FUNDAMENTAL ASPECTS OF MOTOR CONTROL AND HANDWRITING Neuroanatomical and Neurochemical Bases of Motor Control Historical Perspective on Brain Function for Hand Motor Control Neuroanatomical Bases of Hand Motor Control Basal Ganglia Neurochemistry Frontal-Subcortical Neural Circuits and Motor Function The Cerebellum and Brain Stem Neuroanatomical Bases of Handwriting Movements Lesion Studies Functional Neuroimaging Studies Models of Handwriting Motor Control Handwriting as a Motor Program Hierarchical Models of Handwriting Motor Control Cost Minimization Models Equilibrium Point Model Neurological Disease and Motor Control Parkinson¿s Disease Progressive Supranuclear Palsy and Corticobasal Degeneration Essential Tremor Multiple System Atrophy Multiple Sclerosis Huntington¿s Disease Lower Motoneuron Disease Alzheimer¿s Disease and Dementia with Lewy Bodies Psychotropic Medications: Effects on Motor Control An Overview of Psychotropic Medications Neurobiology of Psychotropic-Induced Movement Disorders Aging and Motor Control Neurotransmitter Mechanisms of Motor Aging Aging Effects on Motor Behavior KINEMATICS OF SIGNATURE AUTHENTICATION A Kinematic Approach to Signature Authentication The Kinematic Approach Isochrony in Genuine, Autosimulated, and Forged Signatures Methods: Writers and Procedures Results Discussion Kinematic Analyses of Stroke Direction in Genuine and Forged Signatures Methods: Writers and Procedures Results Upstroke/Downstroke Ratio Scores NEUROLOGIC DISEASE, DRUGS, AND AGING AND THEIR EFFECTS ON HANDWRITING Neurological Disease and Handwriting Handwriting in Specific Neurological Diseases Effects of Psychotropic Medications on Handwriting Empirical Research on Effects of Psychotropics on Handwriting Kinematics Substance Abuse and Handwriting Methamphetamine Cannabis Alcohol Aging and Handwriting Empirical Research on Effects of Aging on Handwriting Conclusions Bibliography.