Psych Unit 1.1 - 1.4c

nature-nurture issue

The longstanding controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors. Today's science sees traits and behaviors arising from the interaction of nature and nurture.--

natural selection

The principle that, among the range of inherited trait variations, those contributing to reproduction and adaptation to a particular environment will most likely be passed on to succeeding generations.--

evolutionary psychology

The study of the evolution of behavior and the mind, using principles of natural selection.--

behavior genetics

The study of the relative power and limits of genetic and environmental influences on behavior.--

mutation

A random error in gene replication that leads to a change.--

environment

Every nongenetic influence, from prenatal nutrition to the people and things around us.--

heredity

The genetic transfer of characteristics from parents to offspring.--

genes

The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins.--

genome

The complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes.--

identical (monozygotic) twins

Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.--

fraternal (dizygotic) twins

Twins who develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment.--

interaction

The interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity).--

epigenetics

"Above" or "in addition to" genetics; the study of environmental influences on gene expression that occur without a DNA change.--

nervous system

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the central and peripheral nervous systems.--

central nervous system (CNS)

The brain and spinal cord.--

peripheral nervous system (PNS)

The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.--

nerves

Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.--

sensory (afferent) neurons

Neurons that carry incoming information from the body's tissues and sensory receptors inward to the brain and spinal cord.--

motor (efferent) neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.--

interneurons

Neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.--

somatic nervous system

The division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system.--

autonomic [aw-tuh-NAHM-ik] nervous system (ANS)

The part of the peripheral nervous system that controls the glands and the internal organs. Its sympathetic division arouses; its parasympathetic division calms.--

sympathetic nervous system

The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.--

parasympathetic nervous system

The division of the autonomic nervous system that calms the body, conserving its energy.--

reflex

A simple, automatic response to a sensory stimulus, such as the knee-jerk response.--

neuron

A nerve cell; the basic building block of the nervous system.--

cell body

The part of a neuron that contains the nucleus; the cell's life support center.--

dendrites

A neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body.--

axon

The neuron extension that passes messages through its branches to other neurons or to muscles or glands.--

myelin [MY-uh-lin] sheath

A fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.--

glial cells (glia)

Cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning, thinking, and memory.--

action potential

A neural impulse; a brief electrical charge that travels down an axon.--

threshold

The level of stimulation required to trigger a neural impulse.--

refractory period

A period of inactivity after a neuron has fired.--

all-or-none response

A neuron's reaction of either firing (with a full-strength response) or not firing.--

synapse [SIN-aps]

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.--

neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.--

reuptake

A neurotransmitter's reabsorption by the sending neuron.--

agonist

A molecule that increases a neurotransmitter's action.--

antagonist

A molecule that inhibits or blocks a neurotransmitter's action.--

endocrine [EN-duh-krin] system

The body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.--

hormones

Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.--

psychoactive drug

A chemical substance that alters perceptions and moods.--

substance use disorder

A disorder characterized by continued substance craving and use despite significant life disruption and/or physical risk.--

depressants

Drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions.--

tolerance

The diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug's effect.--

addiction

A primary, chronic disease of brain reward, motivation, memory, and related circuitry. An inability to consistently abstain, impairment in behavioral control, craving, diminished recognition of significant problems with one's behaviors and interpersonal relationships, and a dysfunctional emotional response.--

withdrawal

The discomfort and distress that follow discontinuing an addictive drug or behavior.--

barbiturates

Drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgment.--

opioids

Opium and its derivatives, such as morphine and heroin; depress neural activity, temporarily lessening pain and anxiety.--

stimulants

Drugs (such as caffeine, nicotine, and the more powerful amphetamines, cocaine, Ecstasy, and methamphetamine) that excite neural activity and speed up body functions.--

hallucinogens

Psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input.--

near-death experience

An altered state of consciousness reported after a close brush with death (such as through cardiac arrest); often similar to drug-induced hallucinations.--

biological psychology

The scientific study of the links between biological (genetic, neural, hormonal) and psychological processes. (Also called behavioral neuroscience, neuropsychology, behavior genetics, physiological psychology, or biopsychology.)--

biopsychosocial approach

An integrated approach that incorporates biological, psychological, and social-cultural levels of analysis.--

levels of analysis

The differing complementary views, from biological to psychological to social-cultural, for analyzing any given phenomenon.--

neuroplasticity

The brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.--

lesion [LEE-zhuhn]

Tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.--

EEG (electroencephalogram)

An amplified recording of the waves of electrical activity sweeping across the brain's surface. These waves are measured by electrodes placed on the scalp.--

MEG (magnetoencephalography)

A brain-imaging technique that measures magnetic fields from the brain's natural electrical activity.--

CT (computed tomography) scan

A series of X-ray photographs taken from different angles and combined by computer into an composite representation of a slice of the brain's structure. (Also called CAT scan).--

PET (positron emission tomography)

A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.--

MRI (magnetic resonance imaging)

A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy.--

fMRI (functional MRI)

A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as its structure.--

hindbrain

The rear part of the brain, including the cerebellum, pons, and medulla.--

midbrain

A small central part of the brainstem, developing from the middle of the embryonic brain.--

forebrain

The anterior part of the brain, including the cerebral hemispheres, thalamus, and hypothalamus.--

brainstem

The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.--

medulla [muh-DUL-uh]

The base of the brainstem; controls heartbeat and breathing.--

thalamus [THAL-uh-muss]

The brain's sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.--

reticular formation

A nerve network that travels through the brainstem and thalamus and plays an important role in controlling arousal.--

cerebellum [sehr-uh-BELL-um]

The "little brain" at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.--

limbic system

Neural system (including the amygdala, hypothalamus, and hippocampus) located below the cerebral hemispheres; associated with emotions and drives.--

amygdala [uh-MIG-duh-la]

Two lima-bean-sized neural clusters in the limbic system; linked to emotion.--

hypothalamus [hi-po-THAL-uh-muss]

A neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.--

hippocampus

A neural center located in the limbic system; helps process for storage explicit (conscious) memories of facts and events.--

cerebral [seh-REE-bruhl] cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.--

frontal lobes

The portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.--

parietal [puh-RYE-uh-tuhl] lobes

The portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.--

occipital [ahk-SIP-uh-tuhl] lobes

The portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.--

temporal lobes

The portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.--

motor cortex

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

somatosensory cortex

An area at the front of the parietal lobes that registers and processes body touch and movement sensations.--

association areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.--

neurogenesis

The formation of new neurons.--

corpus callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.--

split brain

A condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.--

Acetylcholine (ACh)

Function: Enables muscle action, learning, and memory. Malfunction: Undersupply, as with Alzheimer's disease, neurons deteriorate.--

Dopamine

Function: Influences movement, learning, attention, and emotion. Malfunction: Oversupply linked to schizophrenia. Undersupply linked to tremors and decreased mobility in Parkinson's disease.--

Serotonin

Function: Affects mood, hunger, sleep, and arousal. Malfunction: Undersupply linked to depression. Some antidepressant drugs raise serotonin levels.--

Norepinephrine

Function: Helps control alertness and arousal. Malfunction: Undersupply can depress mood.--

GABA (gamma-aminobutyric acid)

Function: A major inhibitory neurotransmitter. Malfunction: Undersupply linked to seizures, tremors, and insomnia.--

Glutamate

Function: A major excitatory neurotransmitter; involved in memory. Malfunction: Oversupply can overstimulate the brain, producing migraines or seizures (which is why some people avoid MSG in food).--

Endorphins

Function: Natural, opiate-like neurotransmitters linked to pain control and to pleasure. Malfunction: Involved in the 'runner's high' but imbalances can play a role in pain disorders.--

Substance P

Function: A neurotransmitter involved in transmitting pain signals. Malfunction: Involved in the perception and transmission of pain; excessive levels can lead to heightened pain sensitivity.--

Alcohol

Depressant; reduces neural activity and slows body functions. Causes disinhibition, slowed neural processing, memory disruption, and reduced self-awareness.--

Heroin

Depressant; a highly addictive opiate drug derived from morphine; depresses neural activity, temporarily lessening pain and anxiety.--

Caffeine

Stimulant; increases alertness and wakefulness, often by blocking adenosine.--

Methamphetamine

Stimulant; a powerfully addictive drug that stimulates the central nervous system, with speeded-up body functions and associated energy and mood changes. Reduces baseline dopamine levels over time.--

Cocaine

Stimulant; a powerful and addictive stimulant derived from the coca plant, producing temporarily increased alertness and euphoria. Depletes dopamine, serotonin, and norepinephrine, leading to intense crashes.--