Customer Reviews

Learning to Smell: Olfactory Perception from Neurobiology to Behavior

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The biggest felonies in sensory science have to do with equating (1) the physical stimulus, or (2) early neural signals, with psychological perception. For instance, as long as a vision scientist confuses wavelength with color, he will have no tenable scientific understanding of color, and he will at best publish confusing research. Alternatively, if he thinks that he can understand color based on the simple outputs of three cone photoreceptors, he will remain in the dark, so to speak.

Perhaps it is not fair to accuse most olfactory scientists of the aforementioned felony. However, most of them, apparently, have focused on the front end of system, attempting to understand how chemicals are transduced into neural signals and represented in the olfactory system. If their explanation of odor detection and discrimination ends there, they've blown it.

The authors suggest that, historically, researchers have mostly attempted to determine how a chemical stimulus is represented in the olfactory system, without considering context and learning.

However, the authors note that this perspective is at odds with considerable neurobiological and psychological data, which demonstrate the importance of perceptual learing (i.e., synthetic processing and experiential factors) as opposed to the structural features of the stimulus as critical for odor discrimination. In reviewing the evidence, the authors conclude that the initial odorant features are not consciously accessible, and that this extraction is at best a first necessary stage for subsequent cortical synthetic processing. "Cortical synthetic coding reflects an experience-dependent process that allows synthesis of novel co-occurring features, similar to processes used for visual object coding. Thus, we propose that experience and cortical plasticity are not only important for traditional associative olfactory memory (e.g. fear conditioning, maze learning, and delayed-match-to-sample paradigms), but also play a critical, defining role in odor discrimination."

So, this book is on target because it frees itself from the shackles of simple models of chemical pattern recognition.

I'm not an expert on olfaction. My appreciation of this book was greatly enhanced by reading a very good introductory chapter on olfaction. This chapter appeared in Wolfe et al (Sensation & Perception, 2005), and was authored primarily (I believe) by Rachel Herz. This chapter included many informative illustrations, and the textbook website at Sinauer included an excellent section on sensory memory cues based on Herz' research. (I wish this book had colorful illustrations).

The authors do a superb job of comparing olfaction and olfaction research to research on the other senses, in particular the visual sense. They note the many similarities among sensory systems, and use these similarities to inform their analyses and their research. Moreover, they integrate their understanding of learning, memory and pattern recognition into the theoretical approach.

The integrative nature of this book was definitely a plus. If you are a psychophysicist or cognitive scientist, then it is hard to disagree with the authors on the key points of their theory.

LEARNING TO SMELL: OLFACTORY PERCEPTION FROM NEUROBIOLOGY TO BEHAVIOR is written by a neurobiologist and psychologist and provides a new theory of olfactory perception, making it a recommended pick for any college-level health library holding. The major research in the area lies in determining how the brain identifies and separates smells: chapters reviews research approaches and propose that experience and cortical plasticity combine to play a defining role in odor perception. A review of the physiology of olfactory systems and mechanics of detection enhances this excellent discourse.

Diane C. Donovan
California Bookwatch