AP Psychology: Biological Bases of Behavior

Kaplan Prep Plus

Neurons

The basic functional units of the nervous system; cells which contain specialized structures to communicate signals

Soma/cell body

The part of the neuron that contains its nucleus and other standard cellular structures

Dendrites

The multiple thin, treelike fibers that branch off from a neuron’s soma and contain receptors to accept incoming signals from other neurons

Axon

A long, tubular structure in a neuron that transmits action potentials

Myelin sheath

A fatty substance that coats an axon, insulating it and enhancing its ability to transmit action potentials

Terminal buttons

The branching structures at the ends of the axons that release neurotransmitters

Synapse

The small gap between the axon of a presynaptic neuron and the dendrites of a postsynaptic neuron

Action potential

The electrical impulse sent along an axon when the dendrites of a neuron are sufficiently excited

Neurotransmitter

A specialized chemical messenger that sends signals between neurons

Excitatory

Describes a neurotransmitter that causes a postsynaptic neuron to propagate more action potentials

Inhibitory

Describes a neurotransmitter that causes a postsynaptic neuron to propagate fewer action potentials

Acetylcholine

A neurotransmitter involved in learning, memory, and muscle contraction

Dopamine

A neurotransmitter involved in mood, movement, attention, and learning

Serotonin

A neurotransmitter that regulates sleep, mood, appetite, and body temperature

GABA

The primary inhibitory neurotransmitter in the nervous system

Norepinephrine

A neurotransmitter important in controlling alertness, wakefulness, mood, and attention

Glutamate

The main excitatory neurotransmitter in the central nervous system; important for learning and memory

Agonists

Drugs that mimic a particular neurotransmitter, activating the same receptors that it does

Antagonists

Drugs that block a particular neurotransmitter from activating its receptors

Reuptake inhibitors

Drugs that prevent a neurotransmitter from being reabsorbed by presynaptic axons, causing greater activation of postsynaptic receptors

SSRIs

Drugs that prevent the reabsorption of serotonin, leading to greater activation of serotonin receptors

Nervous system

The organ system that governs the reception, processing, and transmission of information throughout the body

Nerves

Fibrous bundles of neurons

Brain

The primary organ in the nervous system, which oversees most of its operations

Central nervous system (CNS)

The brain and spinal cord

Hindbrain

The lowest segment of the brain, primarily involved in the regulation of basic bodily functions and consisting of the cerebellum, medulla, pons, and reticular formation

Cerebellum

Regulates motor coordination

Medulla

Controls autonomic responses, including breathing, heart rate, and blood pressure

Pons

Transfers information between the cerebellum and other parts of the brain

Reticular formation

Contributes to attention and conscious state by filtering incoming stimuli and selectively relaying information

Midbrain

The middle segment of the brain, involved with motor control, vision, hearing, arousal, sleep, temperature regulation, and the transmission of sensory information

Forebrain

The highest segment of the brain, consisting of the thalamus, hypothalamus, hippocampus, amygdala, and cerebrum

Thalamus

Relays signals from other parts of the brain to the cerebral cortex and regulates sleep, consciousness, appetite, and alertness

Hypothalamus

Regulates a variety of drives, including hunger, thirst, sexual arousal, and temperature; the master regulator in the endocrine system

Amygdala

Involved with fear, aggression, and other emotions, as well as memory consolidation

Hippocampus

Involved in the formation of long-term memories

Limbic system

Regulates emotions and drives; consists of the thalamus, hypothalamus, amygdala, hippocampus, and other structures

Cerebrum

The largest part of the human brain; contains the cerebral cortex

Cerebral cortex

The wrinkled surface of the cerebrum, divided into four lobes and two hemispheres

Lobes

Four specialized regions in the cerebral cortex

Frontal lobe

Controls voluntary movement and higher-order cognitive processes; at the front of the brain

Parietal lobe

Integrates perceptions from different senses; at the top of the brain

Temporal lobe

Controls hearing and language; at both sides of the brain

Occipital lobe

Controls vision; at the back of the brain

Hemisphere

One of two symmetrical halves (left and right) of the brain, specialized for particular functions

Lateralization

The localization of some functions in one of the two hemispheres

Wernicke’s area

The region in the temporal lobe of a person’s dominant hemisphere that controls speech comprehension

Broca’s area

The region in the frontal lobe of a person’s dominant hemisphere that controls speech production

Spinal cord

The long tube of nerves that connects the brain to most of the rest of the body; protected by the vertebral column

Reflex

An automatic, involuntary response to a particular stimulus

Peripheral nervous system (PNS)

All nerves outside of the brain and spinal cord

Somatic nervous system

Part of the PNS that controls skeletal muscles and their voluntary movements

Automatic nervous system

Part of the PNS that controls involuntary bodily functions

Sympathetic nervous system

Part of the autonomic nervous system activated during the “fight or flight” response to stress

Parasympathetic nervous system

Part of the autonomic nervous system activated during the “rest and digest” response to non-stressful situations

Neuroplasticity

The capacity of the brain to reorganize itself at a high level, such as might happen in response to traumatic injury; it decreases with age

Synaptic plasticity

The ability for certain neural connections to be strengthened or weakened over time, a process essential for memory and learning

Neurogenesis

The processes that create new neurons

Endocrine system

The system of glands that secrete hormones into the bloodstream in order to maintain the body’s homeostasis

Homeostasis

A dynamic state of internal equilibrium within a changing external environment

Hormones

Chemical messengers that travel through the bloodstream, interacting with organs to stimulate or inhibit various biological processes

Glands

Endocrine organs that produce and secrete hormones

Pituitary gland

The primary gland in the endocrine system, regulated by the hypothalamus; produces hormones that interact with the other endocrine glands

Thyroid gland

Produces and secrete stress hormones like cortisol and epinephrine (adrenaline); found directly above the kidneys

Ovaries

Female gonads (sex glands) that secrete hormones like estrogen and progesterone, which regulate the menstrual cycle and pregnancy

Testes

Male gonads (sex glands) that secrete androgens (male sex hormones) like testosterone, which regulates sexual development and sexual desire

Electroencephalograph (EEG)

A device that uses electrodes on the scalp to detect and record brain waves

MRI

Stands for “magnetic resonance imaging”; a technique that uses magnetic fields and radio waves to produce high-resolution images of brain structure

Functional MRI (fMRI)

An imaging technique similar to MRI, which measures blood oxygen levels to determine brain function

PET scan

A technique that uses a radioactive dye injected into the bloodstream to detect neurological activity

CT scan

A technique that uses X-rays to create 3-D images of brain structure

Traumatic brain injury (TBI)

Damage to some part of the brain caused by an external force; may impede cognitive, emotional, or behavioral functions

Corpus callosum

The bundle of nerves that serves as the primary connection between the left and right cerebral hemispheres

Split-brain patients

Individuals with a severed corpus callosum; used in studies of brain lateralization

Contralateral organization

The tendency of the left cerebral hemisphere to control and perceive from the right side of the body, and vice versa

Twin study

A research design that investigates the traits of identical and fraternal twins to determine the extent to which traits are genetically or environmentally controlled

Variation

The natural range of differences found among the traits of members of a species

Inheritance

The transmission of various traits from one generation to the next

Fitness

The tendency of a trait or organism to be well-suited to a particular environment

Natural selection

The process by which fitter organisms are able to genetically outcompete others of their species by living longer and having more offspring

Adaptations

Evolved traits that are well-suited to a particular environmentt

Sexual selection

The process by which organisms with more attractive traits are able to genetically outcompete others of their species by having more offspring

Consciousness

A state of being awake and aware of external stimuli and one’s own mental activity

State of consciousness

The features of consciousness experienced by an individual at a particular point in time

Altered state of consciousness

A temporary state that differs significantly from a normal waking state; includes sleep, meditation, a coma, hypnosis, or the influence of drugs

Conscious levels

All the things within one’s awareness at the present moment, including information about one’s self and current environment

Nonconscious level

The body’s automatic biological processes, like breathing and heartbeat, which are controlled by the brain but are generally outside of one’s active awareness

Preconscious level

In Freud’s psychoanalytic theory, all of the unrepressed stored memories, thoughts, and information that can be recalled and moved from the unconscious to the conscious level in a matter of seconds

Unconscious level

In Freud’s psychoanalytic theory, the unconscious mind represents the thoughts, desires, and urges that are actively repressed from consciousness and that affect mental activity outside of active awareness

Subconscious level

Information beyond a person’s conscious awareness that affects mental processesPriming

Priming

When exposure to a stimulus beneath conscious awareness influences a response to other stimuli

Mere-exposure effect

The preference for familiar stimuli over new stimuli, even when exposure to the stimuli does not occur on a conscious level

Non-rapid eye movement (NREM) sleep

A period of dreamless sleep divided into four distinct, continuous stages

Rapid eye movement (REM) sleep

The period of sleep that is most associated with dreaming

Hypnagogic hallucinations

Sensory phenomena, like visions and sounds, that a sleeper perceives in the transition between wakefulness and sleep

Sleep spindles

Bursts of neural activity that take place in stage 2 of NREM sleep and may be important for memory consolidation

Slow wave sleep

Stages 3 and 4 of NREM sleep. the deepest stages of sleep, hen neural activity and brain waves are slowest

Paradoxical sleep

Another name for REM sleep, due to the contradictor way in which the brain is active but the body is at rest

Manifest content

The actual events and imagery within a dream that, according to Freud, serves to mask the unconscious thoughts and desires of the dreamer

Latent content

In Freudian terms, the unconscious thoughts and desires underlying the manifest content of dreams