Biology of Mind Essay

* Everything mental is concurrently biological * Plato correctly located the mind in the spherical head * Aristotle believed mind was in the sum total * Although heart is the symbol for love, psychological science has proven that you fall in love using your caput * 1800s Franz chafe (German psychologist) invented phrenology theory that claims that bumps on our skull could reveal our mental ability and character traits * Biological Psychology the branch of psychology concerned with the links between biology and behaviour * Biological psychologists some(prenominal)times called Behavioural neuroscientist, neuropsychologist, behaviour geneticist, psychological psychologist, bio psychologist * We atomic number 18 a system of substances, that are composed of even smaller substances (tiny kiosks make up form organs) * Bodys datarmation system is built from billions of tiny interconnected system of neur nonpareils * Sensory Neurones neurons that tolerate incoming information fr om the sensory receptor the champion and the spinal anesthesia anesthesia cord for membering afferent * ride Neurons the neurons that carry outgoing information from the school principal to the vigors and the glands efferent * Interneurons neurons within the mastermind and the spinal corf that that communicate internally and intervene between the sensory inputs and the ride widenings * Each neuron consists of a* Cell proboscis and furcation fibres (the cells life support center) * Dendrite fibres receive information and conduct it toward the cell personate * axone passes messages away from the cell body to a nonher(prenominal) neurons, muscles and glands * Can be very long projecting several(prenominal) feet into the body * Myelin sheath a layer of fatty tissue paper segmentally encasing the fibres of many neurons * Allows for fast nervous im nerve impulse transmission among neurons * If myelin sheath degenerates, chat to muscles slow with eventual loss of m uscle control * military act potential drop brief electric charge that travels down a neurons axon (neural impulse) * primarily an axon is in a negative state, while the fluid outside an axon is in a positive state * Resting potential the positive outside/ negative inside state of an inert neuron * K+ in axon Na+ outside axon (-70mv)* Axon membrane is Selectively semipermeable does not allow everything inside (selective) * When a neuron fires, the first bit of the axon renders up allowing positively charged sodium ions to enter * That section of the ion becomes depolarized, making the axons next channel to open up * During resting period(refractory period) the neurons pump the positively charged sodium ions back outside * Each neuron receives signals from hundreds of opposite neurons * Excitatory signals wish pushing a neuron accelerator * Inhibitory signals like pushing its breaks* scepter the level of stimulus required to trigger a natural impulse * If the exc itatory signal negatively charged inhibitory signal exceeds a min intensity (-60mv) * How neurons communicate Before thought that axon of one cell fused with dendrites of another, still Sir Charles Sherrington noticed that it takes a long time for the signal to travel. Therefore reason out that there is a gap * Synapse the voice between the axon tip of the sending neuron and the dendrite of the receiving cell * Synapse gap (synaptic c unexpended) the tiny gap at the junction (less than a millionth inch wide) * When action potential reaches the terminals at the axon, release of chemical messenger is triggered (neurotransmitters) * Soon the neurotransmitters cross the synapse gap and moor to the receptor site on the receiving neuron * For an instant the receptors unlock the channels at the receiving site and electrically changed atoms flow in , exciting or inhibiting the receiving neuron readiness to fire * Then reuptake occurs (a cognitive operation when the sending neuron re absorbs the neurotransmitters)* How neurotransmitters Influence Us there is a particular path way in the brain for certain neurotransmitters and particular neurotransmitters may have particular effect on behaviour and feeling * Example Acetylcholine (ACh) one of the best understood neurotransmitters * Has to do with learning and memory* At every junction between tug neurons and otiose muscles * Muscles contract, but when pathway is blocked we are paralyzed * Drugs like hokey opiates (like heroin and morphine) lessen pain and boost mood, may move brain to s hand producing its natural opiates (may cause discomfort) * Drugs and other chemical affect brain chemistry at synapses by either amplifying or blockade a neurotransmitters activity * Agonist a molecule similar to a neurotransmitter that can mimicker its effect or block the reuptake * Black widow spider venom floods synapses with Ach cause muscle contractions and possibly death * Antagonists block neurotransmitters p erformance * May occupy receptor sites but not similar enough to stimulate receptor* Nervous system bodys electrochemical communication nedeucerk consisting of nerve cells from peripheral and central nervous systems * Peripheral Nervous System (PNS) sensory and repulse nervous system that connects the CNS to the rest of the body. Has 2 components * Somatic Nervous System part of the PNS that controls skeletal muscles * Automatic Nervous System part of the PNS that controls the glands and muscles of the internal organs (ie the heart) * Sympathetic nervous System arouses the body and gives energy * Accelerate flare, raise blood pressure, slow digestion when something alarms, enrages or challenges you making you alert and ready for action * Parasympathetic Nervous System calms the body down, conserving energy (opposite of sympathetic) The two work together to keep you in steady internal state* Central Nervous System (CNS) the brain and the spinal cord * anxious networks gro ups of brain neurons cluster into work groups * Neurons network with near-by neurons with which they can make fast connection * Spinal cord information way connecting PNS to the Brain * Reflex an automatic response to a sensory stimulus spinal cords work * Simple reflex pathway is composed of single sensory & take neurons * Communicate through interneurons* Below pt of injury on spinal cord loses connection w/ brain lose all sensation and voluntary movement in body regions with sensory & motor connections * The Endocrine System bodys slow chemical communication system a primed(p) of glands that produce hormones into your bloodstream * Hormones chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream and affect other tissues * Slower than neural massages, but last longer* Adrenal secreter a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body at time of stress * Increase heart rate, blood sugar levels, blood pressure * Pituitary Gland endocrine systems nigh influential gland. When under hypothalamus influence, the pituitary gland regulates growth and controls other endocrine glands * Pea sized structure located in the core of the brain * Example pituitary gland influences the sex glands to release sex hormones * (brain pituitary other hormone brain ) connection b/w endocrine + nervousModule 5* Lesion tissue destruction * Brain lesion -Naturally or experimentally caused destruction of brain tissue * Used in Experiments tiny clusters of normal/defective brain cells would be destroyed w/ surrounding unharmed which part influences what Scientists electrically/chemically/magnetically stimulate mixed parts of the brain note effects * Neuroscientists study the working brain by recording brains electrical activity * Electroencephalogram (EEG) amplified recording of the waves of electrical activity that sweep across the brains surface (measured by electrodes places on scalp) * PET (positron emission tomography) Scan visual display that shows brain activity that detects where radioactive glucose (gamma rays) goes in the brain while it performs a certain task * Active neurons are glucose hogs* MRI (magnetic resonance imaging) technique that uses magnetic field and radio waves to produce computer generated images of the soft tissue show brain anatomy * Align spinning atoms of the brain molecules, then radio wave pulse temporarily disorients atoms return to normal spin formed detailed pic of the brain tissue b/c released signals * fMRI (functional MRI) a technique revealing blood flow (brain activity), by comparing sequential MRIs show brain function and structure* brain stem the oldest part of the central core of the brain * Starts where the spinal cord swells as it enters the skull * Responsible for automatic survival functions * Medulla base of brainstem * Responsible for heartbeat and breathing * Right above the medulla are the pons help coordinate movement Brainstem is where most nerves to and from each side of the brain connects to the opposite side of the body crossover pt * Reticular formation located inside brainstem b/w ears extends from spinal cord thalamus * A nerve network plays an important role in controlling arousal * Filters incoming stimuli and relays important info to other parts of brain * Thalamus brains sensory switchboard receives sensory info leave out smell from all senses, then directs messages to the sensory receiving subject area in the lens cortex and transmits replies to the cerebellum and medulla * Located on top of the brainstem* Cerebellum functions include assisting sensory input and coordinating voluntary movement output and balance located at the back of the brainstem * Enables nonverbal learning + memory judge time, play emotions, discriminate sounds/textures Limbic System neural system associated with emotions and drive * Lo cated below cerebral cerebral hemisphere 2 halves of brain (brain hemisphere) * Hippocampus process memory* Amygdala two neural clusters linked to emotion (influences aggression and fear) * Hypothalamus located below the thalamus keep bodys internal environment in a steady state * Directs several maintenance activities (eating, drinking, body temperature) * Helps govern endocrine system via pituitary glands* conjugated to emotions and rewardModule 6* Older brain networks sustain radical functions and enable emotion, memory and basic derives * Newer brain networks (within the cerebrum the two hemispheres that make up 85% of our brain mass) are responsible for more progress things like speaking and thinking and perceiving Cerebral cortex thin layer of interconnected neural cells covers the brain(cerebral) hemispheres. bodys ultimate control + info-processing center (thinking mostly occurs) * As we move up the physical ladder, cerebral cortex expands, genetic control decr eases, and adaptation increases * small cerebral cortex (ie frogs) operate mostly on programed genetic instructions (instinct) larger cortex larger capacity for learning & thinking more filmable * Humans have a very complex functioning cortexStructure Has lots of wrinkles and if expanded, triples the area * brain hemispheres filled w/ axons connecting cerebral cortex to all other brain regions * Glial cells cells in the nervous system that protect, nourish and support neurons * Provide nutrients, insulating myelin, guide neural connection and mop up ions and neurotransmitters to neurons * May also participate in information transmission and memory * Moving up animal chain proportion of glial cells to neurons increases * Each hemispheres (there are 2) are divided into 4 lobes separated by fissures (folds) * Frontal lobe (behind the forehead) involved in speaking and muscle movement also controls making plans and judgments * Parietal lobe (at the top to rear) receives sensory inp ut for touch & body position * Occipital lobe (at the back of the head) receives information from visual handle * Temporal lobe (above the ear) includes auditory areas (receives info from opposite ear) Functions* German physician Gustav Fritsch and Eduard Hitzing applied mild electric stimulation to a dogs cortex caused parts of the dogs body to move * Worked merely when stimulating the arch shaped regions on the back of the frontal lobe * Stimulating parts of this region in the left/right hemisphere caused movements on opposite side of certain body parts go cortex area at the rear of the frontal lobe that controls voluntary movement * Areas of body that require most control (like fingers and mouth) have largest area * Sensory cortex area at front of parietal lobe that process sensory touch &movement sensations * The more sensitive the body region, the larger area for sensory cortex is developed for it * Association area areas of the cerebral cortex not involved in primary m otor control function or sensory functions they are involved in more complex functions like learning, memory, thinking and speaking * Not dormant areas rather interpret, integrate & act on info neat by sensory areas * found in all four lobes* Front lobe enable judging, processing of newfangled memories and planning * Damage to frontal lobe may cause genius change (Ex Gage, damaged frontal lobe, but still had all memories and skills intact.. just became more irritable and dishonest) * Parietal lobe enable mathematical and three-dimensional argument * Underside of the right temporal lobe allows us to recognize faces * Memory, language & attention results from synchronized activity among brain areas * Brains Plasticity brains ability to change, during childhood, by reorganizing after damage or building new paths based on experience * Severed neurons do not regenerate and some specific brain functions are reassigned to certain areas * Some neural tissue can be reorganize if the p erson is still young * Constraint-induced therapy aims to rewire the brain by warning a fully functioning limb and forcing the used of the disfunctioning limb * Losing a finger may cause the sensory area responsible for that finger to input adjacent figures (making them more sensitive) * Neurogenesis formation of new neurons* The fact that brains two sides serve different functions is seen when there is damage * 1961, Philip Vogel and Joseph Bogen thought that major epileptic seizures were caused by increase in brain activity bouncing back and forth between the cerebral hemispheres * Tried cutting the star callosum the large band of axon fibre connecting the two brain hemispheres and carrying massages between them * Split brain delineate resulting from the surgery that isolates the brains two hemispheres by cutting the fibres (mainly those in corpus callosum) connecting them * Normal personality and intellect hardly affected * Right hemisphere used when a person preforms perc eptual tasks * Makes inferences to languages* go away hemisphere increase activity when a person speaks or calculates * Makes quick, literal interpretations of language * Also responsible for sign language in deaf people* 90% of people are right give and 10% of people are left handed ( a bit more male left handed people and a bit less female) * 96% of right handed people process barbarism in left hemisphere * 70% of left handed people process speech in left hemisphere, and everyone else either left or both * Bias of right hand is peculiar to humans (and other primates like chimpanzees and baboons) * Either genes or parental factor indicates handedness