Multisensory flavour perception

Abstract

As this brief tour of the burgeoning cognitive neuroscience literature on multisensory flavour perception has hopefully made clear, there is far more to flavour perception than merely what happens on the tongue. By applying the cognitive neuroscience insights from the study of multisensory integration of the spatial senses (of vision, hearing, and touch), researchers, not to mention food companies and flavour houses, are currently furthering their understanding of many of the key factors underlying the multisensory perception of flavour. But what should hopefully also be apparent from this Primer is that, in order to really understand the experience of flavour, one needs to move beyond the traditional definitions of flavour (as captured by the International Standards Organization (ISO 5492, 1992, 2008) definition of flavour as a “Complex combination of the olfactory, gustatory and trigeminal sensations perceived during tasting. The flavour may be influenced by tactile, thermal, painful and/or kinaesthetic effects.”). One needs to incorporate the latest findings concerning flavour expectancy, and a whole host of contextual/atmospheric effects that have traditionally been ignored by food scientists, but which the latest research suggests can end up having a very dramatic impact on the flavour experiences of real consumers under ecologically-valid testing conditions.To conclude, it is worth noting that, even if one is not interested specifically in flavour perception, one cannot avoid the fact that, as the eminent biologist J.Z. Young (1968, p. 21) noted some years ago: “No animal can live without food. Let us then pursue the corollary of this: Namely, food is about the most important influence in determining the organization of the brain and the behavior that the brain organization dictates.” Indeed, some of the most dramatic changes in brain activity can be seen when a hungry participant is presented with appetizing food images and aromas while lying passively in the brain scanner.In the years to come, we will need to do everything we can to help preserve the enjoyment in food and drink of the growing elderly population suffering from a loss of their gustatory and olfactory perception, two senses which are critical to flavour perception, but for which there are no prosthesis (akin to hearing aids and glasses used to compensate for auditory and visual loss). There is also hope that our growing cognitive neuroscience understanding of multisensory flavour perception may help the food companies to deliver healthier foods to the marketplace, that taste just like they always did, but which contain less of the unhealthy ingredients (such as sugar, salt, fat and carbonic acid). One development that would likely help further our understanding would be to develop a predictive mathematical account of the relative contribution of each of the senses to multisensory flavour perception in terms of Bayesian decision theory.Eating and drinking are among life’s most enjoyable experiences. It is about time that cognitive neuroscientists took the study of multisensory flavour perception more seriously.