Unsupervised Thinking
a podcast about neuroscience, artificial intelligence and science more broadly

Thursday, June 28, 2018

Episode 34: The Gut-Brain Connection

Because of the sheer number of neurons in the gut, the enteric nervous system is sometimes called the second brain. What're all those neurons doing down there? And what, or who, is controlling them? Science has recently revealed that the incredibly large population of microorganisms in the gut have a lot to say to the brain, by acting on these neurons and other mechanisms, and can impact everything from stress to obesity to autism. In this episode, we give the basic stats and facts about the enteric nervous system (and argue about whether it really is a "second brain") and cover how the gut can alter the brain via nerves, hormones, and the immune system. We then talk about what happens when mice are raised without gut microbes (weird) and whether yogurt has any chance of curing things like anxiety. Throughout, we marvel at how intuitive all this seems despite being incredibly difficult to actually study. All that plus: obscure literary references, Josh's hilariously extreme fear of snakes, multiple misuses of the word "species," and DIY feces transplants! 

We read:
Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour

And mentioned:
Nancy's previous episode Episode 31: Consuming Science
Episode 23: What Can Neuroscience Say About Consciousness?

And our special guest was Nancy Padilla!

To listen to (or download) this episode, (right) click here or use the player below
[apologies for minor audio issues on this one!]




As always, our jazzy theme music "Quirky Dog" is courtesy of Kevin MacLeod (incompetech.com) 

Wednesday, May 30, 2018

Episode 33: Predictive Coding

You may have heard of predictive coding; it's a theory that gets around. In fact, it's been used to understand everything from the retina to consciousness. So, before we get into the details, we start this episode by describing our impressions of predictive coding. Where have we encountered it? Has it influenced our work? Why do philosophers like it? And, finally, what does it actually mean? Eventually we settle on a two-tiered definition: "hard" predictive coding refers to a very specific hypothesis about how the brain calculates errors, and "soft" predictive coding refers to the general idea that the brain predicts things. We then get into how predictive coding relates to other theories, like Bayesian modeling. But like Bayesian models, which we've covered on a previous episode, predictive coding is prone to "just-so" stories. So we discuss what concrete predictions predictive coding can make, and whether the data supports them. Finally, Grace tries to describe the free energy principle, which extends predictive coding into a grand unified theory of the brain and beyond.

We read:
Whatever next? Predictive brains, situated agents, and the future of cognitive science

And mentioned:
Episode 15: "Just-so" stories in Bayesian modeling in psychology
Kok and Lange book chapter on predictive coding
NYU panel/debate on predictive coding

And our special guest was Alex Cayco-Gajic!

To listen to (or download) this episode, (right) click here


As always, our jazzy theme music "Quirky Dog" is courtesy of Kevin MacLeod (incompetech.com) 

Tuesday, May 1, 2018

Episode 32: How Do We Study Behavior?

There is a tension when it comes to the study of behavior in neuroscience. On the one hand, we would love to understand animals as they behave in the wild---with the full complexity of the stimuli they take in and the actions they emit. On the other hand, such complexity is almost antithetical to the scientific endeavor, where control over inputs and precise measurement of outputs is required. Throw in the constraints that come when trying to record from and manipulate neurons and you've got a real mess. In this episode, we discuss these tensions and the modern attempts to resolve them.

First, we take the example of decision-making in rodents to showcase what behavior looks like in neuroscience experiments (and how strangely we use the term "decision-making"). In these studies, using more natural stimuli can help with training and lead to better neural responses. But does going natural make the analysis of the data more difficult? We then talk about how machine learning can be used to automate the analysis of behavior, and potentially remove harmful human biases. Throughout, we provide multiple definitions of "behavior", Grace relates animal training to parenting, and our special guest Adam Calhoun uses his encyclopedic knowledge of this area to provide many insightful examples!

We read:
Decision making behaviors: weighing ethology complexity and sensorimotor compatibility
Computational Analysis of Behavior - Annual Review of Neuroscience [$]

And mentioned:
Episode 18: Does Neuroscience Need More Behavior?
Mala Murthy (fly courtship work)
Low dimensionality of C. elegans (worm) behavior
How sensory neural responses are heavily influenced by behavior

For more, check out this list of behavioral papers Adam made on Twitter!

To listen to (or download) this episode, (right) click here.


As always, our jazzy theme music "Quirky Dog" is courtesy of Kevin MacLeod (incompetech.com) 

Saturday, April 7, 2018

Episode 31: Consuming Science (with Cosyne Interviews)

On this unique episode of Unsupervised Thinking, we talk not about a particular area of science, but about the process of doing science itself. In particular, we're discussing how scientists take in information from their niche research areas and beyond. The topic for this free-form conversation stemmed from interviews we collected at the latest Computational and Systems Neuroscience Conference (Cosyne), where we asked people to tell us about a research finding from outside their area that they thought was cool. You'll hear those interviews in this episode, along with our motivation for asking that question and our reaction to the responses. We then go on to speak broadly about our experiences at different conferences both big and small. In particular, we reveal how attending talks from far-reaching areas of science is a great way to build appreciation for your field and contextual your research. Ultimately, influence from talks and colleagues is how scientists choose their projects, and so decisions of what to consume can have long-lasting effects. We give our personal examples of times when talks have unexpectedly impacted our research, and the concrete things we do to keep up with the literature. Throughout, there is also talk of the culture divides that arise in research and Josh tells us about how Game of Thrones special effects are done. Thanks to all the Cosyne attendees who agreed to be interviewed for this, and special thanks to Nancy Padilla, our special guest for this episode!

We mentioned:
Episode 5: Neural Oscillations
Episode 24: Social Neuroscience Research

Also relevant, Grace wrote a blog on some of these themes for the Simons Foundation: Cross-Pollination at Cosyne 2018

To listen to (or download) this episode, (right) click here.


As always, our jazzy theme music "Quirky Dog" is courtesy of Kevin MacLeod (incompetech.com) 

Tuesday, April 3, 2018

Interviews from Cosyne 2018

At the most recent Computational and Systems Neuroscience Conference ("Cosyne"), held in Denver, we collected some interviews from attendees. The goal was to get people talking about work outside of their own immediate research area. Cosyne is a great conference to get exposed to ideas from other areas, particularly across the experiment-theory boundary.

In total we collected 11 interviews from grad students, postdocs, and professors. We prompted people by asking them to first give their name, position, and describe a bit about their own work. We then asked them to tell us about a finding or research method (not necessarily from the conference, though that was common) that is outside their own area of work that they thought was cool/exciting/interesting. Listen to all these interviews here:


HTML5 Audio Player


Based on these interviews and the general Cosyne experience, Grace wrote a column for the Simons Foundation blog on how small, single-track conferences can foster scientific creativity. You can check that out here: Cross-Pollination at Cosyne 2018

These interviews will also be incorporated into our upcoming episode, where we'll have an informal chat about the difficulties and benefits of keeping up with the broad scientific literature.

Wednesday, February 28, 2018

Episode 30: The Neuroscience of Sleep

Sleep is such a ubiquitous part of our lives we may forget just how weird of a thing it is to spend a third of our days laying in darkness. In this episode on the science of sleep, we start by describing types of sleep (while appreciating its strangeness) and the negative cognitive effects of missing out on it. We also discuss the potential role of rapid eye movement (REM) sleep in training neural connections and how that idea has been ported to artificial intelligence. We then take a rare (for us) trip to the brain stem to understand the neural mechanisms of switching from wake to sleep and nonREM to REM sleep. While there we appreciate how difficult it is to tease apart the function of different neuron types in a heavily redundant system. Finally, we dip our toes into the world of dreams, discussing a theory of dreaming's role in developing consciousness and our own experiences with lucid dreaming. Throughout, we go down tangents to argue about the value of speculative science and how to quantify knowledge via Google search results.

We read:
Sleep State Switching
REM sleep and dreaming: Towards a theory of proto-consciousness 

And mentioned:
Bence's motor learning work
Episode 23: What Can Neuroscience Say About Consciousness? 
and possibly relevant: Episode 5: Neural Oscillations


To listen to (or download) this episode, (right) click here


As always, our jazzy theme music "Quirky Dog" is courtesy of Kevin MacLeod (incompetech.com) 

Monday, January 29, 2018

Episode 29: The Neuron Doctrine

In the late 19th century, many of the most basic foundations of neuroscience were laid, but not without a fight. In this episode, we cover the famous debate between Camillo Golgi and Santiago Ramón y Cajal regarding the very nature of neurons: are they separate cells or one conjoined mass? We also tell the story of some of the lesser known players, remark on the inability of those on the losing side to let go, and ask what a modern Neuron Doctrine debate would look like. After covering the history, we discuss two modern rethinkings of the Neuron Doctrine that focus the question not just on anatomy, but on whether neurons are the functional unit of the brain. What does "functional unit" mean? We don't know, but as we grapple with it we speak about the need to balance simplification with appreciation of details and (unfortunately) attempt to understand emergence again.

We read:
Neuron theory, the cornerstone of neuroscience, on the centenary of the Nobel Prize award to Santiago Ramón y Cajal
The Neuron Doctrine, Redux
From the neuron doctrine to neural networks

And mentioned:
Episode 5: Neural Oscillations
Episode 28: Past, Present, and Future of Neuroscience
Shadlen-Newsome work

To listen to (or download) this episode, (right) click here or use the player below


As always, our jazzy theme music "Quirky Dog" is courtesy of Kevin MacLeod (incompetech.com)