Biological Psychology PDF

?? CH 1: THE MAJOR ISSUES 2. Mentalism only the mind truly exists BIOLOGICAL PSYCHOLOGY 3. Identity Position study of the physical roots of mental processes are...

?? CH 1: THE MAJOR ISSUES 2. Mentalism only the mind truly exists BIOLOGICAL PSYCHOLOGY 3. Identity Position study of the physical roots of mental processes are the behavior same as brain processes but Emphasizes: simply described in different ○ Physiology ways ○ Evolution (genetics) ○ Development DUALISM ○ Brain functioning ➔ belief that there are different kinds of substances THE GENETICS OF BEHAVIOR ➔ mind and the body are separate Both genes and environment interact entities to shape human behavior. ➔ defended by Rene Descartes How much of a role does genetics play ◆ French philosopher in shaping human behavior? ➔ most common belief among ○ (psychological disorders, nonscientists weight gain, personality, ➔ rejected by most neuroscientists sexual orientation, sexual identity) HEREDITY a mechanism used to pass the Biological explanations of behavior fall message of inheritance from one generation to the next into four categories: High Heritability 1. PHYSIOLOGICAL ○ a trait that depends largely emphasis on the brain and on hereditary influences other vital organs 2. ONTOGENETIC MULTIPLIER EFFECT describes the development of ➔ Genetic tendencies that guide a structure or behavior behavior 3. EVOLUTIONARY ◆ result in a change in the focuses upon the genetic environment history of a behavior ◆ magnifies the original 4. FUNCTIONAL tendency describes why a structure or behavior evolved as it did Research: TWINS AND ADOPTED CHILDREN THE MIND-BRAIN RELATIONSHIP Researchers study identical and Biological explanations of behavior fraternal twins to infer how much of a bring into focus the relationship genetic component exists for a between the mind and the brain particular behavior ○ "mind-body” ○ Monozygotic = identical ○ "mind-brain problem” ○ Dizygotic = fraternal Researchers also study adopted MONISM children and their resemblance to their ➔ belief that the universe is only biological parents comprised of one type of substance ○ infer the influence of heredity FORMS OF MONISM Traits with a strong hereditary influence 1. Materialism can be modified by environmental everything that exists is intervention. physical by nature PKU (Phenylketonuria) ○ Each base determines one a genetic inability to metabolize base of the RNA phenylalanine RNA results in brain damage ○ Copy of one strand of the ○ unless phenylalanine is DNA removed from the diet triplet of bases = one amino acid Protein GENETICS OF HUMAN LIFE ○ Some proteins become part of Chromosomes the body's structure. ○ contain genetic information ○ Others are enzymes that Every cell = 46 chromosomes control the rate of chemical ○ Except for sex cells reactions. eggs and sperm have 23 RIBONUCLEIC ACID (RNA) chromosomes single strand chemical Sexual reproduction = making 23 can serve as a template/model for new chromosome pairs protein synthesis Proteins determine the development of GENES the body by: Basic units of heredity ○ forming part of the structure of Maintain their structural identity the body from one generation to another ○ serving as enzymes Inheritance through genes biological catalysts ○ demonstrated by Gregor regulate chemical Mendel reactions in the body ○ 19th century monk Strands of genes form chromosomes (picture) 23rd chromosome pair = sex Genes come in pairs. chromosomes (sex of child) By Pair: DURING REPRODUCTION HOMOZYGOUS GENE Females give: X ➔ a person has an identical pair of Males give: X or Y genes on the two chromosomes ○ determines the sex of the child HETEROZYGOUS GENE ○ Male gives X chromosome = ➔ a person has an unmatched pair of female off-spring genes on the two chromosomes ○ Male gives Y chromosome = male off-spring By Effect: DOMINANT GENE DEOXYRIBONUCLEIC ACID (DNA) shows a strong effect in either the double-stranded chemical homozygous or heterozygous contains genetic information condition genes/chromosomes are composed of RECESSIVE GENE DNA shows its effect only in the homozygous condition (picture) One strand of DNA serves as a model for Types of Genes the synthesis of ribonucleic acid (RNA). A. AUTOSOMAL DNA ○ all genes ○ Self-replicating molecule ○ except for sex-linked genes  B. SEX-LINKED natural selection and provide a ○ genes located on the sex survival advantage chromosomes ○ Examples: differences in ○ human chromosomes peripheral/color vision, sleep (picture) mechanisms in the brain, eating habits, temperature HUMAN SEX-LINKED GENES regulation. usually refer to X-linked genes ❖ Y chromosome ARTIFICIAL SELECTION genes for 27 proteins Organisms with desired traits are ❖ X chromosome chosen to be parents of the next generation genes for ~1500 proteins Used by breeders ❖ Sex-limited genes Sometimes used by human parents genes that are present in both sexes but mainly have Reasons for studying animals include: an effect on one sex 1. The underlying mechanisms of Chest hair, breast behavior are similar across species size, etc. and often easier to study in nonhuman species. 2. We are interested in animals for their own sake. Evolution of Behavior 3. What we learn about animals sheds light on human evolution. Genetic Variation 4. Some experiments cannot use ➔ RECOMBINATION humans because of legal or ethical ◆ a new combination of genes reasons. in the off-spring ◆ yield characteristics not The Use of Animals in Research found in either parent Important source of information ➔ MUTATION Highly controversial topic ◆ a change in a single gene Amount of stress and/or pain that is that is: caused to the animal varies rare Colleges and research institutions in random the US are required to have an often independent of Institutional Animal Care and Use the needs of the Committee (IACUC). organism ○ Oversees and determines acceptable procedures EVOLUTION ➔ a change in the frequency of Opposition to animal research varies: various genes in a population over Minimalists: generations ○ favor firm regulation on ➔ It attempts to answer two questions: research 1. How did some species evolve? ○ place consideration upon: 2. How do species evolve? type of animal used amount of stress EVOLUTIONARY PSYCHOLOGY induced focuses on functional explanations Abolitionists: of how behaviors evolved ○ maintain that all animals have assumes that behaviors characteristic the same rights as humans of a species have arisen through  ○ any use of animals is ○ metabolic activities unethical ○ provides energy for cells 4. RIBOSOMES ○ protein synthesis 5. ENDOPLASMIC RETICULUM >> CH 2: NERVE CELLS AND NERVE IMPULSES MAJOR COMPONENTS OF NEURONS THE CELLS OF THE NERVOUS SYSTEM The human nervous system is comprised of two kinds of cells: 1. Neurons 2. Glia ❖ ~100 billion individual neurons ❖ Behavior depends upon the communication between neurons ❖ Neuron cells similar to other cells of the body 1. DENDRITES have a distinctive shape ○ branching fibers surface lined with MOTOR NEURON synaptic receptors its soma is in the spinal cord ○ brings in information from receives excitation from other other neurons neurons ○ Some also contain dendritic ○ conducts impulses along its spines axon to a muscle branches out increase the surface SENSORY NEURON area of the dendrite specialized at one end to be highly 2. SOMA/CELL BODY sensitive to a particular type of ○ contains the organelles stimulation ○ responsible for the metabolic ○ (touch, temperature, odor etc.) work of the neuron 3. AXON Santiago Ramon y Cajal (1852- 1934) ○ single, long, thin fiber with first to demonstrate that the branches near its tip individual cells comprising the nervous ○ responsible for transmitting system remained separate nerve impulses away to ○ showed that they did not other neurons grow into each other as (dendrites/soma), glands, or previously believed muscles ○ Some neurons (axons) are STRUCTURES IN NEURONS covered with myelin sheath insulating material 1. MEMBRANE speeds up ○ separates the inside of the transmission cell from the outside ○ Nodes of Ranvier 2. NUCLEUS interruptions/gaps in ○ contains the chromosomes the sheath 3. MITOCHONDRIA  short, unmyelinated during embryonic sections development ASTROCYTES 4. PRESYNAPTIC TERMINALS ○ helps synchronize the activity ○ endpoints of an axon of the axon ○ Responsible for releasing wrapping around the chemicals to communicate presynaptic terminal with other neurons taking up chemicals released by the axon Terms used to describe the neuron OLIGODENDROCYTES & include the following SCHWANN CELLS ○ build the myelin sheath AFFERENT AXON ○ bringing information into a structure EFFERENT AXON ○ carrying Information away from a structure INTERNEURONS / INTRINSIC NEURONS ○ Their dendrites and axons are completely contained within a structure Neurons vary in size, shape, and Types of Glia function. The shape of a neuron BLOOD-BRAIN BARRIER ○ determines its connection mechanism that surrounds the brain with other neurons blocks most chemicals from Its function is closely related to the entering shape of a neuron. ○ form = function The immune system destroys ○ Example: Purkinje cells of the damaged or infected cells cerebellum branch extremely throughout the body. widely within a single plane ➔ Because neurons in the brain GLIA the other major component of the generally do not regenerate: nervous system ◆ important for the blood brain ○ connective tissue barrier to block harmful material from entering MICROGLIA ○ remove waste material and other harmful microorganisms ACTIVE TRANSPORT protein mediated process RADIAL GLIA useful chemicals are brought into the ○ guides: brain the migration of ○ glucose, hormones, amino neurons acids, and vitamins the growth of their axons and dendrites GLUCOSE ○ simple sugar  ○ primary source of nutrition while drawing two K+ ions into the for neurons cell THIAMINE ○ helps to maintain the ○ chemical that is necessary electrical gradient for the use of glucose THE NERVE IMPULSE SODIUM-POTASSIUM PUMP (cont.) The electrical gradient and the concentration gradient work to pull NERVE IMPULSE sodium ions into the cell. electrical message ○ electrical gradient tends to transmitted down the axon pull potassium ions into the ○ does not travel directly cells down the axon The resting potential remains stable ○ regenerated at points along until the neuron is stimulated. the axon speed: ~1 m/s to 100 m/s HYPERPOLARIZATION increasing the polarization or the RESTING POTENTIAL difference between the electrical the state of the neuron prior to the charge of two places sending of a nerve impulse DEPOLARIZATION membrane of a neuron maintains an decreasing the polarization towards electrical gradient zero ○ a difference in the electrical charge inside and outside of THRESHOLD OF EXCITEMENT the cell any stimulation beyond a certain At rest, the membrane maintains an level electrical polarization ○ massive depolarization ○ a difference in the electrical charge of two locations ACTION POTENTIAL inside of membrane is slightly a rapid depolarization of the neuron negative stimulation of the neuron past the ○ ~70 millivolts threshold of excitation ○ selectively permeable ○ triggers a nerve impulse allowing some (action potential) chemicals to pass more freely than VOLTAGE-ACTIVATED CHANNELS others membrane channels whose ○ Sodium, potassium, permeability depends upon the calcium, and chloride pass voltage difference across the through channels in the membrane membrane. Sodium channels When the membrane is at rest: ○ voltage activated channels ○ Na+ channels are closed. ○ When opened: ○ K+ channels are partially Na+ rushes in closed. a subsequent nerve slow passage of impulse occurs sodium SODIUM-POTASSIUM PUMP protein complex that continually pumps three Na+ out of the cells After an action potential occurs, Na+ In a motor neuron, the action channels are quickly closed. potential begins at the axon hillock. The neuron is returned to its resting AXON HILLOCK state by the opening of potassium a swelling where the axon exits the soma channels ○ Potassium ions flow out due PROPAGATION OF THE ACTION to the concentration POTENTIAL gradient transmission of the AP down the takes positive charge axon with them ○ action potential does not The sodium-potassium pump later directly travel down the axon restores the original distribution of The myelin sheath of axons are ions. interrupted by nodes of Ranvier ○ Local anesthetic drugs block ○ At each node of Ranvier: sodium channels and ○ action potential is therefore prevent action regenerated by a chain of potentials from occurring. positively (+) charged ions Novocain ○ pushed along by the previous segment ALL-OR-NONE LAW states that the amplitude and SALTATORY CONDUCTION velocity of an action potential are describes the "jumping" of the independent of the intensity of the action potential from node to node stimulus that initiated it ○ rapid impulse conduction ○ Once an action potential is ○ conserves energy for the cell triggered: Multiple Sclerosis always fire at the ○ disease in which the myelin same strength and sheath is destroyed and poor speed muscle coordination regardless of how strong or weak the stimulus Not all neurons have lengthy axons. Action potentials are equal in intensity and speed within a given Local neurons = short axons neuron. exchange information with only close neighbors REFRACTORY PERIOD do not produce action potentials after an action potential produce graded potentials during which time the neuron resists ○ “membrane potentials” another action potential vary in magnitude ABSOLUTE refractory period do not follow the the first part of the period all-or-none law membrane cannot produce ○ depolarizes or an action potential hyperpolarizes RELATIVE refractory period proportion to the stimulation second part takes a stronger than usual stimulus to trigger an action potential !! CH 3: BIOLOGICAL allows the message to reach the PSYCHOLOGY brain at full strength ○ but slows it down compared to regular electrical conduction REDUCTIONISM attempts to explain complex How an action potential works: phenomena by reducing them to combinations of simpler An un-stimulated axon has resting components potential ○ electrical polarization NERVOUS SYSTEM CELLS across the membrane covering the axon NEURONS IN CNS ○ maintained by the process and interpret that sodium-potassium pump information (sensory) Na+: mostly outside send commands to muscles, glands the neuron and organs K+: mostly inside ○ human nervous system = are held in place by ~100 billion neurons special "gates" polarization is GLIA maintained by provide insulation and remove the pump waste/foreign bodies sends Na+ out of the ○ 1/10th the size of the neurons cell ○ ~10 times as numerous brings in a smaller number of K+ NERVE CELL GROWTH ○ The result = outside of the neurons do not have a fixed cell has more positive anatomy charges than the inside ○ neurons are constantly When a message from a growing and losing neighboring cell excites part of branches to dendrites and the axon's membrane: axons ○ some of the Na+ gates are new experiences, opened = Na+ can enter learning axon neuron plasticity ≠ intelligence ○ makes the charge inside the more connections = faster thought cell positive (depolarization) process ○ The charge is now briefly the same inside and outside ACTION POTENTIALS the cell. = action potential an excitation that travels along the Polarized axon axon at a constant strength ○ inside negative charge (-70 ○ regardless of distance millivolts) a combination of electrical and ○ relative to the outside chemical processes that axons use to convey information ALL-OR-NONE LAW An action potential is all-or-nothing it's either happening or not ○ no "sort of” action potential  either more or less likely to produce an action potential ○ This activity at the synapses is crucial to everything the brain does. TERMINAL BOUTON ○ end of the presynaptic axon ○ contains many neurotransmitter molecules ○ ready for release Figure 3.4: Sodium and Potassium SYNAPTIC COMMUNICATION Gradients for a Resting Membrane The electrochemical messages carried Inside of the neuron = negative by neurons either increase or ○ (-) protein ions decrease the likelihood that the next Outside of the neuron = positive cell will continue to transmit. ○ relative to the inside ○ takes 1-2 milliseconds Protein and chloride ions EXCITATORY MESSAGES ○ contribute to the overall ○ increase the probability that charge balance (not shown) the next cell will "fire" Few sodium ions cross the membrane ○ continue to carry the at rest, except via the SP pump. transmission Potassium ions tend to flow: INHIBITORY MESSAGES ○ Into cell = electrical gradient ○ decrease the likelihood that ○ Out cell = concentration transmission will continue to gradient travel Figure 3.6: Action Potential E.g. brain sending a (a) During an action potential: message to inhibit ○ Na gates open in the neuron pain in on injured membrane. extremity ○ Na+ enter the axon, bringing positive charges with them. (b) After an action potential at one point along the axon: ○ Sodium gates close at that point and open at the next point along the axon. ○ K gates open. ○ K+ flow out of the axon, carrying positive charges out. SYNAPSES where communication between neurons occur a specialized junction between two neurons where chemical messages cross from one to the other ○ The chemicals released by one will either excite or inhibit the other SYNAPTIC COMMUNICATION (cont.) ○ Na⁺ channels close Each axon has a bulge at the end 6. REPOLARIZATION: called a presynaptic ending ○ voltage-gated K⁺ channels ○ “terminal bouton” open When the action potential reaches ○ allows K⁺ ions to flow out of the terminal bouton: the neuron ○ molecules of a returns membrane neurotransmitter are released potential to a NEUROTRANSMITTER: negative value ○ chemical that is stored in the 7. HYPERPOLARIZATION: neuron and activates special ○ K⁺ channels remain open receptors of other neurons longer ○ Neurons use a variety of causing the neurotransmitters membrane potential to uses a particular dip below the neurotransmitter or a resting level combination of them (more negative) ○ diffuses over the synapse to 8. RETURN TO RESTING STATE: the surface of the receiving ○ K⁺ channels close neuron (“postsynaptic ○ Na⁺/K⁺ ATPase pump neuron”) restores the original ion The neurotransmitter attaches to concentrations receptors on the dendrite or cell body returns neuron to its of the receiving neuron and either resting membrane excites or inhibits it potential ACTION POTENTIAL (SIMPLIFIED) NEUROTRANSMITTERS AND BEHAVIOR 1. RESTING STATE: ○ neuron is at rest PARKINSON’S ○ resting membrane potential = ➔ a condition in which the individual has: about -70 mV ◆ trouble executing voluntary High K⁺ inside movements High Na⁺ outside ◆ has tremors and rigidity 2. STIMULUS: ◆ depressed mood ○ stimulus causes the ➔ linked to a gradual decay in a system membrane potential to of axons that release dopamine become less negative ◆ promotes activity levels and ○ approaching threshold facilitated movement (around -55 mV). ➔ symptoms can be managed in mild 3. THRESHOLD REACHED: cases with a drug called L-dopa ○ voltage-gated Na⁺ channels ◆ synthesized into dopamine by open the neurons 4. DEPOLARIZATION: ➔ axons from the substantia nigra ○ Na⁺ ions rush into the neuron gradually die ○ membrane potential becomes more positive (up to +30 mV). 5. PEAK POTENTIAL: ○ inside of the neuron is now positively charged  SUBDIVISIONS OF THE PERIPHERAL NERVOUS SYSTEM SOMATIC ❖ made up of the peripheral nerves ❖ communicate with the skin and muscles ❖ voluntary, sensory AUTONOMIC ❖ controls the involuntary actions of the heart, stomach and other organs The link is not always so clear though. Attention-Deficit Disorder or ADD DIVISIONS OF THE AUTONOMIC ➔ symptoms include: NERVOUS SYSTEM ◆ impulsive ◆ agitated behavior SYMPATHETIC ◆ short attention span “crisis management center” ➔ suggest an oversupply of dopamine increases heart and respiration rate ◆ doesn't seem to be any prepares the body for fight or flight relationship between controlled by a chain of neurons lying dopamine and ADD just outside the spinal cord expends energy THE MAJOR DIVISIONS OF THE NERVOUS SYSTEM PARASYMPATHETIC in charge of long-term survival CENTRAL NERVOUS SYSTEM related functions, nutrition and ❖ brain and spinal cord energy conservation ❖ communicates with the rest of the ○ decreases heart rate body via the peripheral nervous ○ increases digestive activities system ○ promotes processes in the PERIPHERAL NERVOUS SYSTEM body that happen during rest ❖ composed of bundles of axons controlled by neurons at the upper between the spinal cord and the rest and lower levels of the spinal cord of the body conserves energy Although both systems are active at all times, the balance can shift from a predominance of one to a predominance of the other. THE CENTRAL NERVOUS SYSTEM  ○ consists of neuronal cell Embryological development bodies and their dendrites During the embryonic stage, the WHITE MATTER vertebrate nervous system forms out ○ makes up the interior of the of a simple tube with three lumps: forebrain a. FOREBRAIN ○ axons of cortical neurons becomes the cerebral white = myelin that cortex and other coats axons higher structures especially dominant THE FOUR LOBES OF THE CEREBRAL in human beings CORTEX (birth) has grown 1. OCCIPITAL much larger than the ○ at the rear of the head mid/hindbrain ○ contains many specialized b. MIDBRAIN areas for interpreting visual c. HINDBRAIN information becomes brain stem ○ has areas both inside and outside it for shape, color and motion vision 2. PARIETAL ○ directly in front of the occipital lobe ○ contains the PRIMARY SOMATOSENSORY CORTEX body senses awareness of the location of body parts 3. TEMPORAL ○ the sides of the head (ears) ○ main processing areas for hearing and complex aspects THE FOREBRAIN of vision two hemispheres: left and right ○ left temporal lobe contains ○ Each hemisphere controls important areas for language sensation and motor processing and functioning on the opposite comprehension side of the body 4. FRONTAL ○ communicate with each other ○ at the front of the brain through a thick bundle of ○ PRIMARY MOTOR axons crossing between CORTEX them (corpus callosum) important for control of fine movements CEREBRAL CORTEX ○ PREFRONTAL CORTEX outer covering of the forebrain foremost part of the made up of the gray matter + the cell frontal lobes bodies of the cortical neurons responsible for GRAY MATTER organization, ○ type of tissue in the brain and planning of action, spinal cord and aspects of memory  MEDULLA OBLONGATA, PONS OTHER STRUCTURES ○ two important structures in the hindbrain (TEMPORAL): ○ contain the axons control breathing and 1. HYPOTHALAMUS heart rate ○ regulate emotional and ○ in charge of relaying sensory motivated behavior information from the head and 2. AMYGDALA sending motor messages back ○ almond-shaped structure to it ○ crucial for emotional processing Figure 3.14 ○ deep inside the temporal lobes HOW THE CEREBRAL CORTEX 3. HIPPOCAMPUS COMMUNICATES WITH THE BODY ○ vital structure for memory processing SPINAL CORD receives sensory information from all parts of the body except the head Both reflex and voluntary responses are conducted through the spinal cord. REFLEX ○ a rapid, automatic response to a stimulus ○ usually originates from the spinal cord VOLUNTARY RESPONSE ○ originates in the brain ○ travels through the spinal cord to the muscles (movements) communicates with the body below the head via: BETWEEN THE SPINAL CORD AND ○ SENSORY NEURONS carry information THE FOREBRAIN received by the senses (extremities) HIND AND MIDBRAIN to the spinal cord MEDULLA, PONS AND ○ MOTOR NEURONS MIDBRAIN transmit messages ○ contain the reticular from the CNS to the activating system muscles/glands reticular formation regulates levels of arousal in the brain CEREBELLUM ○ important for coordination and timing ○ in charge of tasks that require shifting of attention and discrimination between stimuli  using radioactivity from chemicals injected into the blood ○ color of the image indicates the level of activity red areas = most active least active areas = followed by yellow, green and blue ENDOCRINE SYSTEM ○ expensive and can be risky ❖ controlled by the nervous system to the subject ❖ a system of glands that release 3. Functional Magnetic Resonance hormones into the bloodstream Imaging (fMRI) ❖ HORMONES ○ uses magnetic detectors chemicals that affect mood, outside the head behavior and anatomy ○ to measure the amounts of ❖ Some neurotransmitters act as hemoglobin and oxygen in hormones. different areas of the brain EPINEPHRINE ○ Highly active areas of the “adrenaline” as a brain appear to use more hormone oxygen in fMRI EXPERIENCE AND THE BRAIN NERVE CELL GENERATION Neurons can be generated later in life (to a limited extent). STEM CELLS ○ undifferentiated cells growing in some brain areas ○ capable of developing into neurons in older organisms ○ action seems to be stimulated after some types of brain MEASURING BRAIN ACTIVITY damage purpose may be in Methods for looking at and mapping the part compensatory brain include: NEURONAL GENERATION 1. Electroencephalography and ○ generally very limited in Magnetoencephalography scope (EEGs and MEGs) ○ growth of new neurons is more limited ○ record electrical and vs skin and hair cells magnetic activity in the brain ○ does not allow the viewing of brain activity TWO HALVES OF THE BRAIN 2. Positron Emission Tomography ❖ Work with individuals who have had the "split-brain" operation: (PET) severing the corpus callosum ○ provides a high-resolution to control seizures picture of brain activity  evidence that the two 7. CORONAL PLANE = shows brain hemispheres are highly structures as seen from the front specialized (frontal plane) ❖ Right needs to communicate with 8. SAGITTAL PLANE = shows brain the left structures as seen from the side to name the objects in its 9. HORIZONTAL PLANE = shows visual field brain structures as seen from above left needs the right to (transverse plane) synthesize details into a whole picture Figure: Planes face into a whole recognizable image CENTRAL NERVOUS SYSTEM CORPUS CALLOSUM a large set of axons that convey information THE SPINAL CORD between the two hemispheres of the ➔ found within the spinal column cerebral cortex ➔ communicates with the sense organs and muscles below the head THE BELL-MAGENDIE LAW ?! CH 4: ANATOMY OF THE ➔ states the entering dorsal roots carry sensory information NERVOUS SYSTEM ➔ exiting ventral roots carry motor information NEUROANATOMY ➔ the study of the various parts of the DORSAL ROOT GANGLIA nervous system and their functions ➔ clusters of sensory neuron cell bodies located just outside the 1. VENTRAL OR ANTERIOR: spinal cord ○ toward the front (stomach) ○ in charge of motor COMPOSITION OF THE SPINAL CORD 2. DORSAL OR POSTERIOR: ○ toward the back GREY MATTER ○ in charge of sensory (brain located in the center of the SC and spine) densely packed with cell bodies and dendrites 1. LATERAL = toward the side WHITE MATTER 2. MEDIAL = toward the midline mostly composed of myelinated 3. PROXIMAL = close axons (approximate) to the point of carries information from gray matter attachment to the brain or other areas of the 4. DISTAL = more distant from the spinal cord point of attachment *Each segment sends sensory information to 5. CONTRALATERAL = opposite the brain and receives motor commands. side ○ one on the left and the right 6. IPSILATERAL= same side of the body ○ E.g., two parts on the left or two on the right  PERIPHERAL NERVOUS SYSTEM ○ Hypo/Thalamus TELENCEPHALON SOMATIC ○ End ❖ sends sensory info to the CNS ○ Cerebral cortex ❖ sends motor messages from the ○ Hippocampus CNS to the body ○ Basal ganglia AUTONOMIC 2. MIDBRAIN ❖ sends and receives messages to MESENCEPHALON regulate the automatic behaviors ○ Middle (heart rate, blood pressure, ○ Tectum respiration, digestion, etc). ○ Tegmentum ○ Superior/Inferior colliculus AUTONOMIC NERVOUS SYSTEM ○ Substantia nigra 1. SYMPATHETIC 3. FOREBRAIN network of nerves that prepares the RHOMBENCEPHALON organs for rigorous activity ○ Parallelogram ○ increases heart rate, blood METENCEPHALON pressure, respiration, etc. ○ After ("fight or flight" response) MYENCEPHALON comprised of ganglia on the left and ○ Marrow right of the spinal cord mainly uses norepinephrine HINDBRAIN ○ at the postganglionic consists of the medulla, pons, and the synapses cerebellum 2. PARASYMPATHETIC Located in posterior portion of brain facilitates vegetative, non emergency responses BRAIN STEM ○ decreases functions ○ made from hindbrain increased by the sympathetic structures, the midbrain and NS other central structures of ○ dominant during relaxed the brain states consists of: ○ long preganglionic axons extending from the SC ○ short postganglionic fibers attach to the organs mostly release acetylcholine (postganglionic axons) THREE MAJOR DIVISIONS OF THE BRAIN 1. HINDBRAIN PROSENCEPHALON ○ Forward DIENCEPHALON ○ Between  modifies the brain's MEDULLA readiness to respond to Location: stimuli ○ just above the SC ○ considered an enlarged CEREBELLUM extension of the SC Location: Function: ○ hindbrain ○ vital reflexes ○ many deep folds Breathing Function: Heart rate ○ helps regulate: Vomiting movement Salivation balance Coughing coordination Sneezing ○ important for shifting Control: attention between auditory ○ CRANIAL NERVES and visual stimuli allows the medulla to manage sensations MIDBRAIN and muscle movements in the TECTUM head, and roof of the midbrain parasympathetic outputs to organs SUPERIOR/INFERIOR COLLICULUS located on each side of the tectum PONS processes sensory information Location: ○ lies on each side of the TEGMENTUM medulla (front) the intermediate level of the midbrain Structure: containing nuclei for cranial nerves ○ Contains the reticular and part of the reticular formation formation and raphe system, along with the medulla SUBSTANTIA NIGRA Function: gives rise to dopamine ○ Works with the medulla containing pathway facilitating ○ enhance arousal and readiness for movement readiness of other brain parts RETICULAR FORMATION FOREBRAIN DESCENDING PORTION ○ control the motor FOREBRAIN areas of the SC most anterior and prominent part of ASCENDING PORTION the mammalian brain ○ sends output to has two hemispheres much of the cerebral Consists of the outer cortex and cortex subcortical regions ○ selectively CEREBRAL CORTEX = outer increasing arousal portion and attention SUBCORTICAL REGIONS ○ structures that lie underneath RAPHE SYSTEM the cortex sends axons to much of the forebrain Each side receives sensory information and eating, drinking, controls motor movement from the opposite sexual behavior, etc. (contralateral) side of the body. Thalamus + hypothalamus = "diencephalon" Subcortical structures *Thalamus = sensory THALAMUS *Hypothalamus = motives relay station from the sensory organs BASAL FOREBRAIN main source of input to the cortex Composition: ○ several structures that lie on BASAL GANGLIA the dorsal surface of the Composition: forebrain ○ caudate nucleus ○ NUCLEUS BASALIS ○ putamen receives input from ○ globus pallidus the hypothalamus Function: and basal ganglia ○ associated with planning of Function: motor movement ○ sends axons that release ○ aspects of memory and acetylcholine to the cerebral emotional expression cortex basal ganglia ○ key part of the brain’s system tweaking = motor for arousal, wakefulness, problems and attention LIMBIC SYSTEM HIPPOCAMPUS consists of a number of other Location: interlinked structures that form a ○ large structure border around the brain stem ○ between the thalamus and a. olfactory bulb cerebral cortex b. hypothalamus ○ posterior portion of the c. hippocampus forebrain d. amygdala Function: e. cingulate gyrus ○ critical for storing certain (cerebral cortex) types of memory associated with motivation, emotion, drives and aggression CENTRAL CANAL fluid-filled channel HYPOTHALAMUS in the center of the SC Location: ○ small area VENTRICLES ○ near the base of the brain four fluid-filled cavities within the Function: brain ○ conveys messages to the CEREBROSPINAL FLUID pituitary gland to alter the ○ clear release of hormones in brain and SC ○ PITUITARY GLAND "cushioning" hormone producing ○ reservoir of hormones at the base of the ○ nutrition for the brain and hypothalamus SC ○ Associated with motivated behaviors MENINGES ○ eye, head and body membranes that surround the brain positions and SC ○ from information sent from muscles and joints CEREBRAL CORTEX most prominent part of the 3. TEMPORAL LOBE mammalian brain Location: lateral portion of each Composition: hemisphere ○ cellular layers on the outer ○ near the temples surface of the cerebral Function: target for auditory hemispheres information divided into two ○ processing spoken language joined by two ○ responsible for complex bundles of axons aspects of vision (corpus callosum) movement and the anterior some emotional and commissure motivational behaviors Klüver-Bucy syndrome ORGANIZATION OF THE CEREBRAL ○ associated with temporal CORTEX lobe damage Contains six distinct laminae (layers) ○ parallel to the surface of the 4. FRONTAL LOBE cortex Contains: Cells of the cortex ○ PRECENTRAL GYRUS ○ also divided into columns primary motor ○ lie perpendicular to the cortex laminae responsible for the control of fine motor Divided into four lobes: movement 1. OCCIPITAL LOBE ○ PREFRONTAL CORTEX Location: posterior end of the integration center for cortex all sensory ○ “striate cortex” information and other ○ primary visual cortex areas of the cortex Function: Highly responsible for most anterior visual input portion of the ○ Damage = cortical blindness frontal lobe 2. PARIETAL LOBE FUNCTIONS: ○ higher functions Contains the postcentral gyrus abstract thinking Function: primary somatosensory and planning cortex ○ ability to remember recent ○ primary target for touch events and information sensations "working memory" information from allows for regulation of: muscle-stretch ○ impulsive behaviors receptors and joint ○ control of more complex receptors behaviors ○ responsible for processing Various parts of the cerebral cortex do and integrating information not work independently of each about: other.  ○ All areas of the brain 2. Magnetic Resonance Imaging communicate with each other, (MRI) but no single central processor exists that puts it all NONINVASIVE METHODS: together 1. Electroencephalograph (EEG) 2. Positron-emission tomography THE BINDING PROBLEM (PET) how the visual, auditory, and other 3. Regional Cerebral Blood Flow areas of the brain produce a (rCBF) perception of a single object ○ radioactive chemicals are ○ brain may bind activity in dissolved in the blood where different areas when they a PET scanner is used produce synchronous waves ○ to trace their distribution of activity and indicate high levels of brain activity RESEARCH METHODS 4. Functional Magnetic Resonance Main categories of research methods to study the brain include those that attempt to: Imaging 1. Correlate brain anatomy with behavior. Examining the effects of damage to the 2. Record brain activity during behavior. brain is done using laboratory animals and 3. Examine the effects of brain damage. includes: 4. Examine the effects of stimulating LESION TECHNIQUES particular parts of the brain. ○ purposely damaging parts of the brain PHRENOLOGY ABLATION TECHNIQUES process of relating skull anatomy to ○ removal of specific parts of behavior the brain One of the first ways used to study the Researchers use a stereotaxic brain instrument to damage structure in the ○ Yielded few accurate results interior of the brain Correlating brain activity with behavior can Other research methods used to inhibit involve: particular brain structures include: identifying of peculiar behaviors Gene-knockout approach looking for abnormal brain structures ○ use of various biochemicals or function to inactivate parts of the brain Abnormal brain structures can be ○ by causing gene mutations identified using: critical to their development or 1. Computerized Axial Tomography functioning (CAT scan) Transcranial magnetic ○ involves the injection of a stimulation dye into the blood and a ○ application of intense passage of x-rays through magnetic fields to the head temporarily inactivate neurons ○ Scanner is rotated slowly until a measurement has been taken at each angle and a computer constructs the image Brain Stimulation techniques assume stimulation of certain areas should increase activity Researchers observe the corresponding change in behavior as a particular region is stimulated. ○ Ex: transcranial magnetic stimulation Limitation is that many interconnected structures are responsible for certain behaviors No strong evidence supports a link between larger brain size and higher intelligence. Brain-to-body ratio research has limited validity. ○ moderate correlation (0.3) exists between brain size and IQ IQ is correlated with the amount of grey matter in the brain. ○ grey and white matter Twins show greater resemblance in both brain size and IQ. ○ In monozygotic (identical) twins: one twin's brain size significantly correlates with the other's IQ (genetic link). Men have larger brains than women, but both have similar IQs. ○ Differences exist between men and women in specific brain structures ○ e.g., left/right cortex, hippocampus, amygdala Differences in cognitive abilities may be better explained by interests rather than actual abilities