Myers AP Psychology 4th Edition Unit 1,

biological perspective

concerned with the links between biology and behavior. Includes psychologists working in neuroscience, behavior genetics, and evolutionary psychology. These researchers may call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists.

neuron

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

dendrites

a neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body. (Myers Psychology 11e CH02 p. 53)

axon

the neuron extension that passes messages through its branches to other neurons or to muscles or glands. (Myers Psychology 11e CH02 p. 53)

myelin sheath

a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next. (Myers Psychology 11e CH02 p. 53)

glial cells (glia) cells

in the nervous system that support, nourish, and protect neurons; they may also play a role in learning, thinking, and memory. (Myers Psychology 11e CH02 p. 54)

action potential

a neural impulse; a brief electrical charge that travels down an axon. (Myers Psychology 11e CH02 p. 54)

refractory period

a period of inactivity after a neuron has fired.

threshold

the level of stimulation required to trigger a neural impulse.

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 gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor 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

"morphine within"—natural, opiate-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.

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.

peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

nerves

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

sensory (afferent) neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

motor (efferent) 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; 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. Also called the skeletal nervous system.

autonomic nervous system (ANS)

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

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

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.

hormones

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

adrenal

glands a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

pituitary gland

the endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

lesion

tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.

electroencephalogram (EEG)

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.

PET (positron emission tomography) scan

a visual display of brain activity that detects 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 bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as structure.

brainstem

the oldest part and 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 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 into the 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 (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

hippocampus

a neural center located in the limbic system; helps process explicit memories for storage.

amygdala

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

hypothalamus

a neural structure lying below (hypo) 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.

frontal lobes

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.

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 the 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 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.

neurogenesis

the formation of new neurons.

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 (mainly those of the corpus callosum) connecting them. (Myers Psychology 11e CH02 p. 83)

nature-nurture issue

the longstanding controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors. Today's science sees traits and behaviors arising from the interaction of nature and nurture

Charles Darwin

-Evolution by "natural selection" (the weaker die out) wrote On the Origin of Species

natural selection

the principle that, among the range of inherited trait variations, those contributing to reproduction and survival will 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

mutations

a random error in gene replication that leads to a change

environment

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

hereditary

the genetic transfer of characteristics from parents to offspring

genes

the biochemical units of heredity

genome

the complete instructions for making an organism

identical (monozygotic) twins

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

fraternal (dizygotic) twins

develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share 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

"above" or "in addition to" (epi) genetics; the study of environmental influences on gene expression that occur without a DNA change

psychoactive drug

a chemical substance that alters perceptions and moods

substance use disorder

a disorder characterized by continued substance use despite significant life disruption

depressants

drugs that reduce neural activity and slow body functions

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, such as out-of-control gambling) that continue despite harmful consequences

withdrawal

the discomfort and distress that follow discontinuing the use of an addictive drug

barbituates

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

opiods

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

Nicotine

drugs that excite neural activity and speed up body functions

hallucinogens

psychedelic ("mind-manifesting") drugs, such as LSD, that distort 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 through cardiac arrest); often similar to drug-induced hallucinations

biological psychology

the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes

biopsychosocial approach

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

level of analysis

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

lesion

tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue

MEG (magnetoencephalogram)

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

sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. (Myers Psychology 11e CH06 p. 230)

perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. (Myers Psychology 11e CH06 p. 230)

bottom-up processing

analysis that begins with the sensory receptors and works up to the brain's integration of sensory information. (Myers Psychology 11e CH06 p. 230)

top-down processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations. (Myers Psychology 11e CH06 p. 230)

transduction

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret. (Myers Psychology 11e CH06 p. 230)

psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them. (Myers Psychology 11e CH06 p. 230)

absolute threshold

the minimum stimulus energy needed to detect a particular stimulus 50 percent of the time. (Myers Psychology 11e CH06 p. 231)

signal detection theory

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness. (Myers Psychology 11e CH06 p. 231)

subliminal

below one's absolute threshold for conscious awareness. (Myers Psychology 11e CH06 p. 231)

priming

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response. (Myers Psychology 11e CH06 pp. 231, 334)

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (or jnd). (Myers Psychology 11e CH06 p. 232)

Weber's law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount). (Myers Psychology 11e CH06 p. 233)