Biological basis of behavior🧪

Psychology

the science of behavior and mental processes

nature-nurture issue

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

natural selection

the principle that the inherited traits enabling an organism to survive and reproduce in a particular environment will (in competition with other trait variations)

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 non genetic 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

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)

epigenetics

“above” or “in addition to” (epi) genetics; the study or 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

the brain and spinal cord

sensory (afferent) neurons

neurons that carry incoming information from the body’s tissues and 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; they communicate internally and process information between the sensory inputs and motor outputs

peripheral nervous system [somatic & autonomic nervous system]

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 sensory organs

autonomic nervous system [sympathetic & parasympathetic nervous system]

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

reflex

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

neuron [dendrite—axon—myelin sheath—cellbody]

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

glial cell

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

action potential [threshold—refractory—all or none responsee]

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

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

synaptic gap

the tiny gap between the buttons and dendrites

reuptake

a neurotransmitter’s reabsorption by the sending neurons

neurotransmitters

chemical messengers that cross the synaptic gap 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

neurotransmitter pathway

each of the brain’s differing chemical messengers has designated pathways where it operates, as shown here for serotonin and dopamine

endorphins

“morphine within”; natural, opioid-like neurotransmitters linked to pain control and pleasure

agonists

a molecule that increases a neurotransmitter’s action

antagonists

a molecule that inhibits or blocks a neurotransmitter’s action

adrenal glands [epinephrine—norepinephrine]

produce hormones that help regulate your metabolism, immune system, blood pressure, response to stress and other essential functions

pituitary gland

endocrine gland located in the core of the brain - controlled by the hypothalamus - releases growth hormone & oxytocin

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 abuse disorder

a disorder characterized by continued substance use despite resulting life disruption

depressants

drugs that reduce neural activity and slow body functions

tolerance

the finishing effect with regular use of the same dose of a drug, requiring the used 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 an addictive drug or behavior

barbiturates

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

opioids

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

psychedelic (“mind-manifesting”) drugs 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 cardiac arrest); often similar to drug-induced hallucinations

biological psychology

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

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

fMRI (functional fMRI)

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain 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 brain stem; 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

reticular formation

a nerve network that travels through the brainstem into the thalamus; it filters information and plays an important role in controlling arousal

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

cerebellum

the hindbrain’s “little brain” at the rear of the brainstem; its functions include processing sensory input, coordinating movement output

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

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

hippocampus

a neural center in the limbic system that helps process explicit (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 lobe

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 plans and judgements)

parietal lobe

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 lobe

the portion of the cerebral cortex lying at the back of the head; it is primarily responsible for processing visual information from the eyes, including aspects like color, shape, and motion.

temporal lobe

the portion of the cerebral cortex located on the sides of the head, responsible for processing auditory information, as well as being involved in memory, language comprehension, and emotional responses.

motor cortex

the area of the cerebral cortex located at the back of the frontal lobe, responsible for planning, controlling, and executing voluntary movements.

somatosensory cortex

the area of the cerebral cortex located at the front of the parietal lobe, responsible for processing sensory information related to touch, temperature, pain, and body position