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.Communication Aids for Disabled: Equipment that provides mentally or physically disabled persons with a means of communication. The aids include display boards, typewriters, cathode ray tubes, computers, and speech synthesizers. The output of such aids includes written words, artificial speech, language signs, Morse code, and pictures.Man-Machine Systems: A system in which the functions of the man and the machine are interrelated and necessary for the operation of the system.User-Computer Interface: The portion of an interactive computer program that issues messages to and receives commands from a user.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)Imagination: A new pattern of perceptual or ideational material derived from past experience.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.Neurofeedback: A technique to self-regulate brain activities provided as a feedback in order to better control or enhance one's own performance, control or function. This is done by trying to bring brain activities into a range associated with a desired brain function or status.Computer Peripherals: Various units or machines that operate in combination or in conjunction with a computer but are not physically part of it. Peripheral devices typically display computer data, store data from the computer and return the data to the computer on demand, prepare data for human use, or acquire data from a source and convert it to a form usable by a computer. (Computer Dictionary, 4th ed.)Imagery (Psychotherapy): The use of mental images produced by the imagination as a form of psychotherapy. It can be classified by the modality of its content: visual, verbal, auditory, olfactory, tactile, gustatory, or kinesthetic. Common themes derive from nature imagery (e.g., forests and mountains), water imagery (e.g., brooks and oceans), travel imagery, etc. Imagery is used in the treatment of mental disorders and in helping patients cope with other diseases. Imagery often forms a part of HYPNOSIS, of AUTOGENIC TRAINING, of RELAXATION TECHNIQUES, and of BEHAVIOR THERAPY. (From Encyclopedia of Human Behavior, vol. 4, pp29-30, 1994)Signal Processing, Computer-Assisted: Computer-assisted processing of electric, ultrasonic, or electronic signals to interpret function and activity.Biofeedback, Psychology: The therapy technique of providing the status of one's own AUTONOMIC NERVOUS SYSTEM function (e.g., skin temperature, heartbeats, brain waves) as visual or auditory feedback in order to self-control related conditions (e.g., hypertension, migraine headaches).Electrodes, Implanted: Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.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.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Quadriplegia: Severe or complete loss of motor function in all four limbs which may result from BRAIN DISEASES; SPINAL CORD DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; NEUROMUSCULAR DISEASES; or rarely MUSCULAR DISEASES. The locked-in syndrome is characterized by quadriplegia in combination with cranial muscle paralysis. Consciousness is spared and the only retained voluntary motor activity may be limited eye movements. This condition is usually caused by a lesion in the upper BRAIN STEM which injures the descending cortico-spinal and cortico-bulbar tracts.Viscoelastic Substances: Substances that display the physical properties of ELASTICITY and VISCOSITY. The dual-nature of these substances causes them to resist applied forces in a time-dependent manner.Paralysis: A general term most often used to describe severe or complete loss of muscle strength due to motor system disease from the level of the cerebral cortex to the muscle fiber. This term may also occasionally refer to a loss of sensory function. (From Adams et al., Principles of Neurology, 6th ed, p45)Evoked Potentials, Visual: The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways.Motor Cortex: Area of the FRONTAL LOBE concerned with primary motor control located in the dorsal PRECENTRAL GYRUS immediately anterior to the central sulcus. It is comprised of three areas: the primary motor cortex located on the anterior paracentral lobule on the medial surface of the brain; the premotor cortex located anterior to the primary motor cortex; and the supplementary motor area located on the midline surface of the hemisphere anterior to the primary motor cortex.Electrodes: Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Feedback, Psychological: A mechanism of information stimulus and response that may control subsequent behavior, cognition, perception, or performance. (From APA Thesaurus of Psychological Index Terms, 8th ed.)Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Prostheses and Implants: Artificial substitutes for body parts, and materials inserted into tissue for functional, cosmetic, or therapeutic purposes. Prostheses can be functional, as in the case of artificial arms and legs, or cosmetic, as in the case of an artificial eye. Implants, all surgically inserted or grafted into the body, tend to be used therapeutically. IMPLANTS, EXPERIMENTAL is available for those used experimentally.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.Evoked Potentials, Motor: The electrical response evoked in a muscle or motor nerve by electrical or magnetic stimulation. Common methods of stimulation are by transcranial electrical and TRANSCRANIAL MAGNETIC STIMULATION. It is often used for monitoring during neurosurgery.Evoked Potentials, Somatosensory: The electric response evoked in the CEREBRAL CORTEX by stimulation along AFFERENT PATHWAYS from PERIPHERAL NERVES to CEREBRUM.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.Robotics: The application of electronic, computerized control systems to mechanical devices designed to perform human functions. Formerly restricted to industry, but nowadays applied to artificial organs controlled by bionic (bioelectronic) devices, like automated insulin pumps and other prostheses.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.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.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Neurophysiology: The scientific discipline concerned with the physiology of the nervous system.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.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.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.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.