Unit 1: Biological Bases of Behavior

Flashcards containing the vocabulary terms and definitions from the lecture notes.

Expressive aphasia

Loss of the ability to speak, connected to the destruction of Broca’s area (left frontal lobe).

Receptive aphasia

Loss of the ability to comprehend written and spoken language, resulting from destruction of Wernicke’s area (left temporal lobe).

Lesions

Precise destruction of brain tissue for systematic study of loss of function

Brain lateralization

The specialization of the left and right hemispheres of the brain for different functions.

Computerized axial tomography (CAT or CT)

Computerized image using X-rays passed through various angles of the brain.

Magnetic resonance imaging (MRI)

A magnetic field and pulses of radio waves cause the emission of faint radio frequency signals that depend upon the density of the tissue.

EEG (electroencephalogram)

Amplified tracing of brain activity produced by electrodes on the scalp.

Evoked potentials

Changes in voltage resulting from a response to a specific stimulus.

Positron emission tomography (PET)

Color computer graphics that depend on the amount of metabolic activity in the imaged brain region.

Functional MRI (fMRI)

Shows the brain at work at higher resolution than the PET scanner by recording changes in oxygen in the blood.

Magnetic source image (MSI)

Produced by magnetoencephalography (MEG scan), detects the slight magnetic field caused by the electric potentials in the brain.

Central nervous system

Consists of the brain and spinal cord.

Peripheral nervous system

Includes the somatic and autonomic nervous systems; carries sensory and motor information to and from the central nervous system.

Somatic nervous system

Has motor neurons that stimulate skeletal (voluntary) muscle.

Autonomic nervous system

Has motor neurons that stimulate smooth (involuntary) and heart muscle.

Sympathetic nervous system

Division of the autonomic nervous system that helps the body deal with stressful events.

Parasympathetic nervous system

Division of the autonomic nervous system that calms the body following sympathetic stimulation.

Meninges

Membranes that protect the spinal cord.

Reptilian brain

Maintains homeostasis and instinctive behaviors; includes the brainstem (medulla, pons, cerebellum).

Old mammalian brain/Limbic System

Controls emotional behavior, some aspects of memory, and vision; includes the septum, hippocampus, amygdala, cingulate cortex, hypothalamus, and thalamus.

New mammalian brain/Neocortex/Cerebral cortex

Associated with higher functions of judgment, decision making, abstract thought, language, computing, sensation, and perception; constitutes about 80% of brain volume.

Association areas

Regions of the cerebral cortex involved in higher mental functions like thinking, planning, remembering, and communicating.

Medulla oblongata

Regulates heart rhythm, blood flow, breathing rate, digestion, vomiting.

Pons

Includes portion of reticular activating system critical for arousal and wakefulness; sends information to and from medulla, cerebellum, and cerebral cortex.

Cerebellum

Controls posture, equilibrium, and movement.

Basal ganglia

Regulates initiation of movements, balance, eye movements, and posture; functions in the processing of implicit memories.

Thalamus

Relays visual, auditory, taste, and somatosensory information to/from appropriate areas of cerebral cortex.

Hypothalamus

Controls feeding behavior, drinking behavior, body temperature, sexual behavior, threshold for rage behavior, activation of the sympathetic and parasympathetic systems, and secretion of hormones of the pituitary.

Hippocampus

Enables formation of new long-term memories.

Cerebral cortex

Center for higher-order processes such as thinking, planning, judgment; receives and processes sensory information and directs movement.

Plasticity

The brain's ability to reorganize itself by forming new neural connections throughout life.

Glial cells

Guide the growth of developing neurons, help provide nutrition for and get rid of wastes of neurons, and form an insulating sheath around neurons that speeds conduction.

Neuron

Basic unit of structure and function of the nervous system.

Cell body (cyton or soma)

Contains cytoplasm and the nucleus, which directs synthesis of neurotransmitters.

Dendrites

Branching tubular processes capable of receiving information.

Axon

Single conducting fiber emerging from the cyton that branches and ends in terminal buttons.

Neurotransmitters

Chemicals stored in synaptic vesicles of the terminal buttons.

Neurogenesis

The growth of new neurons throughout life.

Dopamine

Stimulates the hypothalamus to synthesize hormones and affects alertness and movement.

Glutamate

Major excitatory neurotransmitter involved in information processing throughout the cortex and especially memory formation in the hippocampus.

Serotonin

Associated with sexual activity, concentration and attention, moods, and emotions.

Opioid peptides (endorphins)

Often considered the brain’s own painkillers.

Gamma-aminobutyric acid (GABA)

Inhibits firing of neurons.

Norepinephrine (noradrenaline)

Associated with attentiveness, sleeping, dreaming, and learning.

Agonists

Mimic a neurotransmitter and bind to its receptor site to produce the effect of the neurotransmitter.

Antagonists

Block a receptor site, inhibiting the effect of the neurotransmitter or agonist.

Action potential

Net flow of sodium ions into the cell that causes a rapid change in potential across the membrane.

All-or-none principle

The strength of the action potential is constant whenever it occurs.

Nodes of Ranvier

Spaces between segments of myelin.

Saltatory conduction

Conduction speed is increased since depolarizations jump from node to node.

Reflex arc

Path of impulse conduction over a few neurons in response to a stimulus.

Sensory/afferent neurons

Transmit impulses from sensory receptors to the spinal cord or brain.

Interneurons

Located entirely within your brain and spinal cord, intervene between sensory and motor neurons.

Motor/efferent neurons

Transmit impulses from sensory or interneurons to muscle cells that contract or gland cells that secrete.

Effectors

Muscle and gland cells that are stimulated by motor neurons.

Endocrine system

Glands that secrete chemical messengers called hormones into the blood.

Pineal Gland

Endocrine gland in brain that produces melatonin that helps regulate circadian rhythms.

Hypothalamus

Portion of brain part that acts as endocrine gland and produces hormones that stimulate (releasing factors) or inhibit secretion of hormones by the pituitary.

Pituitary Gland

Endocrine gland in brain that produces stimulating hormones, which promote secretion by other glands.

Thyroid Gland

Endocrine gland in neck that produces thyroxine, which stimulates and maintains metabolic activities.

Parathyroids

Endocrine glands in neck that produce parathyroid hormone, which helps maintain calcium ion level in blood.

Pancreas

Gland near stomach that secretes the hormones insulin and glucagon, which regulate blood sugar.

Ovaries and Testes

Gonads in females and males, respectively, that produce hormones necessary for reproduction and development of secondary sex characteristics.

Nature-nurture controversy

Deals with the extent to which heredity and the environment each influence behavior.

Evolutionary psychologists

Study how natural selection favored behaviors that contributed to survival and the spread of our ancestors’ genes.

Behavioral geneticists

Study the role played by our genes and our environment in mental ability, emotional stability, temperament, personality, interests, and so forth.

Identical twins

Two individuals who share all of the same genes because they develop from the same fertilized egg or zygote; they are monozygotic twins.

Fraternal twins

Siblings that share about half of the same genes because they develop from two different fertilized eggs or zygotes; they are dizygotic twins.

Heritability

Proportion of variation among individuals in a population that is due to genetic causes.

Gene

DNA segment of a chromosome that determines a trait.

Genotype

Genetic makeup for a trait of an individual.

Phenotype

Expression of the genes.

Tay-Sachs syndrome

Produces progressive loss of nervous function and death in a baby.

Albinism

Arises from a failure to synthesize or store pigment and also involves abnormal nerve pathways to the brain.

Phenylketonuria (PKU)

Results in severe, irreversible brain damage unless the baby is fed a special diet low in phenylalanine within 30 days of birth.

Huntington’s disease

Dominant gene defect that involves degeneration of the nervous system.

Preconscious

Level of consciousness that is outside of awareness but contains feelings and memories that you can easily bring into conscious awareness.

Nonconscious

Level of consciousness devoted to processes completely inaccessible to conscious awareness, such as blood flow, filtering of blood by kidneys, secretion of hormones, and lower-level processing of sensations.

Unconscious (subconscious)

Level of consciousness that includes often unacceptable feelings, wishes, and thoughts not directly available to conscious awareness.

Dual processing

Processing information on conscious and unconscious levels at the same time.

Unconsciousness

Characterized by loss of responsiveness to the environment, resulting from disease, trauma, or anesthesia.

Circadian rhythm

Natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours.

Sleep

Combination of states of consciousness, each with its own level of consciousness, awareness, responsiveness, and physiological arousal.

Theta waves

EEGs of NREM-1 sleep show these, which are higher in amplitude and lower in frequency than alpha waves.

NREM-2

EEG shows high-frequency bursts of brain activity (called sleep spindles) and K complexes.

NREM-3

EEG shows very high amplitude and very low-frequency delta waves.

Manifest content

Remembered story line of a dream .

Latent content

Underlying meaning of a dream.

Pons

Bursts of action potentials to the forebrain, which is activation.

Insomnia

Inability to fall asleep and/or stay asleep.

Narcolepsy

Condition in which an awake person suddenly and uncontrollably falls asleep, often directly into REM sleep.

Sleep apnea

Sleep disorder characterized by temporary cessations of breathing that awaken the sufferer repeatedly during the night.

Night terrors

Childhood sleep disruptions from the deepest part of NREM-3 characterized by a bloodcurdling scream and intense fear.

Sleepwalking (somnambulism)

Childhood sleep disruption that occurs during deep NREM-3 sleep characterized by trips out of bed or carrying on complex activities.

Hypnosis

Altered state of consciousness characterized by deep relaxation and heightened suggestibility.

Dissociation theory

Theory that hypnotized individuals experience two or more streams of consciousness cut off from each other.

Meditation

Set of techniques used to focus concentration away from thoughts and feelings in order to create calmness, tranquility, and inner peace.

Psychoactive drugs

Chemicals that can pass through the blood-brain barrier into the brain to alter perception, thinking, behavior, and mood.

Psychological dependence

When the person has an intense desire to achieve the drugged state in spite of adverse effects.

Tolerance

Decreasing responsivity to a drug.