U1: History & Approaches

behavior genetics

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

environment

every external influence, from prenatal nutrition to the people and things around us

chromosomes

threadlike structures made of DNA molecules that contain the genes

DNA

a complex molecule containing the genetic information that makes up the chromosome

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 twins

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

fraternal twins

twins who develop from separate fertilized eggs

molecular genetics

the subfield of biology that studies the molecular structure and function of genes

heritability

the proportion of variation among individuals that we can attribute to genes

gene-environment interaction

the interplay that occurs when the effect of one factor (ex. environment) depends on another factor (ex. heredity)

epigenetics

the study of environmental influences on gene expression that occur without a DNA change

evolutionary psychologists

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

natural selection

the principle that, among variations, those contributing to reproduction and survival are most likely to be passed on to succeeding generations

mutation

a random error in gene replication that leads to evolutionary success

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)

The brain and spinal cord.

Peripheral nervous system (PNS)

Sensory and motor neurons that connect the CNS to the rest of the body.

Nerves

Bundled axons that form neural 'cables' connecting the CNS with muscles, glands, and sense organs.

Sensory (afferent) neurons

Neurons that carry incoming information from the sensory receptors to the CNS.

Motor (efferent) neurons

Neurons that carry outgoing information from the CNS to muscles and glands.

Interneurons

Neurons within the CNS that communicate internally and intervene between sensory and motor neurons.

Somatic nervous system

Division of PNS that controls the body's skeletal muscles.

Autonomic nervous system

Part of PNS that controls glands and muscles of internal organs.

Sympathetic nervous system

Division of autonomic nervous system that arouses the body, mobilizing its energy.

Parasympathetic nervous system

Division of autonomic nervous system that calms the body, conserving energy.

Reflexes

Simple, automatic responses to sensory stimuli, e.g., knee-jerk response.

Endocrine 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.

Adrenal glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

Pituitary gland

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

Feedback system

Brain → pituitary → other glands → hormones → body and brain.

Localization of function

The idea that various brain regions have particular functions.

Biological psychologists

Psychologists who study links between biology, behavior, and mind.

Phrenology

The study of bumps on the skull that could reveal a person's mental abilities and character traits.

Neurons

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

Dendrites

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

Axon

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

Myelin Sheath

Layer of fatty tissue that insulates axons and speeds their impulses.

Action Potential

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

Resting Potential

Positive outside/negative inside of axon's membrane; surface is selectively permeable.

Refractory Period

A period of inactivity after a neuron is fired.

Threshold

The level of stimulation required to trigger a neural impulse.

All-or-Nothing Response

Neuron's reaction of either firing (full strength) or not firing.

Synapse

The junction between the axon tip of the sending neuron and the dendrite/cell body of the receiving neuron.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons; influence a neural impulse.

Reuptake

A neurotransmitter's reabsorption by the sending neuron.

Endorphins

"Morphine within" - natural, opiate-like neurotransmitters linked to pain control and 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/blocks a response.

Acetylcholine (Ach)

Enables muscle action, learning, and memory.

Dopamine

Involved in movement, learning, attention, and emotion.

Serotonin

Affects mood, hunger, sleep, and arousal.

Norepinephrine

Controls alertness and arousal.

GABA

An inhibitory neurotransmitter.

Brainstem

Oldest and central part of the brain, responsible for automatic survival functions.

Medulla

Base of the brainstem; controls heartbeat and breathing.

Thalamus

Brain's sensory control center; directs messages to sensory receiving areas in the cortex.

Reticular Formation

Nerve network that travels through the brainstem and thalamus; plays an important role in controlling arousal.

Cerebellum

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

Limbic System

Neural system located below the cerebral hemispheres, associated with emotions and drives.

Amygdala

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

Hypothalamus

Neural structure lying below the thalamus; directs several maintenance activities and helps govern the endocrine system.

Cerebral Cortex

Intricate fabric of interconnected neural cells covering the cerebral hemispheres.

Glial Cells

Cells in the nervous system that support, nourish, and protect neurons.

Frontal Lobes

Located just behind the forehead; involved in speaking, muscle movements, and making plans/judgments.

Parietal Lobes

Located at the top of the head; receives sensory input for touch and body position.

Occipital Lobes

Located at the back of the head; includes areas that receive visual information.

Temporal Lobes

Located above the ears; includes auditory areas.

Glutamine

..

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

Lateralizarion

concept that each hemisphere of the brain is associated with specialized functions

Corpus Callosum

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

Split Brains

condition resulting from surgery isolating brain's two hemispheres by cutting fibers connecting them

Right vs. Left Hemisphere

R: perceptual tasks (writing, drawing, inferring); linked with left side of body

L: speaking tasks; linked with right side of the body

Consciousness

our awareness of ourselves and our environment

Cognitive Neuroscience

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

Dual Processing

the principle that information is often simultaneously processed on separate conscious and unconscious tracks

Neurogenesis

the process of generating new neurons in the brain.

Substance use disorder

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

Psychoactive drug

a chemical substance that alters perceptions and moods

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

compulsive drug craving and use, despite adverse consequences

Withdrawal

the discomfort and distress that follow discontinuing the use of an addictive drug

Depressants

drugs that reduce neural activity and slow body functions

Alcohol use disorder

alcohol use marked by tolerance, withdrawal, and a drive to continue problematic use

Barbiturate

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

Stimulants

drugs that excite neural activity and speed up body functions

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

a powerful hallucinogenic drug; also known as acid (lysergic acid diethylamide)

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