Biological Psychology

What is behavioral neuroscience? Study of how the brain and nervous system produce behavior, cognition, and emotion
What is biopsychology? Another term for behavioral neuroscience
What is the main goal of neuroscience? Understand how brain activity causes behavior and mental processes
What is a correlation? A relationship between two variables
Why does correlation not prove causation? Because another factor may explain the relationship
What is an experiment? A study where variables are manipulated to determine causation
What is an independent variable? The variable manipulated by the researcher
What is a dependent variable? The variable measured by the researcher
What is functional localization? The idea that specific brain regions perform specific functions
What was phrenology? A pseudoscience claiming skull bumps reflected personality traits
Why was phrenology historically important? It introduced the idea of localization of function
Who was Wilder Penfield? Neurosurgeon who electrically stimulated the cortex during surgery
What did Penfield discover? Specific cortical areas produce specific sensations and movements
What is dualism? The idea that the mind and body are separate
Who proposed dualism? René Descartes
What is a reflex? Automatic response to a stimulus
What did Galen conclude about the brain? The brain is involved in behavior and sensation
Why did Egyptians underestimate the brain? They believed the heart controlled behavior and emotion
What is the CNS? Central nervous system consisting of the brain and spinal cord
What is the PNS? Peripheral nervous system consisting of nerves outside the CNS
What is the somatic nervous system? System controlling skeletal muscles and voluntary movement
What is the autonomic nervous system? System controlling glands and internal organs
What are the two divisions of the autonomic nervous system? Sympathetic and parasympathetic nervous systems
What is the sympathetic nervous system? Division involved in fight-or-flight responses
What does the sympathetic nervous system increase? Heart rate, respiration, and alertness
What does the sympathetic nervous system decrease? Digestion and energy storage
What neurotransmitter is commonly used by the sympathetic nervous system? Norepinephrine
What is the parasympathetic nervous system? Division involved in rest-and-digest functions
What does the parasympathetic nervous system promote? Digestion, relaxation, and energy conservation
What neurotransmitter is commonly used by the parasympathetic nervous system? Acetylcholine
What is encephalization? Relative brain size compared to body size
Why are humans considered highly encephalized? They have large brains relative to body size
Does a larger brain always mean greater intelligence? No, relative organization and connectivity matter more
What is the brainstem? Lower brain structure controlling survival functions
What functions does the brainstem regulate? Breathing, heart rate, sleep, and arousal
What is the cerebellum? Brain region important for coordination and motor learning
What happens with cerebellar damage? Movement becomes uncoordinated and inaccurate
What are ventricles? Fluid-filled spaces in the brain
What fluid fills the ventricles? Cerebrospinal fluid (CSF)
What are the functions of CSF? Cushioning, buoyancy, and waste removal
What is an ischemic stroke? Stroke caused by blocked blood flow
What is a hemorrhagic stroke? Stroke caused by bleeding in the brain
What is the cerebral cortex? Outer layer of the brain involved in higher cognition
What are gyri? Ridges of the cerebral cortex
What are sulci? Grooves of the cerebral cortex
What are lobes? Large subdivisions of the cortex with specialized functions
What does the frontal lobe do? Decision making, movement, and planning
What does the parietal lobe do? Processes touch and spatial information
What does the temporal lobe do? Processes hearing and memory
What does the occipital lobe do? Processes vision

What is neuron doctrine? The idea that neurons are separate cells communicating at synapses
Who helped establish neuron doctrine? Santiago Ramón y Cajal
What was reticular theory? The incorrect idea that the nervous system is one continuous network
What is a neuron? A specialized cell that communicates using electrical and chemical signals
What are dendrites? Branch-like structures that receive information
What is the soma? The cell body containing the nucleus
What is the axon hillock? The region where action potentials begin
What is an axon? Long projection that carries electrical signals away from the soma
What are axon terminals? Endings that release neurotransmitters
What is myelin? Fatty insulation around axons that speeds conduction
What cells produce myelin in the CNS? Oligodendrocytes
What are Nodes of Ranvier? Gaps in myelin where ions cross the membrane
What is saltatory conduction? Action potentials jumping node to node
Why does myelin increase conduction speed? It prevents current leakage and allows jumping between nodes
What are astrocytes? Glial cells involved in support and blood-brain barrier function
What are microglia? Immune cells of the nervous system
What is the blood-brain barrier? Protective barrier controlling substances entering the brain
What is the resting membrane potential? Voltage difference across membrane when neuron is at rest
What is the resting membrane potential of most neurons? Approximately -70 mV
Why is the inside of the neuron negative? K+ leak and negatively charged proteins inside the cell
What ion is most concentrated inside the neuron? Potassium (K+)
What ion is most concentrated outside the neuron? Sodium (Na+)
What does the sodium-potassium pump do? Moves 3 Na+ out and 2 K+ in
Why is the sodium-potassium pump important? It maintains ion gradients necessary for signaling
What is depolarization? Membrane becomes less negative
What is hyperpolarization? Membrane becomes more negative
What is threshold? Voltage level needed to trigger an action potential
What is the threshold value for most neurons? About -55 mV
What is an action potential? Rapid electrical signal traveling down the axon
What does “all-or-nothing” mean? Action potentials occur fully or not at all
What ion causes the rising phase of the action potential? Sodium (Na+)
What happens to voltage-gated sodium channels during depolarization? They open and allow Na+ influx
What causes repolarization? Potassium leaving the neuron
What happens during hyperpolarization after an action potential? The membrane becomes temporarily more negative than resting potential
What is the refractory period? Brief time when another action potential cannot occur easily
Why is the refractory period important? It ensures one-way signal propagation
What is temporal summation? Addition of signals occurring close together in time
What is spatial summation? Addition of signals occurring close together in space
Where are signals integrated in the neuron? Axon hillock
What is electrochemical gradient? Combined electrical and concentration forces acting on ions
Why does Na+ move into neurons when channels open? Both electrical and concentration gradients favor influx
What is membrane permeability? How easily ions cross the membrane
Why is the membrane more permeable to K+ at rest? More potassium leak channels are open
What happens if sodium channels cannot open? Action potentials cannot occur
What happens if potassium channels are blocked? Repolarization is slowed

What is synaptic transmission? Communication between neurons at synapses
What is a synapse? Junction where neurons communicate
What is the presynaptic neuron? The neuron sending the signal
What is the postsynaptic neuron? The neuron receiving the signal
What triggers neurotransmitter release? Action potential reaching the terminal
What ion enters the presynaptic terminal to trigger release? Calcium (Ca2+)
What do synaptic vesicles contain? Neurotransmitters
What happens when calcium enters the terminal? Vesicles fuse with membrane and release neurotransmitter
What is exocytosis? Process of vesicles releasing contents outside the cell
What is a receptor? Protein that binds neurotransmitters
What are ionotropic receptors? Fast receptors that directly open ion channels
What are metabotropic receptors? Slower receptors using G-proteins and second messengers
Which receptor type acts faster? Ionotropic receptors
What is glutamate? Main excitatory neurotransmitter in the brain
What is GABA? Main inhibitory neurotransmitter in the brain
What is an EPSP? Excitatory postsynaptic potential causing depolarization
What is an IPSP? Inhibitory postsynaptic potential causing hyperpolarization
How does glutamate usually affect neurons? Makes them more likely to fire
How does GABA usually affect neurons? Makes them less likely to fire
What is neurotransmitter reuptake? Transporters recycling neurotransmitter into presynaptic neuron
What is enzymatic degradation? Breaking neurotransmitters down with enzymes
Why must neurotransmitters be cleared from the synapse? To stop signaling and reset the synapse
What is acetylcholine? Neurotransmitter involved in movement and parasympathetic signaling
What enzyme breaks down acetylcholine? Acetylcholinesterase
What is dopamine? Neurotransmitter involved in reward, movement, and motivation
What is serotonin? Neurotransmitter involved in mood and arousal
What is norepinephrine? Neurotransmitter involved in alertness and stress responses
What brainstem region produces dopamine? Substantia nigra and VTA
What brainstem region produces serotonin? Raphe nuclei
What brainstem region produces norepinephrine? Locus coeruleus

What is genotype? An organism’s genetic makeup
What is phenotype? Observable traits resulting from genes and environment
What is neurogenesis? Formation of new neurons
What is neuronal migration? Movement of neurons to target locations during development
What is differentiation? Process where cells become specialized
What is synaptogenesis? Formation of synapses between neurons
What is pruning? Elimination of excess synapses
Why does pruning occur? To strengthen useful neural connections
What is apoptosis? Programmed cell death
Why is apoptosis important? It removes unnecessary cells during development
What is a critical period? Time window when experience strongly affects development
What happens if visual input is blocked during a critical period? Visual cortex develops abnormally
What is neuroplasticity? The brain’s ability to change with experience
How does learning affect the brain? It changes synaptic connections and circuitry
What is environmental enrichment? Stimulating environment that enhances brain development
How does stress affect development? It can alter brain structure and behavior
What is epigenetics? Changes in gene expression caused by environment
Can experience influence gene expression? Yes, through epigenetic mechanisms

What is movement? Coordinated activity of muscles controlled by the nervous system
What is a reflex? Automatic response to a stimulus
What is the knee-jerk reflex? Stretch reflex involving spinal cord circuits
Why are reflexes important? They provide rapid protective responses
What is a motor plan? Prepared sequence of movements
What is the primary motor cortex? Cortical area controlling voluntary movement
What side of the body does each motor cortex control? The opposite side
What is the premotor cortex? Region involved in movement preparation
What is the supplementary motor area? Region involved in internally generated movement plans
What are mirror neurons? Neurons active during action and observation of action
Why are mirror neurons important? They may contribute to imitation and learning
What is the prefrontal cortex? Brain region involved in planning and decision making
What role does the prefrontal cortex play in movement? Goal-directed control and inhibition of actions
What is the neuromuscular junction? Synapse between motor neuron and muscle
What neurotransmitter is released at the neuromuscular junction? Acetylcholine
What happens when acetylcholine binds muscle receptors? Muscle contraction occurs
What is muscle tone? Baseline level of muscle contraction
What is Parkinson’s disease? Movement disorder caused by dopamine neuron loss
What symptoms occur in Parkinson’s disease? Tremor, rigidity, and slowed movement
What brain structure degenerates in Parkinson’s disease? Substantia nigra
What neurotransmitter is reduced in Parkinson’s disease? Dopamine
What is Huntington’s disease? Genetic disorder causing uncontrolled movements
What are basal ganglia? Subcortical structures involved in movement control
What role do the basal ganglia play? Initiating and regulating movement

What is sensation? Detection of stimuli by sensory receptors
What is perception? Interpretation of sensory information by the brain
What is sensory transduction? Conversion of physical stimuli into neural signals
What is adaptation? Reduced response to constant stimulation
Why is adaptation useful? It increases sensitivity to changes in the environment
What are labeled lines? Specific sensory pathways carrying specific information
What is the thalamus? Major relay station for sensory information
What is a receptive field? Area where stimulation activates a neuron
Why are receptive fields important? They determine stimulus localization and sensitivity
What is lateral inhibition? Process enhancing contrast between stimuli
What is the somatosensory cortex? Cortical region processing touch information
What is the sensory homunculus? Map showing exaggerated representation of sensitive body parts
Why are hands and lips large on the homunculus? They have many receptors and high sensitivity
What are mechanoreceptors? Receptors responding to touch and pressure
What are Pacinian corpuscles? Receptors detecting vibration
What are Meissner corpuscles? Receptors detecting light touch and texture
What are Merkel discs? Receptors detecting fine detail and pressure
What are Ruffini endings? Receptors detecting stretch
What are nociceptors? Pain receptors
What is pain? Experience associated with tissue damage or threat
What are thermoreceptors? Receptors detecting temperature
What is proprioception? Sense of body position and movement
What is vision? Perception of light
What structure detects light? Retina
What are rods? Photoreceptors specialized for dim light vision
What are cones? Photoreceptors specialized for color and detail
Which photoreceptors provide color vision? Cones
Which photoreceptors work best in darkness? Rods
What are bipolar cells? Retinal neurons connecting photoreceptors to ganglion cells
What are ganglion cells? Output neurons of the retina
What forms the optic nerve? Axons of ganglion cells
What is visual acuity? Sharpness of vision
Why is foveal vision sharpest? It contains many cones packed closely together
What is color vision based on? Different cone photopigments responding to wavelengths
What are the three cone types? Short, medium, and long wavelength cones
What is color blindness? Inability to distinguish certain colors due to cone abnormalities

What is taste? Chemical sense detecting substances dissolved in saliva
What are the five classic tastes? Sweet, sour, salty, bitter, and umami
What is umami? Savory taste associated with amino acids
What is a taste bud? Cluster of taste receptor cells
What is gustation? The sense of taste
What detects salty taste? Sodium ions entering channels
What detects sour taste? Hydrogen ions (H+)
What receptors detect sweet taste? T1R2 and T1R3 receptors
What receptors detect umami taste? T1R1 and T1R3 receptors
What receptors detect bitter taste? T2R receptors
Why is bitter sensitivity important? It may help avoid toxins
What are supertasters? People highly sensitive to bitter compounds
What causes supertasting? Genetic differences in taste receptors
What cranial nerves carry taste information? Facial, glossopharyngeal, and vagus nerves
Where does taste information go after the brainstem? Thalamus and gustatory cortex
What is olfaction? The sense of smell
What makes olfaction unique compared to other senses? It bypasses the thalamus initially
What are olfactory receptors? Receptors detecting airborne chemicals
Where are olfactory receptors located? Olfactory epithelium in the nose
What is the olfactory bulb? Brain structure processing smell information
Why are smell and memory strongly linked? Olfactory pathways connect closely with limbic regions

What is a circadian rhythm? Biological rhythm lasting about 24 hours
What is a free-running rhythm? Circadian rhythm occurring without external cues
What is a zeitgeber? External cue that synchronizes rhythms
What is the strongest zeitgeber? Light
What is the SCN? Suprachiasmatic nucleus, the brain’s master clock
Where is the SCN located? Hypothalamus
What happens if the SCN is damaged? Circadian rhythms become disrupted
How does light affect circadian rhythms? It resets the SCN through retinal input
What hormone increases at night? Melatonin
What gland releases melatonin? Pineal gland
What hormone rises before waking? Cortisol
What is phase shift? Change in timing of circadian rhythm
What causes jet lag? Misalignment between internal clock and local time
What is chronotype? Natural tendency toward being a morning or evening person
What are ultradian rhythms? Rhythms shorter than 24 hours
What are infradian rhythms? Rhythms longer than 24 hours

What is sleep? Reversible state of reduced responsiveness and activity
What are the two major sleep categories? NREM and REM sleep
What is NREM sleep? Non-rapid eye movement sleep
What is REM sleep? Rapid eye movement sleep associated with vivid dreams
What percentage of sleep is NREM? About 80%
What brain activity occurs during REM sleep? Wake-like EEG activity
What happens to muscles during REM sleep? Muscle paralysis occurs
Why is REM paralysis important? It prevents acting out dreams
What are delta waves? Slow high-amplitude brain waves during deep sleep
What EEG pattern occurs during alert wakefulness? Beta waves
What EEG pattern occurs during relaxed wakefulness? Alpha waves
What EEG pattern occurs during deep sleep? Delta waves
How long is a typical sleep cycle? About 90–110 minutes
How many sleep cycles occur per night? About 4–5 cycles
What changes later in the night? REM periods become longer
What is sleep deprivation? Insufficient sleep causing impairment
How does sleep deprivation affect cognition? Impairs attention, memory, and decision making
How does sleep deprivation affect the immune system? It weakens immune function
Why do infants sleep more than adults? Brain development requires more sleep and REM
What is insomnia? Difficulty falling or staying asleep
What is narcolepsy? Disorder involving sudden sleep attacks
What is sleep apnea? Repeated breathing interruptions during sleep
What is REM behavior disorder? Condition where REM paralysis fails
What is dreaming? Mental experiences occurring during sleep
During which stage are vivid dreams most common? REM sleep
What is sleep consolidation theory? Idea that sleep strengthens memories
How does sleep help learning? It promotes memory consolidation and synaptic plasticity

What is learning? Relatively permanent change in behavior due to experience
What is memory? Ability to encode, store, and retrieve information
What is working memory? Short-term storage system used for immediate tasks
What is the capacity of working memory? About 7 ± 2 items
What is long-term memory? Storage system for information over long periods
What is explicit memory? Conscious memory for facts and events
What is episodic memory? Memory for personal experiences
What is semantic memory? Memory for facts and knowledge
What is implicit memory? Unconscious memory involving skills and habits
What did patient H.M. demonstrate? Hippocampus is necessary for forming new explicit memories
What is anterograde amnesia? Inability to form new memories
What is retrograde amnesia? Loss of previously formed memories
What is consolidation? Process where memories stabilize over time
What brain structure is critical for consolidation? Hippocampus
What is retrieval? Accessing stored memories
What are retrieval cues? Stimuli that improve recall

What is habituation? Reduced response to repeated harmless stimulus
What is sensitization? Increased response after strong stimulus
What is Hebbian learning? Neurons that fire together strengthen connections
What is synaptic plasticity? Ability of synapses to change strength
What is long-term potentiation (LTP)? Long-lasting increase in synaptic strength
Where was LTP first discovered? Hippocampus
What neurotransmitter is central to LTP? Glutamate
What receptor is important for LTP induction? NMDA receptor
What ion enters during LTP? Calcium
What does calcium do during LTP? Triggers signaling that strengthens synapses
What happens to AMPA receptors during LTP? More are added to synapse
Why is LTP important? It is a major mechanism for learning and memory

What is the amygdala? Brain region processing emotion and fear
What is fear? Response to immediate threat
What is anxiety? Anticipation of possible future threat
What is fear conditioning? Learning association between neutral and aversive stimuli
What is a conditioned stimulus (CS)? Previously neutral cue predicting aversive event
What is an unconditioned stimulus (US)? Naturally aversive stimulus
What is the basolateral amygdala (BLA)? Region involved in emotional learning
What is the central amygdala (CeA)? Region producing fear responses
What behavior measures fear in rodents? Freezing
What happens if the amygdala is damaged? Fear learning is impaired

What is stress? Response to challenge or threat
What is the HPA axis? Hypothalamic-pituitary-adrenal stress system
What hormone does the hypothalamus release during stress? CRH
What hormone does the pituitary release? ACTH
What hormone do adrenal glands release? Cortisol
What does cortisol do? Mobilizes energy during stress
What is negative feedback in the HPA axis? Cortisol reduces CRH and ACTH release
What is generalized anxiety disorder (GAD)? Chronic excessive worry lasting 6+ months
What brain region is hyperactive in anxiety? Amygdala
What brain region has reduced control in anxiety? Prefrontal cortex
What can chronic stress damage? Hippocampus

What is the endocrine system? System of hormone-secreting glands
What are hormones? Chemical messengers traveling through bloodstream
What are steroid hormones? Fat-soluble hormones affecting gene expression
What are examples of steroid hormones? Testosterone and estrogen
What are organizational hormone effects? Permanent developmental effects
What are activational hormone effects? Temporary adult hormone effects
What brain region regulates hormones and sexual behavior? Hypothalamus

What is homeostasis? Maintaining stable internal conditions
What is hunger? Motivational state promoting eating
What does the lateral hypothalamus do? Promotes feeding
What happens if the lateral hypothalamus is damaged? Reduced eating
What does the ventromedial hypothalamus do? Promotes satiety
What happens if the VMH is damaged? Overeating
What is ghrelin? Hunger hormone released by stomach
What is leptin? Hormone from fat tissue signaling satiety
What brain reward area is activated by food? Nucleus accumbens

What is motivation? Process energizing and directing behavior
What is intrinsic motivation? Behavior driven by internal satisfaction
What is extrinsic motivation? Behavior driven by external rewards
What neurotransmitter strongly influences motivation? Dopamine
What is incentive salience? Motivational pull of rewarding stimuli

What is a reward? Stimulus increasing likelihood of behavior
What is a punisher? Stimulus decreasing behavior
What is operant conditioning? Learning shaped by consequences
What is extinction? Decrease in behavior when reward removed
What is a primary reinforcer? Innately rewarding stimulus
What is a conditioned reinforcer? Stimulus gaining value through association
What is “wanting”? Motivational drive for reward
What neurotransmitter is associated with wanting? Dopamine
What is “liking”? Pleasurable aspect of reward
What neurotransmitter system is linked to liking? Opioid system
What brain area is central to reward? Nucleus accumbens
Where do dopamine neurons originate? Ventral tegmental area (VTA)
Do dopamine neurons directly produce pleasure? No, mainly motivation and learning
What do mu opioid receptors contribute to? Pleasure and liking
What brain region computes subjective pleasantness? Orbitofrontal cortex (OFC)
What activates the nucleus accumbens socially? Smiles and social reward

What is decision making? Evaluating options to choose actions
What is cognitive flexibility? Ability to adapt behavior to changing situations
What is reversal learning? Switching responses after rules change
What brain region is important for reversal learning? Orbitofrontal cortex
What is subjective value? Perceived worth of an outcome
What does the OFC compute? Current subjective value
What happens after OFC lesions? Poor judgment and reduced flexibility
What famous patient had OFC damage? Phineas Gage
What task measures risky decision-making? Iowa Gambling Task
What happens on Iowa Gambling Task after OFC damage? People continue making poor choices
What is expected value? Reward magnitude multiplied by probability
What is reinforcer devaluation? Reducing value of a reward after satiation

What is addiction? Compulsive drug use despite negative consequences
What are the three stages of addiction? Binge/intoxication, withdrawal, preoccupation/craving
What is tolerance? Reduced response after repeated drug use
What is metabolic tolerance? Faster drug breakdown by body
What is functional tolerance? Reduced receptor sensitivity
What is withdrawal? Opposite effects after stopping drug
What is physical dependence? Body adaptation causing withdrawal symptoms
What is craving? Strong desire for a drug
What triggers relapse? Stress, cues, and negative emotions
What is cue-reward learning? Cues becoming associated with rewards
What brain circuit is central to addiction? VTA to nucleus accumbens pathway
What neurotransmitter increases with addictive drugs? Dopamine
Do all addictive drugs increase dopamine? Yes
What does cocaine do to dopamine? Blocks dopamine reuptake
How do opiates increase dopamine? Reduce inhibitory GABA input
What animal behavior models addiction? Self-administration
What is relapse? Return to drug use after abstinence

What is schizophrenia? Disorder involving loss of contact with reality
When does schizophrenia usually begin? Early adulthood
What are positive symptoms of schizophrenia? Hallucinations, delusions, disorganized thought
What are negative symptoms of schizophrenia? Reduced emotion, speech, and motivation
What are cognitive symptoms of schizophrenia? Impaired attention and working memory
What is a hallucination? False sensory experience
What is a delusion? False fixed belief resistant to evidence
What is flat affect? Reduced emotional expression
Does schizophrenia run in families? Yes
What structural brain abnormality is common in schizophrenia? Enlarged ventricles
What brain tissue decreases in schizophrenia? Gray matter
What is the dopamine hypothesis? Too much dopamine signaling contributes to schizophrenia
What evidence supports dopamine hypothesis? Amphetamines mimic symptoms
What do antipsychotic drugs block? D2 dopamine receptors
What symptoms are best treated by antipsychotics? Positive symptoms
What is the glutamate hypothesis? Too little glutamate signaling contributes
What drug mimics schizophrenia symptoms by blocking NMDA receptors? Ketamine
What neurotransmitters are implicated in schizophrenia? Dopamine, glutamate, and GABA
What environmental factors increase schizophrenia risk? Stress, drugs, infection, urban upbringing