Benadryl for sleep on a regular basis double their risk of developing Alzheimer’s. .
Neurotransmitters Dopamine (DA) Associated Disorders: Parkinson’s (low) Schizophrenia (high) Addiction • Contributes to control of voluntary movement. • Regulates motivation, pleasure, and emotional arousal. • Cocaine and amphetamines elevate activity at DA synapses.
Neurotransmitters Serotonin Associated Disorders: Depression (low) Eating Disorders/OCD (low) Mania (high) • Involved in regulation of sleep and wakefulness, eating, aggression. • Antidepressants keep serotonin in synapses and prevent reuptake.
Neurotransmitters GABA (gammaaminobutyric acid) Associated Disorders: Seizures (too little) Insomnia (too little) Regulation of anxiety • Major inhibitory neurotransmitter. •
Neurotransmitters Endorphins • Released during exercise, excitement, and sex. Associated • Produces well-being Disorders: and euphoria. Opiate addiction • Resemble opiates in (overuse of opiates structure and effect. decreases • Dulls experience of endorphin pain. supply…more pain when addicted)
HOW NEURONS COMMUNICATE
What Causes an Action Potential (electrical signal)? Dendrites pick up chemical signals (neurotransmitter) Signals affect polarization of the cell Excitatory signals (FIRE!) decrease polarization Inhibitory signals (HOLD FIRE!) increase polarization If the cell becomes positive enough, an action potential occurs.
Summary of the Action Potential • Goes by all-or-none principle; either fires or it doesn’t. • Electric impulse travels through dendrite and soma. • Jumps along the Nodes of Ranvier (speeds transmission). • Causes axon terminals to release neurotransmitters
Refractory Period • Occurs after action potential. • New action potential cannot be initiated. 3 D Simulation
Hypothalamus Function: • Hunger/thirst/body temp • Perspiration/bp/heartrate • Shivering Corpus Collosum Function: • Connects left and right hemispheres Damage: • Excessive eating • Aggression • Self-mutilation • Overactive sex drive Damage: • Split-brain Pituitary Gland Function: • “Master Growth” • Release of growth/oxytocin **Works with Endocrine System Cerebellum Controls: • Movement • Posture/timing **Part of Endocrine System Damage: • Loss of coordination, tremor, difficulty walking, slurred speech **Alcohol depresses cerebellar functions. Brain Stem Includes: • Pons/medulla/midbrain Amygdala Function: • Fear/emotion processing • Learning/reward processing Controls: • Breathing, heartrate, swallowing, bp, whether you are awake or asleep. Damage: • Fear response • Loss of emotional control Deficits in **motions Hippocampus Function: • Memory Storage and Formation • Spatial Navigation Damage: • Memory impairment
Frontal Lobe Main Function: • Voluntary motor control • Decision-making • Cognition • Intelligence • Language processing Somatosensory Cortex Main Function: Motor Cortex • Sensory processing/integration Parietal Lobe Main Function: • Coordinate/initiate movement • Sensory information • Pain/touch recognition Pre-Frontal Cortex Main Function: • Decision-making • Inhibition • Intelligence • Social skills Auditory Cortex Main Function: • Ability to hear (process volume and pitch) Temporal Lobe Main Function: • Hearing • Facial/object recognition • Understanding language • Smell Occipital Lobe Main Function: • Vison
Speech Areas in Left Hemisphere Broca’s Aphasia: Trouble with speech production https: //www. youtube. c om/watch? v=JWCc. VQm. Em. Y Wernicke’s Aphasia: inability to comprehend speech. They can speak, but it may be nonsensical. https: //www. youtube. com/watch? v=3 oef 68 Yab. D 0
Brain Plasticity Neurons stop producing after birth, BUT, the brain has the ability to change and adapt as a result of experience. Experience Can Sculpt Structure Damage/Destruction of Sensory Pathways Can Lead to Neural Reorganization The Adult Brain Can Generate New Neurons in Specific Areas. • Can migrate to other areas where they sprout axons and form synapses with existing neurons. The Miracle of Plasticity
Enhancing Neuroplasticity Traveling Learning a musical instrument Non-dominant hand exercises Reading fiction/expanding vocabulary Creating artwork Dancing Sleeping
Central Nervous System Brain • We use more than 10%! Spinal Cord • Spinal Reflexes • Conducts sensory info from body to brain. • Conducts motor information from brain to body
Peripheral Nervous System Consists of neural pathways that bring information to and from brain. Connects CNS to organs and muscles Autonomic Somatic • Sympathetic • Afferent Peripheral Nervous System • Parasympathetic • Efferent
Branches of the Autonomic Nervous System Sympathetic division—mobilizes the body to react in the face of threat; fight or flight Parasympathetic division—demobilizes the body to conserve energy; calms the body down after a stress reaction
Endocrine System: Another Way to Communicate • Endocrine system– glands that secrete chemicals into the bloodstream that help control bodily function. • Nervous system uses neurotransmitters; endocrine system uses hormones. • The Messengers: Hormones-- chemical substances released into the bloodstream by the endocrine glands • Hormones are pulsatile – released several times a day in brief bursts that last only a few minutes
Who’s In Control? Many parts of the endocrine system are under CNS control Neural activation hypothalamus to secrete a particular releasing factor pituitary gland releases specific hormone Pituitary gland (“master gland”) governs release of hormones from the rest of the endocrine glands responsible for major bodily processes Brain Pituitary Other Glands Hormones Body
Governs release of hormones, growth hormone, oxytocin Salt balance, cortisol, sex hormones, adrenaline Makes insulin
Key Hormones • Growth: secreted by pituitary • Oxytocin: secreted by pituitary • “love” hormone • Associated with social behavior, bonding, sexual behavior, trust • Adrenaline (epinephrine) and noradrenaline (norepinephrine) • Secreted by adrenal gland as part of fight or flight response • Insulin: Secreted by pancreas • Regulates amount of glucose in blood • Lack causes a form of diabetes • Testosterone: secreted in gonads (men have more) • Associated with aggression, sex drive, fat distribution, muscle mass • Estrogen: secreted in gonads (women have more) • Associated with reproduction, menstrual cycle, female sex characteristics
CT (Computerized Tomography) • Computer-enhanced x-ray of brain structure. • Multiple x-rays shot from many angles, and computer combines readings.
PET (Positron Emission Tomography) • Use radioactive markers (such as glucose) injected into bloodstream. Metabolism of glucose is assessed. • Radiation detectors scan brain while you do a task.
MRI (Magnetic Resonance Imaging) • Does not show function, but detailed structure than CT scan. • Uses magnetic fields, radio waves, and computerized enhancements to produce 3 -D images.
f. MRI (Functional Magnetic Resonance Imaging) • Monitors blood flow and oxygen consumption in the brain to identify areas of high activity. • Maps actual activity of brain over time.
SPECT (Single-Photon Emission Computerized Tomography) • Uses radioactive substance and a special camera to create 3 -D pictures. • Less accurate than PET, but less expensive. Older technology.
EEG (Electroencephalogam) • Records electrical activity of the brain. • Electrodes are placed on the outside of the head and record then amplify neuronal electrical transmission.
MEG (Magnetoencephalogam) • Measures brain function by assessing speed and strength of magnetic fields created by neuron’s electrical pulses.
Brain Scans at Work Lesioning Destroying tiny clusters of defective brain cells. Electrical Brain Stimulation Electric current is used to simulate neurons or neural networks.
Brain Hemisphere Organization Each hemisphere’s primary connections are on opposite sides of the body. • Corpus Collosum ensures that information is transferred from one side to the other. Corpus Collosum: band of nerve fibers that connect the left and right hemisphere. • For sensory and motor information: left hemisphere control the right side of the body and the right hemisphere controls the left. • For vision, stimuli in right half of visual field go to receptors in left side of the eye, and vice versa. • For auditory stimulation, sounds presented in the left ear are registered in right hemisphere first, and vice versa.
Brain Hemisphere Organization Lateralization: left and right hemispheres serve different functions Left Hemisphere Right Hemisphere • Superiority on nonverbal processing tasks: • Spatial • Musical • Visual Recognition • Perception of Emotions • New Stimuli • Self-Awareness • Superiority on verbal processing: • Language • Speech • Reading • Writing • Prioritizes the Expected Two sides are constantly collaborating. Quality of collaboration is important. Einstein’s brilliance could have been due to exceptional right/left brain connectivity.
Bisecting the Brain: Split-Brain Research Split Brain Surgery (Vogel/Bogen): Sever Corpus Collosum to treat epilepsy. Everyday behavior was normal. BUT Sperry and Gazzaniga thought there was more to the story.
Chimeric Face Study (half-face components of a full face) Split-Brain Research Video
Dual Processing: The Power of the Unconscious Information is often simultaneously processes on separate conscious and unconscious tracks. Parallel Processing: Effortless processing mode. Used to solve simple problems or process information we have already learned. Sequential Processing: Forms representations of novel situations or solves difficult problems. Dual Processing is an example of the way modern psychologists perceive the unconscious.
What Is Life? Consciousness and Brain Death Consciousness: Awareness of self and environment Persistent Vegetative State: patient is unconscious, but has sleep/wake cycles. • No voluntary behavior • No bladder/bowel control • Variable Reflexes • Can feel pain • Typically do not require life support • Can recover, but unlikely after 3 months. f. MRIs have shown cognitive brain activity in patients with persistent vegetative state. Responses to “walking through your house” and “playing tennis” Three Criteria for Brain Death: Coma – no sleep/wake cycle, no movement, no pain response. Absence of Brain Stem Reflexes: no pupil response to light, no gag reflex, “doll’s eyes”. Apnea Test – patient cannot breathe on own. Persists more than 24 hours. Jahi Mc. Math Case
Bioethics Life Support Cost is $8000 a day in the ICU. $2000 -$3000 a day for nursing home. Who Pays? • Your family exhausts all of their resources. • Insurance will pay a set amount. • Family must use all assets to pay. • Go on Medicaid after all assets have been depleted. • Psychological effects of caregivers • What do Catholics believe?
Internal Structures: Brain Stem
Brain Stem: Cannot Live Without It! Midbrain Function: • Eye Movements • Auditory/Visual Processing Damage: • Eyelid drooping • Double vision • Can’t gaze up or down Medulla Oblongata Function: • Breathing/heartrate Damage: • Potential death Pons Function: • Coordinates movement • Regulates breathing • Taste • Sleep/dreaming (REM) Damage: • Impaired breathing • Sleep disturbances • Paralysis • Loss of taste • Locked-in syndrome Reticular Formation Function: • Arousal Damage: • Coma from which you cannot awaken
Internal Structures: Cerebellum
Composed of smaller neurons but contains more neurons than the rest of the brain combined. Cerebellum Function: • Coordination of voluntary movement. • Facilitation of smooth movements. • Posture/timing. • Sequence/nonverbal learning. Damage: • Loss of coordination. • Tremor. • Inability to walk. • Dizziness/slurred speech. Alcohol depresses the cerebellum and leads to “drunken” movements.
Internal Structures: Limbic System
Limbic system Hippocampus Function: • Memory storage and formation • Spatial navigation Damage: • Memory impairment • Disorientation H. M. Case Study Amygdala Function: • Fear/emotion processing • Learning/reward processing Damage: • Fear response • Loss of emotional control • Deficits in recognizing emotions Hypothalamus Function: • Homeostasis • Hunger/thirst/body temp • Arousal • Perspiration/bp/heartrate • Shivering • Pupil dilation Damage: • Excessive eating • Aggression • Hypothermia • Hypersomnia • Lethargy • Self-mutilation • Overactive sex drive **works with endocrine system
Internal Structures: Additional Ones to Know
Pituitary Gland Function: • “Master Gland” • Release of growth/oxytocin **Part of Endocrine System Thalamus Function: • Relaying motor/sensory info • Alertness/Consciousness Damage: • Amnesia/dementia • Coma • Apathy/inattention/loss of alertness • Impaired sensory/motor processing Caudate Nucleus Function: • Learning connections between stimuli and responses • Evaluation of actions and outcomes Damage: • OCD • Hyperactivity Corpus Collosum Function: • Connects left and right hemispheres Damage: • Split-brain
Cerebral Cortex • Seat of complex thought, detailed perceptions, & complex behaviors. • Two hemispheres connected by corpus callosum. • Interconnected neural cells that cover cerebral hemispheres.
New Research on Cerebellum!
Nature vs Nurture: Is It All in the Genes? Heredity: the passing of genetic factors from parent to offspring DNA: molecules containing genetic information. Gene: basic unit of heredity. A section of DNA that codes for the structure of a protein. Chromosomes: strands of DNA wound around each other in a double-helix shape. Genome: All of the genes present inside an organism Genotype: the set of genes responsible for a particular trait Phenotype: the expression of a trait according to an organism’s genes
Genetic Research Twin Studies: comparing resemblance of identical and/or fraternal twins on a specific trait Family Studies: comparing resemblance of family members on a specific trait Adoption Studies: comparing resemblance of adopted children and related and unrelated family members on a specific trait
Epigenetics Environmental influences that determine whether or not genes are expressed (or degree of expression) without altering the DNA sequence. • Adding methyl group OR chemical modifications to proteins called histones. Examples of Causes: • Poor nurturing in youth • Exposure stress • Peculiarities in diet Examples of Studies: • High levels of rat mother licking and grooming added a methyl group to DNA and resulted in lower circulating levels of stress hormones in their babies. • Nurses working in high stress environment vs low-stress environment compared on stress self-reporting and physiological measures. Both measures in high-stress group were correlated with greater DNA methyl groups.
Heritability Measure of the variability of traits in a POPULATION that can be accounted for by genetic factors. • For personality traits (such as extraversion): around. 4 (40 percent). • For intelligence: around. 66 (66 percent). • Height: . 9 (90 percent) • Schizophrenia could be as high as. 79 (79%)
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