Chapter 3 Biological Basis of Behavior PDF

CHAPTER 3: BIOLOGICAL BASIS OF BEHAVIOR Nervous system divided to 2 PARTS CENTRAL NERVOUS SYSTEM (CNS): Contains brain, spinal cord, optic nerve, retina PERIPHERAL NERVOUS SYSTEM(PNS): sympathetic/parasympathetic, EVERYTHING ELSE BRAIN Contains 2 NERVE CELLS: - NEURONS: Unit of nervous system,...

CHAPTER 3: BIOLOGICAL BASIS OF BEHAVIOR Nervous system divided to 2 PARTS CENTRAL NERVOUS SYSTEM (CNS): Contains brain, spinal cord, optic nerve, retina PERIPHERAL NERVOUS SYSTEM(PNS): sympathetic/parasympathetic, EVERYTHING ELSE BRAIN Contains 2 NERVE CELLS: - NEURONS: Unit of nervous system, requires glucose for function - GLIAL CELLS: Provides structural/nutritional help to brain NEURON composed of DENDRITES, CELL BODY, AXON, AXON TERMINAL CELL BODY(SOMA): Integrates electrical signals DENDRITE: Extension of cell body, collects information from other neurons AXON: Conducts information to other neurons, could be myelinated or unmyelinated AXON TERMINALS: Contact dendrites of other neurons AXON TERMINAL AND COMMUNICATION BETWEEN NEURONS - Inside axon terminal are synaptic vesicles(neurotransmitters) - When action potential travels down axon, synaptic vesicles bind to wall of terminal and release neurotransmitters into synaptic cleft between the 2 neurons - They then bind to receptors on the dendrites of other neuron NEURAL IMPULSE (ACTION POTENTIAL) Within neurons are POTASSIUM IONS Outside of neurons are SODIUM IONS - Potassium inside are positively charged but proteins within make the overall charge INSIDE the neuron NEGATIVE - OUTSIDE of neuron is POSITIVELY CHARGED This negative/positive charged create a POTENTIAL for an electrical charge to occur, so neuron membrane separates them until needed PRESYNAPTIC NEURON: neuron releasing neurotransmitters into synaptic cleft POSTSYNAPTIC NEURON: neuron that receives the neurotransmitters NEUROTRANSMITTERS:  1) ACETYLCHOLINE(ACh) - Released by motor neurons for skeletal movement (found in poisons also) - Contributes to regulation of attention, arousal, memory, sleep - Nicotine stimulates, alzheimers associated with low levels of ACh 2) MOANIMINES (DOPAMINE)(DA) - Contributes to control of voluntary movement - Cocaine/Amphetamines elevate dopamine activity - Schizophrenia implicated as OVERACTIVITY of dopamine - Reward pathway (SEROTONIN)(5-HT) - Involved in regulation of sleep/wakefulness, eating, aggression - Prozac and other antidepressants affect serotonin circuits (increase serotonin) (NOREPINEPHRINE)(NE) - Brain arousal and functions like mood, hunger, sleep, sexual behavior - Functions as hormone and neurotransmitter - Adrenaline basically 3) AMINO ACIDS (GABA) - Brain's main INHIBITORY transmitter - Contributes regulation of anxiety, sleep, arousal - Anti anxiety drugs work at Gaba synapses (GLUTAMATE) - Main EXCITATORY neurotransmitter in nervous system - Relay of sensory information and learning (too much = schizophrenia) 4) ANANDAMIDE (unconventional neurotransmitter) - Binds to same receptors as THC(Cannabis) - Plays role in eating, memory, motivation, sleep (Cannabis symptoms) 5) NEUROPEPTIDES (ENDORPHINS) - Regulated by PNS, synthesized in pituitary. - Function as HORMONE and neurotransmitter - Naturally occurring painkiller - Inhibit communication of pain signals to spinal cord NERVOUS SYSTEM (neurotransmitters) is FAST COMMUNICATION SYSTEM, ENDOCRINE SYSTEM (hormones) is SLOWER COMMUNICATION (released into blood) NEURAL PLASTICITY: Nervous system has the ability to adapt/change NEURAL PLASTICITY IN EARLY DEVELOPMENT: 1) Growth of dendrites/axons 2) Synaptogenesis (formation of new synapse)(neurons exchanged through synapse) 3) Pruning (removal of extra synapses to increase efficiency)(occurs until 10, 70% of neurons destroyed 4) Myelination (growth of myelin sheaths) NEURAL PLASTICITY AND LEARNING: - Could occur through STRUCTURAL CHANGES Axonal growth Dendrite branching/growth Enriched environments lead to axonal growth/dendrite branching more POTENTIATION: When a specific presynaptic neuron has a greater say in the postsynaptic neurons ability to fire (EX: unfair democracy, where ONE person has more power)(“neurons that fire together wire together”) NEURAL PLASTICITY FOLLOWING INJURY - Brain can take over functions previously performed by other parts - Searching for treatments to promote healing/prevent damage in brain (stem cells) - Neurogenesis (creation of new neurons in adult brain)(very few) THE MENINGES: 3 LAYERED PROTECTIVE MEMBRANE that covers brain & spinal cord - Dura Mater - Arachnoid Mater - Pia Mater FURTHER PROTECTION: CEREBRAL VENTRICLES containing cerebrospinal fluid FRONTAL LOBE: Has the Central Sulcus, divides frontal & parietal lobe - Primary Motor Cortex: part of frontal lobe responsible for body movement - Prefrontal Cortex: responsible for thinking, planning, language PARIETAL LOBE: Processes touch information, integrates vision and touch TEMPORAL LOBE: Processes auditory information, language, autobiography memory - Wernicke's Area: part of temporal lobe involved in understanding speech OCCIPITAL LOBE: Back part of cerebral cortex, specialized for vision SUBCORTICAL STRUCTURES (beneath the cerebral cortex) THE BASAL GANGLIA - Group of nuclei (clusters of neurons) located beneath the cerebral cortex - Involved in goal motivated motor control - Contains dopamine neurons and associated with reward and motivation LIMBIC SYSTEM: includes THALAMUS, HYPOTHALAMUS, HIPPOCAMPUS, AMYGDALA - THALAMUS: Gateway from sense organs to primary sensory cortex All sensory information, except smell, relayed through thalamus - HYPOTHALAMUS: Bridge between CNS and Endocrine system Regulates the pituitary gland Responsible for: FLEEING, FIGHTING, FEEDING, FORNICATION - HIPPOCAMPUS: Regulates spatial memory, humans have 2 hippocampi May be necessary for formation of new memories - AMYGDALA: Plays key role in fear, excitement, and arousal CEREBELLUM: Hindbrain structure responsible for smoothing fine motor control initiated by other brain regions RETICULAR FORMATION: Responsible for arousal and consciousness THE PERIPHERAL NERVOUS SYSTEM: Lies outside CNS. DIVIDED INTO 2 PARTS: - Somatic Nervous System: conveys information between CNS and body (voluntary) - Autonomic Nervous System: controls involuntary actions of internal organs/glands SYMPATHETIC NS: During crisis; Fight or Flight PARASYMPATHETIC NS: Controls rest and digestion MEASURING THE BRAIN PHRENOLOGY: measuring bumps of skull to measure personality/intellect (??) BRAIN DAMAGE: Brain function can be assessed by examining brain damage and seeing what behavioral issues arise from it EEG: Records brain's electrical activity at the surface of the skull CT/CAT SCAN: scanning technique using multiple X-rays to construct 3D images MRI: uses strong magnetic fields to indirectly visualize brain structure (better than CT) PET SCAN: invasive imaging technique that measures consumption of injected glucose molecules, indicating neural activity in specific regions of the brain fMRI: technique that uses magnetic fields to visualize brain activity using BOLD response: BOLD = Blood Oxygenation Level Dependent TMS: technique that applies strong magnetic fields to surface of skull that can either enhance or interrupt brain function (non invasive)(allows for temporary lesions on brain for studies) GOLGI STAIN : Neural stain that darkens a few of the neurons in slices of tissue, revealing their silhouettes FRANZ JOSEPH GALL - All mental functions arise from the brain - Mind and body are NOT separate entities - Brain divided into functional regions - Phrenologist SENSATION AND PERCEPTION: - SENSATION: Process by which (objective) stimuli are detected, transduced into nerve impulses, and sent to brain - TRANSDUCTION: Process of converting an external energy into electrical activity within neurons (turning external stimuli into a language your brain can understand) - SENSE RECEPTOR: Specialized cell responsible for converting external stimuli into neural activity for a specific sensory system (EX: cones and rods) - SENSORY ADAPTATION: Activation is greatest when a stimulus is FIRST detected, then declines in responsiveness over time (get used to shit)(called neural adaptation) PERCEPTION: Brain's interpretation of raw sensory information. PSYCHOPHYSICS: study of how we perceive sensory stimuli based on physical characteristics ABSOLUTE THRESHOLD: Lowest level of stimulus needed for nervous system to detect a change 50% of the time JUST NOTICEABLE DIFFERENCE (JND): The smallest change in the intensity of a stimulus that we can detect (how much do u have to turn volume down to notice its been turned down?)(WILL NEED TO KNOW HOW TO APPLY WEBER'S LAW ON MIDTERM) WEBER'S LAW: There is a constant proportional relationship between JND and original stimulus intensity JND = K x I I = intensity of stimulus K = constant (the louder the starting volume, the greater change in volume needed to detect difference) SIGNAL DETECTION THEORY: INCREASED SENSITIVITY to the signal causes hits and correct rejection to occur more often DECREASED SENSITIVITY to the signal causes misses and false alarms to occur more often ROC CURVES PERCEPTION: Determined by 3 elements: - What is currently in sensory field - What was in the sensory field moments ago - What we have experienced in the past PARALLEL PROCESSING: Ability to handle different sources of information simultaneously BOTTOM UP PROCESSING: Brain constructs a stimulus based on parts TOP DOWN PROCESSING: Process influenced by beliefs and prior learning PERCEPTUAL SET: A set formed when expectation influence perception PERCEPTUAL CONSTANCY: We perceive stimuli consistently across varied conditions (Not explanations, just labels for the effects) EXTRASENSORY PERCEPTION(ESP): Perceptions of events outside the known channels of sensation(mob psycho idk) - PRECOGNITION: able to predict events before they occur through paranormal means - TELEPATHY: Communicating to another person through your mind - CLAIRVOYANCE: Ability to detect someone with ur mind THE VISUAL SYSTEM VISIBLE LIGHT: Electromagnetic radiation between 400-700 nanometers HUE: The color of light VISUAL PERCEPTION SHAPE AND CONTOUR: - Hubel and Wiesel's experiment with cats - Studied electrical activity of V1 area in the visual cortex of cats viewing light slits on a screen (see what made the cells fire)(line had to be at a specific orientation for the cells to fire) - Called FEATURE DETECTION CELLS GESTALT PSYCHOLOGY emphasized the perception of the whole, rather than focusing on individual parts. HAD 6 PRINCIPLES: PROXIMITY: objects close to each other seen as unified wholes SIMILARITY: similar objects seen as being grouped/related SYMMETRY: Symmetrical arranged objects seen as wholes CONTINUITY: Perceive lines as continuous movement despite abrupt changes (ex: being intercepted by another line) CLOSURE: Incomplete figures will be seen as complete objects FIGURE GROUND SEGREGATION: Tendency to separate elements of image into a foreground and background COLOUR (TRICHROMATIC THEORY) Idea color vision is based on our sensitivity to 3 primary colors Belief there are 3 cones in your eye that are triggered to an extent when looking at different colors (EX: looking at something blue will trigger blue cones the most, other cones the least)(if all equally activated, perceiving WHITE) PROBLEM: AFTERIMAGES (why does staring at one color produce an afterimage of another color?) COLOUR (OPPONENT PROCESS THEORY) Perceive colors in terms of 3 pairs of opponent colors (Red or Green)(Blue or Yellow)(Black or White) Occurs in the retinal ganglion cells COLOUR BLINDNESS Inability to see some or all colors Genetic abnormality that cause the absence/reduction in specific cone type DEPTH PERCEPTION  - Ability to judge distance and 3D relations - TWO TYPES: - MONOCULAR CUES: Stimuli that enable us to judge depth using 1 eye Relative size: farther objects look smaller Texture gradient: father objects less detailed Interposition: close objects block view of far objects Linear Perspective: Height in Plain: distance objects look higher, closer objects look lower Light and Shadow: casting of shadows gives objects 3D forms - BINOCULAR CUES: Stimuli that enable us to judge depth using both eyes Binocular Disparity: Binocular Convergence: Degree to which your eyes converge inwards provides information on abject distance (eyes cross when looking at something close) BLINDNESS - The inability to see due to to problems with eye/eye structures - Rely more on other senses (touching, hearing, etc) - Visual cortex function changes due to neural plasticity MOTION BLINDNESS - The inability of a person to perceive motion - Often caused by brain damage/alzheimers VISUAL AGNOSIA - A failure to recognize visually presented objects, not due to impairments of memory or intelligence (man who mistook his wife for a hat) BLINDSIGHT - The ability of individuals with blindness to detect/respond to visual stimuli despite lacking awareness of seeing anything (cant see but if you throw a ball at them they'll catch it) - Often result of damage to V1 area of visual cortex AUDITORY SYSTEM: - Sense of hearing depends on soundwaves - 3 DIMENSIONS OF SOUND: Frequency, Amplitude, Complexity FREQUENCY perceived as PITCH AMPLITUDE perceived as LOUDNESS COMPLEXITY perceived as TIMBRE - COCHLEA transduces sound vibration into neural impulses - BASILAR MEMBRANE: has to do with frequency - CONDUCTIVE HEARING LOSS: damage to ossicles; CUREABLE - SENSORINEURAL HEARING LOSS: damage to cochlea; INCURABLE BODY SENSES: - TOUCH is transduction of skin sensations into neural impulses  - Receptors located under skin detect pain, pressure, texture, etc - LEFT HALF OF BODY CONTROLLED BY RIGHT SIDE OF BRAIN; VICE VERSA - DIFFERENT LOCATIONS IN BODY SEND SENSORY INFO TO DIFFERENT PARTS OF BRAIN, AND SOME PARTS HAVE GREATER ACUITY THAN OTHERS (ex, lips and fingertips) - WHAT AND WHERE PATHWAYS - Sudden Pain = A Delta Fibers - Throbbing Pain = C Fibers - REFERRED PAIN : When pain originates internally, in a body organ, for instance, we can feel it on the surface of the body. - GATE CONTROL THEORY: Signals arriving from pain receptors in the body can be stopped by interneurons in the spinal cord via feedback from the skin or from the brain TASTE AND SMELL: - Rely on CHEMICALS that enter our mouth/noses - OLFACTORY RECEPTOR NEURONS; What transduce odorant molecules into neural impulses proprioception is your sense of bodily position. GENES, EVOLUTION, AND BEHAVIOR GENETIC EXPRESSION EPIGENETICS: Changes in gene function that does not involve change in DNA sequence (EX: Environmental aspects + Genes) DARWIN: NATURAL SELECTION/GENE MUTATION FOR ADAPTATION GENETIC ENGINEERING(Gene Knockout Studies): Specific gene within an organism is knocked out, so that it doesn't perform its usual function; then compared behavior to normal individual) (not usually effective because behavior is not determined by single gene) BEHAVIORAL GENETICS: Focuses on how heredity and environmental factors combine to cause/control psychological factors (behavior) HERITABILITY: Extent to which variation of a particular trait across individuals within a specific population is due to genes (EX: For Height heritability coefficient is 0.8, meaning 80% of people within a population's height is due to genetics) (population dependent) HEREDITY: Passing of traits from parents to offspring through genes CONCORDANCE: Likelihood that 2 people share the same characteristics DESIGNS IN BEHAVIORAL GENETICS: Family studies, Twin studies, Adoption studies FAMILY STUDIES: Degree to which a trait runs in intact families PROBLEM: Can't separate genes from environmental factors, family live in same home) TWIN STUDIES: Two types of twins: - Identical Twins Come from single zygote that split, share 100% of genes - Fraternal Twins Come from 2 separate zygotes, share 50% of genes LOGIC: identical twins are more similar genetically then fraternal twins, so if identical twins are more similar on a psychological trait then fraternal twins, we can infer that trait is GENETICALLY INFLUENCED (because they both have the same environment, so it must be genes affecting) (Still can't adequately separate genetic/environmental factors, because the difference may be caused BECAUSE of the fact they are identical twins, so treated differently) ADOPTION STUDY: a person who was adopted in early life is compared to their biological parents, and their adoptive parents (will share genes but not environmental factors with biological parents) (will share environmental factors but not genes with adoptive parents) If adopted child is more similar to biological parent then adopted parent on specific trait, that trait is deemed to be GENETIC, and VICE VERSA PROBLEM: SELECTIVE PLACEMENT; Adoption agency likely to place adopted children in environment similar to their original home environment, fucks experiment up REACTION RANGE: How heredity/environment interact to influence behavior. Reaction range shows the range (highs and low limits) that a genetic code allows for. (genetics set boundaries for what's possible, and then environmental opportunities influence)(ex: IQ) EVOLUTIONARY PSYCHOLOGY: Darwin's theory of natural selection in regards to human/animal BEHAVIOR rather then just evolutionary structures