Behavioral Analysis

To test whether our experimental paradigm was able to generate a measurable behavioral bias, we compared ratings for professionally framed performances with student-framed performances (see Fig. 1B). A nonparametric test revealed a significant difference in subjective value as a function of framing condition (Wilcoxon signed-rank test, z = 2.750, p = 0.006, paired two-sided test). Participants rated excerpts framed as the performance of a professional (M = 4.74, SD = 0.65) significantly higher than excerpts framed as the performance of a student (M = 4.48, SD = 0.72). This confirms that the experimental paradigm was able to produce the predicted behavioral effect, replicating the findings in5. Furthermore, to account for possible influencing factors other than the framing, we regressed in a mixed effects model participant’s self-reported musical ratings on the framing condition (professional vs. student), on whether the performer was actually a professional or a student, and on the order of the presented frame. In keeping with reported results, only the framing condition exhibits significance (P = 0.006), whereas participants were not able to ‘guess’ the actual performer (P = 0.29). The presented order of the frame exhibits a trend (P = 0.058) (see full regression table in Supplementary Table 2).

fMRI Analysis

Differential neural activity related to the enjoyment of a musical excerpt

To better understand the cognitive processes that led to a positive bias in favor of the professional, we analyzed neural activity that preceded a preference for excerpts labeled as played by a professional player compared to the neural activity that preceded a preference for excerpts labeled as played by a student player. Thus, we first computed a whole brain contrast between trials in which a professionally framed performance was preferred with trials when a student-framed performance was preferred. This enabled us to detect any differences in the evidence accumulation phase (i.e. the listening period) across conditions and to shed light on the underlying neural mechanisms leading to the observed disparity in preferences.

Our analysis revealed that, when a piece was preferred, the professional pianist frame induced significantly more activity in the primary auditory cortex relative to the student pianist frame (see Fig. 2A). This suggests that beliefs regarding the quality of a performer engendered a bias in attention.

Figure 2 We computed a whole brain contrast between trials in which a professionally framed performance was preferred and trials when a student-framed performance was preferred. (A,B) Provided an excerpt was preferred, the professional pianist frame induced significantly more activity in the primary auditory cortex relative to the student pianist frame. (C,D) Greater activation was also found in the vmPFC following the professional frame relative to the student frame. Full size image

To better understand the evolution of activation during the information accumulation phase in the primary auditory cortex, we extracted brain activity that correlated with the framing stimulus over both the framing and listening periods (see Fig. 2B). We observed higher activation in the primary auditory cortex when the player was described as a professional pianist relative to when the player was described as a student. Moreover, this difference in activity remained consistent, exhibiting no significant changes across the 70 seconds of the excerpt. A panel regression of activity in the primary auditory cortex on time showed no significant linear slope (b 1 = 0.0003, z = 0.56, p > 0.5). This supports the notion that a bias in attention began almost immediately (i.e. 4 sec) after the presentation of the framing information and remained stable throughout the evidence accumulation period. Contrary to the notion that more evidence should diminish any framing effects generating during the relatively short framing period (i.e. 4 sec), we found that the professional framing gave rise to a constant attentional bias in favor of the professional player.

To address the question of how this attentional bias materializes in the behavioral tendency to prefer professionally framed performances, we examined activity in the vmPFC – a region repeatedly shown to play a critical role in the evaluation and encoding of primary and monetary rewards. To identify the region of vmPFC relevant to our task, we tested for brain regions that were more active following professional framing relative to student framing. This analysis identified the region of the vmPFC shown in Fig. 2C and D. Similarly, in averaging over all time points during the framing and listening periods, we found that an overlapping region of the vmPFC signal was significantly biased in favor of the professionally framed performance (Wilcoxon signed-rank test, z = 2.203, p = 0.0276, two-sided). We also tested whether framing-related differences in this regions’ activity changed across time as participants gained more direct experience with the musical piece. A panel regression found no significant linear slope (b 1 = −0.0002, z = −0.14, p > 0.5). Taken together, these findings suggest the presence of a confirmation bias, with the same musical excerpt attracting more attention and correspondingly increased neural signal in the auditory cortex, accompanied by an increase of the neural signal related to subjective value (i.e. vmPFC) when the player was viewed as an established professional in comparison to a conservatory student. Brain activity during the framing period further supports this notion (see Supplementary Information Fig. S1). Particularly, activity in the vmPFC during the framing period—before a single note had been played—correlated with the extent of the behavioral bias. This indicates that the bias was activated in response to the information frame and persisted throughout the duration of the performance (see also Supplementary Information Fig. S2).

Neural activity related to overcoming professional-student bias

The question remains: how did some participants, at least during some trials, successfully overcome the professional-vs.-student bias and express a preference for the student performance? Two possibilities exist. In behavioral analyses, biases are assumed to produce a response tendency, with variability around this tendency conceptualized as a nuisance noise term. If positive responses to excerpts primed as played by a student merely represented a kind of error or noise, trials in which the performance was primed as student should be associated with no consistent pattern of brain responses. Conversely, it is also possible that there is something systematic about these responses, with the response bias acting as an initial response tendency that must be explicitly overcome. If this were the case, we would expect that regions of the executive control network associated with response inhibition or cognitive control to consistently be activated during trials when the student performance was reported as preferred.

To distinguish between these possibilities, we computed a contrast between activity during unfavored performances that were framed as played by a professional and those that were framed as played by a student. In both of these cases, participants reported the same low preference. Differences in neural activity may therefore be attributed to differences in the processing of the information provided prior to the listening period. That is, by computing the difference between trials framed as professional and those framed as student in cases where the trials were not preferred, we were able to analyze the cognitive processes involved in overcoming the framing effect and resisting the tendency to prefer the professional.

As shown in Fig. 3A, relative to student-framed performances that were not preferred, professional-framed performances that were not preferred elicited higher activity in the dlPFC, a region related to cognitive control and deliberative effortful thinking processes16,17,18,19,20,21. The development of neural activity in the dlPFC (see Fig. 3B) remained consistently biased toward the professional throughout the listening period (Wilcoxon signed-rank test, z = 3.472, p = 0.0005, two-sided). This suggests that, as information about the quality of the performance accumulated, participants needed to exert cognitive control in order to form and retain a negative evaluation for performances that had been framed as played by a professional compared to those that had been framed as played by a student. These data suggest that less cognitive effort was required to dislike a performance when it had been described as played by a student rather than a professional. Once again, this pattern of neural activity is consistent with what would be expected from mechanisms underlying a confirmation bias. According to this reading, a low quality auditory experience is easier to associate with a student than a professional. The dlPFC – a critical part of the executive control network – activates differentially when deliberatively overcoming the initial bias evoked by the frame of professionalism.

Figure 3 (A,B) We computed a whole brain contrast between trials in which a professionally framed performance was not preferred and trials when a student-framed performance was not preferred. This contrast identified a region of the dlPFC, indicating that dlPFC activity correlated with instances when the professionally framed performance was perceived as less impressive compared to cases when the student-framed performance was not preferred. Full size image

Based on these findings, we assumed that activity in both regions–the vmPFC and dlPFC–would also be indicative of the magnitude of the behavioral bias shown by participants, extending beyond a simple dichotomy of expressed preferences. To confirm that activity in these two regions predicted the magnitude of the actual behavioral bias, we first extracted the activity for each subject in the vmPFC, the dlPFC, and two additional control regions that also showed a significant difference in activity across framing conditions (in fusiform gyrus and left orbitofrontal cortex, OFC). We then regressed the magnitude of the behavioral bias on the extracted activity of each identified region that was averaged across all voxels in a simple OLS regression (see Table 1). Our analysis reveals that only neural activity in the vmPFC had a significant positive impact on the magnitude of the behavioral bias, whereas regions in the sensory (fusiform) and lateral OFC were not correlated with the size of the behavioral bias. Additionally, dlPFC activation correlated with a significantly reduced behavioral bias, suggesting that the exertion of cognitive control counteracts the behavioral bias induced in the vmPFC.

Table 1 Predicting the Magnitude of the Behavioral Bias. Full size table

We conclude that the consistent bias in vmPFC activity indicated a preference in favor of the ostensibly professional pianist over the ostensibly student one, and additionally, that the magnitude of this behavioral bias is mitigated by the exertion of cognitive control in the form of dlPFC activation.

White-matter structure of cortico-striatal fiber tracts predict framing effects

Given the relationship between trial-level dlPFC activity and behavioral bias, we reasoned that individual differences in the connectivity between the executive control network and areas of the reward network would predict participants’ behavioral bias. Two methods are available to test this prediction. First, diffusion weighted imaging may be used to estimate individual anatomical connectivity of cognitive control structures with the reward network. We predicted that this structural connectivity would negatively correlate with the bias to prefer a professional player. Alternatively, functional connectivity between dlPFC and vmPFC can be assessed using psychophysiological interaction (PPI) analyses18. DTI and PPI analyses ostensibly both measure brain connectivity. For brevity, we report DTI analyses below and refer readers to Supplementary Information (S4) for the qualitatively equivalent results using PPI.

We based our analysis strategy on previous findings demonstrating the importance of striatal structures in integrating and interfacing input from different networks with each other15. In keeping with neuroanatomic findings regarding the integration of separate cortical loops in the striatum14,15, we focused our analysis on the structural connectivity of both pathways, from the dlPFC to the striatum, and from the vmPFC to the striatum. In particular, the caudate is known to receive afferent projections from across the frontal cortex, with separable patches associated with dlPFC and vmPFC connectivity14. Based on the specific properties of the caudate within the cortico-basal ganglia circuit and its role in connecting important parts of the cognitive control network with reward structures, we conducted probabilistic tractography with the dlPFC activation mask as a seed and the caudate as a target region. Analogously, we then performed the same probabilistic tractography with the vmPFC activation mask as a seed and the caudate as a target region (see Fig. 4).

Figure 4 The results of probabilistic tractography were plotted against the magnitude of the behavioral framing effect. Specifically, based on our results from the fMRI analysis, we computed the likelihoods of two cortico-striatal tracts, the dlPFC-caudate and vmPFC-caudate, separately for each participant. We then plotted the averaged cortico-striatal tract likelihoods against the magnitude of the behavioral bias. A non-parametric test revealed a significant correlation between the magnitude of the framing effect and the averaged likelihood of both cortico-striatal tracts (Spearman’s rho = −0.4917, P = 0.0277, two-sided). Full size image

To obtain a single measure for structural connectivity of cortico-striatal fiber tracts that link and integrate reward structures with cognitive control structures, we computed the average likelihood of both fiber tracts connecting to striatal regions. Since possible fiber tracts need to be restricted to the originating hemisphere, and task-related dlPFC activation was only present in the right hemisphere, we used the right caudate as the nexus between the dlPFC and the vmPFC (see Supplementary Information Fig. S4). An ipsilateral caudate mask obtained qualitatively similar results.

In line with our hypothesis, we found that the average connectivity of both pathways (i.e. dlPFC to caudate as well as vmPFC to caudate) negatively correlated with the tendency to prefer a professional player (Spearman’s rho = −0.4917, P = 0.0277, two-sided). To confirm our results, and to differentiate activity-related effects from structural connectivity between these regions, we regressed the behavioral bias on the structural connectivity of both identified cortico-striatal pathways together with activation in vmPFC and dlPFC (see Table 2). Thus, controlling for activation, participants with greater structural connectivity along the sum of both frontal striatal pathways demonstrated a significantly lower extent of the behavioral bias and showed a lower propensity to prefer the professional player.