The real deal: Willingness-to-pay and satiety expectations are greater for real foods versus their images

Abstract

Laboratory studies of human dietary choice have relied on computerized two-dimensional (2D) images as stimuli, whereas in everyday life, consumers make decisions in the context of real foods that have actual caloric content and afford grasping and consumption. Surprisingly, few studies have compared whether real foods are valued more than 2D images of foods, and in the studies that have, differences in the stimuli and testing conditions could have resulted in inflated bids for the real foods. Moreover, although the caloric content of food images has been shown to influence valuation, no studies to date have investigated whether 'real food exposure effects' on valuation reflect greater sensitivity to the caloric content of real foods versus images. Here, we compared willingness-to-pay (WTP) for, and expectations about satiety after consuming, everyday snack foods that were displayed as real foods versus 2D images. Critically, our 2D images were matched closely to the real foods for size, background, illumination, and apparent distance, and trial presentation and stimulus timing were identical across conditions. We used linear mixed effects modeling to determine whether effects of display format were modulated by food preference and the caloric content of the foods. Compared to food images, observers were willing to pay 6.62% more for (Experiment 1) and believed that they would feel more satiated after consuming (Experiment 2), foods displayed as real objects. Moreover, these effects appeared to be consistent across food preference, caloric content, as well as observers' estimates of the caloric content of the foods. Together, our results confirm that consumers' perception and valuation of everyday foods is influenced by the format in which they are displayed. Our findings raise important new insights into the factors that shape dietary choice in real-world contexts and highlight potential avenues for improving public health approaches to diet and obesity.

Object responses are highly malleable, rather than invariant, with changes in object appearance

“…The relevance of conceptual information about location for both real and 2-D objects is consistent with the idea that we frequently encounter and use real objects in specific locations which could elicit powerful expectations about co-occurrence 55 . At the same time, our results from inverse MDS complement and critically extend emerging data from behavioral 56 , fMRI 57,58 , EEG 59 and neuropsychological studies 13,60,61 , which have highlighted quantitative and qualitative differences in the way real objects and computerized images are processed during perception 13 , memory 62 , attention 63 and decision-making 64,65 . For example, real objects have been shown to elicit little if any fMRI repetition suppression (fMRI-RS), unlike 2-D images of the same objects, for which fMRI-RS effects are widespread throughout ventral and dorsal cortex 57 .…”

Distinct visuo-motor brain dynamics for real-world objects versus planar images

“…In summary, these data provide critical empirical support for recent speculations that realworld objects elicit stronger and more prolonged neural responses in action-related visuomotor networks than images do (Cisek and Kalaska, 2010;Gallivan et al, 2009;Gomez et al, 2017). The results provide new insights into the underlying neural mechanisms that drive the unique effects of real objects on human cognition, including eye movements in infants (Gerhard et al, 2016), object recognition (Chainay and Humphreys, 2001;Humphrey et al, 1994), attention (Gomez et al, 2017), memory (Snow et al, 2014), and decision-making (Mischel and Moore, 1973;Romero et al, 2017). Compared to images, real objects may trigger more vivid motor imagery, more detailed or well-specified action plans, and/or a greater number of competing action plans that must be resolved prior to decision (Gallivan et al, 2009;Gallivan et al, 2011a;Gomez et al, 2017).…”

“…A fundamental assumption in psychology and cognitive neuroscience has been that images of objects, which do not afford action, are processed similarly by the brain as are real-world solid objects. However, there is accumulating behavioral evidence that humans process realworld objects differently to stimuli presented in other display formats, including both 2-D planar (Chainay and Humphreys, 2001;Gerhard et al, 2016;Gomez et al, 2017;Humphrey et al, 1994;Romero et al, 2017;Snow et al, 2011;Snow et al, 2014) and 3-D stereoscopic images of objects (Gomez et al, 2017).The underlying neural mechanisms for these formatrelated effects on behavior have received scant investigation. Although real-world objects have been hypothesized to trigger stronger or more prolonged activation in visuo-motor networks involved in automatic action planning (Cisek and Kalaska, 2010;Gallivan et al, 2009;Gallivan et al, 2011b;Gomez et al, 2017), few studies have tested these ideas directly, most likely because of the difficulty of presenting real-world objects under controlled viewing conditions, and because of limitations in the temporal sensitivity of brain activity as measured by fMRI (Freud et al, 2017;Snow et al, 2011).…”

“…Emerging evidence from cognitive psychology has begun to challenge the assumption of equivalence between real objects and images. Compared to 2-D images of objects, realworld objects elicit different gaze patterns in infants (Gerhard et al, 2016), facilitate object recognition (Chainay and Humphreys, 2001;Humphrey et al, 1994), enhance memory (Snow et al, 2014), increase attentional capture (Gomez et al, 2017), and bias valuation and decision-making (Romero et al, 2017). These unique effects of real objects on behavior are thought to be driven at the neural level by format-specific increases in the strength and/or duration of activation in visuo-motor networks involved in automatic planning of motor actions (Cisek and Kalaska, 2010;Gallivan et al, 2009;Gomez et al, 2017).…”

Tasting Pictures: Viewing Images of Foods Evokes Taste-Quality-Specific Activity in Gustatory Insular Cortex

“…Previous studies have demonstrated that the physical presence of a food, compared to viewing a picture of it, increases subjects' willingness to pay for that food and the expected satiety upon its consumption (43,44). Additionally, cephalic phase responses such as insulin release and salivation all greatly increase with our degree of sensory exposure to a food, going from sight and smell all the way to initial digestion (45).…”