Attention, Arousal and the Orientation Reaction aims to present in a volume the works of Pavlov, an eminent Russian physiologist known for his contributions, specifically the classical conditioning. This book contains the interpretations and theories in physiological terms, and elaborates on the neurological models of significant interest. The “orientation reaction” is described, and the Sokolov's model, which is claimed to be the most comprehensive model for the orientation reaction, is then illustrated. This text also explains the phenomenon of habituation, wherein facts involved are summarized in a chapter. A discussion on the numerous neurological models of the habituation process is then given. This text notes that the models are divided into ""one-stage models"" and ""two-stage models."" Other topics presented are the effects of transforming a neutral stimulus into a conditioned stimulus; the orientation reaction in ontogenetic and phylogenetic development; and the orientation reaction in the measurement of individual differences. This book will be beneficial to those fascinated with the works of Pavlov, especially the psychology students and practitioners.