Vocabulary

Absolute threshold: The smallest amount of stimulation needed for detection by a sense.
Action Potential: A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Agnosia: Loss of the ability to perceive stimuli.
Anchoring: The bias to be affected by an initial anchor, even if the anchor is arbitrary, and to insufficiently adjust our judgments away from that anchor.
Anosmia: Loss of the ability to smell.
Anterograde amnesia: Inability to form new memories for facts and events after the onset of amnesia.
Audience design: Constructing utterances to suit the audience’s knowledge.
Audition: Ability to process auditory stimuli. Also called hearing.
Auditory canal: Tube running from the outer ear to the middle ear.
Auditory hair cells: Receptors in the cochlea that transduce sound into electrical potentials.
Autobiographical memory: Memory for the events of one’s life.
Axon: Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Basic-level category: The neutral, preferred category for a given object, at an intermediate level of specificity.
Behaviorism: The study of behavior.
Biases: The systematic and predictable mistakes that influence the judgment of even very talented human beings.
Big-C Creativity: Creative ideas that have an impact well beyond the everyday life of home or work. At the highest level, this kind of creativity is that of the creative genius.
Binocular disparity: Difference is images processed by the left and right eyes.
Binocular vision: Our ability to perceive 3D and depth because of the difference between the images on each of our retinas.
Blood-oxygen-level-dependent (BOLD): The signal typically measured in fMRI that results from changes in the ratio of oxygenated hemoglobin to deoxygenated hemoglobin in the blood.
Bottom-up processing: Building up to perceptual experience from individual pieces.
Bouncing balls illusion: The tendency to perceive two circles as bouncing off each other if the moment of their contact is accompanied by an auditory stimulus.
Bounded awareness: The systematic ways in which we fail to notice obvious and important information that is available to us.
Bounded ethicality: The systematic ways in which our ethics are limited in ways we are not even aware of ourselves.
Bounded rationality: Model of human behavior that suggests that humans try to make rational decisions but are bounded due to cognitive limitations.
Bounded self-interest: The systematic and predictable ways in which we care about the outcomes of others.
Bounded willpower: The tendency to place greater weight on present concerns rather than future concerns.
Brain Stem: The “trunk” of the brain comprised of the medulla, pons, midbrain, and diencephalon.
Broca’s Area: An area in the frontal lobe of the left hemisphere. Implicated in language production.
Category: A set of entities that are equivalent in some way. Usually the items are similar to one another.
Central Nervous System: The portion of the nervous system that includes the brain and spinal cord.
Central nervous system: The part of the nervous system that consists of the brain and spinal cord.
Cerebellum: The distinctive structure at the back of the brain, Latin for “small brain.”
Cerebrum: Usually refers to the cerebral cortex and associated white matter, but in some texts includes the subcortical structures.
Chemical senses: Our ability to process the environmental stimuli of smell and taste.
Chunk: The process of grouping information together using our knowledge.
Chutes and Ladders: A numerical board game that seems to be useful for building numerical knowledge.
Classical conditioning: Describes stimulus-stimulus associative learning.
Cochlea: Spiral bone structure in the inner ear containing auditory hair cells.
Cognitive psychology: The study of mental processes.
Common ground: Information that is shared by people who engage in a conversation.
Concept: The mental representation of a category.
Concrete operations stage: Piagetian stage between ages 7 and 12 when children can think logically about concrete situations but not engage in systematic scientific reasoning.
Cones: Photoreceptors of the retina sensitive to color. Located primarily in the fovea.
Consciousness: Awareness of ourselves and our environment.
Conservation problems: Problems pioneered by Piaget in which physical transformation of an object or set of objects changes a perceptually salient dimension but not the quantity that is being asked about.
Consolidation: The process occurring after encoding that is believed to stabilize memory traces.
Consolidation: Process by which a memory trace is stabilized and transformed into a more durable form.
Continuous development: Ways in which development occurs in a gradual incremental manner, rather than through sudden jumps.
Contralateral: Literally “opposite side”; used to refer to the fact that the two hemispheres of the brain process sensory information and motor commands for the opposite side of the body (e.g., the left hemisphere controls the right side of the body).
Convergent thinking: The opposite of divergent thinking, the capacity to narrow in on the single “correct” answer or solution to a given question or problem (e.g., giving the right response on an intelligence tests).
Corpus Callosum: The thick bundle of nerve cells that connect the two hemispheres of the brain and allow them to communicate.
Crossmodal phenomena: Effects that concern the influence of the perception of one sensory modality on the perception of another.
Crossmodal receptive field: A receptive field that can be stimulated by a stimulus from more than one sensory modality.
Crossmodal stimulus: A stimulus with components in multiple sensory modalties that interact with each other.
Cue overload principle: The principle stating that the more memories that are associated to a particular retrieval cue, the less effective the cue will be in prompting retrieval of any one memory.
Dark adaptation: Adjustment of eye to low levels of light.
Decay: The fading of memories with the passage of time.
Declarative memory: Conscious memories for facts and events.
Dendrites: Part of a neuron that extends away from the cell body and is the main input to the neuron.
Deoxygenated hemoglobin: Hemoglobin not carrying oxygen.
Depolarization: A change in a cell’s membrane potential, making the inside of the cell more positive and increasing the chance of an action potential.
Depth perception: The ability to actively perceive the distance from oneself of objects in the environment.
Dichotic listening: A task in which different audio streams are presented to each ear. Typically, people are asked to monitor one stream while ignoring the other.
Dichotic listening: An experimental task in which two messages are presented to different ears.
Differential threshold (or difference threshold): The smallest difference needed in order to differentiate two stimuli. (See Just Noticeable Difference (JND))
Diffuse Optical Imaging (DOI): A neuroimaging technique that infers brain activity by measuring changes in light as it is passed through the skull and surface of the brain.
Discontinuous development: Discontinuous development
Dissociative amnesia: Loss of autobiographical memories from a period in the past in the absence of brain injury or disease.
Distinctiveness: The principle that unusual events (in a context of similar events) will be recalled and recognized better than uniform (nondistinctive) events.
Divergent thinking: The opposite of convergent thinking, the capacity for exploring multiple potential answers or solutions to a given question or problem (e.g., coming up with many different uses for a common object).
Divided attention: The ability to flexibly allocate attentional resources between two or more concurrent tasks.
Dorsal pathway: Pathway of visual processing. The “where” pathway.
Double flash illusion: The false perception of two visual flashes when a single flash is accompanied by two auditory beeps.
Electroencephalography (EEG): A neuroimaging technique that measures electrical brain activity via multiple electrodes on the scalp.
Empiricism: The belief that knowledge comes from experience.
Encoding: The pact of putting information into memory.
Encoding: The initial experience of perceiving and learning events.
Encoding: Process by which information gets into memory.
Encoding specificity principle: The hypothesis that a retrieval cue will be effective to the extent that information encoded from the cue overlaps or matches information in the engram or memory trace.
Engrams: A term indicating the change in the nervous system representing an event; also, memory trace.
Episodic memory: Memory for events in a particular time and place.
Eugenics: The practice of selective breeding to promote desired traits.
Exemplar: An example in memory that is labeled as being in a particular category.
False memories: Memory for an event that never actually occurred, implanted by experimental manipulation or other means.
Flashbulb memory: Vivid personal memories of receiving the news of some momentous (and usually emotional) event.
Flashbulb memory: A highly detailed and vivid memory of an emotionally significant event.
Flavor: The combination of smell and taste.
Foils: Any member of a lineup (whether live or photograph) other than the suspect.
Formal operations stage: Piagetian stage starting at age 12 years and continuing for the rest of life, in which adolescents may gain the reasoning powers of educated adults.
Framing: The bias to be systematically affected by the way in which information is presented, while holding the objective information constant.
Frontal Lobe: The front most (anterior) part of the cerebrum; anterior to the central sulcus and responsible for motor output and planning, language, judgment, and decision-making.
Functional Magnetic Resonance Imaging (fMRI): Functional magnetic resonance imaging (fMRI): A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood.
Functionalism: A school of American psychology that focused on the utility of consciousness.
g or general mental ability: The general factor common to all cognitive ability measures, “a very general mental capacity that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings—‘catching on,’ ‘making sense of things,’ or ‘figuring out’ what to do” (Gottfredson, 1997, p. 13).
Gestalt psychology: An attempt to study the unity of experience.
Gustation: Ability to process gustatory stimuli. Also called taste.
Habituation: Occurs when the response to a stimulus decreases with exposure.
Hemoglobin: The oxygen-carrying portion of a red blood cell.
Heuristics: cognitive (or thinking) strategies that simplify decision making by using mental short-cuts
Hyperpolarization: A change in a cell’s membrane potential, making the inside of the cell more negative and decreasing the chance of an action potential.
Implicit learning: Occurs when we acquire information without intent that we cannot easily express.
Implicit memory: A type of long-term memory that does not require conscious thought to encode. It's the type of memory one makes without intent.
Inattentional blindness: The failure to notice a fully visible, but unexpected, object or event when attention is devoted to something else.
Inattentional blindness: The failure to notice a fully visible object when attention is devoted to something else.
Inattentional deafness: The auditory analog of inattentional blindness. People fail to notice an unexpected sound or voice when attention is devoted to other aspects of a scene.
Incidental learning: Any type of learning that happens without the intention to learn.
Individual differences: Ways in which people differ in terms of their behavior, emotion, cognition, and development.
Information processing theories: Theories that focus on describing the cognitive processes that underlie thinking at any one age and cognitive growth over time.
Ingroup: Group to which a person belongs.
Integrated: The process by which the perceptual system combines information arising from more than one modality.
Intentional learning: Any type of learning that happens when motivated by intention.
Interference: Other memories get in the way of retrieving a desired memory
Introspection: A method of focusing on internal processes.
Invasive Procedure: A procedure that involves the skin being broken or an instrument or chemical being introduced into a body cavity.
Just noticeable difference (JND): The smallest difference needed in order to differentiate two stimuli. (see Differential Threshold)
Latent inhibition: The ability to filter out extraneous stimuli, concentrating only on the information that is deemed relevant. Reduced latent inhibition is associated with higher creativity.
Lesions: Abnormalities in the tissue of an organism usually caused by disease or trauma.
Lexicon: Words and expressions.
Light adaptation: Adjustment of eye to high levels of light.
Limbic System: Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Limited capacity: The notion that humans have limited mental resources that can be used at a given time.
Linguistic intergroup bias: A tendency for people to characterize positive things about their ingroup using more abstract expressions, but negative things about their outgroups using more abstract expressions.
Little-c creativity: Creative ideas that appear at the personal level, whether the home or the workplace. Such creativity needs not have a larger impact to be considered creative.
McGurk effect: An effect in which conflicting visual and auditory components of a speech stimulus result in an illusory percept.
Mechanoreceptors: Mechanical sensory receptors in the skin that response to tactile stimulation.
Medial temporal lobes: Inner region of the temporal lobes that includes the hippocampus.
Memory traces: A term indicating the change in the nervous system representing an event.
Metacognition: Describes the knowledge and skills people have in monitoring and controlling their own learning and memory.
Misinformation effect: A memory error caused by exposure to incorrect information between the original event (e.g., a crime) and later memory test (e.g., an interview, lineup, or day in court).
Misinformation effect: When erroneous information occurring after an event is remembered as having been part of the original event.
Mnemonic devices: A strategy for remembering large amounts of information, usually involving imaging events occurring on a journey or with some other set of memorized cues.
Mock witnesses: A research subject who plays the part of a witness in a study.
Multicultural experiences: Individual exposure to two or more cultures, such as obtained by living abroad, emigrating to another country, or working or going to school in a culturally diverse setting.
Multimodal: Of or pertaining to multiple sensory modalities.
Multimodal perception: The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
Multimodal perception: The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
Multimodal phenomena: Effects that concern the binding of inputs from multiple sensory modalities.
Multisensory convergence zones: Regions in the brain that receive input from multiple unimodal areas processing different sensory modalities.
Multisensory enhancement: See “superadditive effect of multisensory integration.”
Myelin Sheath: Fatty tissue, that insulates the axons of the neurons; myelin is necessary for normal conduction of electrical impulses among neurons.
Nature: The genes that children bring with them to life and that influence all aspects of their development.
Nervous System: The body’s network for electrochemical communication. This system includes all the nerves cells in the body.
Neural impulse: An electro-chemical signal that enables neurons to communicate.
Neural plasticity: The ability of synapses and neural pathways to change over time and adapt to changes in neural process, behavior, or environment.
Neurons: Individual brain cells
Neuroscience methods: A research method that deals with the structure or function of the nervous system and brain.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Nociception: Our ability to sense pain.
Nonassociative learning: Occurs when a single repeated exposure leads to a change in behavior.
Noninvasive procedure: A procedure that does not require the insertion of an instrument or chemical through the skin or into a body cavity.
Numerical magnitudes: The sizes of numbers.
Nurture: The environments, starting with the womb, that influence all aspects of children’s development.
Object permanence task: The Piagetian task in which infants below about 9 months of age fail to search for an object that is removed from their sight and, if not allowed to search immediately for the object, act as if they do not know that it continues to exist.
Occipital Lobe: The back most (posterior) part of the cerebrum; involved in vision.
Odorants: Chemicals transduced by olfactory receptors.
Olfaction: Ability to process olfactory stimuli. Also called smell.
Olfactory epithelium: Organ containing olfactory receptors.
Openness to experience: One of the factors of the Big Five Model of personality, the factor assesses the degree that a person is open to different or new values, interests, and activities.
Operant conditioning: Describes stimulus-response associative learning.
Opponent-process theory: Theory proposing color vision as influenced by cells responsive to pairs of colors.
Originality: When an idea or solution has a low probability of occurrence.
Ossicles: A collection of three small bones in the middle ear that vibrate against the tympanic membrane.
Outgroup: Group to which a person does not belong.
Overconfident: The bias to have greater confidence in your judgment than is warranted based on a rational assessment.
Oxygenated hemoglobin: Hemoglobin carrying oxygen.
Parasympathetic nervous system (PNS): One of the two major divisions of the autonomic nervous system, responsible for stimulation of “rest and digest” activities.
Parietal Lobe: The part of the cerebrum between the frontal and occipital lobes; involved in bodily sensations, visual attention, and integrating the senses.
Perception: The psychological process of interpreting sensory information.
Perceptual learning: Occurs when aspects of our perception changes as a function of experience.
Peripheral Nervous System: All of the nerve cells that connect the central nervous system to all the other parts of the body.
Peripheral nervous system: The part of the nervous system that is outside the brain and spinal cord.
Phantom limb: The perception that a missing limb still exists.
Phantom limb pain: Pain in a limb that no longer exists.
Phonemic awareness: Awareness of the component sounds within words.
Photo spreads: A selection of normally small photographs of faces given to a witness for the purpose of identifying a perpetrator.
Piaget’s theory: Theory that development occurs through a sequence of discontinuous stages: the sensorimotor, preoperational, concrete operational, and formal operational stages.
Pinna: Outermost portion of the ear.
Positron: A particle having the same mass and numerically equal but positive charge as an electron.
Positron Emission Tomography (PET): A neuroimaging technique that measures brain activity by detecting the presence of a radioactive substance in the brain that is initially injected into the bloodstream and then pulled in by active brain tissue.
Practitioner-Scholar Model: A model of training of professional psychologists that emphasizes clinical practice.
Preoperational reasoning stage: Period within Piagetian theory from age 2 to 7 years, in which children can represent objects through drawing and language but cannot solve logical reasoning problems, such as the conservation problems.
Primary auditory cortex: Area of the cortex involved in processing auditory stimuli.
Primary auditory cortex: A region of the cortex devoted to the processing of simple auditory information.
Primary somatosensory cortex: Area of the cortex involved in processing somatosensory stimuli.
Primary visual cortex: Area of the cortex involved in processing visual stimuli.
Primary visual cortex: A region of the cortex devoted to the processing of simple visual information.
Priming: A stimulus presented to a person reminds him or her about other ideas associated with the stimulus.
Principle of inverse effectiveness: The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large. However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.
Principle of Inverse Effectiveness: The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large. However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.
Psychological essentialism: The belief that members of a category have an unseen property that causes them to be in the category and to have the properties associated with it.
Psychophysics: Study of the relationships between physical stimuli and the perception of those stimuli.
Psychophysiological methods: Any research method in which the dependent variable is a physiological measure and the independent variable is behavioral or mental (such as memory).
Qualitative changes: Large, fundamental change, as when a caterpillar changes into a butterfly; stage theories such as Piaget’s posit that each stage reflects qualitative change relative to previous stages.
Quantitative changes: Gradual, incremental change, as in the growth of a pine tree’s girth.
Realism: A point of view that emphasizes the importance of the senses in providing knowledge of the external world.
Receptive field: The portion of the world to which a neuron will respond if an appropriate stimulus is present there.
Recoding: The ubiquitous process during learning of taking information in one form and converting it to another form, usually one more easily remembered.
Remote associations: Associations between words or concepts that are semantically distant and thus relatively unusual or original.
Retina: Cell layer in the back of the eye containing photoreceptors.
Retrieval: Process by which information is accessed from memory and utilized.
Retrieval: The process of accessing stored information.
Retroactive interference: The phenomenon whereby events that occur after some particular event of interest will usually cause forgetting of the original event.
Retrograde amnesia: Inability to retrieve memories for facts and events acquired before the onset of amnesia.
Rods: Photoreceptors of the retina sensitive to low levels of light. Located around the fovea.
Rubber hand illusion: The false perception of a fake hand as belonging to a perceiver, due to multimodal sensory information.
Sapir-Whorf hypothesis: The hypothesis that the language that people use determines their thoughts.
Satisfaction: Correspondence between an individual’s needs or preferences and the rewards offered by the environment.
Satisfactoriness: Correspondence between an individual’s abilities and the ability requirements of the environment.
Schema (plural: schemata): A memory template, created through repeated exposure to a particular class of objects or events.
Scientist-practitioner model: A model of training of professional psychologists that emphasizes the development of both research and clinical skills.
Selective attention: The ability to select certain stimuli in the environment to process, while ignoring distracting information.
Selective listening: A method for studying selective attention in which people focus attention on one auditory stream of information while deliberately ignoring other auditory information.
Semantic memory: The more or less permanent store of knowledge that people have.
Sensation: The physical processing of environmental stimuli by the sense organs.
Sensitization: Occurs when the response to a stimulus increases with exposure
Sensorimotor stage: Period within Piagetian theory from birth to age 2 years, during which children come to represent the enduring reality of objects.
Sensory adaptation: Decrease in sensitivity of a receptor to a stimulus after constant stimulation.
Sensory modalities: A type of sense; for example, vision or audition.
Shadowing: A task in which the individual is asked to repeat an auditory message as it is presented.
Shape theory of olfaction: Theory proposing that odorants of different size and shape correspond to different smells.
Signal detection: Method for studying the ability to correctly identify sensory stimuli.
Situation model: A mental representation of an event, object, or situation constructed at the time of comprehending a linguistic description.
Social brain hypothesis: The hypothesis that the human brain has evolved, so that humans can maintain larger ingroups.
Social networks: Networks of social relationships among individuals through which information can travel.
Sociocultural theories: Theory founded in large part by Lev Vygotsky that emphasizes how other people and the attitudes, values, and beliefs of the surrounding culture influence children’s development.
Soma: Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
Somatosensation: Ability to sense touch, pain and temperature.
Somatotopic map: Organization of the primary somatosensory cortex maintaining a representation of the arrangement of the body.
Sound waves: Changes in air pressure. The physical stimulus for audition.
Spatial principle of multisensory integration: The finding that the superadditive effects of multisensory integration are observed when the sources of stimulation are spatially related to one another.
Spatial resolution: The degree to which one can separate a single object in space from another.
Spatial Resolution: A term that refers to how small the elements of an image are; high spatial resolution means the device or technique can resolve very small elements; in neuroscience it describes how small of a structure in the brain can be imaged.
Specific abilities: Cognitive abilities that contain an appreciable component of g or general ability, but also contain a large component of a more content-focused talent such as mathematical, spatial, or verbal ability; patterns of specific abilities channel development down different paths as a function of an individual’s relative strengths and weaknesses.
Split-brain Patient: A patient who has had most or all of his or her corpus callosum severed.
Storage: The stage in the learning/memory process that bridges encoding and retrieval; the persistence of memory over time.
Structuralism: A school of American psychology that sought to describe the elements of conscious experience.
Subliminal perception: The ability to process information for meaning when the individual is not consciously aware of that information.
Superadditive effect of multisensory integration: The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
Superadditive effect of multisensory integration: The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
Sympathetic nervous system (SNS): One of the two major divisions of the autonomic nervous system, responsible for stimulation of “fight or flight” activities.
Synapses: Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Synaptic Gap: Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.
Syntax: Rules by which words are strung together to form sentences.
System 1: Our intuitive decision-making system, which is typically fast, automatic, effortless, implicit, and emotional.
System 2: Our more deliberative decision-making system, which is slower, conscious, effortful, explicit, and logical.
Tastants: Chemicals transduced by taste receptor cells.
Taste receptor cells: Receptors that transduce gustatory information.
Temporal Lobe: The part of the cerebrum in front of (anterior to) the occipital lobe and below the lateral fissure; involved in vision, auditory processing, memory, and integrating vision and audition.
Temporal Resolution: A term that refers to how small a unit of time can be measured; high temporal resolution means capable of resolving very small units of time; in neuroscience it describes how precisely in time a process can be measured in the brain.
Temporal resolution: The degree to which one can separate a single point in time from another.
Temporally graded retrograde amnesia: Inability to retrieve memories from just prior to the onset of amnesia with intact memory for more remote events.
Tip-of-the-tongue phenomenon: The inability to pull a word from memory even though there is the sensation that that word is available.
Top-down processing: Experience influencing the perception of stimuli.
Transduction: The conversion of one form of energy into another.
Transfer-appropriate processing: A principle that states that memory performance is superior when a test taps the same cognitive processes as the original encoding activity.
Trichromatic theory: Theory proposing color vision as influenced by three different cones responding preferentially to red, green and blue.
Tympanic membrane: Thin, stretched membrane in the middle ear that vibrates in response to sound. Also called the eardrum.
Typicality: The difference in “goodness” of category members, ranging from the most typical (the prototype) to borderline members.
Under-determined or misspecified causal models: Psychological frameworks that miss or neglect to include one or more of the critical determinants of the phenomenon under analysis.
Unimodal: Of or pertaining to a single sensory modality.
Unimodal components: The parts of a stimulus relevant to one sensory modality at a time.
Unimodal cortex: A region of the brain devoted to the processing of information from a single sensory modality.
Unusual uses: A test of divergent thinking that asks participants to find many uses for commonplace objects, such as a brick or paperclip.
Ventral pathway: Pathway of visual processing. The “what” pathway.
Vestibular system: Parts of the inner ear involved in balance.
Voltage: The difference in electric charge between two points.
Weber’s law: States that just noticeable difference is proportional to the magnitude of the initial stimulus.
Working memory: The form of memory we use to hold onto information temporarily, usually for the purposes of manipulation.