Unit 1

Nature-Nurture Issue

The long-standing controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors

Charles Darwin

A naturalist who proposed the evolutionary process of natural selection

Natural Selection

the principle that inherited traits enabling an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations

Evolutionary Psychology

the study of the evolution of behavior and the mind, using principles of natural selection

Behavior Genetics

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

Mutation

a random error in gene replication that leads to a change

Environment

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

Heredity

the genetic transfer of characteristics from parents to offspring

Genes

the biochemical units of heredity

Genome

the complete instructions for making an organism

Indentical (monozygotic) twins

individuals who developed from a single fertilized egg that split in two, creating two genetically identical organisms

Fraternal (dizygotic) twins

individuals who developed from separate fertilized eggs. They are genetically no closer than ordinary siblings, but they shared a prenatal environment

Interaction

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

Epigenetics

the study of the molecular mechanisms by which environments can influence genetic expression (without a DNA change)

Nervous System

the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

Central Nervous System (CNS)

the brain and spinal cord (the body’s decision maker)

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the central nervous system to the rest of the body

Nerves

bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs

Sensory Neurons

neurons that carry incoming information from the body;s tissues and sensory receptors to the brain and spinal cord

Motor Neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Interneurons

neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs

Somatic Nervous System

the division of the peripheral nervous system that controls the body’s skeletal muscles (the skeletal nervous system)

Autonomic Nervous System

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms

Sympathetic Nervous System

the division of the autonomic nervous system that arouses the body, mobilizing its energy

Parasympathetic Nervous System

the division of the autonomic nervous system that calms the body, conserving its energy

Reflex

simple, automatic response to a sensory stimulus, such as the knee-jerk reflex

Neuron

a nerve cell; the basic building block of the nervous system

Cell Body

the part of a neuron that contains the nucleus; the cell’s life-support center

Dendrites

a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body

Axon

the segmented neuron extension that passes messages through its branches to other neurons or to muscles or glands

Myelin Sheath

a fatty tissue layer segmentally encasing the axons of some neurons; it enables vastly greater transmission speed as neural impulses hop from one node to the next

Glial Cells

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

Action Potential

a neural impulse; a brief electrical charge that travels down an axon

Threshold

the level of stimulation required to trigger a neutral impulse

Refractory Period

in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state

All-Or-None Response

a neuron’s reaction of either firing (with a full-strength response) or not firing

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft

Neurotransmitters

chemical messengers that cross the synaptic gap between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptors sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse

Reuptake

a neurotransmitter’s reabsorption by the sending neuron

Endorphins

natural, opiod-like neurotransmitters linked to pain control and to pleasure

Agonist

a molecule that increases a neurotransmitter’s action

Antagonist

a molecule that inhibits or blocks a neurotransmitter’s action

Endocrine System

the body’s slow chemical communication system; a set of glands and fat tissue that secrete hormones into the bloodstream

Hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues

Psychoactive Drug

a chemical substance that alters the brain, causing changes in perceptions and moods

Substance Use Disorder

a disorder characterized by continued substance use despite resulting life disruption

Tolerance

the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect

Addiction

an everyday term for compulsive substance use (and sometimes for dysfunctional behavior patterns) that continue despite harmful consequences

Withdrawal

the discomfort and distress that follow discontinuing an addictive drug or behavior

Depressants

drugs that reduce neural activity and slow body functions

Barbiturates

drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgement

Opiods

opium and its derivatives; they depress neural activity, temporarily lessening pain and anxiety

Stimulants

drugs that excite neural activity and speed up body functions

Hallucinogens

psychedeli drugs that distory perceptions and evoke sensory images in the absence of sensory input

Near-Death Experience

an altered state of consciousness reported after a close brush with death (such as cardiac arrest); often similar to drug-induced hallucinations

Biological Psychology

the scientific study of the links between biological and psychological processes

Biopsychosocial Approach

an integrated approach that incorporates biological, psychological, and social-cultural levels of analysis

Levels of Analysis

the differing complementary views, from biological to psychological to social-cultural, for analyzing any given phenomenon

Neuroplasticity

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

Lesion

tissue destruction. Brain lesions may occur naturally (from disease or trauma), during surgery, or experimentally (using electrodes to destroy brain cells)

EEG (electroencephalogram)

an amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp

MEG (magnetoencephalography)

a brain-imaging technique that measures magnetic fields from the brain’s natural electrical activity

CT (computed tomography) Scan

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 (positron emission tomography)

a technique for detecting brain activity that displays where a radioactive form of glucose goes while the brain performs a given task

MRI (magnetic resonance imaging)

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

fMRI (functional MRI)

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show Brian function as well as structure

Hindbrain

consists of the medulla, pons, and cerebellum; directs essential survival functions, such as breathing, sleeping, and wakefulness, as well as coordination and balance

Midbrain

found atop the brainstem; connects the hindbrain with the forebrain,, controls some motor movement, and transmits auditory and visual information

Forebrain

consists of the cerebral cortex, thalamus, and hypothalamus; manages complex cognitive activities, sensory and associative functions, and voluntary motor activities

Brainstem

the central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions

Medulla

the hindbrain structure that is the brainstem’s base; controls heartbeat and breathing

Thalamus

the forebrain’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 into the thalamus; it filters information and plays an important role in controlling arousal

Cerebellum

the hindbrain’s “little brain” at the rear of the brainstem; its functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory

Limbic System

neural system located mostly in the forebrain—below the cerebral hemispheres—that includes the amygdala, hypothalamus, hippocampus, thalamus, and pituitary gland; associated with emotions and drives

Amygdala

two lima-bean-sized neural clusters in the limbic system; linked to emotion

Hypothalamus

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

Hippocampus

a neural center in the limbic system that helps process explicitly (conscious) memories—of facts and events—for storage

Cerebral Cortex

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

Frontal Lobes

the portion of the cerebral cortex lying just behind the forehead. They enable linguistic processing, muscle movements, higher-order thinking, and executive functioning (such as making judgements)

Parietal Lobes

the portion of the cerebral cortex lying at the top of the head and toward the rear; it receives sensory input for touch and body position

Occipital Lobes

the portion of the cerebral cortex lying at the back of the head; it includes areas receive information from the visual fields

Temporal Lobes

the portion of the cerebral cortex lying roughly above the ears; it includes the auditory areas, each of which receives information primarily from the opposite ear. They also enable language processing

Motor Cortex

a cerebral cortex area at the rear of the frontal lobes that controls voluntary movements

Somatosensory Cortex

a cerebral 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 primary motor or sensory functions, but rather are involved in higher mental functions such as learning, remembering, thinking; and speaking

Neurogenesis

the formation of new neurons

Corpus Callosum

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

Roger Sperry and Michael Gazzaniga

they divided cats’ and monkeys’ brains by severing the corpus callosum and had no serious ill effects

Split Brain

a condition resulting from surgery that separates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

Consciousness

our subjective awareness of ourselves and our environment

Cognitive Neuroscience

the interdisciplinary study of the brain activity linked with cognition (thinking, knowing, remembering, and communicating)

Dual Processing

the principle that information is often simultaneously processed on separate conscious and unconscious tracks

Blindisight

a condition in which a person can respond to a visual stimulus without consciously experiencing it

Parallel Processing

processing multiple aspects of a stimulus or problem simultaneously

Sequential Processing

processing one aspect of a stimulus or problem at a time; generally used to process new information or to solve difficult problems

Sleep

a periodic natural loss of consciousness—as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation

Circadian Rhythm

our biological clock; regular bodily rhythms that occur on a 24-hour cycle

REM Sleep (Rapid Eye Movement Sleep)

a recurring sleep stage during which vivid dreams commonly occur; also known as paradoxical sleep, because the muscles are relaxed but other body systems are active

Alpha Waves

the relatively slow brain waves of a relaxed, awake state