PSY 150 Test 2

Absolute refractory period

is the minimum length of time after an action potential, during which another action potential cannot begin.

Action potential

is a very brief shift in a neuron’s electrical charge that travels along an axon.

Adaptation

is an inherited characteristic that increased in a population (through natural selection) because it helped solve a problem of survival or reproduction during the time it emerged.

Adoption studies

assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents.

Afferent nerve fibers

are axons that carry information inward to the central nervous system from the periphery of the body.

Autonomic nervous system

is made up of nerves that connect to the heart, blood vessels, smooth muscles, and glands.

Axon

is a long, thin fiber that transmits signals away from the soma to other neurons or to muscles or glands.

Central nervous system

consists of the brain and the spinal cord.

Cerebral cortex

is the convoluted outer layer of the cerebrum.

Cerebral hemispheres

are the right and left halves of the cerebrum.

Chromosomes

are threadlike strands of DNA (deoxyribonucleic acid) molecules that carry genetic information.

Corpus callosum

is the major structure that connects the two cerebral hemispheres.

Critical period

is a limited time span in the development of an organism when it is optimal for certain capacities to emerge because the organism is especially responsive to certain experiences.

Dendrites

are the parts of a neuron that are specialized to receive information.

Efferent nerve fibers

are axons that carry information outward from the central nervous system to the periphery of the body.

Electrical stimulation of the brain (ESB)

involves sending a weak electric current into a brain structure to stimulate (activate) it.

Endocrine system

consists of glands that secrete chemicals into the bloodstream that help control bodily functioning.

Endorphins

internally produced chemicals that resemble opiates in structure and effects.

Epigenetics

is the study of heritable changes in gene expression that do not involve modifications to the DNA sequence.

Family studies

researchers assess hereditary influence by examining blood relatives to see how much they resemble one another on a specific trait.

Fitness

refers to the reproductive success (number of descendants) of an individual organism relative to the average reproductive success in the population.

Forebrain

is the largest and most complex region of the brain, encompassing a variety of structures, including the thalamus, hypothalamus, limbic system, and cerebrum.

Genes

are DNA segments that serve as the key functional units in hereditary transmission.

Glia

are cells found throughout the nervous system that provide various types of support for neurons.

Hindbrain

includes the cerebellum and two structures found in the lower part of the brainstem

Hormones

are the chemical substances released by the endocrine glands.

Hypothalamus

is a structure found near the base of the forebrain that is involved in the regulation of basic biological needs.

Lesioning

involves destroying a piece of the brain.

Limbic system

is a loosely connected network of structures located roughly along the border between the cerebral cortex and deeper subcortical areas.

Midbrain

is the segment of the brainstem that lies between the hindbrain and the forebrain.

Myelin sheath

is insulating material that encases some axons.

Natural selection

posits that heritable characteristics that provide a survival or reproductive advantage are more likely than alternative characteristics to be passed on to subsequent generations, and thus they come to be “selected” over time.

Neurogenesis

the formation of new neurons.

Neurons

are individual cells in the nervous system that receive, integrate, and transmit information.

Neurotransmitters

chemicals that transmit information from one neuron to another.

Oxytocin

a hormone that is released by the pituitary gland and regulates reproductive behaviors.

Parasympathetic division

is the branch of the autonomic nervous system that generally conserves bodily resources.

Peripheral nervous system

is made up of all those nerves that lie outside the brain and spinal cord. Nerves are bundles of neuron fibers (axons) that are routed together in the peripheral nervous system.

Pituitary gland

releases a great variety of hormones that fan out within the body, stimulating actions in the other endocrine glands.

Polygenic traits

or characteristics that are influenced by more than one pair of genes.

Postsynaptic potential

a voltage change at a receptor site on a postsynaptic cell membrane.

Resting potential

resting potential of a neuron is its stable, negative charge when the cell is inactive.

Reuptake

a process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane.

Soma

or cell body, contains the cell nucleus and much of the chemical machinery common to most cells.

Somatic nervous system

somatic nervous system is made up of nerves that connect to voluntary skeletal muscles and to sensory receptors.

Split-brain surgery

the bundle of fibers that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures.

Sympathetic division

is the branch of the autonomic nervous system that mobilizes the body’s resources for emergencies.

Synapse

is a junction where information is transmitted from one neuron to another

Synaptic cleft

a microscopic gap between the terminal button of one neuron and the cell membrane of another neuron.

Terminal buttons

are small knobs that secrete chemicals called neurotransmitters.

Thalamus

is a structure in the forebrain through which all sensory information (except smell) must pass to get to the cerebral cortex.

Twin studies

researchers assess hereditary influence by comparing the resemblance of identical twins and fraternal twins with respect to a trait.

Animism

belief that all things are living, just like oneself.

Attachment

the close emotional bonds of affection that develop between infants and their caregivers.

Centration

tendency to focus on just one feature of a problem and neglect other important aspects.

Cognitive development

transitions in youngsters’ patterns of thinking, including reasoning, remembering, and problem solving.

Conservation

Piaget’s term for the awareness that physical quantities remain constant.

Dementia

an abnormal deterioration of memory and other cognitive functions that interferes with activities of daily living.

Development

the sequence of age-related changes that occur as a person progresses from conception to death.

Developmental norms

typical (median) age at which individuals display various behaviors and abilities.

Egocentrism

thinking characterized by a limited ability to share another person’s viewpoint.

Embryonic stage

second stage of prenatal development, lasting from two weeks until the end of the second month.

Fast mapping

the process by which children map a word onto an underlying concept after only one exposure.

Fetal alcohol syndrome

collection of congenital (inborn) problems associated with excessive alcohol use by the mother during pregnancy.

Fetal stage

the third stage of prenatal development lasting from two months through birth.

Gender differences

disparities between males and females in typical behavior or average ability.

Gender roles

expectations about what constitutes appropriate behavior for each gender.

Germinal stage

first phase of prenatal development, encompassing the first two weeks after conception.

Irreversibility

the inability to envision reversing an action.

Maturation

development that reflects the gradual unfolding of one’s genetic blueprint.

Menarche

first occurrence of menstruation, which reflects the culmination of a series of hormonal changes.

Motor development

the progression of muscular coordination required for physical activities.

Object permanence

when a child recognizes that objects continue to exist even when they are no longer visible.

Overextension

when a child incorrectly uses a word to describe a wider set of objects or actions than intended.

Overregularizations

when grammatical rules are incorrectly generalized to irregular cases where they do not apply.

Placenta

structure that allows oxygen and nutrients to pass into the fetus from the mother’s bloodstream; bodily wastes are passed through the placenta to the mother.

Prenatal period

time from conception to birth, usually encompassing nine months of pregnancy.

Puberty

stage during which sexual functions reach maturity, which marks the beginning of adolescence.

Secondary sex characteristics

physical features that distinguish one sex from the other but are not essential for reproduction such as facial hair and broader shoulders in males and breast growth and wider hips in females.

Separation anxiety

emotional distress seen in many infants when they are separated from people with whom they have formed an attachment.

Spermarche

the first occurrence of male ejaculation; occurs around 13-14 years of age.

Stage

developmental period during which characteristic patterns of behavior are exhibited and certain capacities become established.

Telegraphic speech

speech that consists mainly of content words; articles, prepositions, and other less critical words are omitted.

Underextensions

when a child incorrectly uses a word to describe a narrower set of objects or actions than it is meant to.