Being the RNG

How would you generate a sequence of random numbers, if you didn’t have a computer or calculator? Each time you typ rng default or random.randint, numbers get drawn from precise observations of some natural process or special algorithms to produce sequences of numbers with certain properties of randomness. But what if your laptop died, your phone had no reception, or you’d suddenly find yourself transported 50 years back in time? How could you approximate random sampling from different distributions just using pen, paper, and whatever you could find in your house?

I thought of three categories (to start with): A. human-made randomization gadgets, B. measurement, C. just you in an empty room.
Rules: Please share your best guesses and intuitions and limitations of each method. If you know what exact distribution can be approximated with each process, please let me know – I’ll update the post as more ideas come in. Do not Google (or be honest if you did). Let’s play!

Update: see the Twitter thread for a bunch of interesting responses and suggestions – I’ve copied some of those into the list of suggestions below (no guarantees).

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#ShutDownSTEM; fighting racism in academia

The last few weeks in the US have been a political and emotional tornado. As protests spread around the country and beyond, I compulsively read the news, went to a local protest and watched Ava DuVernay’s chilling documentary 13th. I also thought a lot about the different ways in which societal and systemic racism manifests itself in the US vs. in Europe. I’m most familiar with the situation in The Netherlands, where (after some initial squabbling about social distancing during a large Amsterdam protest) there has been a more serious conversation about structural obstacles facing people of color and those without traditional Dutch last names (see e.g. here and here).

After a week or so, the conversation among academic on Twitter rightfully shifted. People went from focusing their outrage at police brutality, to examining the many problems with racism that take place in our own professional spheres. On Twitter, #BlackInTheIvoryTower launched a much-needed, painfully honest conversation about the many ways racism pervades academic culture.

I’m here sharing my thoughts, personal commitments to fighting racism in science, and resources.

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Climate action for (neuro)scientists: a concrete guide

Climate change is the most urgent problem currently facing humanity – including a subset who call themselves (neuro)scientists. While many academics still consider (political) activism far outside their comfort zone, the broader scientific community is slowly waking up to the urgency of the situation and the role we can play as a community of evidence-minded individuals. I believe there are few excuses for not engaging with this issue, and there are many ways to productively do so.

Since many scientists seem reluctant to speak up or unsure where to start, I’m collecting a short list of concrete things you can do (in approximate order of effort/difficulty). Pick one, get started and join the global effort necessary to tackle this problem; after all, aren’t we problem-solvers?

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Choice history biases subsequent evidence accumulation

This post describes my latest paper: Urai AE, de Gee JW, Tsetsos K, Donner TH. (2019) Choice history biases subsequent evidence accumulation. eLife, 8:e46331, and was  reposted from the DonnerLab website.


To study the mechanisms of decision-making, researchers often treat individual decisions as isolated events. However, as we go around the world, our decisions can be strongly influenced by previous experiences. Even in cases where it may be best to focus only on the current situation, our choices can be hard to separate from contextual factors. For example, studies of perceptual decision-making use well-controlled, but artificial, stimuli about which observers have no prior knowledge. Still, it has long been known that the choice an observer made seconds ago influences what she will report next.

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Gender diversity in academia

Although we’d all like academia to be a true meritocracy, ample research shows that implicit biases create significant hurdles to achieving diversity in our communities.

Here is an overview of the data (showing both the extent to which gender biases cause problems in science, and the different factors that may be significant contributors) and possible solutions. Different iterations of slides I presented on this topic are here and here.

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Of men and mice: a cognitive neuroscientist in a biology lab

For the last eight years, I called myself a cognitive neuroscientist. Throughout undergrad and grad school, I spent my days finding out how humans make decisions based on the information they extract from the outside world, and what factors play a role in determining our choices.

Half a year ago I started working with mice, asking many of the same questions. I was (and am) excited about the possibilities of recording from actual cells. I was (and am) inspired by the many genetic tools available, and the opportunities for collecting quantities of data from single individuals that are very rare in human subjects research. I also thought it would be cool to do something different – wrap my head around some fresh ideas, and perhaps build up a useful combined skill set.

“Science would be ruined if (like sports) it were to put competition above everything else, and if it were to clarify the rules of competition by withdrawing entirely into narrowly defined specialties. The rare scholars who are nomads-by-choice are essential to the intellectual welfare of the settled disciplines.”

– Benoit Mandelbrot

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How I start each paper review

I strongly believe in the value of openness and transparency, and I encourage the authors to make their data and analysis code publicly available. Over and above increasing the transparency and reproducibility of scientific findings as a whole, sharing data and code increases the visibility and impact of individual papers (McKiernan et al. 2016 eLife). Please see the standards of the Peer Reviewers’ Openness Initiative (https://opennessinitiative.org/the-initiative/) for guidelines.

I hope this is useful to others – so far this has always worked (but my N is pretty small).

You can call me Dr. Urai now

That’s it.
After 4+ years, a good number of triumphs and vastly more failures, I’ve defended my PhD!

For the occasion, I’d like to share a short piece about my experience as a PhD student that I originally wrote for a friend when she graduated. I recommend the original if you read Dutch.

Enjoy.
Or let me know how I’ve got it all wrong.
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Thesis formatting in Latex

After four years of experimental design, data acquisition and analysis I just finished putting together everything into my PhD thesis. I did not find any templates that really worked for me (although classicthesis looks quite nice), so I put together my own set of random LaTex commands. I’m not a graphics designer but I’m quite happy with the end results – so here are the choices I made and the corresponding LaTex code. Continue reading