The total product experience and the position of the sensory and consumer sciences: More than meets the tongue

Traditionally, much food research focuses on the physical and chemical product characteristics, using the so called ‘hard-sciences’. The consumer science side of the product, its use, its perception and its choice rely on the psychological sciences. In the ‘harder’ sciences, a number of recent insights appear which we introduce in this article using the philosophy of the Total Product Experience.

This TPE approach is built on the following four principles:

1. Multisensory perception: products are perceived by humans using all their sensory systems, i.e. more than the proverbial five sense systems, and there are many ways the systems interact

2. Top-down effects: ideas, expectations, information, emotions, in addition to direct sensory perception affect the perception, and liking, of products

3. Consumer-product interactions: the inter – action of consumers with a food product ranges much wider than just oral ingestion

4. Unconscious influences: there is much information about food products and their sensory perception than is consciously and volitionally available to a consumer

The next sections briefly introduce these four principles of the Total Product Experience.

A uni-sensory perception is a laboratory animal: multisensory perception

A human being possesses many more senses than the usually presented five: seeing, hearing, feeling, tasting, smelling. Many distinct sensory systems are brushed together under the moniker feeling or touch, and the internal senses are often ignored altogether. In total, one could easily distinguish 12 distinct sensory systems. In particular, the senses of heat, cold and pain are often overlooked, but are very important in food perception1.

In addition to such ‘forgotten’ sensory systems, the many senses give rise to a multitude of interactions. In as complex a process of handling, preparing and consuming food products, new interactions are bound to occur. There is hardly a sensory system that is not involved in food consumption. We see a food, smell it, feel the food, its temperature, its texture in our mouth, we even hear the sound it makes when we break down the food into small pieces in our mouths2. But we also feel the pack, the resistance of the carton when we open a box, hear the crackling noise a wrapping paper makes, even integrate background noise in our sensory perception of food3 (Figure 1, page 40).

The interactions between taste, flavour and texture obviously are, and will remain to be, very important for food products4,5, but with the recent developments in multisensory science6,7, one can make use of these interactions to a much larger extent than seems to be currently happening.

Interoception is often not included in studies of multisensory interactions, although in food research, the effects of a hunger-state, e.g. ‘feeling full’, are often studied, which is certainly mediated by interoception8. Emotions are internal states too9 so they can be seen as contributing to multisensory interactions.

Conception is as real as perception: top down effects

In addition to the input from the different sensory systems, there is the often overlooked interplay of conception (forming or understanding ideas or abstractions or their symbols) and perception. The stream of information coming from the sensory systems is called bottom up, but they do not build the total picture of what we perceive of a food product. There is a wealth of additional information that is added to this picture and it comes from within our brains. Information of previous encounters with products, memories of advertisements or hearsay, expectations of products, our own thoughts and ideas, all exert their influence on how we perceive and even on what we perceive (Figure 1, page 40).

One illustration of the impact of cognitive effects onto perception was delivered by de Araujo et al10. They presented subjects with an odorous substance and information about the source of the odour. When told the odour came from a cheese, the subjects liked the odour more than when they were told that it was a body odour. What’s more interesting is that the subjects’ activation of relevant brain regions activated by the odours depended on the cognitive labels received. Woods et al11 have shown a similar effect where an expectation of the intensity of a sweet stimulus (‘You will receive a very sweet drink’, versus ‘You will receive a not-so-sweet drink’) showed an effect in the primary taste cortex. The ‘very sweet’ label resulted in higher psychophysical intensity scores in a separate study, but more interestingly also in more activation in the primary taste brain region. This means that such top down effects as labels and expectations can impact low-level neural perceptual processes. They as-it-were change the perceptual reality of the subject.

Emotions have also been shown to exert like influences on subsequent food perception12, but what’s most interesting is that many of these influences often are unconscious.

Preferences need no inferences13: unconscious influences

Many of the sensations, perceptions and emotions related to a food product will remain outside our conscious awareness. And luckily so, as one would likely panic over the sheer overwhelming number of impressions. But very many of them are somehow stored in memory even inattentively, and they help build our total experience of a product, shape our expectations, and affect our likes, dislikes and ultimately our buying behaviour. It is rather the exception than the rule that a consumer can reliably relate the motivation for his or her food choice. It has become clear that behaviour is not always the result of consciously willing it. Wilson14 writes about the ‘adaptive unconscious’, shaped by evolution, guiding us through a complicated environment, and helping us with decisions through intuition. This all happens without our explicit knowledge, and often even without the possibility of knowledge (People can no more observe how they are unconsciously categorising their environments, setting goals, and generating intuitions than they can observe how their kidneys work15).

For the study of food perception and food choice, this has important implications. A large part of the processes presented in the previous sections take place in an unaware consumer. There thus is no point in talking to consumers in order to find out anything about their motivation for liking or buying certain products. You will only probe the part within a consumer’s conscious awareness, shaped through an explicit reasoning process. This may be unrelated to any psychological process that actually governs consumers’ behaviour. What one does get from such direct interactions with consumers is information about how they explicitly reason and express themselves about products. This can be useful e.g. for advertise – ment and consumer communication purposes but it is of limited worth in understanding how consumers’ likes, dislikes and purchase behaviour are shaped.

It has been shown that sensory perceptions can be stored in memory, and shape later choice, in a completely implicit way, i.e. without the consumers being aware of it16. This means that there are sensory perceptions being processed outside our awareness but stored in memory nevertheless.

Even with such superficially mundane experiences as smell and taste, one is mostly not aware of many facts. A flavour perceived is an amalgamate of a taste, perceived on the tongue, and a smell, perceived retronasally in the nose (and textures felt in the mouth) but one cannot disentangle them (not before being seriously trained to do so, e.g. as a sensory panellist). What’s more, the location of a flavour seems to be in the mouth, while this of course must be illusory17.

Unconscious influences of emotions are also possible. The induction of an affective state (an emotion), can take place without the subject being aware of it (i.e. without the subject perceiving feelings). Winkielman and Berridge9 and Winkielman et al.12 have shown that such affective, unconscious, priming can affect consumption behaviour and judgements of value.

In addition, information about a food product will enter a consumer’s memory possibly long before the first physical and conscious ‘first’ contact with the product.

More than meets the tongue: consumer-product interactions

In sensory food science, we’re inclined to think the processes we need to understand begin when a consumer ingests a product. This idea cannot be adhered to anymore. The eating (drinking) experience does not commence when a food (or drink) is put in the mouth.

Figure 2 illustrates the many different points of impact between a consumer and the food product. Note that long before actual ingestion takes place, the interaction between the consumer and the product has already started. The first contact a consumer has with a product often consists of hearing about it, seeing an advertisement or commercial, or seeing it in a shop. When further exploration of the product follows, the consumer may look at the pack in more detail, feel the packaging material and the product’s weight and perhaps hear the pack, or the product inside the pack. Suppose the product is bought in a shop, it will be handled further, unwrapped, opened, poured, scooped, shaken, etc. It will be prepared or directly eaten, where the senses of sight, audition, smell, taste, pain, temperature, will work together to build a coherent sensory experience out of all those impressions. The total will be liked, or not, and that, including the sensations giving rise to it, will be somehow passed on to memory.

The ‘Total Product Experience’ is the combination of events, memories and sensations that occur before, during and after the sensation proper (see Figure 2 opposite). Using the TPE as a guideline, the many disciplines involved in product development should be harmonised. Some of these disciplines are product formulation, flavour, fragrance, structure, processing, manufacturing, packaging, marketing, pricing, advertisement, retail, and there may be more, depending on the type of product.

Conclusion

What good is the above for the practising sensory and consumer scientist? The principles have been known for a while, but their methodological consequences appear not fully explored. The exception being multisensory perception which is used to an increasing extent, and indeed studies of the interaction between the many sensory systems that are active in consumption appear in the literature, and in unpublished reports. Using standard methods like sensory profiling, sensory scientists know the importance of studying the multitude of sensory impressions.

The effect of cognition onto perception is not explored to the extent that it could be. Producing a food product with a ‘good’ taste is relatively easy, but presenting it in such a way that consumers repeatedly want it, will distinguish the peak from the pedestrian. It is the many top down effects, through pack, information, marketing, presentation (and marketing’s other ‘P’s) that can make the difference. Understanding the interplay between cognitive input, perception, liking and purchase behaviour transgresses the traditional borders between the product oriented R&D and the consumer oriented marketing functions, both in academic and corporate environments. The same could be said about the consumerproduct interactions. Some studies around food behaviour are carried out without the consumers actually using the product, e.g. in the form of questionnaires or interviews, or on the contrary, with a focus on in-mouth aspects of a product only. The link of the latter type of ‘blind’ studies with the final consumerready product can be hard to establish. The reason is the different domains the two traditionally stem from; being the product orientated R&D versus the consumer orientated marketing functions, respectively.

There are classes of sensory tests exempt from this type of criticism, viz. the productorientated ones where changes in formulations are tested for their perceptual consequences, or tests carried out where the relationships between sensory perception, ingredients, processing, etc. are studied. There will always be a place for this type of product-orientated sensory testing. As soon as a step towards a consumer and a product-as-marketed is made, the four principles from the TPE-philosophy should be addressed.

Finally, there are the unconscious processes, of which emotional influences are an important part. The existence of many ‘non-rational’ effects on choice and behaviour has been well established18,19, but resulting methodological innovations in the field of food perception and choice appear scarce. The model of a rational consumer pondering what products to buy and why is still encountered underlying many a consumer test.

Ideally, the four principles of the Total Product Experience are addressed in harmony and simultaneously, resulting in a holistic product development approach. Sensory science is developing from a product orientated ‘sensory analysis’ approach to a much wider field with an increasingly more psychological and consumer-orientated view, up to including effects of the marketing mix. This will mean that its position in a product orientated R&D surrounding, where it can be typically be found both in academia and in industry, could prove suboptimal, and a position alongside the marketing and consumer-insight functions may be a more natural one.

Acknowledgements

Johanneke Busch, Liesbeth Zandstra, for comments and suggestions.

About the author

Garmt Dijksterhuis is a Science Leader at the Sensation, Perception & Behaviour Department of Unilever R&D Vlaardingen, the Netherlands and Professor of Sensory Science at the Sensory Science group of the University of Copenhagen, Denmark. Garmt studied Psychology at the University of Utrecht and has a PhD in Data Theory from the University of Leiden, in the Netherlands. Garmt has written or co-authored over a hundred publications in sensory and consumer science, statistics and psychology. His main research interests are the psychology of perception (taste and smell in particular), both theoretical and applied, and measurement issues in psychology in general.

References

1. McGlone, F., Spence, C. (2009). The cutaneous senses: Touch, temperature, pain/itch, and pleasure. Neuroscience and Biobehavioural Reviews, 34(2):145-7

2. Dijksterhuis, G.B., Luyten, H.M., De Wijk, R., Mojet, J. (2007). A new sensory vocabulary for crisp and crunchy dry model foods applied. Food Quality and Preference. 18, 1, 37-50

3. Woods, A.T., Poliakoff, E., Lloyd, D.M., Kuenzel, J., Batchelor, J., Hodson, R., Gonda, H., Dijksterhuis, G.B., Thomas, A.T. (2010). Effect of background noise on food perception. Food Quality and Preference, 22, 1, 42-47

4. Delwiche J. (2004). The impact of perceptual interactions on perceived flavor. Food Quality and Preference. 15, 137-146

5. Lundstrom, J. N., Boesveld, S., Albrecht, J. (2011), Central Processing of the Chemical Senses: An Overview. ACS Chemical Neuroscience. 2, 5-16

6. Ernst, M. O., & Banks, M. S. (2002). Humans integrate visual and haptic information in a statistically optimal fashion. Nature, 415, 429-433

7. Calvert, G.A., Spence, C., Stein, B.E. (2004). The Handbook of Multisensory Processes. MIT Press

8. Cameron, O.G. (2002). Visceral Sensory Neuroscience. Interoception. Oxford: OUP.

9. Winkielman, P., Berridge, K. C. (2004). Unconscious emotion. Current Directions in Psychological Science, 13, 120-123

10. de Araujo, I., Rolls, E.T., Velazco, M.I., Margot, C., Cayeux, I. (2005). Cognitive Modulation of Olfactory Processing. Neuron, 46, 671–679

11. Woods, A.T., Lloyd, D.M.,. Künzel, J., Poliakoff, E, Dijksterhuis, G.B., Thomas, A. (2011). Expected taste intensity affects response to sweet drinks in primary taste cortex. Neuroreport. 22, 8, p. 365-369

12. Winkielman, P., Berridge, K. C.,. Wilbarger, J.L. (2005). Unconscious Affective Reactions to Masked Happy Versus Angry Faces Influence Consumption Behavior and Judgments of Value. Personality and social psychology bulletin, 121-135

13. Zajonc, R.B. (1980). Feeling and Thinking: Preferences need no inferences. American Psychologist, 35, 151-175

14. Wilson, T. (2001). Strangers to ourselves: Discovering the Adaptive Unconscious. Cambridge, MA: Harvard University Press

15. Wilson, T. (2004). http://asweb.clas. virginia.edu/ psych/x1115.xml

16. Mojet, J., Köster, E.P. (2002). Texture and flavour memory in foods: An incidental learning experiment. Appetite, 38, 110-117

17. Lim, J., Johnson, M.B. (2010). Potential Mechanisms of Retronasal Odor Referral to the Mouth. Chemical Senses 36: 283–289

18. Kahneman, D. (2011). Thinking Fast and Slow. Penguin Books Ltd (UK)

19. Gigerenzer, G. (2007). The Intelligence of the Unconscious. Penguin Books