1. The effect of cognitive load on neural responses to sweet and sour tastes
- Author
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Van Steenbergen, Henk, Van Dillen, Lotte, H. Van Steenbergen, and Van Meer, Floor
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FOS: Psychology ,Food Studies ,Cognition and Perception ,Neuroscience and Neurobiology ,Cognitive Neuroscience ,Psychology ,Life Sciences ,Social and Behavioral Sciences - Abstract
There is a pressing need to better understand when and why people overconsume, especially in the realm of unhealthy eating. For instance, the recommended limit for the daily dose of sugar that is considered healthy roughly lies at 5% of the daily calorie intake. Yet, 15-22% of the average European citizen’s energy intake now comes from sugar, with Germany and The Netherlands taking up the second and third position worldwide, respectively (Azaïs-Braesco et al., 2017). Moreover, Europeans consume on average between 8 and 12 grams of salt per day (European Commission, 2013) with all countries exceeding the recommended maximum. At the same time, people often consume foods in non-optimal settings. Almost half of all weekly meals are reportedly consumed in a room with a television switched on (Gore et al., 2003) and foods consumed away from home are typically higher in fat, sugar, and salt than foods consumed at home (Drewnowski, 2003). This accords with experimental work showing that, when people are engaged in (mentally) taxing tasks, they tend to eat more, especially palatable foods (Ward & Mann, 2000). In the current project, we propose that these two trends (consuming too much and consuming while engaged in other activities) have not developed independently, and that the latter trend may at least in part explain the first. To this end, we have introduced the concept of hedonic compensation - consuming more of a hedonic good in order to compensate for reduced pleasure from its consumption – and we will examine its contextual triggers. Our project will contribute to a better understanding of the relationship between mental capacity, hedonic experiences, and consumption, and of the problems resulting from an imbalance between these factors, such as overconsumption. This study builds on our previous projects ‘Hedonic responses to sweet taste are moderated by cognitive load’ and ‘Neural correlates of hedonic compensation. How cognitive load moderates sweetness preferences’ which provided first neuropsychological evidence that neural responses to sweet taste stimuli (tastants) are down-regulated by concurrent cognitive load. Participants received on a trial-by-trial basis, small doses of high versus low glucose concentrations, while they concurrently engaged in a one-digit versus seven-digit memory span task. We observed a suppression of activation, especially in response to high sweet tastants, under high load compared to low load in the anterior insula, suggesting that mental load interferes with sensory processing of taste at the neural level (Van Dillen et al., in preparation). This suppressed activity coincided with less intense ratings of the sweet solutions under high versus low cognitive load, thus replicating our earlier results (Van der Wal & Van Dillen, 2013) using a taste paradigm in a setting compatible to the scanner and adding to our earlier fMRI results using a food picture paradigm (Van Dillen & Van Steenbergen, 2018). These experiments show a clear effect of cognitive load on the processing of the intensity of sweet taste. However, it remains unknown how cognitive load affects hedonic value. In other words, people seem to taste sweet stimuli less, but do they also value them less? To answer this question in this study we aim to disentangle the effect of cognitive load on taste intensity and hedonic valuation. We do this by including both sweet and sour tastants that differ in intensity. We hypothesize that sweeter solutions will be valued more (i.e. participants will indicate they want to consume them more often) and be rated as more intense, while more sour solutions will be rated as more intense but not valued more. We then have the opportunity to examine whether cognitive load differentially affects neural processing of these different types of tastants. Furthermore, this study adds to our previous work by examining possible individual differences in the effect of cognitive load on the neural processing of tastes. As hedonic compensation is thought to influence overconsumption, we will examine the association with body mass index (BMI). Since the magnitude of the effect of cognitive load on taste processing may be related to attentional control, which in turn has been related to BMI (Gunstad et al., 2006), we will take this into account as well. Taken together, the study described above will be the next step in elucidating the mechanisms behind hedonic compensation.
- Published
- 2023
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