Differences in gene expression related to environment and experience.

Collection of nerve cells that function somewhat like a brain.

Group of organisms that can interbreed.

Explanation of behavior as a function of the nonmaterial mind.

Division into a number of parts that are similar; refers to the idea that many animals, including vertebrates, are composed of similarly organized body segments.

Body plan in which organs or parts present on both sides of the body are mirror images in appearance. For example, the hands are bilaterally symmetrical, whereas the heart is not.

Part of the central nervous system encased within the vertebrae (spinal column); provides most of the connections between the brain and the rest of the body.

Condition in which a person is alive but unaware, unable to communicate or to function independently at even the most basic level.

Condition in which a patient is aware and awake but cannot move or communicate verbally because of complete paralysis of nearly all voluntary muscles except the eyes.

The nervous system’s potential for physical or chemical change; enhances its adaptability to environmental change and its ability to compensate for injury. (Also called neuroplasticity.)

Jerison’s quantitative measure of brain size obtained from the ratio of actual brain size to expected brain size, according to the principle of proper mass, for an animal of a particular body size.

Simple nervous system that has no center but consists of neurons that receive sensory information and connect directly to other neurons that move muscles.

Consensual experiment directed toward developing a treatment.

Particular genetic makeup of an individual.

An idea, behavior, or style that spreads from person to person within a culture.

Learned behaviors that are passed on from one generation to the next through teaching and imitation.

The brain and spinal cord, which together mediate behavior.

Phylogenetic tree that branches repeatedly, suggesting a taxonomy of organisms based on the time sequence in which evolutionary branches arise.

Literally, half a sphere, referring to one side of the cerebrum.

Major structure of the forebrain that consists of two mirror-image hemispheres (left and right) and is responsible for most conscious behavior.

Central structure of the brain; responsible for most unconscious behavior.

Animal that has both a brain and a spinal cord.

Darwin’s theory for explaining how new species evolve and how existing species change over time. Differential success in the reproduction of different characteristics (phenotypes) results from the interaction of organisms with their environment.

Proposed nonmaterial entity responsible for intelligence, attention, awareness, and consciousness.

All of the neurons in the body outside the brain and spinal cord; provides sensory and motor connections to and from the central nervous system.

Difficulty of explaining how a nonmaterial mind and a material body interact.

General term referring to primates that walk upright, including all forms of humans, living and extinct.

Forebear of two or more lineages or family groups; ancestral to both groups.

Set of individual characteristics that can be seen or measured.

Specialized nerve cell engaged in information processing.

Synonym for mind, an entity once proposed to be the source of human behavior.

Wound to the brain that results from a blow to the head.

Theory that the movements we make and the movements we perceive in others are central to communication with others.

Behavior that is characteristic of all members of a species, such as walking in amphibians.

Major brainstem structure specialized for learning and coordinating movements; assists the cerebrum in generating many behaviors.

Condition in which a person can display some rudimentary behaviors, such as smiling or uttering a few words, but is otherwise not conscious.

Philosophical position that both a nonmaterial mind and a material body contribute to behavior.

Process in which juvenile stages of predecessors become adult features of descendants; idea derived from the observation that more recently evolved species resemble the young of their common ancestors.

Neurosurgery in which electrodes implanted in the brain stimulate a targeted area with a low-voltage electrical current to facilitate behavior.

Philosophical position that behavior can be explained as a function of the nervous system without recourse to the mind.