AP PSYCHOLOGY UNIT 4: Biological Bases of Behaviour Set II

Lesion

Naturally or experimentally caused destruction of tissue.

EEG

An amplified recording of the waves of electrical activity sweeping across the brain’s surface.

CT

A series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure.

PET

A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.

MRI

A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue; scans show brain anatomy.

Brainstem

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

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, coordinating movement output and balance, and enabling nonverbal learning and memory.

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

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Cerebral Cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center.

Glial Cells

Cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning and thinking.

Frontal Lobes

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 Lobes

Portion of the cerebral cortex, lying at the back of the head; includes areas that receive information from visual fields.

Temporal Lobes

Portion of the cerebral cortex, lying 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 the primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

Plasticity

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

Corpus Callosum

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

Split Brain

A condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers connecting them.

Chromosomes

Threadlike structures made of DNA molecules that contain the genes.

DNA

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

Genes

The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins.

Genomes

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

Monozygotic Twins

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

Dizygotic Twins

Twins who develop from separate fertilized eggs; they are genetically no closer than brothers and sisters, but they share a fetal environment.