Acetylcholine (ACh)
*Enables muscle action, learning, and memory; Blocked ACh → weakness, paralysis.**
Dopamine
*Influences movement, learning, attention, and emotion; Oversupply → schizophrenia; Undersupply → tremors, Parkinson’s.**
Serotonin
*Affects mood, hunger, sleep, arousal; Undersupply → depression.**
Norepinephrine
*Helps control alertness and arousal; Undersupply → depressed mood.**
GABA
*Major inhibitory neurotransmitter; Undersupply → seizures, tremors, insomnia.**
Glutamate
*Major excitatory neurotransmitter; involved in memory; Oversupply → migraines, seizures.**
Endorphins
*Natural painkillers; influence perception of pain/pleasure; Oversupply with opioids → body reduces own production.**
Substance P
*Involved in pain perception and immune response; Oversupply → chronic pain.**
Alcohol
*Depressant; initial high then relaxation/disinhibition; Negatives: depression, memory loss, organ damage, impaired reactions.**
Heroin
*Depressant; rush of euphoria, pain relief; Negatives: depressed physiology, loss of natural endorphins.**
Caffeine
*Stimulant; increased alertness/wakefulness; Negatives: anxiety, restlessness, insomnia.**
Nicotine
*Stimulant; arousal and relaxation; Negatives: heart disease, cancer.**
Cocaine
*Stimulant; rush of euphoria, confidence, energy; Negatives: cardiovascular stress, suspiciousness, depression, crash.**
Methamphetamine
*Stimulant; euphoria, alertness, energy; Negatives: irritability, insomnia, hypertension, seizures.**
Ecstasy (MDMA)
*Stimulant + mild hallucinogen; emotional elevation, disinhibition; Negatives: dehydration, overheating, depressed mood, impaired cognition/immune function.**
LSD
*Hallucinogen; visual “trip”; Negatives: risk of panic.**
Marijuana (THC)
*Mild hallucinogen; enhanced sensation, pain relief, time distortion, relaxation; Negatives: impaired learning/memory, increased risk of psychological disorders.**
EEG
*Electrodes on scalp measure brain waves; Finding: Depression/anxiety → ↑ right frontal lobe activity.**
MEG
*Head coil records magnetic fields from brain; Finding: PTSD soldiers → stronger visual cortex activity when viewing trauma images.**
CT
*X-rays of head show brain damage; Finding: Children’s injuries predict lower intelligence/memory.**
PET
*Tracks radioactive glucose in brain during tasks; Finding: Anxious monkeys → more glucose use in fear/memory regions.**
MRI
*Maps brain structure with magnetic fields/radio waves; Finding: History of violence → smaller frontal lobes (self-control/moral judgment).**
fMRI
*Measures blood flow via MRI scans; Finding: Plane crash survivors → more fear/memory/visual center activity when viewing trauma footage.**
Insomnia
*1 in 5 adults; difficulty falling/staying asleep; Effects: tiredness, depression, obesity, hypertension, pain.**
Narcolepsy
*1 in 2000 adults; sudden overwhelming sleepiness; Effects: risk of falling asleep at dangerous times, attacks <5 min.**
Sleep Apnea
*1 in 20 adults; stopping breathing during sleep; Effects: fatigue, depression, linked to obesity (esp. men).**
Sleepwalking
*1–15 in 100 adults; complex motor behavior in Stage 3 sleep; Effects: few concerns, rarely remember episode.**
REM Sleep Behavior Disorder
*1 in 100 adults (general), 1 in 50 (50+); acting out dreams; Effects: risk of accidental injury to self/partner.**
Information Processing
*Dreams help sort events and consolidate memories; Critique: sometimes dream about things not experienced.**
Physiological Function
*REM stimulation helps develop/preserve neural pathways; Critique: doesn’t explain meaningful dreams.**
Activation Synthesis
*REM activity evokes random visuals, brain weaves stories; Critique: brain creates stories but reveals info about dreamer.**
Cognitive Development
*Dream content reflects cognitive level; simulates life/worst-case scenarios; Critique: no adaptive function proposed.**
Vision
*Source:** Light waves; **Receptors:** Rods/cones; **Brain Area:** Occipital lobes
Hearing
*Source:** Sound waves; **Receptors:** Cochlear hair cells; **Brain Area:** Temporal lobes
Touch
*Source:** Pressure, warmth, cold, chemicals; **Receptors:** Pain-sensitive skin receptors; **Brain Area:** Somatosensory cortex
Taste
*Source:** Chemical molecules; **Receptors:** Sweet, sour, salty, bitter, umami, oleogustus; **Brain Area:** Frontal/temporal border
Smell
*Source:** Chemical molecules in nose; **Receptors:** Nasal receptors; **Brain Area:** Olfactory bulb
Kinesthesis
*Source:** Body part movement; **Receptors:** Proprioceptors in joints/tendons/muscles; **Brain Area:** Cerebellum
Vestibular Sense
*Source:** Head/body movement; **Receptors:** Hair-like receptors in inner ear; **Brain Area:** Cerebellum
Figure 1.5-4
*Electrodes measure EEG (brain waves), EMG (muscle tension), EOG (eye movement); other devices track heart rate, respiration, genital arousal.**
Figure 1.5-5
*Beta waves = awake; Alpha = relaxed; Delta = Stage 3/N3; REM = resembles Stage 1 but body internally aroused.**
Figure 1.5-6
*Moment of falling asleep (Stage 1/N1); we are unaware, EEG shows slowed, irregular waves.**
Figure 1.5-7
*Sleep cycle repeats ~90 min; Stage 3 shortens over night; Stage 2 & REM get longer; older adults → more awakenings.**
AP Exam Tip
*REM does NOT come directly after Stage 3; usually Stage 2 → REM.**