Unit 1 Realistic

Brainstem

The base of the brain that controls basic survival functions. Ex: Keeps you breathing while you sleep.

Medulla

Part of the brainstem that controls heartbeat and breathing. Ex: Keeps your heart beating without thought.

Reticular activating system

A brainstem network that controls arousal and alertness. Ex: Wakes you up when your alarm goes off.

Reward center

Brain circuits (like the nucleus accumbens) that release dopamine for pleasurable experiences. Ex: Feeling good after eating your favorite dessert.

Cerebellum

Controls balance, coordination, and movement, and helps with procedural memory. Ex: Riding a bike without falling.

Cerebral cortex

The brain's wrinkled outer layer, responsible for higher thinking. Ex: Solving a math problem.

Hemispheres

The left and right halves of the brain. Ex: The left side handles language for most people.

Limbic system

Brain structures involved in emotion, memory, and drives. Ex: Feeling scared and remembering why.

Thalamus

The sensory relay station that sends information to the proper cortex area (except smell). Ex: Routes the sound of a bell to your auditory cortex.

Hypothalamus

Regulates hunger, thirst, body temperature, and sex drive, and controls the pituitary. Ex: Makes you sweat when you're hot.

Pituitary gland

The "master gland," which releases hormones that control other glands. Ex: Releases growth hormone during childhood.

Hippocampus

Forms new explicit (conscious) memories. Ex: Remembering what you did yesterday.

Amygdala

Processes emotions, especially fear and aggression. Ex: Your heart jumps when you see a spider.

Corpus callosum

The band of fibers connecting the two hemispheres so they can communicate. Ex: Lets your right brain share what your left eye sees with your left brain.

Lobes of the cortex

The four regions of each hemisphere: frontal, parietal, temporal, and occipital. Ex: Each lobe handles different jobs, like vision or movement.

Occipital lobes

Located at the back of the brain; process visual information. Ex: Recognizing a friend's face.

Temporal lobes

Located above the ears; process hearing, language comprehension, and some memory. Ex: Understanding a song's lyrics.

Parietal lobes

Located at the top and back of the head; process touch and spatial awareness. Ex: Feeling a tap on your shoulder.

Somatosensory cortex

Strip at the front of the parietal lobe that registers touch, pressure, temperature, and pain. Ex: Feeling a cold drink in your hand.

Association areas

Cortex areas that integrate information rather than handle basic sensory or motor tasks. Ex: Combining what you see and hear to understand a conversation.

Frontal lobes

Located at the front of the brain; involved in planning, judgment, speech, and movement. Ex: Deciding to study instead of go out.

Prefrontal cortex

The front part of the frontal lobes; handles decision making, self-control, and personality. Ex: Resisting the urge to blurt out an answer.

Motor cortex

Strip at the back of the frontal lobes that controls voluntary movement. Ex: Moving your fingers to type.

Split brain research

Studies of people whose corpus callosum was cut, showing how each hemisphere functions on its own. Ex: A patient can't name an object shown only to the right hemisphere.

Specialization of hemispheres

Each hemisphere is better at certain tasks (left: language, logic; right: spatial skills, faces). Ex: The left hemisphere helps you speak, while the right helps you recognize faces.

Broca's area

Left frontal lobe area that controls speech production. Ex: Damage means you understand speech but can't speak fluently.

Wernicke's area

Left temporal lobe area that handles language comprehension. Ex: Damage means you speak fluently but your words make no sense.

Aphasia

Impairment of language caused by brain damage. Ex: A stroke patient can't find the right words.

Test with split-brain patients

Information is flashed to one visual field so only one hemisphere sees it. Ex: A word flashed to the left visual field can be drawn by the left hand but not spoken.

Cortex specialization

Different cortex areas are specialized for different functions. Ex: The occipital lobe handles vision, while the motor cortex handles movement.

Contralateral organization

Each hemisphere controls and receives information from the opposite side of the body. Ex: The left hemisphere moves your right hand.

Brain plasticity

The brain's ability to change and reorganize itself after experience or injury. Ex: After a stroke, other brain areas take over lost functions.

EEG

Records the brain's electrical activity using electrodes on the scalp. Ex: Used to measure brain waves during sleep.

fMRI

Uses blood flow to show which brain areas are active during a task. Ex: Shows which areas light up when you solve a math problem.

Case studies

In-depth studies of one individual, often used for rare brain conditions. Ex: Phineas Gage's injury showed the frontal lobes affect personality.

Lesioning procedure

Destroying or removing part of the brain to see how behavior changes. Ex: Researchers damage a rat's hypothalamus to see its effect on eating.

Varying levels of consciousness

Awareness ranges from fully alert to unconscious. Ex: You're alert in class, drowsy at bedtime, and unaware during deep sleep.

Sleep/wake cycle

The daily pattern of sleeping and being awake, controlled by the body's internal clock. Ex: Feeling sleepy at night and awake in the morning.

Circadian rhythm (disruptions)

The roughly 24-hour biological clock; disruptions throw off sleep and alertness. Ex: Staying up all night makes you feel off the next day.

Jet lag

Circadian disruption from traveling across time zones. Ex: Flying from Michigan to Europe and feeling wide awake at 3 a.m.

Shift work

Working schedules that go against the natural circadian rhythm, leading to poor sleep. Ex: A night-shift nurse struggles to sleep during the day.

Stages of sleep

Cycles of NREM stages 1-3 and REM, repeating about every 90 minutes. Ex: You move from light sleep to deep sleep to dreaming several times a night.

EEG patterns for each stage

Awake: beta; relaxed: alpha; N1: theta; N2: sleep spindles and K-complexes; N3: delta; REM: beta-like, similar to waking. Ex: Slow, large delta waves show up when you're in deep sleep.

NREM 1, 2, 3

N1 is light sleep, N2 is deeper sleep with spindles, and N3 is the deepest, slow-wave sleep. Ex: It's easy to wake in N1 but very hard in N3.

Hypnagogic sensations

Strange sensations like falling or jerking while drifting into sleep. Ex: Suddenly jolting awake feeling like you tripped.

REM (paradoxical sleep)

Sleep stage with vivid dreams, rapid eye movements, and a nearly paralyzed body, while the brain is very active. Ex: Dreaming while your body stays still.

Dreaming and REM

Most vivid, story-like dreams occur during REM sleep. Ex: Waking from a vivid dream about flying.

REM increases throughout the night

REM periods get longer and NREM deep sleep gets shorter as the night goes on. Ex: Your longest dreams happen just before you wake up.

REM rebound

After REM deprivation, the body spends extra time in REM the next night. Ex: After several nights of poor sleep, you dream a lot when you finally rest.

Activation-synthesis theory (dreams)

Dreams are the brain's attempt to make sense of random neural activity during REM. Ex: A random mix of images becomes a weird story about school and animals.

Consolidation theory (dreams)

Dreams reflect the brain processing and storing the day's memories. Ex: Dreaming about a test you studied for.

Memory consolidation (sleep)

Sleep helps strengthen and store new memories. Ex: Studying and then sleeping helps you remember the material.

Restoration (sleep)

Sleep lets the body and brain repair, recover, and clear waste. Ex: You feel refreshed and energized after a good night's sleep.

Sleep disruptions (deprivation)

Lack of sleep harms attention, mood, memory, and health. Ex: Staying up late makes it hard to focus in class.

Insomnia

Persistent trouble falling or staying asleep. Ex: Lying awake for hours every night worrying.

Narcolepsy

Sudden, uncontrollable sleep attacks, sometimes falling straight into REM. Ex: Someone falls asleep suddenly in the middle of a conversation.

REM sleep behavior disorder

Loss of normal REM paralysis, causing people to act out dreams. Ex: A person punches or kicks while dreaming.

Sleep apnea

Repeated pauses in breathing during sleep, causing frequent awakenings. Ex: A loud snorer wakes up gasping and feels tired all day.

Somnambulism

Sleepwalking, which occurs during deep NREM (N3) sleep. Ex: A child gets up and walks around the house asleep.

Sensation

The process of detecting physical stimuli from the environment and body with our sensory receptors. Ex: Your eyes detect light from a lamp.

Transduction

Converting physical energy (light, sound) into neural signals the brain can use. Ex: Your ear turns sound waves into neural impulses.

Perception

The brain organizing and interpreting sensory information to give it meaning. Ex: Recognizing the light as a lamp.

Absolute threshold

The minimum stimulus needed to detect it 50% of the time. Ex: Barely hearing a whisper in a quiet room.

Just-noticeable difference

The smallest change in a stimulus that a person can detect. Ex: Noticing the music got slightly louder.

Sensory adaptation

Decreased sensitivity to a constant, unchanging stimulus. Ex: You stop noticing your clothes against your skin.

Weber's Law

The just-noticeable difference is a constant proportion of the original stimulus. Ex: A 1 lb change is noticeable on a 10 lb weight but not on a 100 lb weight.

Sensory interaction

One sense influences another. Ex: Food tastes bland when you have a stuffy nose.

Synesthesia

A rare condition where one sense triggers another. Ex: Seeing the number 5 as red.

Retina

The light-sensitive inner surface of the eye containing rods and cones. Ex: Like the film or sensor in a camera.

Blind spot

The spot where the optic nerve leaves the eye and there are no receptors. Ex: An object disappears when you cover one eye and focus on a spot.

Lens

The clear structure behind the pupil that focuses light onto the retina. Ex: Like a camera lens focusing an image.

Accommodation

The lens changing shape to focus on near or far objects. Ex: Your eyes adjust when you look from your phone to the board.

Nearsightedness

Distant objects look blurry because light focuses in front of the retina. Ex: Needing glasses to read the board.

Farsightedness

Near objects look blurry because light focuses behind the retina. Ex: Having trouble reading a book up close.

Rods

Retina receptors that detect black, white, and gray and work in dim light; located in the periphery. Ex: Helping you see in a dark room.

Cones

Retina receptors that detect color and fine detail in bright light; concentrated in the fovea. Ex: Telling a red apple from a green one.

Ganglion cells

Neurons whose axons form the optic nerve and carry visual information to the brain. Ex: They pass a signal from the retina to the brain.

Light adaptation

The eyes adjusting to bright light by becoming less sensitive. Ex: Squinting when you walk outside, then adjusting.

Dark adaptation

The eyes becoming more sensitive in dim light as rods take over. Ex: Gradually seeing in a dark movie theater.

Trichromatic theory

Color vision comes from three cone types (red, green, blue) working together. Ex: Seeing yellow when red and green cones fire.

Fovea

The center of the retina, packed with cones, giving the sharpest vision. Ex: Looking directly at a word to read it.

Photoreceptors

Rods and cones, the retina cells that detect light. Ex: They turn light into signals.

Blue - short wavelengths of light

Short-wavelength cones respond to blue. Ex: The sky looks blue.

Green - medium wavelengths of light

Medium-wavelength cones respond to green. Ex: Grass looks green.

Red - long wavelengths of light

Long-wavelength cones respond to red. Ex: A stop sign looks red.

Opponent-process theory

Color is processed in opposing pairs (red/green, blue/yellow, black/white) beyond the cones. Ex: You can't see a reddish green.

Afterimages

A color image that lingers after staring at a color and looking away, caused by fatigue of opponent cells. Ex: Staring at a red dot and then seeing green.

Ganglion cells (red/green, blue/yellow, black/white)

Ganglion cells respond in opposing pairs, which explains opponent-process theory. Ex: Red excites a cell while green inhibits it.

Color vision deficiencies (Dichromatism, Monochromatism)

Dichromatism: missing one cone type (like red-green color blindness). Monochromatism: only one cone type, so only shades of gray. Ex: A person with dichromatism can't tell red from green.

Prosopagnosia (face blindness)

Inability to recognize faces despite normal vision, linked to the temporal lobe. Ex: Not recognizing your own mom's face.

Blindsight

Responding to visual stimuli without consciously seeing them, after damage to the visual cortex. Ex: A person says they see nothing but can point to a light.

Wavelength of sound = pitch

Shorter wavelengths (higher frequency) mean higher pitch. Ex: A whistle has a high pitch.

Amplitude of wave = loudness

Taller sound waves are louder. Ex: A shout has greater amplitude than a whisper.

Place theory

Pitch is determined by where on the basilar membrane the wave peaks; best for high pitches. Ex: High sounds stimulate the base of the cochlea.

Frequency theory

Pitch matches the rate at which the auditory nerve fires; best for low pitches. Ex: A low hum makes nerves fire slowly.

Volley theory

Neurons take turns firing in volleys to handle higher frequencies. Ex: Neurons fire in teams to keep up with a fast sound.

Sound localization

Finding where a sound comes from using the slight differences in timing and loudness between the two ears. Ex: Turning your head toward a person calling your name.

Conduction deafness

Hearing loss from damage to the eardrum or ear bones, which block sound transmission. Ex: Hearing loss after a ruptured eardrum.

Sensorineural deafness

Hearing loss from damage to the cochlea's hair cells or auditory nerve. Ex: Hearing loss from years of loud concerts.

Chemical senses

Senses that detect chemicals: smell and taste. Ex: Smelling and tasting pizza.