I. Introductionn n Historical Issues in the Study of Behavioral Dysfunction in Movement Disordersn Christopher G. Goetzn n II. Mental Processing in the Motor Structures of the Brainn n Fundamental and Clinical Evidence for Basal Ganglia Influences on Cognitionn Frank A. Middletonn n Integrating Cognition and Motivation into the Basal Ganglia Pathways of Actionn Suzanne N. Habern n Understanding Corticobasal Ganglia Networks as Part of a Habit Formation Systemn Ann M. Graybiel and Yasuo Kubotan n The Role of the Cerebellum in Cognition and Emotionn Jeremy D. Schmahmannn n III. Cognition in Movement Disordersn n Assessing Cognition in Movement Disordersn Julie C. Stout and Jane S. Paulsenn n Disorders of Intention in Parkinsonian Syndromesn Richard G. Brownn n Cognitive Control in Frontostriatal Disordersn Francois Richer and Sylvain Chouinardn n Disorders of Speech and Language in Parkinson's Diseasen Henri Cohenn n Distinctive Features of Apraxia in Corticobasal Degeneration and Other Neurological Illnessesn Ramón Leiguardan n Neuropsychological Deficits in Cerebellar Syndromesn Hermann Ackermann and Irene Daumn n IV. Neurophysiology of Cognition in Movement Disordersn n Induction and Reversal of Cognitive Deficits in a Primate Model of Huntington's Diseasen Stéphane Palfi, Emmanuel Brouillet, Françoise Condé, and Philippe Hantrayen n Induction and Reversal of Cognitive Deficits in a Primate Model of Parkinson's Diseasen Jay S. Schneidern n Catecholamines and Cognition: Bridging the Gap Between Animal Studies and Clinical Syndromesn Trevor W. Robbins, Harriet S. Crofts, Roshan Cools, and Angela C. Robertsn n Nondopaminergic Influences on Cognition in Parkinson's Diseasen Marc-André Bédard, Maxime Lévesque, Simon Lemay, and FrançoisPaquetn n Cognitive Consequences of Neurosurgery for Parkinson's Diseasen Jean A. Saint-Cyrn n V. Dementia in Movement Disordersn n The Clinical Spectrum of Dementia in Movement Disorders: An Overviewn Andrew Kerteszn n Neuropathological Distinctions and Similarities in Movement Disorders with Dementian Kurt A. Jellingern n Homologies Between the Genetic Etiology and Pathogenesis of the Synucleinopathies and Tauopathiesn John Hardyn n Prevalence, Incidence, and Risk Factors for Dementia in Parkinson's Diseasen Gilberto Levy and Karen Mardern n Neuropsychiatric Co-Morbidity in Dementia With and Without Movement Disordersn Clive G. Ballard and Alan Thomas.n n Neurotransmitter Correlates of Neuropsychiatric Symptoms in Dementia with Lewy Bodiesn Elaine K. Perry, Margaret A. Piggott, Mary Johnson, Clive G. Ballard, Ian G. McKeith, Robert Perry, and David Burnn n Acetylcholinesterase Inhibitors in the Treatment of Dementia in Parkinson's Diseasen Amos D. Korczyn and Nir Giladin n VI. Neuropsychiatric Aspects of Movement Disordersn n Mood Disorders and the Globus Pallidusn Edward C. Lauterbachn n Cortical-Limbic-Striatal Dysfunction in Depression: Converging Findings in Basal Ganglia Diseases and Primary Affective Disordersn Taresa L. Stefurak and Helen S. Maybergn n Agitation and Apathy in Hyper- and Hypokinetic Movement Disordersn Irene Litvan and Jaime Kulisevskyn n Diagnosis and Treatment of Depression in Parkinson's Diseasen Vladimir S. Kosti¿c, Elka Stefanova, Nataþsa Dragaþsevi¿c, and Saþska Potrebi¿cn n Diagnosis and Treatment of Hallucinations and Delusions in Parkinson's Diseasen Dag Aarsland and Jan Petter Larsenn n REM Sleep Behavior Disorder in Parkinson's Disease, Dementia with Lewy Bodies, and Multiple System Atrophyn Bradley F. Boeve, Michael H. Silber, Tanis J.