AP Psych Brain Parts/Functions

Evolutionary Perspective

A branch of psychology that attributes human behaviors, cognitive processes, and traits to natural selection and adaptations.

Natural Selection

The biological process where organisms with traits better adapted to their environment are more likely to survive and reproduce.

Nature

The genetic and biological influences that shape an individual's development, traits, and behavior.

Nurture

The environmental influences, experiences, culture, and upbringing that shape individual development.

Twin Studies

Research comparing identical (monozygotic) and fraternal (dizygotic) twins to estimate the relative contributions of genetics versus environment.

Adoption Studies

Research comparing adopted children to their biological and adoptive parents to evaluate genetic versus environmental impacts.

Family Studies

Research examining family members to determine how specific traits or disorders run across biological relatives.

Heredity

The transmission of genetic characteristics from parents to offspring.

Genetic Predisposition

An increased likelihood of developing a particular disease or trait based on an individual's genetic makeup.

Eugenics

The historical, controversial movement advocating for the selective breeding of humans to alter inherited characteristics.

Cerebral Cortex

The outer layer of neural tissue covering the cerebrum, responsible for high-level functions such as thought, language, and perception.

Association Areas

Regions of the cerebral cortex not involved in primary motor or sensory functions, but rather in integrating and interpreting information.

Lobes of the Brain

The four main anatomical divisions of the cerebral cortex: frontal, parietal, occipital, and temporal.

Frontal Lobes

The brain region located behind the forehead involved in decision-making, reasoning, planning, voluntary movement, and speech production.

Prefrontal Cortex

The forward-most portion of the frontal lobe, essential for executive functions, working memory, personality, and social behavior.

Executive Functioning

Higher-order cognitive processes including planning, decision-making, working memory, goal-directed behavior, and self-control.

Motor Cortex

An area located at the rear of the frontal lobes that controls voluntary muscle movements.

Parietal Lobes

The brain region located at the top-rear of the head that processes sensory information related to touch, temperature, pressure, and spatial awareness.

Somatosensory Cortex

A strip of tissue at the front of the parietal lobe that receives and registers touch and body sensations.

Occipital Lobes

The brain region located at the back of the head primarily responsible for visual processing.

Temporal Lobes

The brain region located above the ears responsible for auditory processing, language comprehension, and memory encoding.

Corpus Callosum

A thick band of nerve fibers connecting the left and right cerebral hemispheres, enabling communication between them.

Brainstem

The oldest central core structure of the brain connecting to the spinal cord, responsible for automatic survival functions.

Medulla

The base of the brainstem that automatically controls vital autonomic functions like heartbeat, breathing, and blood pressure.

Reticular Activating System (RAS)

A network of nerves in the brainstem that regulates alertness, arousal, sleep-wake transitions, and sensory filtering.

Cerebellum

The structure located at the rear of the brainstem responsible for coordinating voluntary movement, balance, posture, and motor learning.

Limbic System

A neural network (including the hippocampus, amygdala, and hypothalamus) associated with emotions, drives, and memory formation.

Reward Center

Neural structures within the limbic system (such as the nucleus accumbens) that mediate feelings of pleasure and reinforcement.

Thalamus

The brain's primary sensory control relay station atop the brainstem, routing sensory signals (except smell) to the cortex.

Hypothalamus

A neural structure lying below the thalamus that directs maintenance activities (eating, drinking, temperature regulation) and governs the endocrine system via the pituitary gland.

Pituitary Gland

The master gland of the endocrine system, regulated by the hypothalamus, that secretes hormones governing growth and other glands.

Hippocampus

A limbic system structure vital for processing and consolidating new explicit memories into long-term storage.

Amygdala

Two almond-shaped neural clusters in the limbic system linked to emotional processing, particularly fear and aggression.

Nervous System

The body's electrochemical communication network, comprising all nerve cells across the central and peripheral divisions.

Central Nervous System (CNS)

The primary control division of the nervous system consisting strictly of the brain and spinal cord.

Peripheral Nervous System (PNS)

The sensory and motor neurons connecting the central nervous system to the limbs, organs, and rest of the body.

Autonomic Nervous System (ANS)

The subdivision of the PNS that regulates involuntary bodily functions such as heartbeat, digestion, and respiration.

Sympathetic Nervous System

The branch of the ANS that mobilizes bodily energy during stress or perceived threats (the fight-or-flight response).

Parasympathetic Nervous System

The branch of the ANS that calms the body and conserves energy after exertion (rest and digest).

Somatic Nervous System

The division of the PNS that controls the voluntary movements of skeletal muscles and transmits sensory feedback to the CNS.

Neurons

Individual nerve cells that serve as the fundamental structural and functional units of the nervous system.

Glial Cells

Non-neuronal cells in the nervous system that nourish, protect, insulate with myelin, and structurally support neurons.

Motor Neurons (Efferent)

Neurons that transmit outgoing motor signals from the central nervous system to muscles and glands.

Sensory Neurons (Afferent)

Neurons that transmit incoming sensory information from peripheral receptors toward the central nervous system.

Interneurons

Neurons located entirely within the brain and spinal cord that process information internally between sensory inputs and motor outputs.

Reflex Arc

A fast, automatic neural pathway mediating an involuntary response, often operating through the spinal cord without initial cortical involvement.

Neural Transmission

The electrochemical process wherein neurotransmitters are released from an axon terminal to cross the synapse and bind to target receptors.

Threshold

The minimum membrane potential level of stimulation required to trigger an action potential in a neuron.

Action Potential

A brief electrical impulse that travels down an axon when a neuron depolarizes and fires.

All-or-Nothing Principle

The physiological law stating that a neuron generates a complete action potential or none at all, maintaining uniform strength regardless of stimulus intensity.

Depolarization

The influx of positively charged sodium ions into a neuron that reduces negative membrane charge and triggers an action potential.

Refractory Period

The brief recovery phase following neural firing during which a neuron cannot generate another action potential until repolarized.

Resting Potential

The baseline electrical polarization across an inactive neuronal membrane, typically measured at approximately $-70\,\text{mV}$.

Reuptake

The reabsorption of excess neurotransmitter molecules by the presynaptic neuron's axon terminal following synaptic signaling.

Multiple Sclerosis (MS)

A chronic autoimmune disorder in which the immune system degrades the myelin sheath of axons in the central nervous system.

Myasthenia Gravis

An autoimmune neuromuscular condition that causes muscle weakness by impairing acetylcholine receptor function at the neuromuscular junction.

Neurotransmitters

Endogenous chemical messengers that travel across the synaptic cleft to transmit, amplify, or modulate signals between neurons.

Excitatory Neurotransmitters

Chemical messengers that depolarize the postsynaptic membrane, increasing the probability that the receiving neuron will fire.

Glutamate

The primary excitatory neurotransmitter within the central nervous system, critical for synaptic plasticity, learning, and memory.

Inhibitory Neurotransmitters

Chemical messengers that hyperpolarize the postsynaptic membrane, decreasing the probability that the receiving neuron will fire.

GABA (Gamma-Aminobutyric Acid)

The primary inhibitory neurotransmitter in the brain, responsible for dampening neuronal excitability and reducing anxiety.

Dopamine

A monoamine neurotransmitter involved in motor control, motivation, reward pathways, and the experience of pleasure.

Serotonin

A neurotransmitter involved in the regulation of mood, sleep architecture, appetite, and emotional stability.

Endorphins

Endogenous peptide neurotransmitters structurally similar to opiates that alleviate pain and enhance feelings of well-being.

Substance P

A neuropeptide neurotransmitter involved in the transmission and perception of pain signals to the central nervous system.

Acetylcholine (ACh)

A neurotransmitter essential for triggering voluntary muscle contractions, as well as mediating attention, arousal, and memory.

Hormones

Chemical messengers synthesized by endocrine glands that travel through the circulatory system to regulate distant target organs.

Ghrelin

A peptide hormone primarily synthesized by the stomach that signals hunger to the hypothalamus and stimulates appetite.

Leptin

A hormone produced by adipose (fat) tissue that signals satiety to the brain and reduces food intake.

Melatonin

A hormone synthesized and secreted by the pineal gland that regulates sleep-wake patterns and circadian rhythms.

Oxytocin

A hormone synthesized in the hypothalamus and released by the pituitary gland, promoting prosocial bonding, trust, and maternal behavior.

Adrenaline (Epinephrine)

An endocrine hormone released by the adrenal glands during acute stress to elevate heart rate, blood pressure, and energy reserves.

Norepinephrine

A chemical functioning as both a hormone and neurotransmitter that promotes vigilance, physiological arousal, and alertness.

Plasticity (Neuroplasticity)

The capacity of the nervous system to modify its structural organization and functional pathways in response to experience or injury.

Split Brain Research

Investigations of patients who underwent surgical transection of the corpus callosum, illustrating functional hemispheric asymmetry.

Contralateral Hemispheric Organization

The anatomical arrangement wherein each cerebral hemisphere receives sensory information from and directs motor commands to the opposite side of the body.

Hemispheric Specialization (Lateralization)

The localization of distinct cognitive processes or functional operations predominantly to one cerebral hemisphere.

Linguistic Processing

The cognitive and neurobiological operations that govern the comprehension, generation, and structural encoding of language.

Broca's Area

A region located in the left frontal lobe responsible for speech production and the grammatical sequencing of language.

Broca's Aphasia

A language disorder resulting from damage to the left frontal cortex, characterized by non-fluent, halting speech with largely preserved comprehension.

Wernicke's Area

A cortical area situated in the posterior left temporal lobe essential for the comprehension and semantic formulation of language.

Wernicke's Aphasia

A condition caused by damage to the posterior superior temporal gyrus, marked by fluent yet meaningless speech and impaired language comprehension.

Electroencephalogram (EEG)

A neuroimaging method that detects and records the brain's macroscopic electrical wave patterns via scalp electrodes.

Functional Magnetic Resonance Imaging (fMRI)

A neuroimaging procedure that evaluates active brain regions by mapping blood-oxygen-level-dependent (BOLD) hemodynamic signals.

Lesioning

The targeted ablation, removal, or pathological damage of specific tissue areas to observe the resultant loss of behavioral or cognitive function.