Absolute threshold
The minimum level of stimulus intensity needed for a stimulus to be detected.
Accommodation of the lens
The process by which the eye's lens changes shape to focus on near or distant objects.
Action potential
A rapid rise and fall in voltage or membrane potential across a cellular membrane.
Activation-synthesis theory for dreaming
A theory suggesting that dreams are the brain's attempt to make sense of random neural activity during sleep.
Adaptations
Changes in behavior or physiology that enhance an organism's ability to survive in its environment.
Addiction
A psychological or physical dependence on a substance or behavior.
Afterimages
Visual sensations that remain after the original stimulus has been removed.
Agonists vs antagonists
Agonists are substances that activate receptors, while antagonists block receptor activity.
All-or-nothing principle
The principle that a neuron either fires completely or not at all.
Amygdala
A brain structure involved in emotion regulation and processing, particularly fear and pleasure.
Association areas
Regions of the cerebral cortex that integrate sensory information and are involved in higher mental functions.
Autonomic nervous system
The part of the nervous system that controls involuntary bodily functions.
Autopsy
A postmortem examination to determine the cause of death or study disease effects.
Axon
The long, slender projection of a neuron that conducts electrical impulses away from the cell body.
Blind spot
The area of the retina where the optic nerve exits the eye, lacking photoreceptors.
Blindsight
A condition in which a person can respond to visual stimuli without consciously perceiving them.
Brain imaging techniques
Methods such as EEG, PET, CAT, MRI, and fMRI used to visualize brain activity and structure.
Brain lateralization
The specialization of the left and right hemispheres of the brain for different functions.
Brain waves
Electrical impulses in the brain categorized into alpha, beta, delta, and theta waves.
Brainstem
The part of the brain that connects the brain to the spinal cord and controls basic life functions.
Broca’s area
A region in the left frontal lobe associated with speech production
Central nervous system
The part of the nervous system consisting of the brain and spinal cord.
Cerebellum
A brain structure that coordinates voluntary movements and maintains posture and balance.
Cerebral cortex
The outer layer of the brain involved in complex functions such as thought and action.
Cerebrum
The largest part of the brain, responsible for higher brain functions, including thought and action.
Circadian rhythm
The natural, internal process that regulates the sleep-wake cycle and other bodily functions.
Confederate
An individual who is part of a research study but acts as a participant to manipulate social situations.
Consciousness
The state of being aware of and able to think about one's own existence, thoughts, and surroundings.
Contralaterality
The concept that each hemisphere of the brain controls the opposite side of the body.
Corpus callosum
The bundle of nerve fibers connecting the left and right hemispheres of the brain.
Cortical areas of the brain
Regions of the cerebral cortex responsible for various sensory and cognitive functions.
Debriefing
The process of informing participants about the nature of a study after it has concluded.
Deception
The act of misleading participants about the true purpose of a study in research.
Deep sleep
A stage of sleep characterized by slow brain waves and minimal responsiveness to external stimuli.
Dendrites
The branching extensions of a neuron that receive signals from other neurons.
Depolarization
The process by which a neuron's membrane potential becomes less negative, leading to an action potential.
Depressants
Substances that reduce neural activity and slow body functions.
Dichromatism and monochromatism
Types of color vision deficiencies; dichromatism involves two color receptors, while monochromatism involves one.
Disorders related to sleep
Conditions such as insomnia, narcolepsy, REM sleep behavior disorder, sleep apnea, and somnambulism.
Drug tolerance
A condition in which a person requires more of a drug to achieve the same effect due to repeated use.
Drug withdrawal
Symptoms that occur when a person stops using a drug they are dependent on.
Dual processing
The principle that information is often processed simultaneously on separate conscious and unconscious tracks.
Effects of sleep deprivation
Negative impacts on cognitive function, mood, and physical health due to lack of sleep.
Electrochemical reaction
The process by which neurons communicate through electrical impulses and chemical signals.
Endocrine system
A collection of glands that produce hormones to regulate various bodily functions.
Epigenetics
The study of changes in gene expression that do not involve alterations to the underlying DNA sequence.
Eugenics
A controversial movement aimed at improving the genetic quality of a human population.
Evolutionary perspective
A viewpoint that explains psychological traits as adaptations that have evolved over time.
Excitatory and inhibitory postsynaptic potential
Changes in the postsynaptic membrane potential that can either increase or decrease the likelihood of a neuron firing.
Fight-or-flight
A physiological response to perceived harmful events, attacks, or threats, preparing the body to either confront or flee from danger.
Forebrain
The largest part of the brain, responsible for complex behaviors, emotions, and cognitive functions.
Fovea
The central region of the retina responsible for sharp central vision.
Ganglion cells
Neurons located in the retina that transmit visual information from the photoreceptors to the brain.
Gate control theory of pain
A theory suggesting that the perception of pain is controlled by a "gate" mechanism in the spinal cord.
Generalizable and generalizability
The extent to which findings from a study can be applied to broader populations or settings.
Glands
Organs that secrete hormones or other substances into the bloodstream or onto surfaces.
Glial cells
Supportive cells in the nervous system that assist neurons in various functions.
Gustation
The sense of taste, which allows the detection of different flavors.
Hallucinogens
Substances that cause alterations in perception, mood, and cognitive processes.
Hemispheric specialization
The idea that the two hemispheres of the brain have different functions and processes.
Heredity and heritability
The genetic transmission of traits from parents to offspring and the proportion of variation in a trait attributable to genetic factors.
Hindbrain
The lower part of the brain that controls basic life functions such as breathing and heart rate.
Hippocampus
A brain structure involved in memory formation and spatial navigation.
Homeostasis
The process by which biological systems maintain stability while adjusting to changing external conditions.
Hormones
Chemical messengers in the body, including adrenaline, leptin, ghrelin, melatonin, and oxytocin, that regulate various physiological processes.
Hyperpolarization
An increase in a cell's membrane potential, making it more negative and less likely to fire.
Hypothalamus and the 4Fs
A brain region involved in regulating hunger, thirst, temperature, and sexual behavior (the four Fs).
Independent variable
The variable that is manipulated in an experiment.
Informed consent
The process of obtaining permission from participants before an experiment, ensuring they understand the study's purpose and risks.
Interneurons
Neurons that connect other neurons within the central nervous system.
Ions
Charged particles that play a crucial role in neural signaling and cellular functions.
Just-noticeable difference
The smallest difference in stimulation that can be detected 50% of the time.
K complex
A large wave pattern observed in sleep that may be related to the brain's response to external stimuli.
Kinesthesis
The sense of body position and movement, allowing awareness of body parts' locations.
Left and right hemispheres of the brain
The two halves of the brain, each responsible for different cognitive and motor functions.
Lesioning
The process of damaging specific brain areas to study their functions.
Limbic system
A group of structures in the brain involved in emotion, memory, and motivation.
Lobes
The four main divisions of the brain:frontal, parietal, occipital, and temporal, each with distinct functions.
Long-term potentiation
A long-lasting increase in synaptic strength, believed to be a mechanism for learning and memory.
Measures of central tendency
Statistical measures that summarize a set of data, including mean, median, and mode.
Measures of variability
Statistical measures that describe the spread of data, including range and standard deviation.
Medulla
The part of the brainstem that controls vital functions such as heart rate and breathing.
Melatonin
A hormone that regulates sleep-wake cycles.
Microsleep
Brief episodes of sleep that occur when a person is normally awake.
Midbrain
A portion of the brain involved in vision, hearing, and motor control.
Mirror neurons
Neurons that fire both when an individual performs an action and when they observe the same action performed by another.
Mitochondria:
This organelle is responsible for converting nutrients into energy, playing a crucial role in cellular respiration. It has its own DNA and is involved in various metabolic processes.
Endocrine system
A collection of glands that produce hormones to regulate various bodily functions.
Epigenetics
The study of changes in gene expression that do not involve alterations to the underlying DNA sequence.
Eugenics
A controversial movement aimed at improving the genetic quality of a human population.
Evolutionary perspective
A viewpoint that explains psychological traits as adaptations that have evolved over time.
Excitatory and inhibitory postsynaptic potential
Changes in the postsynaptic membrane potential that can either increase or decrease the likelihood of a neuron firing.
Fight-or-flight
A physiological response to perceived harmful events, attacks, or threats, preparing the body to either confront or flee from danger.
Forebrain
The largest part of the brain, responsible for complex behaviors, emotions, and cognitive functions.
Fovea
The central region of the retina responsible for sharp central vision.
Ganglion cells
Neurons located in the retina that transmit visual information from the photoreceptors to the brain.
Gate control theory of pain
A theory suggesting that the perception of pain is controlled by a "gate" mechanism in the spinal cord.
Generalizable and generalizability
The extent to which findings from a study can be applied to broader populations or settings.
Glands
Organs that secrete hormones or other substances into the bloodstream or onto surfaces.
Glial cells
Supportive cells in the nervous system that assist neurons in various functions.