The problem the researchers set out to solve was one of fit. Existing imagery questionnaires tend to be modality-specific, probing only how vividly people visualise objects or conjure smells in isolation, or they rely on generic prompts that were never designed with eating in mind. Food, however, is an inherently multisensory experience. A single bite of chocolate recruits orthonasal smell as the aroma drifts up from the plate, retronasal smell as volatile compounds travel from the back of the mouth, basic taste qualities such as sweetness and bitterness, the mechanical feel of texture, and the visual appearance of the food itself. A measure that captures only one of these channels risks missing the very individual differences that matter most for eating behaviour research, from craving susceptibility to appetite control.

The project began with a preliminary item-generation study designed to identify foods and drinks with distinct, recognisable sensory characteristics. The goal was to source items that would reliably evoke each sensory channel, so that a participant rating their mental image of brewed coffee, for example, would be engaging the olfactory system rather than guessing at a vague, undifferentiated food memory. The final scale asks respondents to imagine 25 items across five domains: smell, flavour, taste, texture and appearance. Each item is rated from zero, meaning no image at all, to ten, meaning an image as clear and vivid as real life. The published version includes prompts such as imagining the smell of freshly baked bread and cinnamon rolls, the flavour of parmesan cheese and dark chocolate, the bitterness of coffee, the sourness of a lemon, ice cream melting in the mouth, and the look of a red apple or a scoop of ice cream.

With the item pool in hand, the team subjected the scale to a four-experiment validation programme involving well over a thousand participants in total. Experiment 1, with 354 participants, used exploratory factor analysis and parallel analysis, two statistical techniques for uncovering the latent structure underlying a set of questionnaire items, to refine the pool and examine internal consistency. The results supported a correlated five-factor solution, meaning the data were best explained by five related but separable dimensions corresponding to the five sensory channels. The fit statistics were strong: a root mean square residual of 0.023, a root mean square error of approximation of 0.065, and a comparative fit index of 0.962, alongside high internal consistency, indicating that items within each factor measured the same underlying trait coherently.

Reliability over time is just as important as internal structure, and here the team turned to Experiment 2. Eighty-three participants completed the scale twice, three to four weeks apart, allowing the researchers to compute a test–retest reliability coefficient. The total score achieved an intraclass correlation of 0.75, with a 95 percent confidence interval ranging from 0.62 to 0.82. In practical terms, this means a person’s standing on the scale is reasonably stable over a month, which is precisely what one would expect if the instrument is measuring a genuine trait, a stable disposition of the mind, rather than a fleeting mood or situational appetite. For a tool intended to characterise individual differences in eating-related cognition, that temporal stability is a foundational credential.

Experiment 3 then put the five-factor structure to a stricter test. Using a new sample of 393 participants, the researchers applied confirmatory factor analysis, a method that tests a predefined structure rather than letting one emerge from the data, and examined correlations with established questionnaires of visual and olfactory imagery vividness. The five-factor structure replicated cleanly, with a chi-squared statistic of 503.15 on 265 degrees of freedom, comparative and Tucker–Lewis fit indices both at 0.998, RMSEA of 0.048 and a standardised root mean square residual of 0.040. The convergent validity results were particularly elegant. The appearance factor correlated most strongly with visual imagery vividness, at a Spearman coefficient of 0.47, while the smell factor correlated most strongly with olfactory imagery vividness, at 0.51, both highly statistically significant. In other words, the food-specific channels behave as they should: they align with their general-domain counterparts without collapsing into them, suggesting the FIS captures something genuinely food-tuned.

The final and arguably most consequential experiment addressed the question that motivated the whole project: does food imagery vividness relate to actual eating-related tendencies? Experiment 4 recruited 781 participants and examined criterion-related associations with trait food craving, the dispositional tendency to experience intense desires for specific foods. After adjusting for covariates, the researchers found small but reliable positive associations for two of the sensory channels. Smell imagery vividness correlated with trait food craving at r = 0.110, significant at p = 0.002, and flavour imagery showed an association of r = 0.080, significant at p = 0.026. The effect sizes are modest, as is typical for single-trait predictors of complex behaviour, but their pattern is telling: the chemosensory channels, smell and flavour, the ones most intimately tied to the reward and pleasure of eating, are the ones that link to craving.

That pattern has intriguing implications. Flavour, as the scale clarifies for respondents, refers to the combined in-mouth experience arising primarily from taste and retronasal smell, distinct from the basic taste qualities of sweetness, sourness, saltiness, bitterness and umami. If people who more vividly imagine smells and flavours also report stronger trait cravings, vivid multisensory imagery may act as a kind of mental rehearsal of eating, priming desire before any food is present. This connects to a broader literature in which imagery is understood to function as a weak form of perception, recruiting overlapping neural machinery. It also opens practical questions for interventions: if imagery vividness shapes craving, techniques that modulate imagery, from vividness training to competing-task strategies that load the sensory systems and blunt craving episodes, could be tailored according to an individual’s FIS profile.

The authors are careful about the boundaries of what they have established. They note that future work should establish the scale’s incremental predictive validity, that is, whether it predicts eating outcomes better than general imagery measures already exist, and should test its cross-cultural generalisability, since foods like miso soup, soy sauce and roast dinners carry very different familiarity across populations, and food familiarity is known to shape both imagery and craving. The project was funded by a grant from the Royal Society of New Zealand through the Marsden Fund, with the design, conduct, analyses and interpretation conducted independently of the sponsor, and the work received ethics approval from the University of Otago Human Ethics Committee.

Even with those caveats, the arrival of a reliable, food-specific, multisensory imagery measure is a notable addition to the psychologist’s toolkit. For decades, eating behaviour research has had to borrow instruments built for other purposes, averaging across senses that food never treats separately. The FIS treats the imagined meal as what it actually is, a symphony of smell, flavour, taste, texture and sight, and offers researchers a way to ask not just whether a person thinks vividly, but whether their culinary imagination in particular runs hot. Given the scale’s documented psychometric credentials across four experiments and more than 1,600 participants, and its open-access availability, it seems likely to find its way into studies of craving, dietary choice, appetite and sensory science for years to come.

Subject of Research: Development and validation of a self-report scale measuring trait vividness of multisensory food imagery for eating behaviour research

Article Title: Developing and validating the Food Imagery Scale: a trait measure of multisensory food imagery for eating behaviour research

Article References: Peng, M., McCormack, J., Golo, S., Hames, M., Roberts, R., & Spence, C. (2026). Developing and validating the Food Imagery Scale: a trait measure of multisensory food imagery for eating behaviour research. BMC Psychology. https://doi.org/10.1186/s40359-026-05526-x

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05526-x

Keywords: mental imagery, food imagery, eating behaviour, food craving, psychometrics, sensory perception, flavour, olfaction, questionnaire validation, BMC Psychology, Developing, validating

The research team, led by Tong Wu and Jiashuo Huang of Beijing Technology and Business University, set out to answer a deceptively simple question: what actually happens inside a cup when coffee meets milk? To find out, they prepared four different coffee-milk systems, combining coffee with ultra-high-temperature treated and pasteurized milk, in both whole and skim varieties. This design allowed them to isolate the effects of two variables that matter enormously to the dairy industry and to consumers: how intensely the milk has been heat-treated, and how much fat it contains.

The first surprise came from just how thoroughly coffee transforms milk’s internal architecture. When milk was added to coffee, the mixture’s pH rose, its color became lighter, and its viscosity increased. The particles suspended in the liquid grew larger, and spectroscopic analysis using Fourier-transform infrared spectroscopy revealed distinct shifts in the chemical signatures of the mixture. Under the electron microscope, the researchers could see the evidence directly: aggregates had formed, clusters of milk proteins bound together with coffee components into structures that neither ingredient possessed on its own.

To understand why these aggregates form at all, the team turned to molecular docking, a computational technique more commonly associated with drug discovery than with breakfast beverages. The simulations revealed that coffee components latch onto milk proteins primarily through hydrogen bonding and pi-pi stacking interactions, the latter being a form of molecular attraction between flat, ring-shaped chemical structures. These weak but numerous bonds act like microscopic Velcro, stabilizing the complexes that form when the two liquids merge. It is a molecular handshake, repeated billions of times throughout the cup, that gives the drink its new physical identity.

Here is where the physics becomes genuinely counterintuitive. One might assume that larger, more numerous particles would make a drink feel smoother, the way cream enriches a soup. The opposite occurred. The structural reorganization triggered by coffee actually enhanced interactions between particles in the liquid, and this crowded, interactive environment reduced the lubrication at the interface between the beverage and the surfaces of the mouth. The measurable consequence was an increase in the friction coefficient, a tribological parameter that quantifies how much resistance arises when the liquid slides across a surface, in this case a simulated tongue.

Tribology, the study of friction and wear, has quietly become one of the most powerful tools in modern food science. Traditional rheology measures how a liquid flows in bulk, but it cannot capture what happens in the thin films that exist between the tongue and the roof of the mouth during swallowing. Those thin-film dynamics are where mouthfeel lives. A beverage can have identical viscosity readings yet feel dramatically different in the mouth if its particles interact differently with oral surfaces. By measuring friction coefficients across their four coffee-milk systems, the researchers could connect the invisible molecular architecture of the drink directly to the felt experience of drinking it.

The role of fat emerged as the decisive counterweight. In the systems made with whole milk, fat globules physically disrupted the aggregate structures that coffee components and milk proteins had built together. The fat essentially wedged itself into the protein-coffee networks, breaking them apart and restoring lubrication to the oral interface. The result was lower friction and, presumably, the smoother, rounder mouthfeel that whole-milk coffee drinkers know and love. To confirm that fat was genuinely the causal agent rather than a bystander, the team performed fat add-back experiments, reintroducing fat into the systems and watching the friction coefficients fall in response. The evidence was direct: fat is the friction-reducer, the natural lubricant of the coffee-milk world.

This finding carries real weight for an industry under pressure. Reduced-fat dairy products are in growing demand as consumers seek healthier options, but skim-milk coffee has never fully replicated the sensory appeal of its full-fat counterpart, and this study now explains why in physical terms. Remove the fat, and the protein-coffee aggregates remain intact, interparticle interactions intensify, lubrication drops, and friction rises, producing the thinner, sometimes astringent sensation that makes skim lattes disappointing. The researchers frame their work as a step toward optimizing the mouthfeel and sensory quality of reduced-fat coffee-milk beverages, suggesting that if manufacturers can find other ways to disrupt aggregates or restore interfacial lubrication, they might engineer low-fat drinks that feel indulgent without the fat.

The study also highlights how much sensory science has matured as a discipline. Rather than relying solely on taste panels to describe differences that panelists may struggle to articulate, researchers can now trace those differences down through multiple levels of organization: the molecular bonds between coffee polyphenols and milk proteins, the microscopic aggregates visible under electron microscopy, the bulk properties like viscosity and particle size, and finally the tribological behavior at the oral interface. Each level feeds into the next, and the sensory experience that reaches the consumer is the integrated output of this entire cascade. It is a reminder that even the most everyday pleasures rest on remarkably intricate physical foundations.

There is something almost poetic in the conclusion. Every morning, billions of people perform an unwitting experiment in soft-matter physics, pouring milk into coffee and setting off a cascade of hydrogen bonds, pi-pi stacking interactions, and aggregate formation that will register on their tongues as nothing more than a pleasant smoothness. The Beijing team’s work transforms that daily ritual into a map, showing exactly which molecular events produce which physical consequences and which sensory outcomes. For the coffee industry, it offers a blueprint for building better low-fat beverages. For everyone else, it offers a new appreciation of the hidden engineering in the cup, and of the humble fat globule, quietly dismantling protein networks one interface at a time so that your morning coffee glides instead of drags.

Subject of Research: Structural reorganization of milk matrices in coffee-milk systems and its effect on oral friction and sensory perception

Article Title: Milk matrix-driven structural reorganization modulates oral friction and sensory perception in coffee-milk systems

Article References: Wu, T., Huang, J., Hu, Y., Guo, K., Zeng, H., & Wang, Y. (2026). Milk matrix-driven structural reorganization modulates oral friction and sensory perception in coffee-milk systems. npj Science of Food. https://doi.org/10.1038/s41538-026-01173-z

Image Credits: AI Generated

DOI: 10.1038/s41538-026-01173-z

Keywords: coffee, milk, mouthfeel, tribology, food science, milk fat, molecular docking, oral friction, sensory perception, reduced-fat beverages, protein aggregates, npj Science of Food

Hygiene is a cornerstone of public health. Poor hygiene is closely tied to infection, disease transmission, and preventable illness, which is why public health researchers have long sought to understand the psychological drivers of behaviors such as handwashing, housecleaning, and personal grooming. Decades of work on disgust—the emotion thought to have evolved as a behavioral defense against pathogens—have established that people who are more easily disgusted tend to engage in more protective hygiene behavior. At the same time, olfaction has repeatedly been implicated in this picture: the sense of smell is our most direct chemical sensor of the environment, capable of detecting spoilage, contamination, and body odors that signal potential health threats.

The new research set out to connect these threads more rigorously. Rather than treating olfaction as a single, undifferentiated capacity, the team distinguished between olfactory metacognition—how people think and feel about their own sense of smell—and olfactory function measured objectively in the laboratory. The central hypothesis was that olfactory functioning relates to hygiene behavior at least partly through disgust sensitivity, the tendency to experience revulsion in response to potential contaminants. To test this, the researchers conducted two studies with distinct designs and measurement approaches.

Study 1 recruited 270 participants and focused on three indicators of olfactory metacognition: odor awareness, the subjective importance people attach to their sense of smell, and self-rated olfactory ability. Each of these indicators was positively associated with self-reported hygiene behavior. Crucially, when the researchers used mediation analysis to examine indirect pathways, each indicator showed a significant indirect effect through disgust sensitivity. In other words, people who were more attuned to odors, who valued their sense of smell more highly, and who rated their olfactory ability as stronger also tended to report higher disgust sensitivity—and that heightened disgust, in turn, was associated with more frequent and thorough hygiene practices.

These findings align with a conceptual framework in which disgust functions as part of the so-called behavioral immune system, a suite of psychological mechanisms that guard against disease threat before pathogens ever reach the body. According to this view, sensory inputs—especially smells—provide cues about potential contamination, and disgust converts those cues into avoidance and cleaning behavior. The Study 1 results suggest that individual differences in how prominently smell figures in daily awareness may shape the intensity of this disgust-based defense, and thereby the vigor of one’s hygiene routine.

But subjective self-reports are not the same as measured sensory ability. Study 2 therefore extended the investigation with 66 participants who completed psychophysical odor-threshold testing and suprathreshold ratings for one pleasant and one unpleasant odor. This design allowed the researchers to ask whether the ability to detect faint odors—rather than merely one’s beliefs about one’s own nose—also relates to hygiene behavior, and whether the valence of the odor matters. The results were more nuanced here. Odor sensitivity itself was not directly associated with hygiene behavior, a finding that echoes earlier work suggesting that disgust sensitivity relates to affective responses to odors rather than to the raw capacity to detect them.

Yet the indirect pathway through disgust sensitivity did appear in Study 2, though selectively. A significant indirect effect through disgust sensitivity was observed for the pleasant odor but not for the unpleasant odor. That an unpleasant smell failed to show the same pathway may seem counterintuitive, but the authors caution that a bootstrap comparison did not support a statistically reliable difference between the two indirect effects. In other words, the apparent pleasant-versus-unpleasant asymmetry at the threshold level should be interpreted with care, as the data could not confirm that the two odor conditions truly differed in the strength of this mediated pathway.

Where odor-condition differences did emerge clearly was at the suprathreshold level—when participants judged clearly perceivable odors. The associations of hygiene behavior with odor pleasantness and familiarity differed significantly between the pleasant and unpleasant odor conditions, with positive associations observed specifically for the pleasant odor. This suggests that how people appraise and contextualize everyday smells—their emotional coloring and their sense of familiarity—may relate to hygiene behavior differently depending on the hedonic character of the odor in question, whereas simple detection ability appears less consequential.

Taken together, the two studies paint a differentiated picture: subjective and psychophysical aspects of olfactory functioning are related to hygiene behavior in partly different ways. Disgust sensitivity emerges as one affective correlate of these associations, providing a plausible psychological route by which smelling and thinking about smells translates into washing, cleaning, and grooming. Meanwhile, odor valence effects were more clearly supported for conscious appraisal of suprathreshold odors than for basic odor sensitivity, implying that the emotional meaning of smell, rather than the acuity of the nose per se, drives much of the connection to hygiene.

The findings carry practical weight for public health. If disgust sensitivity mediates the link between olfaction and hygiene behavior, interventions aimed at improving hygiene might benefit from strategies that engage the sense of smell and the emotion of disgust together—approaches that earlier experimental and field-based work on hand hygiene has begun to explore. At the same time, the authors emphasize limits: the indirect pathway was not uniformly observed across odor conditions, the pleasant-versus-unpleasant asymmetry in threshold-based mediation was not statistically reliable, and the data underlying the study will be shared only on reasonable request to the corresponding author. Future research with larger and more diverse samples will be needed to determine when, and for whom, the nose-disgust-hygiene pathway operates most strongly—and whether it can be harnessed to promote healthier behavior at the population scale.

Subject of Research: The relationship between olfactory functioning, disgust sensitivity, and hygiene behavior

Article Title: Disgust sensitivity as an indirect pathway linking olfactory functioning and hygiene behavior

Article References: Jiang, C., Modi, U., & Han, P. (2026). Disgust sensitivity as an indirect pathway linking olfactory functioning and hygiene behavior. Current Psychology, 45(17), Article 1487. https://doi.org/10.1007/s12144-026-10057-0

Image Credits: AI Generated

DOI: 10.1007/s12144-026-10057-0

Keywords: olfaction, disgust sensitivity, hygiene behavior, odor awareness, olfactory metacognition, odor threshold, odor valence, behavioral immune system, public health, psychology, sensory perception, handwashing