Institute of Cognitive Neuroscience


Crowd Cognition

Crowd Cognition group investigates cognitive and neurobiological basis of interactive decision making. The group is led by Dr Bahador Bahrami.

Bahador Bahrami

Group Leader



+44 20 7679 1005

Bahador Bahrami

Crowd Cognition Research

Humans interact with each other to share information and make decisions. Our lab investigates the cognitive and neurobiological basis of interactive decision making. We use behavioural psychological testing, functional and structural brain imaging and psychopharmacology techniques to understand human interactive behaviour. 

Our research is organized in two main branches: 

  1. Cognitive basis of Advising and Consultancy
  2. Wisdom and Madness of crowds

 Cognitive basis of Advising and Consultancy

We live in the age of persuasion. From the outcomes of political campaigns to our stand on issues such as global warming, immigration crisis and taxation, the fate of the most critical issues in our public life depends on persuaders working to influence public opinion. The research on social influence has been dominated by the motivation to understand the mind of the targets of influence (e.g. consumers, voters) in order to exert even more influence on them. Far less is known about the cognitive and neurobiological underpinnings of the source of the influence (e.g. spin doctors, financial advisers, pundits etc). 

In our lab, Uri Hertz investigates the workings of the minds of the advisers and persuaders, asking: 

  • What are the psychological and cognitive of attempting to influence others? We investigate the mental processes behind the formulation of strategic advising that is aimed not only at benefiting the client but also ensuring the consultant’s influence. The psychological theory providing the framework of our research is portrayed in comic story displayed below:

Grandmother Story Part 1…
Grandmother Story Part 2…
  • What are the neural substrates of strategic advising? Can we identify the neuronal implementations of the cognitive processes mentioned in 1-1 in the human brain? Are these neuronal substrates predictive of the inter-individual differences we observe in people’s advising behaviour? We use functional and structural brain imaging (MRI) to address these questions. 

FMRI Comparison…
  • Is it possible to cast consultancy as a game theoretic problem between rival consultants who compete for influence over a common client? We use this approach to search for and draw the optimal strategies for consulting that maximise the consultant’s influence over their client in the long run. 

Wisdom and Madness of crowds 

What is the cognitive, computational and psychological basis of success and failure of collective decision making? Joaquin Navajas employs computational modelling and behavioural psychology to address this problem. Our lab has a long standing collaboration with the Gatsby Computational Neuroscience Unit in developing the math of interactive decision making.

  • What computational principles underlie the idiosyncratic variations in human behaviour in communication of probability and uncertainty?

Football Image…

How does the referee integrate his opinion with those of his assistants to make a decision?

  • What information do individuals communicate to one another when making joint decisions? What kind of decision rule(s) do they apply to the communicated information? 
  • How do people learn to cooperate with each other? In collaborations with the Summerfield Laboratory at University of Oxford and Robotics Laboratory in Tehran University we develop dynamic models of how individuals learn to calibrate their opinion against those of their peers in order for the group to do best. 


Group Members

Post-Doctoral Research Fellows

Marwa El Zein

Maria El Zein
m.zein@ucl.ac.uk or marwaelzein@gmail.com

My research investigates how and why humans engage in collective decisions despite prevalent collective failure and aims to characterize the cognitive and neural mechanisms underlying collective decisions. I test the idea that humans cooperate to share responsibility for decision outcomes, thereby minimizing regret and/or punishment in negative circumstances.

Group Alumni

Uri Hertz

Uri Hertz

I use behavioral measurements, computational models and neuroimaging to study the processes underlying collective decision making and human cooperation.

Shiro Kumano

Shiro Kumano

My main interest is to explore the effect of emotion on behaviours in social interaction, including empathy, nonverbal behaviours and choice behaviours or decision making. My approach is interdisciplinary, ranging from computer science, in particular computer vision and machine learning, to cognitive science.

Joaquin Navajas

Joaquin Navajas

Joaquin Navajas is a research associate in the Crowd Cognition Group at the ICN, working with Bahador Bahrami. With a background in Physics (University of Buenos Aires, Argentina), and a PhD in Neuroscience (University of Leicester, UK), his interests lie in the interface between social, computational, and visual cognitive neuroscience. In collaboration with the Gatsby Unit, his research projects at the ICN mostly involve the development and testing of computational models of crowd-emergent behaviours, with especial focus on decision making.