PSYC Midterm 2 Flashcards
Neurons + Function + Replaceability
- Neurons basic units of brain structure.
- Neurons can turn their neighbors on/off depending on the neurotransmitters it sends
- Stable pattern of neurons firing represents memories, feelings, behaviors & thoughts
-Aren’t easily replaceable with its unique functions & connections based on experiences
Structure of Neuron + Function
- Soma=Cell body contains:
- Nucleus contains DNA & renewal of cell components/proteins
- Dendrites (ears): connections with other neurons to receive signals/info & pass to soma
3.A Synaptic Cleft: space between receptors/dendrites and transmitters/axon terminals where info is exchanged - Axon is thin 1mm-1m long: send messages
4.A Synaptic Vesicles: tiny spheres that travel full length of axon & waits at axon terminals for electrical signal causing it to release its calculated amount of neurotransmitters - Axon Ending/Terminals (voice box): door knob shape releases chemicals to communicate with other neurons
Presynaptic Cell vs Postsynaptic Cell & EPSP vs IPSP
- Presynaptic Cell: sending information
- Postsynaptic Cell: receiving information
- Excitation EPSP (Excitatory Postsynaptic Potential) created within the excitatory synapse: increases likelihood to fire
Depolarizes postsynaptic membrane -70mV to -67mV
Inhibitory IPSP (Inhibitory - Postsynaptic Potential) created within the inhibitory synapse: decreases likelihood to fire
Hyperpolarizes postsynaptic membrane from -70mV to -73mV
Depolarization vs Hyperpolarization + Which Stage + Which Ions
Depolarization: less negative = more positive charged neuron. Occurs during depolarization, threshold, rising phase by opening sodium channels letting in +sodium & closing potassium channels keeping +potassium
Hyperpolarization: more negative charged neuron. Occurs during undershoot, refractory phase, stays negative resting phase. Sodium channels are opening & closing to keep out & let out +sodium, potassium channels open to let out +potassium
Glial Cell + Function
Glial Cells (glue): same number as neurons, protective scaffolding, sending healing chemicals, clears away debris, create new neurons to heal spinal cord injuries, digest dead, glue of communication between neurons, more accurate transmissions, produces myelin sheaths
Draw + Explain steps for Action Potential to Occur
Action Potential: within cell process carries information through nervous system, electrical signal that is conducted along the length of an axon to the synapse, massive momentary massive reversal of membrane potential, all-or-none response, generating a release of electricity triggering the release of neurotransmitters.
- Resting Potential: Unstimulated neurons maintain a constant electrical potential across their cell membranes, always negative inside the cell -70mV, only +potassium ions can travel across specific protein called potassium channels in membrane, +sodium channels remain closed, balance is kept through:
+Potassium ions are more concentrated within neuron so they diffuse outside leaving the large -organic neurons → neuron become increasingly -charged
Opposites attract so the positive force that develops from the neuron attracts the +potassium back into cell - Depolarization: More +Sodium channels open & +potassium channels close creating significantly less negative/more positive until it reaches the threshold (level of depolarization needed to set off action potential) triggering action potential
- Rising Phase: All +sodium channels open & +potassium channels closed
Action potential maxing potential to +20-50mV for a few milliseconds, positively charged particles flow rapidly inside sum of EPSP & IPSP larger than threshold - Falling Phase: +sodium channels close & +potassium channels open +potassium leaves causing, positively charged particles flow rapidly out
- Undershoot: hyperpolarization than resting phase until
Refractory period: a brief period during which another action potential cannot occur, resets - Restoring resting potential
See drawing on Ipad
7 Major Transmitters
- Glutamate: major excitatory NT, learning, enhanced memory, relaying sensory info, MSG in food
- GABA-Gamma-Amino Butyric Acid: major inhibitory NT, learning, memory, sleep
- Acetylcholine:
-Peripheral Nervous System (PNS): voluntary muscle control, internal organs
-Brain: regulation of attention, learning, memory, sleeping & dreaming - Dopamine: regulates motivation, pleasure, emotional arousal, motor behavior, addiction
- Serotonin: regulation of sleep, wakefulness, drugs for depression
- Norepinephrine: vigilance or heightened awareness of dangers in the environment
- Endorphins: pain pathways, reducing pain, emotional centers, elevate mood
Synapse
Synapse: between cell process, when an action potential reaches the synaptic terminal of the axon it becomes positively charged, releasing neurotransmitters from vesicles fused to cell membrane into the synaptic cleft, diffusing rapidly & binding to the receptors in the membrane of the dendrites or cell body of postsynaptic cell.
Each type of receptor binds to a specific type of neurotransmitter (lock & key), causing specific channels of the postsynaptic membrane to open
Ions flow across the cell membrane along concentration gradients causing synaptic potentials which might not travel far and after awhile fade balancing out signal becoming lost or reach far enough to reach threshold
Neurotransmission: chemical potential between neurons, either to excite or inhibit postsynaptic neuron
Many simulations, excitatory & inhibitory, from different channels can occur, at the same time too
Why amount of NT matters + How to Regulate Amount of Neurotransmitters in Synaptic Cleft + Drugs
More of the NT means more signal is more likely to be continued on & concentration is controlled by
Too much too little can cause mental illnesses
- Autoreceptors: regulates firing patterns of NT
- Reuptake transporters: continuous recycling/reabsorption of NT from presynaptic cell
- Degrading Enzymes: degrades NT
Psychoactive Drugs & Synaptic Transmission: Drugs impact receptor binding lock & key or influence concentration of NT in the synaptic cleft is a NT
- Agonists: increase or mimic effect of neurotransmitter, overloading receptors, reducing painful responses
- Antagonists: block or decrease effect of a neurotransmitter, fake neurotransmitters jamming receptors
2 Types of Axonal Transmission + Draw Process
- Unmyelinated Axonal Transmission: +sodium pulled forward by -charged inside of axon, leaving a trail of +charged inside & -charged outside pulling +potassium forward leaving a trail of -charged inside & +charged outside resetting axon, creating a slower & fading signal
- Saltatory Conduction/Myelinated Axonal Transmission: same axonal transmission with additional signal jumps boosted by myelinated axon warranting few action potentials= faster, stronger signal
insulating & speeding up transmissions of electrical signals that jump between gaps called nodes
See Ipad Drawing
Neural Plasticity + 3 Circumstances it Occurs
Plasticity: the nervous system’s ability to change over time
Early Development: the most flexible not fully matured until early adulthood, adaptable to the physical & cultural diverse environments. Network of neurons in the brain changes over the course of development in 4 primary ways:
- Growth of dendrites & axons
- Synaptogenesis, the formation of new synapses
- Pruning, consisting of the death of certain neurons & the retraction of axons to remove connections that aren’t useful, streamline neural organization enhancing communication (as many as 70%)
- Myelination, the insulation of axons with a myelin sheath
Learning: formation of new synapses, generating increased connections & communication among neurons
- Potentiation: strengthening of existing synaptic connections so that neurotransmitters released into synapses produce stronger & more prolonged response from neighboring neurons.
- Structural Plasticity: changes in the shape of neurons critical for learning & adapting to environments
Injury & Degeneration: NS doesn’t change enough → permanent paralysis & disability. Certain brain regions can take over functions previously performed by others
- Neurogenesis: creation of new neurons in the adult brain
Peripheral Nervous System + Major Divisions + Functions
Somatic Nervous System: interaction with external environment
- Afferent Nerves: sensory
- Efferent Nerves: motor
- Reflex Arc connects these 2 instantaneously
Autonomatic Nervous System: regulation of internal environment
- Afferent Nerves: sensory
- Efferent Nerves: motor
- Sympathetic: mobilize energy in threatening situations
- Parasympathetic: conserving energy in calm
Spinal Cord + Reflexes + Function
Spinal Cord: conveys info between brain & rest of body
Sensory nerves: carries signals from body to brain
Motor nerves: carry signals from brain to body
Reflex Arc: connecting sensory neurons to interneurons to motor neurons automatically within the spinal cord without reporting back to the brain. For immediate action when the situation is life threatening
Major Brain Structures
Forebrain: controls highest level of complex cognitive, emotional, sensory & motor function divided into
- Cerebral Cortex: responsible for most complex aspects of perception, emotion, movement, & thought
- Subcortical Structures:
Midbrain: area important for tracking & reflexes toward sensory stimuli, regulates sleep & arousal, controls gross motor movements
Hindbrain: area that coordinates info coming into & out of the spinal cord
Structures Within Cerebral Cortex
- Frontal Lobes: executive functioning coordinating other brain areas, for abstract thinking, movement, planning, memory & judgment & includes the motor cortex=voluntary movement. Separated from rest of cortex by a deep groove - central sulcus
- Motor Cortex: controls specific parts of the body, regions requiring more precise motor control consume more cortical space
- Prefrontal Cortex: responsible for thinking, planning & language, personality, behavior, mood, self-awareness.
- Broca’s Area: producing language
- Occipital Lobe: responsible for processing visual info: Eyes →Thalamus→Occipital Lobe
- Visual Cortex: receives nerve impulses from the visual thalamus
- Visual Association Cortex: analyzes visual data to form images
- Temporal Lobe: responsible for hearing & language, forming long-term memories facts+events & contains primary auditory cortex(detects discrete qualities of sound pitch volume)
- Wernicke’s area: understanding language, found on the left side of the lobe. If damaged makes understanding language difficult with no effect on producing language
- Fusiform Face Area: differentiating between meaningful objects
- Wernicke’s area: understanding language, found on the left side of the lobe. If damaged makes understanding language difficult with no effect on producing language
- Parietal Lobe: process info about touch, spatial perception, tracks objects, guides attention, represents numbers, relays information to motor cortex when we reach grasp or move eyes & contains the somatosensory cortex(receives data about sensations in skin, muscles & joints)
- Damage means hard time making sense of surroundings & unilateral neglect forgetting about one side of everything
- More brain tissue for area the greater sensitivity - Insular Lobe: hidden under other lobes, perception of taste, internal organ states, linked to emotions of compassion & empathy
Subcortical Structures
- Basal Ganglia: set of subcortical structures that direct intentional movements & posture, skill & habit learning. Sensory info after reaching primary & association areas is transmitted here which calculates a course of action and sends the blueprint of the movement to the motor cortex. Helps control emotions, language, decision making, learning, memory.
-Parkinson’s Disease means damage to Basal Ganglia & loss of neurons that supply dopamine - Limbic System (not structure): emotional center of brain, where the subcortical structures meet the cortex
-Hippocampus: critical in creating new memories & integration into a network of knowledge to be stored in other parts of the cerebral cortex, spatial memory, facts, events. Not skill/habit learning doesn’t require conscious access to memory.
-Amygdala: central role in many emotional processes, particularly the formation of emotional memories involved with fear & aggression.
- Thalamus: relays & filters info from the senses & transmits the info to the cerebral cortex, if damaged causes conscious blindness, blindsight when V1 damaged & still reaches associated cortex no conscious experience of visuals
- Hypothalamus: oversees hormone release & autonomic nervous system, regulates body temperature, hunger, thirst, sexual behavior, responsible for the 4 Fs (Feeding, Fighting, Fleeing & Sexual Behavior)
-Pituitary Gland: master gland of the body’s hormone producing system, which releases hormones which direct the functions of many other glands in the body, the slower system of communication
Hindbrain Structures
Reticular Formation/Activation System: responsible for regulation of sleep, wakefulness & arousal, connects forebrain to cerebral cortex, key role in arousal, damaged=coma, selective attention
Medulla: extension of spinal cord that coordinates heart rate, circulation & respiration, death
Cerebellum: largest structure of the hindbrain, controls fine motor skills, precision. Coordination, smooths out movement, balance
Pons (bridge): structure that relays info from the cerebellum to the rest of the brain, key role in sleep & dreaming, rate of breathing
Brain Stem Structures + Function
Midbrain & Hindbrain
Function: basic bodily functions
Contralateral Control + Split Brain Studies
Contralateral Control: right & left lobes control opposite hemispheres of the body
Split Brain Studies: cutting the corpus callosum leads to inability to say or pick up the object they see on the left or right of a screen, showing lateralized function; how the two hemispheres enact different functions & contralateral control
Corpus Callosum: connects left & right hemisphere instantaneously
Lateralized Function: left & right brain hemispheres have divided functions not personality, left (Fine-tuned language skills+Actions), right (Coarse language skills+visuospatial skills)
Optic Chiasm + Draw Cat Dog
Optic Chiasm: point where optic nerves from the inside half of each eye cross over & project ot the opposite half of the brain
See Ipad drawing
Hormones vs Neurotransmitters
Hormones differs from neurotransmitters in that they’re carried through bloodstream, slow in their actions & its effects last longer
Chromosomes + Genes
Chromosomes (46): trillions of combinations, contain strands of DNA (Deoxyribonucleic acid) that carry genetic info
Genes: sections of DNA that contain hereditary info to replicate+reproduce
Allele: one of two or more alternative forms of a gene
Homozygous: when two alleles of a gene in the specific pair are the same
Heterozygous: when the two alleles of a gene in the specific pair are different
Dominant (E): attributes of the dominant allele is the one that is expressed in a heterozygous pair
Recessive (e): the attributes of the recessive allele is maskin in a heterozygous pair
Genotype: a person’s genetic makeup allelic combinations
Phenotype: person’s genotype is manifested in observable characteristics
Monogenic Inheritance: trait determined by one pair of genes
Polygenic Inheritance: trait is determined by the combination of more than one pair of genes
Behavioral Genetic Designs
Measuring influence of heritability, presence or absence of a trait among different relatives
- Family Studies: examining blood relatives to see how much they resemble each other on a common trait
If high heritability: 1st degree relatives should have lots of the trait & 3rd degree less
Drawback: share genetics & environment so can’t determine if nature or nurture
Application: risk of disorders - Twin Studies: comparing the resemblance of identical twins (100% shared genes) & fraternal twins (50% shared genes) within a common environment with respects to a trait, how similar are their traits
If high heritability & similar environments for both twins: identical twins should have stronger correlation with a trait - Adoption Studies: examining the resemblance between adopted children & their biological & adoptive parents, influence of a unique environment
If high heritability, adopted children would have higher resemblance with biological parents
-Selective Placement: both environments are too similar
Why Study Genes + Heritability + Environmentability
Why Study Genes: to understand how much genes & environment affect differences in behavior between individuals
Heritability: the extent to which genes contribute to differences in a trait among individuals. Ratio/Proportion of phenotypic variance attributable to genetic variance
Ranges from 0.0 (genes do not contribute at all/religion) to 1.0 (genes are the only reason for individual differences/eye color)
Environment Ability: proportion of phenotypic variance attributable to environmental variance
Heritability + Environmentability = 1
5 Misconceptions of Heritability
- Applies to a single individual rather than differences among individuals
- Tells us whether a trait can be changed by environmental factors: heritability says nothing about how malleable a trait is.
-Environmental changes can impact everyone in population, but heritability is not involved
-Reaction Range: extent to which genes set limits to how much a trait can change in a new environment. (IQ high vs Eye color low)
3.Fixed number: heritability is the relative influence of genes compared to environment on individual differences in a trait or behavior in a given population at a given point in time.
- Is the same for everybody across the whole population: different heritability in IQ between rich & poor
- Implies destiny & only hope is to alter genes
Epigenetics + GxE Interactions
Epigenetics: heritable changes in phenotype in the absence of changes in DNA sequence, caused by modification of gene expression/readability
GxE Interactions: Nurture & Nature are interactive & additive. Phenotypic effect determined by interaction between environment & genes
-On a graph lines representing different genotypes would intersect at a specific environment & grow farther apart when environment becomes more extreme (depression increasing in increasing stressful environments) or vice versa (speed of trained & untrained rats closing in together in increasingly enriched environments) showing interaction between environment & gene, how they multiply with each other to create overall greater phenotypic variability
Sensation vs Perception
Sensation: the stimulation of the sense organs
Perception: the selection, organization, identification, filling in gaps & interpretation of sensory input in order to form a mental representation
Actions can lead to perceptions & vice versa. Gun embodiment effect.
Transduction & Sensory Adaptation
Transduction: process in which specialized sensors in the body convert physical signals from the environment into encoded neural signals sent to the CNS
Sensory Adaptation: gradual decline in sensitivity due to prolonged stimulation
Psychophysics Principles & Laws
Absolute Threshold: lowest level of stimulus needed to detect its presence 50% of the time starting from 0
Noticeable Difference: smallest change in intensity of a stimulus that one can detect
-Weber’s Law (linear): the change in a stimulus that will be just noticeable is a constant ratio of the original stimulus
-Fechner’s Law (logarithmic): magnitude of perceived intensity increases proportionally to the logarithm of the stimulus intensity = increases at increasing rates
-Steven’s Law (both): different relations for different stimuli
Signal Detection Theory: becomes harder to detect a signal as background noise increases
Response Biases: tendency to make one type of guess over another when a weak signal is present or absent under noisy conditions
Specific Nerve Energies: experience of sensation is by the nature of the sense receptor not the stimulus, vulnerable to cross-talk between senses (Synthesia)
Role of Attention in Perception + Binding Problem
Attention: must be able to focus on one task’s sensory input ignoring all others & must be prepared to use sensory information that signals a potential threat
Selective Attention: reticular activating system & forebrain selects on sensory input & turns off or down others
Inattentional Blindness: poor at detecting stimuli in plain sight when our attention is focused elsewhere
Binding Problem: how does our mind seamlessly combine many different senses into a unified perception (ex. Apple=sweet, juicy, red, shiny, smooth, etc.). Inability to do this visually is Visual Agnosia
Information Processing
Parallel Processing: attending to many sense modalities simultaneously
Bottom Up: begins with perception of raw stimuli & ends with our synthesizing them into a meaningful concept = unknown→known = primary visual cortex → association cortex
Top Down: beings with beliefs & expectations which are imposed onto raw stimuli = association cortex → primary visual cortex
Path of Light + Structures
Functions of Eyeball: channel light to the retina & house retina
Cornea: curved transparent layer bending light to focus image to eye
Pupil: hole that light enters Iris: colored ring of muscle surrounding & controlling pupil regulating amount of light entering eye for both eyes simultaneously Sclera: white part maintains ball shape →
Lens: bends light
Accommodation: adjustment of the curvature of the lens to alter visual focus. Loss of flexibility of lens presbyopia. Farsighted(long lens+ball)=far yes, close no. Nearsighted(flat lens+ball)=far no, close yes
Retina: neural tissue lining inside back surface of the eye that absorbs light & processes light & sends info to the brain
Optic Disk: blind spot hole in the retina where Optic Nerve exits the eye
Optic Nerve: ganglion cells that bundle all their axons together depart the eye to reach the brain & fork at the optic chiasm, half fork the other stays on same side
Optic Chiasm: inside half of each eye cross over & projects to opposite hemisphere of brain allowing for binocular vision
Thalamus → Primary Visual Cortex or Secondary Visual Cortex & Tertiary visual cortex in midbrain
Retina Structures + Receptive Fields
Cones: visual receptors in daylight vision & color vision
Fovea: tiny spot at center of retina containing only cones
Rods: visual receptor in night vision & peripheral vision
Photopigments: chemicals that change following exposure to light.
Dark & Light Adaptation: eyes become more sensitive to light in low illumination & less sensitive to light in high illumination
Receptive Field: collection of rods & cones that funnel signals to a particular visual cell, when stimulated this field affects the firing of the visual cell, pays attention to edges
On Center: center=EPSP, outside=IPSP
Off Center: center=IPSP, outside=EPSP
Feature Detectors Research + Types
Feature Detectors: neurons that respond selectively to very specific features of more complex stimuli (research by Hubel & Wiesel cats neuron firing with certain light shape, size, width & orientation, movement) → our ability to use certain minimal patterns to identify objects
-Simple Cells: respond best to lines of correct width, orientation, & location in receptive field
-Complex Cells: respond best to movement of lines a specific direction
Goal of Visual Perception: navigate our environment, reconstruct 2D-3D can make mistakes
Higher Cortical Regions: process more complex shapes
Color Theories
Trichromatic Theory: additive mixing of 3 colors (blue, green red) as cones are only sensitive to these wavelengths of light which create all colors humans can see
Subtractive color mixing: pigments
Opponent Process Theory: we perceive colors in terms of three pairs of opponent cells: red or green, blue or yellow, and black or white, color perception also depend on receptors that make antagonistic responses to 3 pairs of color, inhibiting certain colors & processing others to create the color one sees
Color Blindness: one or more of the color cone cells are absent, not working, or detect a different color than normal
After Images-Combining both theories: Cones get tired from inhibiting red & processing green that eventually only sees red wavelengths from white screen.
Binocular + Monocular
Binocular Cues: clues about distance based on the differing views of the two eyes
-Retinal Disparity: objects project images to slightly different areas in each eye
-Convergence: sensing the eyes converging towards each other as they focus on closer objects
Monocular Cues: clues about the distance based on the image of one eye
-Motion Parallax: depth cues from difference in rate of movement of objects at different distances across retina
-Pictorial Depth Cues: clues about depth that can be given in a picture: Linear perspective, texture gradients, interposition, relative size, height in plane, light & shadow
Types of Perceptual Constancy
Size/Depth Perception: objects same size although far away, mentally enlarging far away figures
Shape Constancy: see a door as a door even when shut, open & fully open although shapes look nothing alike
-Distal Stimuli: stimuli that lie in the distance = the actual physical stimulus, the physically objective dimensions of the viewed object
Hollow face, black & white checkerboard
-Proximal Stimuli: stimulus energies that impinge directly on the sensory receptors = image that falls on the retina
Looks like an actual 3D face, some of the tiles are the same shade of grey
-Perceptual Hypothesis: an inference about which distal stimuli could be responsible for the proximal stimuli sensed
-Subjective Contours: brain providing missing information about outlines
Color Constancy: perceive color consistently across different levels of lighting
3 Body Senses + Touch vs Pain
3 Different body senses:
1. Skin touch, temperature, & chemical/mechanical injury
2. Body Position
3. Balance
Touch (informs of immediate surroundings) travels faster than pain (alerts us to take care of injuries that can wait) info
3 Major Pain Receptor Groups
- Somatosensory System: touch & pain, multiple stimulus, all nerve endings unevenly distributed across our body surface most in fingertips, fewest in back
-Mechanoreceptors: specialized nerve endings located on the ends of sensory nerves in the skin: light touch or deep pressure
-Free Nerve Endings: more plentiful, touch, temperature: hot or cold & pain from Chemical or Mechanical Injury - Proprioception: body position sense, kinesthetic sense, efficient movement, keep track of where we are
-Proprioceptors: sense muscle stretch & force → brain stem → thalamus → somatosensory & motor cortices combines info+intentions=perception of body’s location
-Stretch Receptors: embedded in our muscles
Force Detectors: embedded in muscle tendons - Vestibular Sense: balance, equilibrium
-3 Semicircular canals: filled with fluid snes equilibrium & help maintain balance, coordinate eye & head movements, info to cerebellum to control bodily responses to rebalance
-Dizziness: mismatches of balance between vestibular sense & visual inputs
Traditional vs Gate Control Theory of Pain
- Traditional theories of pain outdated: pain results from the transmission of pain signals from the site of injury to the brain, amount of pain experienced is directly proportional to the amount of tissue damage
- Gate Control Theory of Pain: pain gate in the spinal cord can open & close to modulate the experience pain determined by psychological factors & context (soldier vs civilian)
-Open: physical-extent of injury, emotional-anxiety, cognitive-boredom
-Close: physical-medication, emotional-relaxation, cognitive-distraction
-Physical, emotional & cognitive factors all interact
Function of Pain + Expressions
Warns us of potential danger to tissue harm or to the presence of injury
Facial expressions, body movements & vocalizations