Science (copy)
action potential: electrical signal that moves down the neuron’s axon
adrenal gland: sits atop our kidneys and secretes hormones involved in the stress response
agonist: drug that mimics or strengthens the effects of a neurotransmitter
all-or-none: phenomenon that incoming signal from another neuron is either sufficient or insufficient to reach the threshold of excitation
allele: specific version of a gene
amygdala: structure in the limbic system involved in our experience of emotion and tying emotional meaning to our memories
antagonist: drug that blocks or impedes the normal activity of a given neurotransmitter
auditory cortex: strip of cortex in the temporal lobe that is responsible for processing auditory information
autonomic nervous system: controls our internal organs and glands
axon: major extension of the soma
biological perspective: view that psychological disorders like depression and schizophrenia are associated with imbalances in one or more neurotransmitter systems
Broca’s area: region in the left hemisphere that is essential for language production
central nervous system (CNS): brain and spinal cord
cerebellum: hindbrain structure that controls our balance, coordination, movement, and motor skills, and it is thought to be important in processing some types of memory
cerebral cortex: surface of the brain that is associated with our highest mental capabilities
chromosome: long strand of genetic information
computerized tomography (CT) scan: imaging technique in which a computer coordinates and integrates multiple x-rays of a given area
corpus callosum: thick band of neural fibers connecting the brain’s two hemispheres
dendrite: branch-like extension of the soma that receives incoming signals from other neurons
deoxyribonucleic acid (DNA): helix-shaped molecule made of nucleotide base pairs
diabetes: disease related to insufficient insulin production
dominant allele: allele whose phenotype will be expressed in an individual that possesses that allele
electroencephalography (EEG): recording the electrical activity of the brain via electrodes on the scalp
endocrine system: series of glands that produce chemical substances known as hormones
epigenetics: study of gene-environment interactions, such as how the same genotype leads to different phenotypes
fight or flight response: activation of the sympathetic division of the autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so that we might fight off a given threat or run away to safety
forebrain: largest part of the brain, containing the cerebral cortex, the thalamus, and the limbic system, among other structures
fraternal twins: twins who develop from two different eggs fertilized by different sperm, so their genetic material varies the same as in non-twin siblings
frontal lobe: part of the cerebral cortex involved in reasoning, motor control, emotion, and language; contains motor cortex
functional magnetic resonance imaging (fMRI): MRI that shows changes in metabolic activity over time
gene: sequence of DNA that controls or partially controls physical characteristics
genetic environmental correlation: view of gene-environment interaction that asserts our genes affect our environment, and our environment influences the expression of our genes
genotype: genetic makeup of an individual
glial cell: nervous system cell that provides physical and metabolic support to neurons, including neuronal insulation and communication, and nutrient and waste transport
gonad: secretes sexual hormones, which are important for successful reproduction, and mediate both sexual motivation and behavior
gyrus: (plural: gyri) bump or ridge on the cerebral cortex
hemisphere: left or right half of the brain
heterozygous: consisting of two different alleles
hindbrain: division of the brain containing the medulla, pons, and cerebellum
hippocampus: structure in the temporal lobe associated with learning and memory
homeostasis: state of equilibrium—biological conditions, such as body temperature, are maintained at optimal levels
homozygous: consisting of two identical alleles
hormone: chemical messenger released by endocrine glands
hypothalamus: forebrain structure that regulates sexual motivation and behavior and a number of homeostatic processes; serves as an interface between the nervous system and the endocrine system
identical twins: twins that develop from the same sperm and egg
lateralization: concept that each hemisphere of the brain is associated with specialized functions
limbic system: collection of structures involved in processing emotion and memory
longitudinal fissure: deep groove in the brain’s cortex
magnetic resonance imaging (MRI): magnetic fields used to produce a picture of the tissue being imaged
medulla: hindbrain structure that controls automated processes like breathing, blood pressure, and heart rate
membrane potential: difference in charge across the neuronal membrane
midbrain: division of the brain located between the forebrain and the hindbrain; contains the reticular formation
motor cortex: strip of cortex involved in planning and coordinating movement
mutation: sudden, permanent change in a gene
myelin sheath: fatty substance that insulates axons
neuron: cells in the nervous system that act as interconnected information processors, which are essential for all of the tasks of the nervous system
neuroplasticity: nervous system's ability to change
neurotransmitter: chemical messenger of the nervous system
Nodes of Ranvier: open spaces that are found in the myelin sheath that encases the axon
occipital lobe: part of the cerebral cortex associated with visual processing; contains the primary visual cortex
pancreas: secretes hormones that regulate blood sugar
parasympathetic nervous system: associated with routine, day-to-day operations of the body
parietal lobe: part of the cerebral cortex involved in processing various sensory and perceptual information; contains the primary somatosensory cortex
peripheral nervous system (PNS): connects the brain and spinal cord to the muscles, organs and senses in the periphery of the body
phenotype: individual’s inheritable physical characteristics
pituitary gland: secretes a number of key hormones, which regulate fluid levels in the body, and a number of messenger hormones, which direct the activity of other glands in the endocrine system
polygenic: multiple genes affecting a given trait
pons: hindbrain structure that connects the brain and spinal cord; involved in regulating brain activity during sleep
positron emission tomography (PET) scan: involves injecting individuals with a mildly radioactive substance and monitoring changes in blood flow to different regions of the brain
prefrontal cortex: area in the frontal lobe responsible for higher-level cognitive functioning
psychotropic medication: drugs that treat psychiatric symptoms by restoring neurotransmitter balance
range of reaction: asserts our genes set the boundaries within which we can operate, and our environment interacts with the genes to determine where in that range we will fall
receptor: protein on the cell surface where neurotransmitters attach
recessive allele: allele whose phenotype will be expressed only if an individual is homozygous for that allele
resting potential: the state of readiness of a neuron membrane’s potential between signals
reticular formation: midbrain structure important in regulating the sleep/wake cycle, arousal, alertness, and motor activity
reuptake: neurotransmitter is pumped back into the neuron that released it
semipermeable membrane: cell membrane that allows smaller molecules or molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules
soma: cell body
somatic nervous system: relays sensory and motor information to and from the CNS
somatosensory cortex: essential for processing sensory information from across the body, such as touch, temperature, and pain
substantia nigra: midbrain structure where dopamine is produced; involved in control of movement
sulcus: (plural: sulci) depressions or grooves in the cerebral cortex
sympathetic nervous system: involved in stress-related activities and functions
synaptic cleft: small gap between two neurons where communication occurs
synaptic vesicle: storage site for neurotransmitters
temporal lobe: part of cerebral cortex associated with hearing, memory, emotion, and some aspects of language; contains primary auditory cortex
terminal button: axon terminal containing synaptic vesicles
thalamus: sensory relay for the brain
theory of evolution by natural selection: states that organisms that are better suited for their environments will survive and reproduce compared to those that are poorly suited for their environments
threshold of excitation: level of charge in the membrane that causes the neuron to become active
thyroid: secretes hormones that regulate growth, metabolism, and appetite
ventral tegmental area (VTA): midbrain structure where dopamine is produced: associated with mood, reward, and addiction
Wernicke’s area: important for speech comprehension
absolute threshold: minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time
afterimage: continuation of a visual sensation after removal of the stimulus
amplitude: height of a wave
basilar membrane: thin strip of tissue within the cochlea that contains the hair cells which serve as the sensory receptors for the auditory system
binaural cue: two-eared cue to localize sound
binocular cue: cue that relies on the use of both eyes
binocular disparity: slightly different view of the world that each eye receives
blind spot: point where we cannot respond to visual information in that portion of the visual field
bottom-up processing: system in which perceptions are built from sensory input
closure: organizing our perceptions into complete objects rather than as a series of parts
cochlea: fluid-filled, snail-shaped structure that contains the sensory receptor cells of the auditory system
cochlear implant: electronic device that consists of a microphone, a speech processor, and an electrode array to directly stimulate the auditory nerve to transmit information to the brain
conductive hearing loss: failure in the vibration of the eardrum and/or movement of the ossicles
cone: specialized photoreceptor that works best in bright light conditions and detects color
congenital deafness: deafness from birth
congenital insensitivity to pain (congenital analgesia): genetic disorder that results in the inability to experience pain
cornea: transparent covering over the eye
deafness: partial or complete inability to hear
decibel (dB): logarithmic unit of sound intensity
depth perception: ability to perceive depth
electromagnetic spectrum: all the electromagnetic radiation that occurs in our environment
figure-ground relationship: segmenting our visual world into figure and ground
fovea: small indentation in the retina that contains cones
frequency: number of waves that pass a given point in a given time period
Gestalt psychology: field of psychology based on the idea that the whole is different from the sum of its parts
good continuation: (also, continuity) we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines
hair cell: auditory receptor cell of the inner ear
hertz (Hz): cycles per second; measure of frequency
inattentional blindness: failure to notice something that is completely visible because of a lack of attention
incus: middle ear ossicle; also known as the anvil
inflammatory pain: signal that some type of tissue damage has occurred
interaural level difference: sound coming from one side of the body is more intense at the closest ear because of the attenuation of the sound wave as it passes through the head
interaural timing difference: small difference in the time at which a given sound wave arrives at each ear
iris: colored portion of the eye
just noticeable difference: difference in stimuli required to detect a difference between the stimuli
kinesthesia: perception of the body’s movement through space
lens: curved, transparent structure that provides additional focus for light entering the eye
linear perspective: perceive depth in an image when two parallel lines seem to converge
malleus: middle ear ossicle; also known as the hammer
Meissner’s corpuscle: touch receptor that responds to pressure and lower frequency vibrations
Ménière's disease: results in a degeneration of inner ear structures that can lead to hearing loss, tinnitus, vertigo, and an increase in pressure within the inner ear
Merkel’s disk: touch receptor that responds to light touch
monaural cue: one-eared cue to localize sound
monocular cue: cue that requires only one eye
neuropathic pain: pain from damage to neurons of either the peripheral or central nervous system
nociception: sensory signal indicating potential harm and maybe pain
olfactory bulb: bulb-like structure at the tip of the frontal lobe, where the olfactory nerves begin
olfactory receptor: sensory cell for the olfactory system
opponent-process theory of color perception: color is coded in opponent pairs: black-white, yellow-blue, and red-green
optic chiasm: X-shaped structure that sits just below the brain’s ventral surface; represents the merging of the optic nerves from the two eyes and the separation of information from the two sides of the visual field to the opposite side of the brain
optic nerve: carries visual information from the retina to the brain
Pacinian corpuscle: touch receptor that detects transient pressure and higher frequency vibrations
pattern perception: ability to discriminate among different figures and shapes
peak: (also, crest) highest point of a wave
perception: way that sensory information is interpreted and consciously experienced
perceptual hypothesis: educated guess used to interpret sensory information
pheromone: chemical message sent by another individual
photoreceptor: light-detecting cell
pinna: visible part of the ear that protrudes from the head
pitch: perception of a sound’s frequency
place theory of pitch perception: different portions of the basilar membrane are sensitive to sounds of different frequencies
principle of closure: organize perceptions into complete objects rather than as a series of parts
proprioception: perception of body position
proximity: things that are close to one another tend to be grouped together
pupil: small opening in the eye through which light passes
retina: light-sensitive lining of the eye
rod: specialized photoreceptor that works well in low light conditions
Ruffini corpuscle: touch receptor that detects stretch
sensation: what happens when sensory information is detected by a sensory receptor
sensorineural hearing loss: failure to transmit neural signals from the cochlea to the brain
sensory adaptation: not perceiving stimuli that remain relatively constant over prolonged periods of time
signal detection theory: change in stimulus detection as a function of current mental state
similarity: things that are alike tend to be grouped together
stapes: middle ear ossicle; also known as the stirrup
subliminal message: message presented below the threshold of conscious awareness
taste bud: grouping of taste receptor cells with hair-like extensions that protrude into the central pore of the taste bud
temporal theory of pitch perception: sound’s frequency is coded by the activity level of a sensory neuron
thermoception: temperature perception
timbre: sound’s purity
top-down processing: interpretation of sensations is influenced by available knowledge, experiences, and thoughts
transduction: conversion from sensory stimulus energy to action potential
trichromatic theory of color perception: color vision is mediated by the activity across the three groups of cones
trough: lowest point of a wave
tympanic membrane: eardrum
umami: taste for monosodium glutamate
vertigos: pinning sensation
vestibular sense: contributes to our ability to maintain balance and body posture
visible spectrum: portion of the electromagnetic spectrum that we can see
wavelength: length of a wave from one peak to the next peak