In 1974 an article appeared in Science magazine with the dry-sounding title “Judgment Under Uncertainty: Heuristics and Biases” by a pair of psychologists who were not well known outside their discipline of decision theory. In it Amos Tversky and Daniel Kahneman introduced the world to Prospect Theory, which mapped out how humans actually behave when faced with decisions about gains and losses, in contrast to how economists assumed that people behave. Prospect Theory turned Economics on its head by demonstrating through a series of ingenious experiments that people are much more concerned with losses than they are with gains, and that framing a choice from one perspective or the other will result in decisions that are exactly the opposite of each other, even if the outcomes are monetarily the same. Prospect Theory led cognitive psychology in a new direction that began to uncover other human biases in thinking that are probably not learned but are part of our brain’s wiring.

Thinking fast and slow.

The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

Overview and Basic Principles. Physiological and Psychological Foundations of Sensory Function. Principles of Good Practise. Discrimination Testing. Discrimination Theories and Advanced Topics. Threshold Testing as a Special Case of Discrimination Tests. Scaling Models and Numerical Measurement. Time Intensity Methods. Context Effects and Biases. Descriptive Analysis. Texture. Color and Appearance Measurement. Acceptance and Preference Testing - Laboratory Applications. Acceptance and Preference Testing - Consumer Tests Outside the Laboratory. Qualitative Research Methods. Data Relationships & Multivariate Applications. Strategic Research. Overview and Recap. Statistical Appendices.

Sensory Evaluation of Food: Principles and Practices

Phenolics in Food and Nutraceuticals is the first single-source compendium of essential information concerning food phenolics. This unique book reports the classification and nomenclature of phenolics, their occurrence in food and nutraceuticals, chemistry and applications, and nutritional and health effects. In addition, it describes antioxidant activity of phenolics in food and nutraceuticals as well as methods for analysis and quantification. Each chapter concludes with an extensive bibliography for further reading. Food scientists, nutritionists, chemists, biochemists, and health professionals will find this book valuable.

Phenolics in food and nutraceuticals

In many everyday situations, our senses are bombarded by many different unisensory signals at any given time. To gain the most veridical, and least variable, estimate of environmental stimuli/properties, we need to combine the individual noisy unisensory perceptual estimates that refer to the same object, while keeping those estimates belonging to different objects or events separate. How, though, does the brain “know” which stimuli to combine? Traditionally, researchers interested in the crossmodal binding problem have focused on the roles that spatial and temporal factors play in modulating multisensory integration. However, crossmodal correspondences between various unisensory features (such as between auditory pitch and visual size) may provide yet another important means of constraining the crossmodal binding problem. A large body of research now shows that people exhibit consistent crossmodal correspondences between many stimulus features in different sensory modalities. For example, people consistently match high-pitched sounds with small, bright objects that are located high up in space. The literature reviewed here supports the view that crossmodal correspondences need to be considered alongside semantic and spatiotemporal congruency, among the key constraints that help our brains solve the crossmodal binding problem.

/pdf/crossmodal-correspondences-a-tutorial-review-20vme8gbi3.pdf

Crossmodal correspondences: A tutorial review

. 

Aproblem central to sensory difference testing is response bias. There are two experimental strategies for dealing with this problem. The first is to use forced choice procedures, like the common duo-trio or triangle tests, while the second is to use signal detection measures like d′, P(A) and the R-index. These strategies are explained and discussed. The relationship between the R-index and the other signal detection measures is explained. The relationship between R-index values obtained by rating and ranking is explored, as are the alternative computations of the R-index by ranking: Rjb and Rmat.

Understanding discrimination tests: a user-friendly treatment of response bias, rating and ranking r-index tests and their relationship to signal detection

The dependence of wine sensory attributes on the water status of the source vines was determined following vineyard irrigation treatments which included early and late season water deficits and continually irrigated vines. In both seasons, the experimental wines made from the different irrigation treatments did not differ in the concentration of residual sugar or ethanol, titratable acidity, or pH. The concentrations of anthocyanins and total soluble phenolics in the wines were greater from water deficit treatments than from continually irrigated vines. For sensory evaluation, a novel protocol for paired comparisons was developed to test separately for differences in wine appearance, flavour, taste and aroma; differences were detected for each wine comparison. In both seasons, continually irrigated wine differed from early and late season water deficit wine, and early season water deficit wine differed from late season water deficit wine in appearance, flavour, taste and aroma. The sensory differences were not attributable to differences in vine yield or fruit maturity. When professional wine tasters were sampled using similar tests, a majority was able to detect visual but not flavour differences between a selected pair of wines. It is concluded that, where vine water status can be altered, irrigation offers a means to manipulate wine sensory characteristics in the vineyard.

Dependence of wine sensory attributes on vine water status

Strawberries (Fragaria ananassa Duch., cv. ‘Selva') were stored 10 days in 1.0%, 0.5%, or 0.25% 02 or air + 20% CO2; or 6 days in air + 50% or 80% CO2 at 0 or 5°C without detrimental effects on quality. Decay and softening were reduced by treatments. An untrained taste panel, under ordinary eating conditions, did not consistently differentiate ‘Pajaro’ strawberries kept in 0.25% 02 from those stored in air. A trained taste panel, under controlled conditions, perceived slight off-flavor in ‘G3’ strawberries kept in 0.25% or 0% 02. This correlated with ethanol, ethyl acetate, and acetaldehyde in juice. The 50% or 80% CO2 treatments caused injury after 8 to 10 days, while 20% CO2 treatments did not. All high CO2 treatments caused increase in pH of juice.

Effects of Short‐term Exposure to Low O2 and High CO2 Atmospheres on Quality Attributes of Strawberries

The sensation produced by carbonated beverages has been attributed to chemical excitation of nociceptors in the oral cavity via the conversion of CO(2) to carbonic acid in a reaction catalyzed by carbonic anhydrase. In separate studies, we tested if the carbonic anyhdrase blocker, acetazolamide, reduced either the intensity of sensation in humans or c-fos expression by trigeminal neurons in rats, evoked by application of carbonated water to the tongue. In the psychophysical experiment, one-half of the dorsal tongue was pretreated with acetazolamide (1 or 2%), after which the tongue was exposed bilaterally to carbonated water. In a two-alternative forced-choice paradigm, subjects chose which side of the tongue yielded a stronger sensation and additionally rated the magnitude of sensation on each side. Pretreatment with acetazolamide reduced the magnitude of sensation elicited by carbonated water in a concentration-dependent manner, since a significant majority of subjects chose the untreated side of the tongue as having a stronger sensation and assigned significantly higher intensity ratings to that side. Acetazolamide did not affect the irritant sensation from citric acid, while capsaicin pretreatment reduced both the sensation elicited by carbonated water and the irritation induced by citric acid application. In a separate experiment using rats, delivery of carbonated water to the tongue significantly increased the number of cells expressing c-fos-like immunoreactivity in the dorsomedial trigeminal nucleus caudalis (versus saline controls); this was significantly reduced by pretreatment with acetazolamide. Our results support the hypothesis that carbonated water activates lingual nociceptors via conversion of CO(2) to carbonic acid; the nociceptors in turn excite trigeminal neurons involved in signaling oral irritation.

/pdf/psychophysical-and-neurobiological-evidence-that-the-oral-7hbqv80bri.pdf

Psychophysical and neurobiological evidence that the oral sensation elicited by carbonated water is of chemogenic origin.

The 9-point hedonic scale has been used routinely in food science, the same way for 60 years. Now, with advances in technology, data from the scale are being used for more and more complex programs for statistical analysis and modeling. Accordingly, it is worth reconsidering the presentation protocols and the analyses associated with the scale, as well as some alternatives. How the brain generates numbers and the types of numbers it generates has relevance for the choice of measurement protocols. There are alternatives to the generally used serial monadic protocol, which can be more suitable. Traditionally, the ‘words’ on the 9-point hedonic scale are reassigned as ‘numbers’, while other ‘9-point hedonic scales’ are purely numerical; the two are not interchangeable. Parametric statistical analysis of scaling data is examined critically and alternatives discussed. The potential of a promising alternative to scaling itself, simple ranking with a hedonic R-Index signal detection analysis, is explored in comparison with the 9-point hedonic scale. © 2014 Society of Chemical Industry

Michael O'Mahony

Papers

Understanding discrimination tests: a user-friendly treatment of response bias, rating and ranking r-index tests and their relationship to signal detection

Dependence of wine sensory attributes on vine water status

Effects of Short‐term Exposure to Low O2 and High CO2 Atmospheres on Quality Attributes of Strawberries

Psychophysical and neurobiological evidence that the oral sensation elicited by carbonated water is of chemogenic origin.

The 9-point hedonic scale and hedonic ranking in food science: some reappraisals and alternatives.