Unit 1 Biological basis for behavior pt 1

Biological psychology

Biological psychology

The scientific study of the links between biological (genetic, neural, hormonal) & psychological processes; some biological psychologists call themselves behavioral neuroscientists neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists

Nature-nurture issue

The longstanding controversy over the relative contributions that genes & experience make to the development of psychological traits & behavior; today's science views traits & behaviors as arising from the interaction of nature & nurture

Natural selection

The principle that the inherited traits enabling an organism to survive & 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 & the mind, using principles of natural selection

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 & things around us

Heredity

The genetic transfer of characteristics from parents to offspring

Genes

The biochemical units of heredity

Identical (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)

Nervous system

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral & central nervous systems

Central nervous system (CNS)

The brain & spinal cord

Peripheral nervous system (PNS)

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

Nerves

Bundled axons that form neural cables connecting the CNS with muscles, glands, & 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 & spinal cord to the muscles & glands

Interneurons

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

Somatic nervous system

The division of the PNS that controls the body's skeletal; muscles; also called the skeletal nervous system

Autonomic nervous system

The part of the PNS that controls the glands & 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 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 & 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 & 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 (glia)

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

Action potential

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

Threshold

The level of stimulation required to trigger a neural 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 & 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 & 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, opioid-like neurotransmitters linked to pain control & 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 & fat tissue that secrete hormones into the bloodstream

Hormones

Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, & affect other tissues

Biopsychosocial approach

An integrated approach that incorporates biological, psychological, & 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

CT (computed tomography)

scan A series of X-ray photographs taken from different angles & 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 & radio waves to produce computer-generated images of soft tissue; MRI scans show brain anatomy

fMRI (functional MRI)

A technique for revealing blood flow &, therefore, brain activity by comparing successive MRI scans; fMRI scans show brain function as well as structure

Hindbrain

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

Midbrain

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

Forebrain

Consists of the cerebral cortex, thalamus, & hypothalamus; manages complex cognitive activities, sensory & associative functions, & 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 function

Medulla

The hindbrain structure that is the brainstem's base; controls heartbeat & breathing

Thalamus

The forebrain's sensory control center, located at the top of the brainstem; it directs messages to the sensory receiving areas in the cortex & transmits replies to the cerebellum & medulla

Reticular activating system

A nerve network that travels through the brainstem into the thalamus; it filters information & 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 & balance, & enabling nonverbal learning & memory

Limbic system

Neural system located mostly in the forebrain - below the cerebral hemispheres - that includes the amygdala, hypothalamus, hippocampus, thalamus, & pituitary gland; associated with emotions & drives

Amygdala

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

Hypothalamus

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

Hippocampus

A neural center in the limbic system that helps process explicit (conscious) memories - of facts & events - for storage

Cerebral cortex

The intricate fabric of interconnected neural cells covering the forebrain's cerebral hemispheres; the body's ultimate control & 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, & executive functioning (such as making plans & judgments)

Parietal lobes

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

Occipital lobes

The portion of the cerebral cortex lying at the back of the head; it includes the areas that 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 & processes body touch & 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, & speaking

Neurogenesis

The formation of new neurons

Corpus callosum

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

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