Dr. Bahador Bahrami

Communication of Subjective Uncertainty

Humans and other animals integrate noisy sensory input to infer the state of the world, and guide action and choice. Action selection is accompanied by a ‘sense of confidence’, a subjective feeling about the validity of the choice. One of the most intriguing features of confidence is that humans tend to communicate this feeling in a largely idiosyncratic way: although confidence reports are typically stable within each person, they tend to be variable across the population.

This creates a fundamental problem for communication: how do we interpret other people’s confidence? How do we accurately communicate to them what we have in mind? Our most recent works on this topic here:

Navajas, J., et al (2017). The idiosyncratic nature of confidence. Nature Human Behaviour, doi:10.1038/s41562-017-0215-1.

Manipulation by Strategic Expression of Uncertainty

The role of social influence in our lives cannot be overstated. Critical issues ranging from the outcomes of political campaigns to our stand on issues such as global warming, immigration and taxation, depend on people trying to persuade the general public. Research on social influence has been dominated by the motivation to understand the minds of the TARGET of influence – the “clients” - (e.g., consumers, voters) in order to exert even more influence on them. Far less is known about the cognitive and neurobiological processes at play in the persuaders – the “advisers” (e.g. politicians, salesmen).

Social influence is most relevant when in human interactive decision making under uncertainty (e.g. parliaments, court juries, corporate boards). We develop laboratory models for how human agents may use strategic expressions of their confidence to influence the preferences and decisions of others. Here is a preprint of our most recent work on this topic:

Hertz, U., Palminteri, S., Brunetti, S., Olesen, C., Frith, CD., Bahrami, B. Neural computations underpinning the strategic management of influence in advice giving. Nature Communications (2017)

Aggregating Uncertain Opinions in Deliberation

The aggregation of many independent estimates can outperform the most accurate individual judgment. Such “wisdom of crowds” has recently been applied to problems ranging from the diagnosis of cancer to financial forecasting. It is widely believed that social influence undermines collective wisdom by reducing the diversity of opinions within the crowd. Our research shows that if a large crowd is structured in small independent groups, deliberation and social influence within groups improve the crowd’s collective accuracy.

Our research now focuses on the psychological and computational characteristics of the deliberation process in order to understand how we can use them to help human groups make better decisions. Here is one of our most recent work: Navajas, J., Niella, T., Garbulsky, G., Bahrami, B., & Sigman, M. Aggregated knowledge from a small number of debates outperforms the wisdom of large crowds. Nature Human Behavior (2018)