NATIONAL BESTSELLER • From the bestselling author of The Drunkard’s Walk, a startling, eye-opening examination of how the unconscious mind shapes our experience of the world. “Mlodinow plunges into the realm of the unconscious mind accompanied by the latest scientific research ... [with] plenty of his trademark humor.” —Los Angeles Times Over the past two decades of neurological research, it has become increasingly clear that the way we experience the world—our perception, behavior, memory, and social judgment—is largely driven by the mind's subliminal processes and not by the conscious ones, as we have long believed. In Subliminal, Leonard Mlodinow employs his signature concise, accessible explanations of the most obscure scientific subjects to unravel the complexities of the subliminal mind. In the process he shows the many ways it influences how we misperceive our relationships with family, friends, and business associates; how we misunderstand the reasons for our investment decisions; and how we misremember important events—along the way, changing our view of ourselves and the world around us.

The author spent over 10 years responsibly, ethically, and scientifically investigating the efficacy of various subliminal procedures. This book comprehensively reviews the subliminal concept (particularly in the auditory modality), explores the technical details of preparing subliminal stimuli, presents the research on the effects of subliminal materials on emotions and behavior in clinical populations, reviews the research methodology required for ethically applying subliminal technology, and discusses the exciting possibilities for using subliminal procedures to enhance the efficacy of more traditional treatment modalities.

Two basic explanatory models have evolved to account for the phenomena of "perception without awareness". One explanation, referred to here as the "two-process" view, posits two distinct perceptual processes, a supraliminal one and a subliminal one (e.g. subception). These two processes are integrated, but also operate relatively independently, and different responses may be evoked by each. In this "two-process" model, a critical stimulus when not perceived via the supraliminal process (consciously) may be perceived via the subliminal process (not consciously); the subliminal process may then set off the appropriate need-related or defense-related responses. The second model referred to here as the “one-process" view, posits a single perceptual process which accounts for the phenomena in question as well as for perceptual behavior in general. This view maintains that "perception without awareness" is essentially a misnomer, insofar as total unawareness of the stimulus in subliminal research has not been adequately demonstrated; and that experiments cited as demonstrating subliminal processes (e.g. Lazarus & McCleary) from which subliminal processes have been inferred have not adequately investigated the possibility some supraliminal cues operating. An elaboration of some of the methodological and logical issues may help clarify the critical differences. "Perception without awareness" is inferred by those who hold the "two-process view" whenever the following three conditions occur: (a) a stimulus is presented at some intensity (or duration, or clarity) below the level at which subjects could identify the stimulus 100% of the trials; (b) the S cannot, does not correctly identify the stimulus verbally or motorically (that is consciously); (c) some response occurs (e.g. autonomic or imagery) which would be expected to occur only if the stimulus were somehow perceived and identified.