Psych: unit 2

Biological Psychology

Study of the links between biological (genetic, neural, hormonal) and psychological processes

Behavior Geneticists

Power and limits of genetic and environmental influences on behavior

Evolutionary psychologists

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

Natural Selection

the principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations

Mutation

a random error in gene replication that leads to a change

Heritability

The proportion of variation among individuals that we can attribute to genes.

Identical (monozygotic) twins

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 brothers and sisters, but they share a fetal environment.

Nervous System

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

Central Nervous System (CNS)

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.

Somatic Nervous System (SMS)

division of the peripheral nervous system associated with skeletal muscle voluntary control of movement (aka skeletal nervous system)

Autonomic Nervous System (ANS)

controls our glands and the muscles of our internal organs, influencing such functions as glandular activity, heartbeat, and digestion. May be consciously overridden, but usually operates on its own

Sympathetic

Dilates pupils

Accelerates heartbeat

Inhibits digestion

Stimulates glucose release by liver

Stimulates secretion of epinephrine, norepinephrine

Relaxes bladder

Parasympathetic

Contracts pupils

Slows heartbeat

Stimulates digestion

Stimulates gallbladder

Contracts bladder

Allows bloodflow to sex organs

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

Endocrine system

Another messenger system in the body. Secrete hormones throughout the body.

Hormone

Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another

Pituitary Gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, regulates growth and controls other endocrine glands.

Adrenal Glands

On top of the kidneys to release epinephrine and norepinephrine (also called adrenaline and noradrenaline).

Sensory (afferent) neurons

Neurons that carry incoming information from the sensory receptors 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 that communicate internally and intervene between the sensory inputs and motor outputs

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

Dendrite

Fibers receive information and conduct it toward the cell body

Axon

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

Axon terminal

Branches of axons that form junctions with other cells

Myelin sheath

A layer of fatty tissue that insulates some axons and speeds their impulses

As myelin is laid down up to about age 25, neural efficiency, judgment, and self-control grow

nerves

bundled axons that form neural "cables" connecting CNS to muscles, glands, and sensory organs

action potential

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

refractory period

a period of inactivity after a neuron has fired

threshold

level of stimulation required to trigger a neural impulse

All or none response

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

Synapse

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, these 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

Endorphins

"morphine within"--natural, opiate-like neurotransmitters linked to pain control and to pleasure.

Agonist

a molecule that, by binding to a receptor site, stimulates a response

Antagonist

a molecule that, by binding to a receptor site, inhibits or blocks a response

Brainstem

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

Cerebral Cortex

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

frontal lobe

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgements

Parietal lobes

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 lobe

Back of the head; includes area that receive information from the visual fields

temporal lobe

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

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

corpus callosum

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

Medulla

the base of the brainstem; controls heartbeat and breathing

Thalamus

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

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

limbic system

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

Amygdala

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

Hippocampus

a neural center located in the limbic system; helps process explicit memories for storage

Hypothalamus

a neural structure lying below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion

glial cells

cells in the nervous system that support, nourish, and protect neurons

plasticity

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

Broca's area

Paul Broca - controls language expression—an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech

Wernicke's area

Carl Wernicke - controls language reception—a brain area involved in language comprehension and expression; usually in the left temporal lobe.

cognitive neuroscience

the interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language)

Electroencephalogram (EEG)

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

CT scan (computed tomography)

a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body

PET scan (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.

lesion

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

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

psychoactive drugs

a chemical substance that alters perceptions and moods

addiction

compulsive craving of drug or behavior, despite adverse consequences

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

withdrawal

the discomfort and distress that follow discontinuing an addictive drug or behavior

substance use disorder

continued substance craving and use despite significant life disruption and/or physical risk

alcohol use disorder

(popularly known as alcoholism). Alcohol use marked by tolerance, withdrawal, and a drive to continue problematic use.

Depressants

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

Stimulants

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

Barbiturates

drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment

Opiates

opium and its derivatives, such as morphine and heroin; they depress neural activity, temporarily lessening pain and anxiety

Amphetamines

drugs that stimulate neural activity, causing speeded-up body functions and associated energy and mood changes

Nicotine

a stimulating and highly addictive psychoactive drug in tobacco

Cocaine

a powerful and addictive stimulant, derived from the coca plant, producing temporarily increased alertness and euphoria

Methamphetamine

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

Ecstasy (MDMA)

a synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition.

Hallucinogens

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

LSD (lysergic acid diethylamide)

a powerful hallucinogenic drug; also known as acid

THC (tetrahydrocannabinol)

the major active ingredient in marijuana; triggers a variety of effects, including mild hallucinations