PSYC Midterm 2

Question 1

Neurons + Function + Replaceability

Answer 1

• 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

Question 2

Structure of Neuron + Function

Answer 2

1. Soma=Cell body contains:
2. Nucleus contains DNA & renewal of cell components/proteins
3. 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
4. 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
5. Axon Ending/Terminals (voice box): door knob shape releases chemicals to communicate with other neurons

Question 3

Presynaptic Cell vs Postsynaptic Cell & EPSP vs IPSP

Answer 3

• 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

Question 4

Depolarization vs Hyperpolarization + Which Stage + Which Ions

Answer 4

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

Question 5

Glial Cell + Function

Answer 5

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

Question 6

Draw + Explain steps for Action Potential to Occur

Answer 6

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.

1. 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
2. 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
3. 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
4. Falling Phase: +sodium channels close & +potassium channels open +potassium leaves causing, positively charged particles flow rapidly out
5. Undershoot: hyperpolarization than resting phase until
   Refractory period: a brief period during which another action potential cannot occur, resets
6. Restoring resting potential

See drawing on Ipad

Question 7

7 Major Transmitters

Answer 7

1. Glutamate: major excitatory NT, learning, enhanced memory, relaying sensory info, MSG in food
2. GABA-Gamma-Amino Butyric Acid: major inhibitory NT, learning, memory, sleep
3. Acetylcholine:
   -Peripheral Nervous System (PNS): voluntary muscle control, internal organs
   -Brain: regulation of attention, learning, memory, sleeping & dreaming
4. Dopamine: regulates motivation, pleasure, emotional arousal, motor behavior, addiction
5. Serotonin: regulation of sleep, wakefulness, drugs for depression
6. Norepinephrine: vigilance or heightened awareness of dangers in the environment
7. Endorphins: pain pathways, reducing pain, emotional centers, elevate mood

Question 8

Synapse

Answer 8

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

Question 9

Why amount of NT matters + How to Regulate Amount of Neurotransmitters in Synaptic Cleft + Drugs

Answer 9

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

1. Autoreceptors: regulates firing patterns of NT
2. Reuptake transporters: continuous recycling/reabsorption of NT from presynaptic cell
3. 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

Question 10

2 Types of Axonal Transmission + Draw Process

Answer 10

1. 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
2. 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

Question 11

Neural Plasticity + 3 Circumstances it Occurs

Answer 11

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

Question 12

Peripheral Nervous System + Major Divisions + Functions

Answer 12

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

Question 13

Spinal Cord + Reflexes + Function

Answer 13

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

Question 14

Major Brain Structures

Answer 14

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

Question 15

Structures Within Cerebral Cortex

Answer 15

1. 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
2. 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
3. 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
4. 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
5. Insular Lobe: hidden under other lobes, perception of taste, internal organ states, linked to emotions of compassion & empathy

Question 16

Subcortical Structures

Answer 16

1. 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
2. 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

Question 17

Hindbrain Structures

Answer 17

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

Question 18

Brain Stem Structures + Function

Answer 18

Midbrain & Hindbrain

Function: basic bodily functions

Question 19

Contralateral Control + Split Brain Studies

Answer 19

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)

Question 20

Optic Chiasm + Draw Cat Dog

Answer 20

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

Question 21

Hormones vs Neurotransmitters

Answer 21

Hormones differs from neurotransmitters in that they’re carried through bloodstream, slow in their actions & its effects last longer

Question 22

Chromosomes + Genes

Answer 22

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

Question 23

Behavioral Genetic Designs

Answer 23

Measuring influence of heritability, presence or absence of a trait among different relatives

1. 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
2. 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
3. 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

Question 24

Why Study Genes + Heritability + Environmentability

Answer 24

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

Question 25

5 Misconceptions of Heritability

Answer 25

1. Applies to a single individual rather than differences among individuals
2. 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.

4. Is the same for everybody across the whole population: different heritability in IQ between rich & poor
5. Implies destiny & only hope is to alter genes

Question 26

Epigenetics + GxE Interactions

Answer 26

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

Question 27

Sensation vs Perception

Answer 27

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.

Question 28

Transduction & Sensory Adaptation

Answer 28

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

Question 29

Psychophysics Principles & Laws

Answer 29

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)

Question 30

Role of Attention in Perception + Binding Problem

Answer 30

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

Question 31

Information Processing

Answer 31

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

Question 32

Path of Light + Structures

Answer 32

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

Question 33

Retina Structures + Receptive Fields

Answer 33

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

Question 34

Feature Detectors Research + Types

Answer 34

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

Question 35

Color Theories

Answer 35

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.

Question 36

Binocular + Monocular

Answer 36

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

Question 37

Types of Perceptual Constancy

Answer 37

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

Question 38

3 Body Senses + Touch vs Pain

Answer 38

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

Question 39

3 Major Pain Receptor Groups

Answer 39

1. 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
2. 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
3. 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

Question 40

Traditional vs Gate Control Theory of Pain

Answer 40

1. 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
2. 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

Question 41

Function of Pain + Expressions

Answer 41

Warns us of potential danger to tissue harm or to the presence of injury

Facial expressions, body movements & vocalizations