Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Attention Deficit Disorder with Hyperactivity: A behavior disorder originating in childhood in which the essential features are signs of developmentally inappropriate inattention, impulsivity, and hyperactivity. Although most individuals have symptoms of both inattention and hyperactivity-impulsivity, one or the other pattern may be predominant. The disorder is more frequent in males than females. Onset is in childhood. Symptoms often attenuate during late adolescence although a minority experience the full complement of symptoms into mid-adulthood. (From DSM-V)Reaction Time: The time from the onset of a stimulus until a response is observed.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Space Perception: The awareness of the spatial properties of objects; includes physical space.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Fixation, Ocular: The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Orientation: Awareness of oneself in relation to time, place and person.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Cognition: Intellectual or mental process whereby an organism obtains knowledge.Parietal Lobe: Upper central part of the cerebral hemisphere. It is located posterior to central sulcus, anterior to the OCCIPITAL LOBE, and superior to the TEMPORAL LOBES.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Discrimination (Psychology): Differential response to different stimuli.Eye Movements: Voluntary or reflex-controlled movements of the eye.Memory, Short-Term: Remembrance of information for a few seconds to hours.Visual Cortex: Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Psychophysics: The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.Methylphenidate: A central nervous system stimulant used most commonly in the treatment of ATTENTION DEFICIT DISORDER in children and for NARCOLEPSY. Its mechanisms appear to be similar to those of DEXTROAMPHETAMINE. The d-isomer of this drug is referred to as DEXMETHYLPHENIDATE HYDROCHLORIDE.Evoked Potentials, Visual: The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways.Task Performance and Analysis: The detailed examination of observable activity or behavior associated with the execution or completion of a required function or unit of work.Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Executive Function: A set of cognitive functions that controls complex, goal-directed thought and behavior. Executive function involves multiple domains, such as CONCEPT FORMATION, goal management, cognitive flexibility, INHIBITION control, and WORKING MEMORY. Impaired executive function is seen in a range of disorders, e.g., SCHIZOPHRENIA; and ADHD.Cognition Disorders: Disturbances in mental processes related to learning, thinking, reasoning, and judgment.Field Dependence-Independence: The ability to respond to segments of the perceptual experience rather than to the whole.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Color Perception: Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Auditory Perception: The process whereby auditory stimuli are selected, organized, and interpreted by the organism.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Saccades: An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Inhibition (Psychology): The interference with or prevention of a behavioral or verbal response even though the stimulus for that response is present; in psychoanalysis the unconscious restraining of an instinctual process.Memory: Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.Emotions: Those affective states which can be experienced and have arousing and motivational properties.Motion Perception: The real or apparent movement of objects through the visual field.Eye Movement Measurements: Methods and procedures for recording EYE MOVEMENTS.Signal Detection, Psychological: Psychophysical technique that permits the estimation of the bias of the observer as well as detectability of the signal (i.e., stimulus) in any sensory modality. (From APA, Thesaurus of Psychological Index Terms, 8th ed.)Mental Processes: Conceptual functions or thinking in all its forms.Behavior: The observable response of a man or animal to a situation.Models, Psychological: Theoretical representations that simulate psychological processes and/or social processes. These include the use of mathematical equations, computers, and other electronic equipment.Awareness: The act of "taking account" of an object or state of affairs. It does not imply assessment of, nor attention to the qualities or nature of the object.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Contrast Sensitivity: The ability to detect sharp boundaries (stimuli) and to detect slight changes in luminance at regions without distinct contours. Psychophysical measurements of this visual function are used to evaluate visual acuity and to detect eye disease.Facial Expression: Observable changes of expression in the face in response to emotional stimuli.Perceptual Disorders: Cognitive disorders characterized by an impaired ability to perceive the nature of objects or concepts through use of the sense organs. These include spatial neglect syndromes, where an individual does not attend to visual, auditory, or sensory stimuli presented from one side of the body.Perceptual Masking: The interference of one perceptual stimulus with another causing a decrease or lessening in perceptual effectiveness.Frontal Lobe: The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.Central Nervous System Stimulants: A loosely defined group of drugs that tend to increase behavioral alertness, agitation, or excitation. They work by a variety of mechanisms, but usually not by direct excitation of neurons. The many drugs that have such actions as side effects to their main therapeutic use are not included here.Nerve Net: A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.Prefrontal Cortex: The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical afferents of visual, auditory, and somatic origin.Form Perception: The sensory discrimination of a pattern shape or outline.Attentional Blink: Temporary visual deficit or impaired visual processing occurring in a rapid serial visual presentation task. After a person identifies the first of two visual targets, the ability to detect the second target is impaired for the next few hundred milliseconds. This phenomenon is called attentional blink.Discrimination Learning: Learning that is manifested in the ability to respond differentially to various stimuli.Visual Pathways: Set of cell bodies and nerve fibers conducting impulses from the eyes to the cerebral cortex. It includes the RETINA; OPTIC NERVE; optic tract; and geniculocalcarine tract.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Choice Behavior: The act of making a selection among two or more alternatives, usually after a period of deliberation.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Event-Related Potentials, P300: A late-appearing component of the event-related potential. P300 stands for a positive deflection in the event-related voltage potential at 300 millisecond poststimulus. Its amplitude increases with unpredictable, unlikely, or highly significant stimuli and thereby constitutes an index of mental activity. (From Campbell, Psychiatric Dictionary, 6th ed)Face: The anterior portion of the head that includes the skin, muscles, and structures of the forehead, eyes, nose, mouth, cheeks, and jaw.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Neural Pathways: Neural tracts connecting one part of the nervous system with another.Learning Disorders: Conditions characterized by a significant discrepancy between an individual's perceived level of intellect and their ability to acquire new language and other cognitive skills. These disorders may result from organic or psychological conditions. Relatively common subtypes include DYSLEXIA, DYSCALCULIA, and DYSGRAPHIA.Social Behavior: Any behavior caused by or affecting another individual, usually of the same species.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Occipital Lobe: Posterior portion of the CEREBRAL HEMISPHERES responsible for processing visual sensory information. It is located posterior to the parieto-occipital sulcus and extends to the preoccipital notch.United StatesPlay and Playthings: Spontaneous or voluntary recreational activities pursued for enjoyment and accessories or equipment used in the activities; includes games, toys, etc.Gyrus Cinguli: One of the convolutions on the medial surface of the CEREBRAL HEMISPHERES. It surrounds the rostral part of the brain and CORPUS CALLOSUM and forms part of the LIMBIC SYSTEM.Dichotic Listening Tests: Tests for central hearing disorders based on the competing message technique (binaural separation).Schizophrenia: A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.Autistic Disorder: A disorder beginning in childhood. It is marked by the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activity and interest. Manifestations of the disorder vary greatly depending on the developmental level and chronological age of the individual. (DSM-V)Stroop Test: Timed test in which the subject must read a list of words or identify colors presented with varying instructions and different degrees of distraction. (Campbell's Psychiatric Dictionary. 8th ed.)Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Vision, Ocular: The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Child Development: The continuous sequential physiological and psychological maturing of an individual from birth up to but not including ADOLESCENCE.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Magnetoencephalography: The measurement of magnetic fields over the head generated by electric currents in the brain. As in any electrical conductor, electric fields in the brain are accompanied by orthogonal magnetic fields. The measurement of these fields provides information about the localization of brain activity which is complementary to that provided by ELECTROENCEPHALOGRAPHY. Magnetoencephalography may be used alone or together with electroencephalography, for measurement of spontaneous or evoked activity, and for research or clinical purposes.Dominance, Cerebral: Dominance of one cerebral hemisphere over the other in cerebral functions.Recognition (Psychology): The knowledge or perception that someone or something present has been previously encountered.Set (Psychology): Readiness to think or respond in a predetermined way when confronted with a problem or stimulus situation.Psychiatric Status Rating Scales: Standardized procedures utilizing rating scales or interview schedules carried out by health personnel for evaluating the degree of mental illness.Subliminal Stimulation: Stimulation at an intensity below that where a differentiated response can be elicited.Schizophrenic Psychology: Study of mental processes and behavior of schizophrenics.Affect: The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves.Mental Recall: The process whereby a representation of past experience is elicited.Intelligence: The ability to learn and to deal with new situations and to deal effectively with tasks involving abstractions.Figural Aftereffect: A perceptual phenomenon used by Gestalt psychologists to demonstrate that events in one part of the perceptual field may affect perception in another part.Evoked Potentials, Auditory: The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.Child Behavior: Any observable response or action of a child from 24 months through 12 years of age. For neonates or children younger than 24 months, INFANT BEHAVIOR is available.Individuality: Those psychological characteristics which differentiate individuals from one another.Social Perception: The perceiving of attributes, characteristics, and behaviors of one's associates or social groups.Impulsive Behavior: An act performed without delay, reflection, voluntary direction or obvious control in response to a stimulus.Contingent Negative Variation: A negative shift of the cortical electrical potentials that increases over time. It is associated with an anticipated response to an expected stimulus and is an electrical event indicative of a state of readiness or expectancy.Alpha Rhythm: Brain waves characterized by a relatively high voltage or amplitude and a frequency of 8-13 Hz. They constitute the majority of waves recorded by EEG registering the activity of the parietal and occipital lobes when the individual is awake, but relaxed with the eyes closed.Spatial Behavior: Reactions of an individual or groups of individuals with relation to the immediate surrounding area including the animate or inanimate objects within that area.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Personality Tests: Standardized objective tests designed to facilitate the evaluation of personality.Anticipation, Psychological: The ability to foresee what is likely to happen on the basis of past experience. It is largely a frontal lobe function.ReadingPsychometrics: Assessment of psychological variables by the application of mathematical procedures.Time Perception: The ability to estimate periods of time lapsed or duration of time.Anxiety: Feeling or emotion of dread, apprehension, and impending disaster but not disabling as with ANXIETY DISORDERS.Practice (Psychology): Performance of an act one or more times, with a view to its fixation or improvement; any performance of an act or behavior that leads to learning.Intelligence Tests: Standardized tests that measure the present general ability or aptitude for intellectual performance.Electrooculography: Recording of the average amplitude of the resting potential arising between the cornea and the retina in light and dark adaptation as the eyes turn a standard distance to the right and the left. The increase in potential with light adaptation is used to evaluate the condition of the retinal pigment epithelium.Reinforcement, Social: The strengthening of a response with a social reward such as a nod of approval, a parent's love or attention.Child Behavior Disorders: Disturbances considered to be pathological based on age and stage appropriateness, e.g., conduct disturbances and anaclitic depression. This concept does not include psychoneuroses, psychoses, or personality disorders with fixed patterns.Temporal Lobe: Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the OCCIPITAL LOBE.Social Control, Informal: Those forms of control which are exerted in less concrete and tangible ways, as through folkways, mores, conventions, and public sentiment.Behavior, Animal: The observable response an animal makes to any situation.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.PropylaminesAging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Problem Solving: A learning situation involving more than one alternative from which a selection is made in order to attain a specific goal.Psychological Tests: Standardized tests designed to measure abilities, as in intelligence, aptitude, and achievement tests, or to evaluate personality traits.Judgment: The process of discovering or asserting an objective or intrinsic relation between two objects or concepts; a faculty or power that enables a person to make judgments; the process of bringing to light and asserting the implicit meaning of a concept; a critical evaluation of a person or situation.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Size Perception: The sensory interpretation of the dimensions of objects.Sensory Thresholds: The minimum amount of stimulus energy necessary to elicit a sensory response.Statistics as Topic: The science and art of collecting, summarizing, and analyzing data that are subject to random variation. The term is also applied to the data themselves and to the summarization of the data.Reinforcement (Psychology): The strengthening of a conditioned response.Verbal Learning: Learning to respond verbally to a verbal stimulus cue.Motivation: Those factors which cause an organism to behave or act in either a goal-seeking or satisfying manner. They may be influenced by physiological drives or by external stimuli.Perception: The process by which the nature and meaning of sensory stimuli are recognized and interpreted.Sex Factors: Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Behavior Therapy: The application of modern theories of learning and conditioning in the treatment of behavior disorders.Interpersonal Relations: The reciprocal interaction of two or more persons.Conflict (Psychology): The internal individual struggle resulting from incompatible or opposing needs, drives, or external and internal demands. In group interactions, competitive or opposing action of incompatibles: antagonistic state or action (as of divergent ideas, interests, or persons). (from Merriam-Webster's Collegiate Dictionary, 10th ed)Fear: The affective response to an actual current external danger which subsides with the elimination of the threatening condition.Longitudinal Studies: Studies in which variables relating to an individual or group of individuals are assessed over a period of time.Receptors, Dopamine D4: A subtype of dopamine D2 receptors that has high affinity for the antipsychotic CLOZAPINE.Verbal Behavior: Includes both producing and responding to words, either written or spoken.Developmental Disabilities: Disorders in which there is a delay in development based on that expected for a given age level or stage of development. These impairments or disabilities originate before age 18, may be expected to continue indefinitely, and constitute a substantial impairment. Biological and nonbiological factors are involved in these disorders. (From American Psychiatric Glossary, 6th ed)Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Anger: A strong emotional feeling of displeasure aroused by being interfered with, injured or threatened.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Macaca: A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of 16 species inhabiting forests of Africa, Asia, and the islands of Borneo, Philippines, and Celebes.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Pulvinar: Large mass of nuclei forming the most caudal portion of the THALAMUS and overhanging the GENICULATE BODIES and the dorsolateral surface of the MIDBRAIN. It is divided into four parts: the lateral, medial, inferior, and oral pulvinar nuclei.Goals: The end-result or objective, which may be specified or required in advance.Wechsler Scales: Tests designed to measure intellectual functioning in children and adults.Decision Making: The process of making a selective intellectual judgment when presented with several complex alternatives consisting of several variables, and usually defining a course of action or an idea.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Meditation: A state of consciousness in which the individual eliminates environmental stimuli from awareness so that the mind can focus on a single thing, producing a state of relaxation and relief from stress. A wide variety of techniques are used to clear the mind of stressful outside interferences. It includes meditation therapy. (Mosby's Medical, Nursing, and Allied Health Dictionary, 4th ed)Brain-Computer Interfaces: Instrumentation consisting of hardware and software that communicates with the BRAIN. The hardware component of the interface records brain signals, while the software component analyzes the signals and converts them into a command that controls a device or sends a feedback signal to the brain.Linear Models: Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.Infant, Newborn: An infant during the first month after birth.Psychophysiology: The study of the physiological basis of human and animal behavior.Touch: Sensation of making physical contact with objects, animate or inanimate. Tactile stimuli are detected by MECHANORECEPTORS in the skin and mucous membranes.Social Environment: The aggregate of social and cultural institutions, forms, patterns, and processes that influence the life of an individual or community.Volition: Voluntary activity without external compulsion.Cortical Synchronization: EEG phase synchronization of the cortical brain region (CEREBRAL CORTEX).Language: A verbal or nonverbal means of communicating ideas or feelings.Sleep Deprivation: The state of being deprived of sleep under experimental conditions, due to life events, or from a wide variety of pathophysiologic causes such as medication effect, chronic illness, psychiatric illness, or sleep disorder.Socioeconomic Factors: Social and economic factors that characterize the individual or group within the social structure.Infant Behavior: Any observable response or action of a neonate or infant up through the age of 23 months.Aggression: Behavior which may be manifested by destructive and attacking action which is verbal or physical, by covert attitudes of hostility or by obstructionism.Neoplasms: New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Illusions: The misinterpretation of a real external, sensory experience.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Mental Disorders: Psychiatric illness or diseases manifested by breakdowns in the adaptational process expressed primarily as abnormalities of thought, feeling, and behavior producing either distress or impairment of function.Comorbidity: The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.History, 20th Century: Time period from 1901 through 2000 of the common era.Temperament: Predisposition to react to one's environment in a certain way; usually refers to mood changes.Anxiety Disorders: Persistent and disabling ANXIETY.Reinforcement, Verbal: Use of word stimulus to strengthen a response during learning.Automobile Driving: The effect of environmental or physiological factors on the driver and driving ability. Included are driving fatigue, and the effect of drugs, disease, and physical disabilities on driving.Association Learning: The principle that items experienced together enter into a connection, so that one tends to reinstate the other.Communication: The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups.Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.