unit 2 - behavioral bases of behavior

behavior genetics

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

environment

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

Chromosomes

threadlike structures made of DNA molecules that contain the genes

DNA(deoxyribonucleic acid)

A complex molecule containing the genetic information that makes up the chromosomes.

Genes

the biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein

Genome

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

identical twins

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

fraternal twins

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

temperament

a person's characteristic emotional reactivity and intensity

Heritability

The proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

molecular genetics

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

molecular behavior genetics

the study of how the structure and function of genes interact with our environment to influence behavior

Epigenetics

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

evolutionary psychology

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

interaction

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

Culture

the enduring behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next

norm

an understood rule for accepted and expected behavior. Norms prescribe "proper" behavior.

individual

giving priority to one's own goals over group goals and defining one's identity in terms of personal attributes rather than group identifications

Collectivism

giving priority to the goals of one's group (often one's extended family or work group) and defining one's identity accordingly

X chromosome

The sex chromosome found in both men and women. Females have two X chromosomes; males have one. An X chromosome from each parent produces a female child.

Y chromosome

the sex chromosome found only in males. When paired with an X chromosome from the mother, it produces a male child.

Testosterone

the most important of the male sex hormones. Both males and females have it, but the additional testosterone in males stimulates the growth of the male sex organs in the fetus and the development of the male sex characteristics during puberty

puberty

the period of sexual maturation, during which a person becomes capable of reproducing

primary sex characteristics

the body structures (ovaries, testes, and external genitalia) that make sexual reproduction possible

secondary sex characteristics

nonreproductive sexual characteristics, such as female breasts and hips, male voice quality, and body hair

spermarche

first ejaculation

menarche

the first menstrual period

disorder of sexual development

an inherited condition that involves unusual development of sex chromosomes and anatomy

Role

a set of expectations (norms) about a social position, defining how those in the position ought to behave

Gender role

a set of expected behaviors for males or for females

gender identity

our sense of being male or female or a combination of the two

social learning theory

the theory that we learn social behavior by observing and imitating and by being rewarded or punished

gender typing

the acquisition of a traditional masculine or feminine role

Androgyny

displaying both traditional masculine and feminine psychological characteristics

Transgender

an umbrella term describing people whose gender identity or expression differs from that associated with their birth sex

Action Potential

The period of time in which a brief electrical impulse travels along the axon because the cell is depolarized which occurs when a neuron sends a message.

Afferent Nerve Fiber

Found on sensory neurons, these axons carry an impulse from a sensory organ to the brain or spinal cord to create a perception of a sensory experience.

Agonist

A type of drug that is effective at increasing the transmission of a given neurotransmitter by either stimulating receptor sites or blocking reuptake.

Alzheimer's Disease

A severe neurocognitive disorder that is characterized by symptoms that include memory loss and cognitive decline.

Amygdala

Limbic system structure linked to strong emotions such as fear and aggression.

Androgen

A masculine hormone produced by the testes.

Antagonist

A type of drug that is effective at preventing neurons from firing by blocking the receptor sites resulting in an overall decrease in the transmission of a given neurotransmitter.

Aphasia

A category of language impairments that results from brain damage to language related areas, frequently in the left hemisphere.

Association Areas

All of the portions of the cerebral cortex that are not devoted to specific sensory or motor functions. Instead, they are involved in higher order functions such as language, cognition, and reasoning.

Auditory Cortex

The area of the temporal lobes devoted to the processing of sound.

Autonomic Nervous System

The branch of the peripheral nervous system that is responsible for controlling the glands and internal organs consisting of both the sympathetic and parasympathetic divisions.

Axon

The long, thin extension from the cell body of a neuron that is responsible for transmitting the action potential.

Axon Terminal (Terminal Button)

The term for the end of each axon that is responsible for storing neurotransmitters in synaptic vesicles.

Basal Ganglia

A cluster of subcortical nuclei that are related to creating goal oriented, voluntary movement.

Behavioral Genetics

The field of study that explores the relationship between heredity and behavior.

Blood-Brain Barrier

The semipermeable barrier created by cells in capillaries that prevents many toxins from reaching the brain and spinal cord.

Brainstem

The oldest part of the brain, similar in all vertebrates, that is responsible for basic life functions such as breathing, heart rate, sleeping, and directing incoming messages to the opposite side of the brain.

Broca's Area

A region of the frontal lobe responsible for speech production typically located in the left hemisphere.

Central Nervous System

The part of the nervous system made up of the brain and spinal cord.

Cerebellum

Area of the hindbrain, often referred to as the little brain, responsible for the control of balance and fine motor coordination. This area also holds procedural memories.

Cerebral Cortex

The approximately quarter inch thick, wrinkled outer layer of the brain that is divided into two hemispheres.

Cerebral Hemisphere

The term used for the roughly symmetrical left and right halves of the brain. The left half holds areas related to language in most individuals; the right half contains areas responsible for recognizing faces. Despite beliefs to the contrary, individuals use both halves for nearly all tasks.

Cerebrum

The largest area of the brain including all of the brain with the exception of the brainstem and cerebellum.

Chromosome

A component of DNA which holds genetic information that is inherited from each of one's biological parents.

Computed Tomography (CT)

A method of brain scanning that examines the structural components of the brain by taking X-rays.

Contralateral Control

The term used for the way the central nervous system is organized, so that each hemisphere controls the motor movements and sensory perceptions of the opposite side of the body.

Corpus Callosum

The collection of nerve fibers that connects the two cerebral hemispheres. It is responsible for relaying information between the two halves of the brain.

Dendrite

A thin branch like extension of a neuron that receives neurotransmitters.

Depolarization

The process by which the fluid filled interior of the axon becomes positive as result of the action potential.

Dominant Gene (Dominant Allele)

A version of a gene whose effect is displayed regardless of the gene that is on the other half of a pair of chromosomes in an individual.

Dopamine

Neurotransmitter responsible for voluntary movement, pleasure, reward, learning, and attention. Low levels of this neurotransmitter is associated with Parkinson's disease and excess levels of this neurotransmitter is associated with schizophrenia.

Efferent Nerve Fiber

Found on motor neurons, these axons carry an impulse away from the brain or spinal cord to create movement.

Electroencephalogram (EEG)

An imaging technique used to examine brain function by measuring brain wave activity. This technique is often used in sleep, dream, and seizure research.

Endocrine System

A system of glands throughout the body that is responsible for distributing various hormones via the bloodstream.

Endorphin

A neurotransmitter responsible for reducing the experience of pain that binds to the same receptor sites as opioids.

Epigenetics

The study of how environmental factors may create changes in gene expression despite the fact that they do not alter a cell's DNA.

Epinephrine

A neurotransmitter and hormone released in response to fear, stress, or excitement resulting in an increase in sympathetic nervous system activity. It is also known as adrenaline

Excitatory Postsynaptic Potential (EPSP)

A brief decrease in the electrical charge of the membrane of a neuron that is due to the reception of neurotransmitters. It increases the chances that an action potential will be generated.

Forebrain

The largest part of the human brain that includes the cerebral cortex and the lobes of the brain. It is especially large in humans which allows for reasoning, language, and sophisticated thought.

Frontal Lobe

The region of the cerebral cortex (left and right) located behind the forehead that controls cognition, higher-level thought, planning, motor movement, language, judgment, and planning.

Functional Magnetic Resonance Imaging (fMRI)

An imaging technique which shows brain structure and function. It uses magnetic fields to produce images of the brain and measures brain activity by charting blood flow carrying oxygen to active brain tissues.

GABA

The major inhibitory neurotransmitter that is responsible for relaxation and sleep. Low levels are connected with anxiety disorders, seizures, and insomnia.

Genotype

The genetic makeup of an individual inherited from one's parents or the two alleles inherited for a particular gene.

Glial Cell

Cells located in the nervous system thought to play a role in learning and memory that support and nourish other neurons.

Glutamate

The major excitatory neurotransmitter that is related to cognitive, sensory, and motor functioning.

Hemispheric Specialization (Lateralization)

The "division of labor" between the two halves of the brain that indicates the specific functions handled by each half. Typically the left half controls most language related functions, and the right half contains areas specializing in recognizing faces and emotional responses.

Heritability

An estimate of the percentage of a given characteristic for a population that can be attributed to genetics. It is expressed as a number between 0 and 1.

Hindbrain

The oldest part of the brain that controls basic survival functions, consisting of the medulla, pons, and cerebellum.

Hippocampus

Limbic system structure surrounding the thalamus. It is responsible for learning and the creation of new explicit memories.

Homeostasis

The internal balance or equilibrium needed for optimal functioning. The desire of an organism to maintain this state leads to the monitoring of factors that impact needs (e.g. stable internal temperature and blood sugar levels).

Hormone

A chemical messenger produced by the endocrine system which impacts bodily functioning that is transported through the blood.

Hypothalamus

A limbic system structure involved in various maintenance functions including hunger, thirst, internal body temperature, and sex.

Inhibitory Postsynaptic Potential (IPSP)

A brief increase in the electrical charge of the membrane of a neuron that is due to the reception of neurotransmitters. It decreases the chances that an action potential will be generated.

Interneuron

Nerve cells found in the brain and spinal cord which connect sensory neurons to motor neurons.

Lateral Hypothalamus

The portion of the hypothalamus responsible for working with hormones and glucose to play a role in the initiation of hunger signals.

Lesion

Any damage to the brain caused by surgical removal, injury, or disease.

Limbic System

A donut shaped group of subcortical forebrain structures located in the temporal lobe. These structures form a network related to memory, learning, and emotional functions.

Lobotomy

A historical procedure in which the frontal lobe or limbic system were damaged to control violent (often psychotic) patients. This was done prior to the introduction of antipsychotic medications. The result left many individuals in a vegetative state.

Long-Term Potentiation (LTP)

The increase in the ability of a given neuron to fire along a frequently used neural pathway which results from repeated stimulation.

Magnetic Resonance Imaging (MRI)

An imaging technique which shows brain structure by using magnetic fields to produce images of the brain or body tissues.

Medulla

The area of the hindbrain just below the pons that is responsible for heartbeat, breathing, and blood pressure, as well as, other survival reflexes including sneezing, coughing, vomiting, and swallowing.

Meninges

The three layers of membranes which create a protective covering for the brain and spinal cord including the dura mater, arachnoid mater, and pia mater.

Menopause

The end of a woman's menstrual cycle.