The basal forebrain has received considerable attention in recent years. This emphasis resulted from observations that the cortically projecting cholinergic neurons found in this region are critical for normal information processing. However, to achieve a complete understanding of such a complex function as "information processing" it is necessary to consider the basal forebrain not as an autonomous structure with a solitary task, but one that plays an integrative role; a structure that is connected intimately with many brain regions. This view evolved from the realization that the basal forebrain interfaces cognitive and reward functions with motor outputs. It is from this integrative and functional perspective that the present book was organized. The book is a unique collection of reports pertaining to the basal forebrain that encompasses a diversity of research approaches and techniques. It provides the reader with a progression of information that begins with anatomical descriptions of the afferent and efferent systems, stressing the integrative nature of various neurotransmitters located within the basal forebrain. The chapters focusing on anatomy are complemented by electrophysiologic studies that merge anatomical concepts with synaptic pharmacology and behavior. In vitro experiments demonstrate physiologic variations in anatomically identified neuronal subtypes and, together with in vivo techniques, provide pharmacologic descriptions of neuronal consequences to various neurotransmitter influences. Additional in vivo reports correlate changes in neuronal activity with specific motivational states and motor behaviors. These functional approaches culminate with behavioral studies that overview current understanding of basal forebrain involvement in mnemonic, reward, and motor processes.

An exploration of the neurological and behavioral mechanisms and processes involved in intrusive thinking. On any given day, unintended, recurrent thoughts intrude on our thinking and affect our behavior in ways that can be adaptive. Such thoughts, however, become intrusive and problematic when they are unwanted, become compulsive, or lead to socially or medically unacceptable behavior. This volume explores what goes on in our brains to create thought intrusions, and how these instrusions lead to maladaptive behavior.