How context alters value: The brain's valuation and affective regulation system link price cues to experienced taste pleasantness

Abstract

Informational cues such as the price of a wine can trigger expectations about its taste quality and thereby modulate the sensory experience on a reported and neural level. Yet it is unclear how the brain translates such expectations into sensory pleasantness. We used a whole-brain multilevel mediation approach with healthy participants who tasted identical wines cued with different prices while their brains were scanned using fMRI. We found that the brain's valuation system (BVS) in concert with the anterior prefrontal cortex played a key role in implementing the effect of price cues on taste pleasantness ratings. The sensitivity of the BVS to monetary rewards outside the taste domain moderated the strength of these effects. These findings provide novel evidence for the fundamental role that neural pathways linked to motivation and affective regulation play for the effect of informational cues on sensory experiences.

Figure 1

Experimental procedure, wine tasting task and results in N = 30 participants. (a) Experimental procedure: The experiment consisted of three events spread over two weeks. (b) Wine tasting task: Screenshots depict events within one trial with durations in seconds. Each trial started with the display of the price and payment condition. Following a jittered interstimulus interval (ISI) with a fixation cross on the screen, 1.25 ml of wine was tasted via a tube and subsequently swallowed. Participants rated on a visual analogous scale their experienced pleasantness. They then rinsed their mouth with a water-like neutral liquid. Trials were separated by a jittered inter-trial interval (ITI) during which a fixation cross was displayed on the screen. (c) Mediation framework and behavioral results from N = 30 participants: Multilevel whole-brain mediation involved high and low price cue trials (€18, €3) as predictor variables, trial-by-trial beta images of brain activation at time of wine tasting as a mediator variable, and experienced taste pleasantness ratings as a dependent outcome variable depicted in the bar graphs. Error bars correspond to the standard error of the mean (SEM). Note that the effect of price cue was linear across the three price conditions, replicating prior work. There was no effect of payment condition (see SI Figs S1–S3), which was fit into the model as a covariate of non-interest alongside wine type.

Figure 2

Brain responses to price cue and experienced pleasantness ratings averaged across N = 30 participants (*p _FWE < 0.05). Significant voxels are displayed for visualization purposes in yellow at p < 0.001 uncorrected, and are superimposed on the average anatomical brain image. The [x, y, z] coordinates correspond to MNI coordinates and are taken at maxima of interest. (a) Path a: price cue–related effect on brain activity. The line graphs depict time courses across seconds for activations in the reported [x, y, z] MNI coordinates. The dotted squares denote the 8-second-long wine tasting period. Shaded errors represent confidence intervals (means ± intersubject SEM). (b) Path b: brain activity underpinning experienced pleasantness ratings. Line graphs depict individual variations in path b coefficients (blue lines) with the group regression slope (grey line) for the activations in the reported [x, y, z] MNI coordinates. Grey lines represent confidence intervals (95%). ACC/vmPFC: anterior cingulate cortex/ventromedial prefrontal cortex; antPFC: anterior prefrontal cortex; dlPFC: dorsolateral prefrontal cortex.

Figure 3

Brain mediators and moderators of price cue effects in N = 30 participants. (a) BOLD activity in the ventral striatum, anterior prefrontal cortex and ventromedial prefrontal cortex mediated price cue effects on experienced pleasantness ratings (p _FWE < 0.05). Significant voxels are displayed for visualization purposes in yellow at p < 0.001 uncorrected, and are superimposed on the average anatomical brain image. (b–d) Multilevel mediation path diagram across N = 30 participants for the three brain mediators of price cue effects: (b) the ventral striatum, (c) the ventromedial prefrontal cortex (vmPFC) and (d) the anterior prefrontal cortex (antPFC). The [x, y, z] coordinates correspond to Montreal Neurological Institute (MNI) coordinates and are taken at maxima of interest. Average path coefficients (a × b (SEM)) and the correlation of a&b coefficients (cov) across participants denote the joint activation in paths a and b at ***p < 0.001, **p < 0.01 or ⁺ p < 0.05 two-tailed. Note that multilevel mediation effects can be driven either by significant path a and b co-activation or by covariance of path a and b coefficients.

Figure 4

Whole-brain moderation of the price cue–related effect (path a) during wine tasting in a subset of N = 17 participants. The yellow and orange voxels depict significant brain activation by experienced reward during an independent monetary decision-making task, and are displayed at a threshold of p _FWE < 0.05 corrected for multiple comparisons on the cluster level. Blue voxels depict brain regions of the BVS that were positively moderated by the reward-related activation of the BVS during the monetary decision-making task. They are displayed at a threshold of p < 0.001 uncorrected at the voxel level for visualization purposes. The path a coefficient corresponds (SEM) to the moderated price cue effect on the vmPFC activation (**p < 0.01, two-tailed), highlighted by a dark blue circle. All voxels are superimposed on the average anatomical brain image. The scatterplot shows the correlation between the vmPFC path a response (p _FWE < 0.05) and the reward-related BVS response.