Organized by Andy Woods and Garmt Dijksterhuis, sponsored by UniLever

Garmt Dijksterhuis: Introduction

Lawrence Marks (John B. Pierce Laboratory, Yale University School of Medicine): “Gustatory-Olfactory Integration in Human Flavor Perception�

Julie Boyle (McGill University): “Neural Correlates of Chemosensory Mixtures�

Donald Katz (Brandeis University): “The taste system modulates olfactory perception�

Massimiliano Zampini (University of Trento): “The role of auditory cues in the multisensory perception of foods and beverages �


Larry Marks
John B. Pierce Laboratory and Yale University School of Medicine
Title: Gustatory-Olfactory Integration in Human Flavor Perception
Abstract: Human flavor perception involves the integration of sensory signals arising from gustation, olfaction, and somatosensation. Research in my laboratory has focused on interaction between gustatory and olfactory components of flavorants in the perception of flavor intensity. Measures of intensity processing include (a) detection of weak flavorants using forced-choice methods, (b) speed of response to detect stronger flavorants, and (c) ratings of flavor intensity of both perithreshold and suprathreshold flavorants. Results obtained from all three paradigms are consistent with the hypothesis that that flavor-intensity signals arising in the gustatory and olfactory channels add linearly. For the most part, changes in stimulus context appear to influence the signals in each channel independently.


Julie Boyle
Montreal Neurological Institute and Department of Psychology McGill University
Title: Neural Correlates of Chemosensory Mixtures
Abstract:In their daily life, humans rarely encounter single odorants. More normally, complex mixtures of odorants and trigeminal sensations sum up to create a single odor-percept (i.e. the gestalt). Our lab is interested in regions of the human brain involved in the integration of these intricate chemosensory mixtures. Our research on binary and ternary odor mixtures has revealed functional specialization in two olfactory regions; the anterior and lateral orbitofrontal cortex (OFC). While the lateral portion of the OFC responds to mixture impurity in a graded fashion, the anterior portion acts as an on-off detector for the presence of mixtures of odorants. More recently, we have shown activation of the lateral OFC in response to odor/ trigeminal and taste mixtures, suggesting that this region may represent a more generalized chemosensory integration center.


Donald Katz
Department of Psychology Brandeis University
Title: The taste system modulates olfactory perception
Abstract: "Flavor" appears to the perceiver to be primarily driven by taste, but is described by researchers as primarily reflecting smell; that is, the flavor percept emerges because activity of the olfactory system influences the taste system. Here, we demonstrate that the interaction of taste and smell is bi-directional--that the taste system is in fact necessary for normal olfaction. We trained rats to prefer a food by pairing the smell of that food with the smell of a conspecific's breath (this learning is called Social Transmission of Food Preference, or STFP). STFP was acquired purely on the basis of the olfactory cues present during the training interaction, but both acquisition and expression of the learning could be inhibited by inactivation of gustatory cortex (GC) via intra-cranial infusions of the GABA-A agonist muscimol. This effect represented a true case of state-dependency: when we inactivated GC in either training or testing sessions, no preference was learned; when we inactivated GC in both sessions, however, normal performance is rescued. We conclude that cortical inactivation does not make it impossible to form flavor percepts, but rather significantly alters flavor percepts. Thus, it makes no more sense to think about olfaction in isolation from gustation than it does to think about gustation in isolation from olfaction.


Massimiliano Zampini
Department of Cognitive Sciences and Education & Center for Mind/Brain Sciences, University of Trento
Title: The sound of food: The role of auditory cues in the multisensory perception of foods and beverages
Abstract: Our perception of the food we eat is derived from the integration of multisensory cues. Not only is it important what a food looks, smells and tastes like, but also what it feels like (i.e., oral texture) and sounds like in the mouth. Auditory cues play an important role in people’s evaluation of food and drink, especially their perception of the crispness of dry food products or of the level of carbonation in beverages. In a series of study, we have demonstrated that the modulation of high frequency components (2–20 kHz) and/or of the overall loudness of the sounds produced by foods can influence our perception of them. In particular, we have shown that the perception of the crispness and staleness of potato chips can be affected by modifying the sounds produced during the biting action. In a follow-up study, we have also found that the perception of carbonation in beverages can be influenced by varying the water sounds. Taken together, these results highlight the significant role that auditory cues can play in modulating the perception and evaluation of foodstuffs (despite the fact that we are often unaware of the influence of such auditory cues).