Unit 1 - Biological Bases Flashcards
absolute threshold
The minimum stimulation needed to detect a particular stimulus 50% of the time.
accomodation
In vision, the process by which the lens of the eye shifts to focus on a particular object.
acetylcholine
A neurotransmitter involved in muscle activation, memory, and learning.
action potential
A brief electrical charge that travels down the axon of a neuron, generated by the movement of positively charged atoms in and out of channels in the neuron’s membrane.
Activation-Synthesis Theory
A theory of dreaming that suggests dreams are the brain’s attempt to make sense of random neural activity.
addiction
A complex condition characterized by compulsive drug use or behaviors despite harmful consequences.
agonist
A drug or chemical that enhances the activity of neurotransmitters.
Alcohol
A depressant that slows down the central nervous system, impairing cognitive and motor functions.
all-or-none response
The principle that a neuron either fires completely or does not fire at all.
alpha waves
The relatively slow brain waves associated with relaxation and wakefulness.
Amplitude
The height of a wave, which determines the loudness of a sound.
amygdala
A limbic system structure involved in processing emotions, particularly fear and aggression.
antagonist
A drug or chemical that inhibits or blocks the action of neurotransmitters.
Aphasia
A condition characterized by the loss of ability to understand or express speech.
association areas
Areas of the cerebral cortex that are not involved in primary motor or sensory functions but are involved in higher mental functions such as learning, remembering, thinking, and speaking.
audition
The sense of hearing.
Auditory Cortex
The part of the brain that processes auditory information.
autonomic nervous system
The part of the peripheral nervous system that controls involuntary functions like heart rate, digestion, and glandular secretion.
axon
The extension of a neuron through which neural impulses are sent.
barbiturates
A class of drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment.
behavior genetics
The study of the relative power and limits of genetic and environmental influences on behavior.
biological psychology
A branch of psychology concerned with the links between biology and behavior.
biopsychosocial approach
An integrated approach that incorporates biological, psychological, and social-cultural levels of analysis.
blind spot
The point at which the optic nerve leaves the eye, creating a small gap in the field of vision.
blindsight
A condition in which a person can respond to visual stimuli without consciously experiencing them.
bottom-up processing
Analysis that begins with sensory receptors and works up to the brain’s integration of sensory information.
brainstem
The oldest part and central core of the brain, responsible for automatic survival functions.
Broca’s Area
A region in the frontal lobe of the brain associated with speech production.
Caffeine
A stimulant found in coffee, tea, and many soft drinks that increases alertness and reduces fatigue.
central nervous system
The brain and spinal cord, responsible for processing and coordinating information.
cerebellum
A structure in the hindbrain that helps coordinate voluntary movement and balance.
cerebral cortex
The outer layer of the brain responsible for complex cognitive processes such as thinking, planning, and language.
Charles Darwin
An English naturalist who proposed the theory of evolution by natural selection.
circadian rhythm
The biological clock; regular bodily rhythms that occur on a 24-hour cycle.
Cocaine
A powerful stimulant drug that increases levels of dopamine in the brain, leading to intense euphoria and increased energy.
cochlea
A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.
cochlear implant
A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.
cognitive neuroscience
The interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language).
computed tomography (CT)
A scanning technique using multiple X-rays to construct a 3D image of the brain’s structure.
conduction hearing loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.
cones
Photoreceptor cells in the retina that are responsible for color vision and fine detail.
consciousness
Our awareness of ourselves and our environment.
Consolidation Theory
The theory that sleep helps strengthen the neural connections that form our memories.
Contralateral Control
The principle that each hemisphere of the brain controls the opposite side of the body.
cornea
The transparent outer layer of the eye that covers the pupil and iris and helps focus incoming light.
corpus callosum
The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.
David Hubel
A Canadian neurophysiologist known for his work with Torsten Wiesel on the processing of visual information in the brain.
delta waves
The large, slow brain waves associated with deep sleep.
dendrites
Branchlike extensions of a neuron that receive messages and conduct impulses toward the cell body.
Depolarization
The process by which a neuron’s membrane potential becomes less negative, leading to the firing of an action potential.
depressants
Drugs that reduce neural activity and slow body functions.
Dichromatism
A type of color blindness where one of the three basic color mechanisms is absent or not functioning.
difference threshold
The minimum difference between two stimuli required for detection 50% of the time; also known as just noticeable difference (JND).
Dopamine
A neurotransmitter involved in reward, motivation, and motor control.
dream
A sequence of images, emotions, and thoughts passing through a sleeping person’s mind.
dual processing
The idea that information is simultaneously processed on separate conscious and unconscious tracks.
electroencephalogram (EEG)
A recording of the electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp.
embodied cognition
The theory that cognition is influenced by the body’s interactions with the environment.
endocrine system
The body’s “slow” chemical communication system, consisting of glands that secrete hormones into the bloodstream.
endorphins
Neurotransmitters that are natural painkillers produced by the brain.
environment
Every nongenetic influence, from prenatal nutrition to the people and things around us.
epigenetics
The study of environmental influences on gene expression that occur without a DNA change.
Ernst Weber
A German physician credited with the formulation of Weber’s law, which describes the relationship between the magnitude of a physical stimulus and the intensity of its perceived sensation.
eugenics
A controversial and unethical movement aimed at improving the genetic quality of the human population.
evolutionary psychology
The study of the evolution of behavior and the mind, using principles of natural selection.
Excitatory Neurotransmitter
A neurotransmitter that promotes the firing of neurons.
Farsightedness (Hyperopia)
A condition where distant objects can be seen clearly, but close objects appear blurry.
feature detectors
Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.
fMRI
A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans.
forebrain
The largest and most prominent part of the brain, including the cerebral cortex and subcortical structures.
fovea
The central focal point in the retina, around which the eye’s cones cluster.
fraternal (dizygotic) twins
Twins who develop from separate eggs and are no more similar genetically than non-twin siblings.
frequency
The number of complete wavelengths that pass a point in a given time.
frequency theory
The theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.
frontal lobes
The portion of the cerebral cortex lying just behind the forehead, involved in planning and judgment.
GABA (Gamma-Aminobutyric Acid)
The main inhibitory neurotransmitter in the brain.
Ganglion Cells
Neurons in the retina that relay information from the photoreceptors to the brain.
gate-control theory
The theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on to the brain.
genes
The biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein.
genome
The complete instructions for making an organism, consisting of all the genetic material in that organism’s chromosomes.
glial cells
Cells in the nervous system that support, nourish, and protect neurons, and play a role in learning and thinking.
Glutamate
The main excitatory neurotransmitter in the brain.
gustation
The sense of taste.
Gustav Fechner
A German psychologist known for his work in psychophysics, particularly his development of Weber’s law and the concept of the just noticeable difference.
hallucinations
Perceptions that have no direct external cause, arising from disorders such as schizophrenia, sensory deprivation, or drug-induced states.
hallucinogens
Drugs that alter perception and cause hallucinations or profound distortions in a person’s perceptions of reality.
heredity
The genetic transmission of characteristics from parents to offspring.
Heroin
An opioid drug that produces intense euphoria and pain relief, highly addictive.
hindbrain
The lower part of the brainstem, comprising the medulla, pons, and cerebellum, responsible for basic life functions.
hippocampus
A neural center located in the limbic system that helps process explicit memories for storage.
hormones
Chemical messengers produced by the endocrine glands and circulated in the bloodstream, regulating the activity of target cells or organs.
hue
The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, etc.
hypnagogic sensations
Sensations experienced during the transition from wakefulness to sleep, including hallucinations, muscle jerks, and sensations of falling.
hypothalamus
A neural structure lying below the thalamus, regulating bodily functions such as hunger, thirst, body temperature, and sexual behavior, and controlling the pituitary gland.
identical (monozygotic) twins
Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.
Inhibitory Neurotransmitter
A neurotransmitter that inhibits the firing of neurons.
inner ear
The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs, involved in balance and hearing.
insomnia
Persistent problems falling asleep or staying asleep.
intensity
The amount of energy in a light or sound wave, which we perceive as brightness or loudness.
interneurons
Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.
iris
The colored part of the eye that regulates the size of the pupil by controlling the amount of light entering the eye.
Jet Lag
A temporary sleep disorder that occurs when a person’s internal body clock is out of sync with the time zone they are in.
Just Noticeable Difference (JND)
The minimum difference in stimulation that a person can detect 50% of the time.
kinesthesis
The sense of the body’s position and movement of body parts relative to each other.
lens
The transparent structure behind the pupil that changes shape to help focus images on the retina.
lesion
Damage to body tissue, often caused by disease or injury.
limbic system
A set of structures in the brain, including the amygdala, hypothalamus, and hippocampus, involved in emotion, motivation, and memory.
magnetic resonance imaging (MRI)
A technique that uses magnetic fields and radio waves to produce detailed images of the brain’s soft tissue.
magnetoencephalography (MEG)
A brain imaging technique that measures magnetic fields generated by neuronal activity in the brain.
Marijuana
A drug containing THC that alters mood, perception, and cognitive function.
medulla
The base of the brainstem, controlling heartbeat and breathing.
Michael Gazzaniga
A pioneering neuroscientist known for his split-brain research, which revealed insights into the functional differences between the brain’s hemispheres.
midbrain
A small region of the brainstem involved in auditory and visual processing and regulation of motor movements.
middle ear
The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window.
Monochromatism
Complete color blindness where only shades of grey are perceived, with no ability to distinguish colors.
motor (efferent) neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
motor cortex
An area at the rear of the frontal lobes that controls voluntary movements.
Multiple Sclerosis
A disease in which the immune system attacks the protective covering of nerves, leading to communication problems between the brain and the rest of the body.
mutation
A random error in gene replication that leads to a change.
Myasthenia Gravis
An autoimmune disorder that affects communication between nerves and muscles, leading to muscle weakness.
myelin
A fatty tissue layer that encases the axons of some neurons, speeding up the neural impulses.
narcolepsy
A sleep disorder characterized by uncontrollable sleep attacks, often triggered by strong emotions.
natural selection
The principle that heritable traits that better enable an organism to survive and reproduce in a particular environment will most likely be passed on to succeeding generations.
nature-nurture issue
The debate over the relative contributions of genetic inheritance and environmental factors to human development.
near-death experience
An altered state of consciousness reported after a close brush with death, often including out-of-body experiences and feelings of peace.
Nearsightedness (Myopia)
A condition where close objects are seen clearly, but distant objects are blurry.
nervous system
The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
neurogenesis
The formation of new neurons.
neuron
A nerve cell; the basic building block of the nervous system.
neuroplasticity
The brain’s ability to reorganize itself by forming new neural connections throughout life, particularly in response to learning, experience, or injury.
neurotransmitters
Chemical messengers that transmit signals across the synaptic gap between neurons.
Norepinephrine
A neurotransmitter and hormone involved in arousal and alertness.
NREM sleep
Non-Rapid Eye Movement sleep; the sleep stages characterized by slow brain waves, relaxed muscles, and decreased heart rate and breathing.
occipital lobes
Regions of the cerebral cortex located at the back of the brain, responsible for processing visual information.
Oleogustus
A proposed sixth taste sensation for the taste of fat.
olfaction
The sense of smell.
opioids
A class of drugs that act on opioid receptors to produce morphine-like effects, including pain relief and feelings of euphoria.
opponent-process theory
A theory of color vision proposing that the brain processes color information in pairs of complementary colors (e.g., red-green, blue-yellow).
optic nerve
The bundle of nerve fibers that carries visual information from the retina to the brain.
parallel processing
The brain’s ability to process multiple aspects of a problem or stimulus simultaneously.
parasympathetic nervous system
The division of the autonomic nervous system that calms the body, conserving its energy and promoting rest and digestion.
parietal lobes
Regions of the cerebral cortex located at the top of the brain, responsible for processing sensory information such as touch and spatial awareness.
perception
The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
peripheral nervous system
The sensory and motor neurons that connect the central nervous system to the rest of the body, transmitting information to and from the brain and spinal cord.
Pheromones
Chemicals secreted by animals that influence the behavior or physiology of others of the same species.
pitch
A tone’s experienced highness or lowness; depends on frequency.
Pituitary Gland
The “master gland” of the endocrine system that regulates other glands and controls various bodily functions.
place theory
The theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated.
Plasticity
The brain’s ability to change and adapt as a result of experience.
positron resonance tomography (PET)
A brain imaging technique that measures brain activity by detecting radioactive glucose uptake in active brain areas.
priming
The activation of certain associations, thus predisposing one’s perception, memory, or response.
Prosopagnosia
A neurological disorder characterized by the inability to recognize faces, also known as face blindness.
psychoactive drug
A chemical substance that alters perception, mood, consciousness, cognition, or behavior.
psychophysics
The study of the relationship between physical characteristics of stimuli and our psychological experience of them.
pupil
The adjustable opening in the center of the eye through which light enters.
reflex
A simple, automatic response to a sensory stimulus, such as the knee-jerk reflex.
Reflex Arc
The neural pathway that controls a reflex action.
refractory period
A brief period after a neuron has fired during which it cannot generate another action potential.
REM rebound
The tendency for REM sleep to increase following REM sleep deprivation.
REM sleep
Rapid Eye Movement sleep; a stage of sleep characterized by rapid eye movements, vivid dreams, and muscle paralysis.
REM sleep behavior disorder
A sleep disorder characterized by the acting out of violent or dramatic dreams during REM sleep.
Resting Potential
The electrical charge of a neuron when it is not active.
Reticular Activating System
A network of neurons in the brainstem involved in arousal and attention.
reticular formation
A network of neurons running through the core of the brainstem, involved in controlling arousal and attention.
retina
The light-sensitive inner surface of the eye, containing receptor cells (rods and cones) and layers of neurons that begin the processing of visual information.
reuptake
The reabsorption of neurotransmitters by the sending neuron after they have been released into the synaptic gap.
Reuptake Inhibitors
Medications that block the reabsorption of neurotransmitters into neurons, increasing their levels in the brain.
rods
Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond.
Roger Sperry
A neuropsychologist who won the Nobel Prize for his split-brain research, showing functional differences between the brain’s hemispheres.
Semicircular Canals
Structures in the inner ear involved in maintaining balance and detecting head movements.
sensation
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
sensorineural hearing loss
Hearing loss caused by damage to the cochlea’s hair cells or the auditory nerve.
sensory (afferent) neurons
Neurons that carry incoming information from the sensory receptors to the brain and spinal cord.
sensory adaptation
Diminished sensitivity to an unchanging stimulus over time.
sensory interaction
The principle that one sense may influence another, as when the smell of food influences its taste.
sensory receptors
Specialized cells that detect sensory stimuli and convert them into neural impulses to be sent to the brain.
sequential processing
The processing of one aspect of a stimulus at a time, used when we focus attention on new or complex tasks.
Serotonin
A neurotransmitter that affects mood, appetite, and sleep.
Sigmund Freud
An Austrian neurologist known as the founder of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst.
signal detection theory
A theory predicting how and when we detect the presence of a faint stimulus amid background noise.
sleep
A natural state of rest for the body and mind, characterized by altered consciousness, reduced sensory activity, and inactivity of nearly all voluntary muscles.
sleep apnea
A sleep disorder characterized by pauses in breathing or shallow breaths during sleep, leading to disrupted sleep and daytime fatigue.
somatic nervous system
The division of the peripheral nervous system that controls the body’s skeletal muscles and transmits sensory information to the central nervous system.
somatosensory cortex
A brain region located in the parietal lobe that processes sensory information from the skin and internal body receptors for touch, temperature, and body position.
Somnambulism
A disorder in which a person walks or performs other complex behaviors while asleep.
Sound Localization
The process by which the position of a sound source is determined.
Spinal Cord
The part of the central nervous system that transmits signals between the brain and the rest of the body.
split brain procedure
A surgical procedure that involves severing the corpus callosum, the bundle of nerve fibers connecting the brain’s hemispheres, typically done to treat severe epilepsy.
stimulants
Drugs that excite neural activity and speed up body functions, such as caffeine, nicotine, amphetamines, and cocaine.
subliminal
Below one’s absolute threshold for conscious awareness.
Substance P
A neurotransmitter involved in the transmission of pain signals.
substance use disorder
A condition characterized by continued use of a substance despite significant substance-related problems.
Supertasters
Individuals with heightened sensitivity to all tastes and mouth sensations.
suprachiasmatic nucleus
A tiny region of the hypothalamus that acts as the body’s internal clock, regulating circadian rhythms such as the sleep-wake cycle.
sympathetic nervous system
The division of the autonomic nervous system that mobilizes the body’s resources during stress and emergencies, preparing the body for “fight or flight” responses.
synapse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron, where neurotransmitters are released.
Synesthesia
A condition in which one sense is simultaneously perceived as if by one or more additional senses.
temporal lobes
The regions of the cerebral cortex located above the ears, responsible for processing auditory information and containing areas involved in memory, language comprehension, and emotion.
thalamus
The brain’s sensory control center, located on top of the brainstem, relaying sensory information (except for smell) to the appropriate areas of the cerebral cortex.
threshold
The level of stimulation required to trigger a neural impulse.
tolerance
The diminishing effect of a drug with regular use, requiring larger doses to achieve the same effect.
top-down processing
Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.
Torsten Wiesel
A Swedish neurophysiologist known for his collaborative work with David Hubel, elucidating the visual processing system and its role in perception.
transduction
The process of converting one form of energy into another, such as sensory stimuli into neural impulses.
Umami
One of the five basic tastes, often described as savory or meaty.
vestibular sense
The sense of body movement and position, including the sense of balance.
Visual Accommodation
The process by which the eye’s lens changes shape to focus on objects at different distances.
Visual Cortex
The part of the brain that processes visual information.
Volley Principle
A theory of hearing which states that groups of neurons respond to sound by firing action potentials slightly out of phase with one another.
wavelength
The distance from the peak of one wave to the peak of the next wave, determining the wave’s color (in vision) or pitch (in audition).
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.
Wernicke’s Area
A region in the temporal lobe of the brain associated with language comprehension.
withdrawal
The discomfort and distress that follow discontinuing the use of an addictive drug or behavior.
Young-Helmholtz (Trichromatic) Theory
The theory that the retina contains three different types of color receptors (cones)—red, green, and blue—that can produce any color by combining the three.
