ABSTRACT
Nutritional health relies on food choices reflecting a balanced diet, and oral sensation plays a significant role in the initiation, consolidation, and expression of these choices both acutely and over time. While many other factors contribute to dietary choice, this relationship makes intuitive sense-your perception of food guides your intake of it, which guides its effect on you. However, defining and quantifying this relationship have proven vexing: not only is food intake famously difficult to measure accurately, but oral sensation and affect also show astonishing individual variation even under healthy conditions. Part of the problem, of course, is that individual experience is subjective: we can describe our experiences, but we cannot directly share them, and it is difficult to compare descriptions that may mean different things
5.1 Introduction .................................................................................................. 103 5.2 Thresholds vs. Intensity: How Should Oral Experience Be Measured? ....... 104
5.2.1 Threshold Procedures ....................................................................... 104 5.2.1.1 Chemical Taste Thresholds ................................................ 106 5.2.1.2 Electrogustometry .............................................................. 107
5.2.2 Direct Scaling of Suprathreshold Intensity ...................................... 108 5.2.2.1 Magnitude Estimation ........................................................ 108 5.2.2.2 Measuring Oral Sensory Differences: Magnitude
Matching ............................................................................ 109 5.2.2.3 Measuring Oral Sensory Differences: Labeled Scales ...... 113
5.3 Methods of Oral Sensory Evaluation ............................................................ 119 5.3.1 Whole Mouth Oral Sensation ........................................................... 120 5.3.2 Videomicroscopy of the Tongue ....................................................... 121 5.3.3 Spatial Taste Testing ......................................................................... 122
5.3.3.1 Clinical Correlates of Localized Taste Loss ...................... 122 5.3.4 Retronasal Olfaction ......................................................................... 125
5.4 Conclusion .................................................................................................... 126 References .............................................................................................................. 126
to different people. Nevertheless, over the past several decades, advances in psychophysical scaling have demonstrated that individual differences in oral sensation (when measured properly) are not simply measurement artifacts but reflect true physiological variation with potent behavioral health impact. This evolutionary process supports the idea that perceptual experiences can be measured and compared, but it has also revealed widespread measurement practices that obscure links among chemosensation, diet, and health. As such, a better understanding of oral sensory measurement promises to clarify both the extent of its variation and its role in human nutrition across the lifespan.
