Hallucinations: The Science of Idiosyncratic Perception

Hallucinatory phenomena remain one of the more enduringly fascinating symptoms to the mental health professional. Hallucinations: The Science of Idiosyncratic Perception, is a comprehensive and intriguing examination, exploring the multiple types of hallucinations and the circumstances in which they appear. Not only an examination of the phenomenology of hallucinatory symptoms, this highly readable volume includes data from multiple disciplines in an all-encompassing construct of how medical science can understand hallucinations.

Recent discoveries in multiple disciplines regarding the characteristics of hallucinations make this book particularly timely. Psychiatry's theories have been increasingly converging with theories from the areas of psychology, neuroanantomy, biochemistry, and radioimaging techniques, to name a few. Andre Aleman and Frank Larøi, neuropsychologists from northern Europe, have integrated the offerings of these disparate fields in a book that will enlighten the professional with even a passing familiarity with these fields of study.

Perhaps because of the relative simplicity of neural pathways for sight and hearing, the book focuses on the accumulated evidence for auditory and visual hallucinations. Beginning with a continuum hypothesis, which defines hallucinations as potentially normal for humans in the right set of circumstances, the authors unravel multiple types of perceptual and cognitive disturbances. And much like the pathophysiology of any disease, perceptual disturbances have elucidated our understanding of how sensory data from our environment are processed in various parts of the brain.

The book then takes an insightful "where are we?" approach to the state of research about hallucinations. Approaching the phenomenon through cognitive data on how sensory information is processed (the authors' top-down approach) and then presenting examples of how sensory data can be altered, damaged, or simply lost within the brain (the bottom-up view), the book drives a much-needed Golden Spike that unifies these perspectives into a cogent mechanism. That their model makes even theoretical sense given the disparate areas of study being brought together is an achievement in itself.

Areas that do not escape analysis in this concise volume include hallucinations among children and adolescents, persons experiencing deficits in the very sensory modalities in which they hallucinate, and the cultural interpretations of hallucinations in different parts of world. (The minimal exploration of the sociologic approach is perhaps a good thing, because the topic would probably require an equally fascinating volume to do it justice.) Even the phenomenon of persons' recognition of their hallucinations helps to support the metacognitive processes intrinsic to how the brain processes data.

This last element foreshadows the cognitive-behavioral techniques for treating hallucinations not fully eliminated through medication. Patients are often left to develop their own coping mechanisms at such times, and this process is rarely written about. Indeed, the topic of pharmacology is minimally discussed in this book, which is curious given the details put forth about transcranial magnetic stimulation. Yet the authors are interested in providing a cohesive paradigm, and they do so clearly and successfully for anyone seeking to find meaning in this most peculiar aspect of the brain's functioning.