psych unit 1

Psychology

science of behavior and mental processes

Nature-nurture issues

long standing controversy over relative contributions that genes and experience make to develop psychological traits and behaviors.

Evolutionary psychology

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

Mutation

random error in gene replication that leads to a change

Environment

every nongenetic influence, from prenatal nutrition to experiences

Heredity

genetic transfer of characteristics from parents to offspring

Genes

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 only shared prenatal environment

Interaction

interplay that occurs when effect of one factor depends on another factor

Epigenetics

study of molecular mechanism by which environments can influence genetic expression without DNA change

Nervous system

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

Central nervous system (CNS)

brain and spinal cord

Peripheral nervous system (PNS)

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

Neurons

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

Sensory (afferent) neurons

carry incoming info from body’s tissues and sensory receptors to brain and spinal cord

Motor (efferent) neurons

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

Interneurons

neurons within brain and spinal cord; communicate internally and process info between sensory inputs and motor outputs

Somatic (skeletal) nervous system

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

Autonomic nervous system (ANS)

part of PNS that controls glands and muscles of internal organs

Sympathetic nervous system

division of ANS that arouses body, mobilizing energy

Parasympathetic nervous system

division of ANS that calms body, conserving energy

Reflex

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

Neuron

nerve call; basic building block of nervous system

Cell body

part of neuron containing nucleus, cell’s life support center

Dendrites

neuron’s bush, branching extension; receive and integrate messages, conducting impulses toward cell body

Axon

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

Myelin sheath

fatty tissue layer segmentally encasing exons of some neurons; enables faster transmission

Glial cells (glia)

cells in nervous system that support neurons, may play role in learning

Action potential

neural impulse; brief electrical charge that travels down axon

Threshold

level of stimulation required to trigger neural impulse

Refractory period

in neural processing, brief resting pause that occurs after neuron fired

All-or-none response

neuron’s reaction of either firing or not firing

Synapse

junction between axon tip of sending neuron and dendrite/cell body of receiving neuron

Neurotransmitters

chemical messengers that cross synaptic gap between neuron, influence whether neuron will generate neural impulse

Reuptake

neurotransmitter’s reabsorption by sending neuron

Agonist

molecule that increases neurotransmitter’s action

Antagonist

molecule that inhibits or blocks a neurotransmitter’s action

Endocrine system

body’s “slow” chemical communication system; secretes hormones into bloodstream

Hormones

chemical messengers manufactured by endocrine glands, travel through bloodstream, affect other tissues

Psychoactive drug

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

Substance use disorder

characterized by continued substance use despite resulting life disruption

Depressants

drugs that reduce neural activity and slow body functions

Tolerance

diminishing effect with regular use of the same dose of drug, requiring larger and larger doses

Addiction

term for compulsive substance use (or dysfunctional behavior patterns) that continues despite harmful consequences

Withdrawal

discomfort and distress that follow discontinuing an addictive drug or behavior

Barbiturates

drugs that depress CNS activity, reducing anxiety but impairing memory and judgement

Opioids

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

Stimulants

drugs that excite neural activity and speed up body functions

Hallucinogens

psychedelic drugs that distort perceptions and evoke sensory images in the absence of sensory input

Near-death experience

altered state of consciousness reported after close brush with death; often similar to drug-induced hallucinations

Acetylcholine

neurotransmitter; enables muscle action, learning, helps with memory

Substance P

neurotransmitter; helps with transmitting pain signals from sensory nerves to CNS

Dopamine

neurotransmitter; helps with movement, learning, attention, emotions

Serotonin

neurotransmitter; impacts hunger, sleep, arousal, mood

Endorphins

neurotransmitter; help pain control, impact pain tolerance

Norepinephrine

neurotransmitter; increases blood pressure, heart rate, alertness, helps with fight or flight response

Glutamate

neurotransmitter; helps with long term memory and learning

GABA

neurotransmitter; helps with sleep, movement, slows down nervous system

Adrenaline

hormone; aka epinephrine, helps with response to high emotional situations, helps form memories

Leptin

hormone; helps regulate energy balance by inhibiting hunger

Ghrelin

hormone; signs to the brain that we are hungry, helps promote release of growth hormone

Melatonin

hormone; produced by pineal gland, helps regulate circadian rhythm, promotes sleep

Oxytocin

hormone; produced in hypothalamus, released by pituitary gland, promotes feelings of affect and emotional bonding

Biological psychology

scientific study of links between biological and psychological processes

Biopsychosocial approach

integrated approach that incorporates biological, psychological, socio-cultural levels of analysis

Neuroplasticity

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

Lesioning

tissue destruction; occur naturally, during surgery, or experimentally

EEG (electroencephalogram)

amplified recording of waves of electrical activity across brain’s surface; measured by electrodes placed on scalp

fMRI (functional MRI)

technique for revealing blood flow/brain activity by comparing successive MRIs

Hindbrain

medulla, pons, cerebellum; directs essential survival functions, coordination, balance

Midbrain

atop the brainstem; controls some motor movement, transmits auditory/visual info

Forebrain

cerebral cortex, thalamus, hypothalamus; manages complex cognitive activities, sensory/associative functions, voluntary motor activities

Brainstem

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

Medulla

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

Thalamus

in limbic system; forebrain’s sensory control center, on top of brainstem; directs messages to sensory receiving area in cortex; transmits replies to cerebellum and medulla

Cerebellum

hindbrain's “little brain” at rear of brainstem; processes sensory input, coordinates movement output and balance, enables nonverbal learning/memory

Limbic system

neural system located mostly in forebrain associated with emotions and drives that includes amygdala, hypothalamus, hippocampus, thalamus, pituitary gland

Amygdala

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

Hypothalamus

limbic system neural structure lying below thalamus; directs maintenance activities, helps govern endocrine system, linked to emotion and reward

Hippocampus

neutral center in limbic system that helps process explicit memories for storage

Cerebral cortex

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

Frontal lobes

portion of cerebral cortex lying just behind forehead; enable linguistic processing, muscle movements; higher-order thinking

Parietal lobes

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

Occipital lobes

portion of cerebral cortex lying at back of head; includes areas that receive info from visual fields

Temporal lobes

portion of cerebral cortex lying roughly above ears; includes auditory areas (receive info from opposite ear); enables language processing

Motor cortex

cerebral cortex area at rear of frontal lobes; controls voluntary movement

Somatosensory cortex

cerebral cortex area at front of parietal lobe that registers and processes body touch and movement sensations

Association areas

areas of cerebral cortex not involved in primary motor or sensory functions, but involved in higher mental functions

Neurogenesis

formation of new neurons

Corpus callosum

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

Split brain

condition resulting from surgery that separates the brain’s two hemispheres by cutting fibers connecting them

Consciousness

subjective awareness of ourselves and environment; sleep and wakefulness two types

Cognitive neuroscience

interdisciplinary study of brain activity linked with cognition

Blindsight

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

Sleep

periodic, natural loss of consciousness; distinct from unconsciousness resulting from coma

Circadian rhythm

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

REM sleep

rapid eye movement sleep; dreams occur; muscles are relaxed by other body systems active

Alpha waves

relatively slow brain waves of relaxed, awake state

NREM sleep

non-rapid eye movement sleep; encompasses all sleep states except REM sleep