How the brain combines our opinions with online reviews

What was the main objective of this study regarding social information integration?

To investigate whether the human brain integrates social information according to its reliability and how this integration affects valuation and confidence judgments.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

According to the Bayesian view, under what conditions should individuals update their beliefs most toward a social consensus?

When they are initially uncertain about their own belief and the social information is highly reliable (such as having a large number of reviewers).

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What dual roles have been proposed for the ventromedial prefrontal cortex (mPFC/vmPFC) in value representation?

Representing subjective value estimates and tracking the reliability (or uncertainty) of those estimates.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Why was the dorsomedial prefrontal cortex (dACC/dmPFC) selected as a primary anatomical region of interest?

Because of its established central role in social cognition and in mediating social influence over value computation.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

For what three specific reasons were four of the twenty-two recruited participants excluded from the final analysis?

One experienced scanner technical problems, another exhibited excessive head motion, and two showed erratic product ratings.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What three elements of social review information were presented to participants during the scanning task?

The mean of the reviews (1–5 stars), the number of reviewers, and a 5-bar histogram showing the distribution of ratings.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What two key ratings did participants provide for each product during the prescanning task?

Their liking rating for the item and their confidence in that liking rating.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Why was the direction of the product rating and confidence scales reversed after two blocks of trials?

To prevent visual and motor confounds during brain imaging in the scanner.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

How were participants incentivized to make honest ratings during the scanning task?

They were told that a product would be chosen randomly as compensation, and higher ratings would increase their chances of receiving that product.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What were the timing constraints for ratings and confidence reports in the scanning task?

Participants had 7 seconds to rate the product and 4 seconds to report their confidence.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What was the scientific rationale for using a 1.5 T MRI scanner instead of a higher-field-strength scanner?

A 1.5 T scanner has less pronounced signal dropoff in the orbitofrontal cortex, which can yield greater BOLD sensitivity in that region.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What two trial-by-trial parametric regressors modulated the item onset in GLM1?

The second liking rating (R2) and the post-choice confidence rating (C2).

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What single parametric regressor was used to modulate item onset in GLM2?

The trial-by-trial Kullback–Leibler (KL) divergence computed from the descriptive Bayesian model.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

How did the study's Bayesian model mathematically formalize the link between reported confidence and prior variance?

Higher reported confidence corresponded to lower prior variance, meaning greater mathematical precision.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

How did the authors validate the descriptive Bayesian model given that it was not directly fit to confidence data?

They verified that the model's posterior precision positively correlated with the participants' second confidence ratings.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What does a 'degree of resistance to Amazon reviews' value of 1 indicate in the study's model?

It indicates that the Amazon reviews were completely ignored, and the participant's prior mean remained equal to the posterior mean.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What predictor in the hierarchical regression confirmed that participants generally conformed to the group consensus?

The initial deviation of the participant's rating from the group mean, which positively predicted their rating update.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

How did initial confidence modulate a participant's susceptibility to social influence?

Lower initial confidence led to a significantly stronger update toward the group consensus.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

How did the volume (number) of Amazon reviews affect participants' likelihood of conforming?

The rating update toward the group mean was largest when the number of reviews was higher, indicating greater social reliability.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Under what condition did participants' overall confidence decrease from their first rating to their second rating?

Confidence decreased when there was a large absolute difference between the participant's initial rating and the group consensus.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What mathematical relationship existed between post-choice confidence (C2) and the final product rating (R2)?

A quadratic relationship, where confidence was highest for products at the extreme ends of the rating scale.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What was revealed by a conjunction analysis of liking rating and confidence in the mPFC/vmPFC?

It isolated a single functional cluster representing both subjective liking (pleasantness) and confidence in that estimate.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Describe the functional gradient observed along the medial prefrontal cortex's (mPFC) ventral-dorsal axis.

Liking (value) ratings were represented more ventrally, whereas confidence ratings were represented more dorsally.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

How do the authors functionally interpret the ventral and dorsal subregions of the mPFC gradient?

The ventral region codes for the mean value estimate, and the more dorsal region codes for the reliability of these estimates.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Why is Kullback–Leibler (KL) divergence a critical parameter for analyzing fMRI data in this study?

It provides a trial-by-trial measure of the belief update that combines initial confidence (internal uncertainty) and review numbers (external reliability).

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What neural activation was associated with parametric increases in trial-by-trial KL divergence?

Activity in the dorsomedial prefrontal cortex (dmPFC) positively correlated with KL divergence, indexing the magnitude of the belief update.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

How did dmPFC activation during belief updating relate to individual differences in susceptibility to social influence?

Activity in the dmPFC was significantly higher for individuals who were more resistant to (less influenced by) social reviews.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

To what domain of cognitive processing do the authors compare the social belief updating mechanism?

Perceptual decision making, suggesting that both utilize an analogous Bayesian-like integration mechanism.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What alternative hypothesis did the researchers test regarding dmPFC's role in social influence?

They tested whether the dmPFC merely detects conflict with group consensus to trigger compromise, or if it is involved in more complex Bayesian updating.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What neuromodulator is hypothesized to trigger internal model updates by signaling mismatches between predictions and feedback?

Noradrenaline.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Why would less conformist individuals show heightened overall dmPFC activity when exposed to divergent social opinions?

Heightened dmPFC activity indicates sensitivity to divergence from the group, which helps the individual monitor differences and maintain their original opinion.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Why, according to the authors, is dmPFC activity reduced in highly conforming individuals?

Highly conforming individuals wholesale accept the group opinion rather than integrating and monitoring differences between conflicting beliefs.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

According to a Bayesian account of integration, when should posterior confidence be highest?

Confidence should be highest when the participant's initial rating and the group mean align.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

Where did the product reviews shown to participants during the scanning task originate?

They were actual, real reviews retrieved directly from the Amazon UK website.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified

What other brain regions have previous studies shown to track simple mismatches between individual and group opinions?

The rostral cingulate cortex and the striatum.

Source: Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability · DOI · quote verified