Motor Skills: Performance of complex motor acts.Weight Perception: Recognition and discrimination of the heaviness of a lifted object.Size Perception: The sensory interpretation of the dimensions of objects.Writing: The act or practice of literary composition, the occupation of writer, or producing or engaging in literary work as a profession.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Motor Skills Disorders: Marked impairments in the development of motor coordination such that the impairment interferes with activities of daily living. (From DSM-V)Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.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.Motor Neurons: Neurons which activate MUSCLE CELLS.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.Deep Brain Stimulation: Therapy for MOVEMENT DISORDERS, especially PARKINSON DISEASE, that applies electricity via stereotactic implantation of ELECTRODES in specific areas of the BRAIN such as the THALAMUS. The electrodes are attached to a neurostimulator placed subcutaneously.Electric Stimulation Therapy: Application of electric current in treatment without the generation of perceptible heat. It includes electric stimulation of nerves or muscles, passage of current into the body, or use of interrupted current of low intensity to raise the threshold of the skin to pain.Subthalamic Nucleus: Lens-shaped structure on the inner aspect of the INTERNAL CAPSULE. The SUBTHALAMIC NUCLEUS and pathways traversing this region are concerned with the integration of somatic motor function.Globus Pallidus: The representation of the phylogenetically oldest part of the corpus striatum called the paleostriatum. It forms the smaller, more medial part of the lentiform nucleus.Parkinson Disease: A progressive, degenerative neurologic disease characterized by a TREMOR that is maximal at rest, retropulsion (i.e. a tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. LEWY BODIES are present in the substantia nigra and locus coeruleus but may also be found in a related condition (LEWY BODY DISEASE, DIFFUSE) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)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.Hypokinesia: Slow or diminished movement of body musculature. It may be associated with BASAL GANGLIA DISEASES; MENTAL DISORDERS; prolonged inactivity due to illness; and other conditions.Essential Tremor: A relatively common disorder characterized by a fairly specific pattern of tremors which are most prominent in the upper extremities and neck, inducing titubations of the head. The tremor is usually mild, but when severe may be disabling. An autosomal dominant pattern of inheritance may occur in some families (i.e., familial tremor). (Mov Disord 1988;13(1):5-10)Stereotaxic Techniques: Techniques used mostly during brain surgery which use a system of three-dimensional coordinates to locate the site to be operated on.Adolescent Psychiatry: The medical science that deals with the origin, diagnosis, prevention, and treatment of mental disorders in individuals 13-18 years.Child Psychiatry: The medical science that deals with the origin, diagnosis, prevention, and treatment of mental disorders in children.Child Development Disorders, Pervasive: Severe distortions in the development of many basic psychological functions that are not normal for any stage in development. These distortions are manifested in sustained social impairment, speech abnormalities, and peculiar motor movements.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)Psychiatry: The medical science that deals with the origin, diagnosis, prevention, and treatment of mental disorders.Social Behavior: Any behavior caused by or affecting another individual, usually of the same species.MissouriMovement: 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.Overlearning: Learning in which practice proceeds beyond the point where the act can just be performed with the required degree of excellence.Wrist: The region of the upper limb between the metacarpus and the FOREARM.Spinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Serial Learning: Learning to make a series of responses in exact order.Foot: The distal extremity of the leg in vertebrates, consisting of the tarsus (ANKLE); METATARSUS; phalanges; and the soft tissues surrounding these bones.Child Development: The continuous sequential physiological and psychological maturing of an individual from birth up to but not including ADOLESCENCE.Motor Activity: The physical activity of a human or an animal as a behavioral phenomenon.