Total passengers carried by planes has grown by a factor of eight in the last 40 years(source: Data Bank)


The following analysis arose from a simple question. Why is it that the MathOverflow, an Internet forum for mathematicians, thrives and the analogous forum for neuroscientists doesn’t? What is the nature of the problem and if so how should it be addressed?

But, let’s start with an easier question. Why are all the neuroscientists on Twitter?

Why are all the neuroscientists on Twitter?:

When Twitter was created with a constraint of 140 words per tweet I doubt that the Twitter product team expected their platform to be heavily used by scientists. You can’t render mathjax/latex and Twitter isn’t ideal for expressing subtleties but it has many desirable features for networking:

  1. Information exchange is efficient. A tweet represents kg CO2.
  2. The message-length constraint incents quasi-synchronous exchanges.
  3. All the scientists are already there for other reasons: sports, politics…etc.

On any given day scientists on Twitter will share their preprints, explain how they achieved their results, and effectively conduct Q&A sessions on their research. Some scientists even joke that it has become the place for peer-review. I think it’s fair to say that Twitter has brought great value to the scientific community by allowing frictionless communication between scientists across the globe; scientists who probably wouldn’t communicate with each other unless they met at a conference. Crucially, relative to science conferences Twitter has a relatively small carbon footprint.

It seems almost like Twitter should be a public good except that it isn’t and this got me thinking about a public neuroscience forum for neuroscientists, a bit like the MathOverflow for mathematicians.

The Psychology and Neuroscience stackexchange and its limits:

What drew me to the Psychology and Neuroscience stack-exchange was that it had several functionalities that weren’t available on Twitter:

  1. You can easily find whether an identical/related question was asked.
  2. Latex is available for mathematical formulas.
  3. Shared tags for easy discoverability of posts.

But, as I started making regular use of the forum I noticed sexist and racist behaviour at all user-reputation levels on the forum including the moderator-level:

  1. How to interpret a BBC news article on the effect of race on intelligence?
  2. IQ gap by race, truth or myth?
  3. Is the logic of “Herrnstein’s syllogism” sound, and are its premises true?

On the balance, the current moderators nurtured an environment where racist and sexist views can coexist with research-level neuroscience questions thus offering them legitimacy. These questions are also terribly outdated, hailing back to a time when intelligence tests were used to justify colonial mentalities i.e. right-to-rule.

Having said this, I am not here to incite outrage and would stop short of labelling them as racist/sexist. We should be skeptical of the desire to punish as it often prevents us from seeing the bigger picture.

There are a couple problems with stack exchange forums which make the problem of sexism and racism difficult to tackle:

  1. Users can create one or more accounts under a pseudonym.
  2. A moderator of a stack-exchange forum may be one of several accounts controlled by a single user.

This allows the possibility of sockpuppeting at the moderator level, a fault that is exploitable on forums where users might want to share racist/sexist viewpoints. For the above reasons, I am not sure the neuroscience and psychology stack exchange is salvageable in its current form.

Finally, I’d like to address the view that scientists should be free to do research of a sexist/racist nature. First, if you had to list the twenty most important problems in neuroscience you would be hard-pressed to find any that require torturing data to ‘discover’ differences in intelligence between people of different gender or race. Second, there have always been ethical limits on scientific inquiry.

In a globalized world, scientists are free to pursue their scientific interests provided that it benefits a multicultural and inclusive society.

The sociology of neuroscience:

Besides sexist and racist behaviour, the Psychology and Neuroscience stack-exchange faces rather unique challenges unlike the MathOverflow, the Physics stack-exchange or the Theoretical Computer Science stack-exchange.

In neuroscience unlike math, physics or theoretical computer science the fundamental concepts are still in development. This is partly due to the complexity of the brain, possibly the most complex object in the universe, and partly due to a relative lack of data. This greater degree of uncertainty in neuroscience encourages much greater specialisation. In fact, it’s fair to say that neuroscience has many tribes that don’t share a common language.

This has a couple consequences:

  1. The probability that a research-level question will be answered on a forum lacking a critical-mass of researchers with diverse research backgrounds is small.
  2. A researcher or masters student is more likely to address another specialist directly via email.

For these reasons, the ratio of research-level questions to lower-tier questions is going to be biased towards lower-level questions and the Psychology and Neuroscience stack-exchange is unlikely to be dominated by research-level queries.

In contrast, neuroscience conferences are much better places for exchanging scientific information and building trust. This is partly because communication isn’t bandwidth-limited, face-to-face communication builds trust and a conference effectively directs the collective intelligence of scientists via synchronous communication. These are the types of forums that really matter to neuroscientists.

No wonder neuroscientists fly to hundreds of conferences per year. But, at what cost?

The carbon footprint of neuroscience conferences:

Plane flights emit on the order of ~,1 kg of CO2 per person per km. This explains why at the level of universities, the carbon footprint of academic conferences may represent up to a third of that universities’ carbon budget. At the level of the individual scientist the situation is much worse, easily representing more than 40% of their carbon footprint.

Most scientists I have met care about the environment and wouldn’t deviate significantly from the European average of ~10 tonnes of CO2 per person per year. However, if we take into account that planes emit ~,1 kg of CO2 per person per km a scientist can easily add six tonnes of CO2 to their carbon footprint. They simply have to get on three return flights from San Francisco to Berlin which represents about 60,000 km of plane flight in total.

Does this mean that scientists should travel less? Probably. But, this doesn’t mean scientists should attend fewer conferences.

In the same way that Twitter has allowed scientists to communicate seamlessly across the Atlantic, I believe virtual reality may replace most brick-and-mortar conferences in the next five years.

Are virtual science conferences possible?

Regarding the feasibility of virtual science conferences, we are not talking about science fiction. Virtual Reality is a technology which is already on the market in the form of the Oculus Rift S and the HTC Vive.

More than a technology, VR realises the vision of philosophers and mathematicians dating back a thousand years who believed that the world we perceive is a construction of the mind:

Nothing of what is visible, apart from light and color, can be perceived by pure sensation, but only by discernment, inference, and recognition, in addition to sensation. -Alhazen

From this perspective, robust VR requires progress on multi-sensory integration theories in order to understand how our senses can be tricked. The challenge is to find the right priors over multi-sensory data streams. On this front, we must recognise the important contributions made by behavioural and perceptual neuroscientists to VR research and development.

If VR technologists can solve multi-party face-to-face interaction in the same way that Twitter has solved global public messaging, this would remove the need for almost all brick-and-mortar conferences. In the process, neuroscientists will make a historic contribution to addressing climate change.


While I think that behavioural and perceptual neuroscientists will play a crucial role in realising the vision of VR and consequently make most flights unnecessary I believe that the broader community of neuroscientists must do better in communicating their role to help address climate change. This will have the effect of unifying neuroscientists around neuroscience-driven solutions for climate change.

I also think this is only the beginning. There are other substantial ways neuroscientists can help address climate change.


  1. WorldBank Data Bank. Air transport, passengers carried. 01/09/2019.
  2. Amanda Thompson. Scientific Racism: The Justification of Slavery and Segregated Education in America. 2003.
  3. Cesare V. Parise , Marc O. Ernst. Noise, multisensory integration, and previous response in perceptual disambiguation. PLOS Biology. 2017.
  4. Fast Company. How Much Energy Does a Tweet Consume? 19/04/2010. 01/09/2019.