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

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) 

Wednesday, January 3, 2018

Episode 28: Past, Present, and Future of Neuroscience

In this very special episode of Unsupervised Thinking, we bring together a group of neuroscientists and neuroscience enthusiasts to have a semi-structured discussion on the past, present, and future of the field of neuroscience. The group includes your three regular hosts plus Yann, Alex, and Ryan (whose voice you may recall from our Deep Learning episode) and we each give our thoughts on what got us into neuroscience, what we feel the field is lacking, and where the field will be in 20 years. This leads us on a path of discussing statistics, emergence, religion, depression, behavior, engineering, society, and more!

For further info on what we discuss, check out:
Conway's Game of Life (example of simple rules leading to complex behavior)
Eric Kandel's Autobiography
Split Brain Studies
Strong vs Weak Emergence (which we called 'hard' and 'soft')
Why Most Published Research Findings are False
Kuhn's Structure of Scientific Revolutions
Rat Park Study
Episode 1: Human Brain Project
Episode 4: Deep Learning/AI
Episode 18: Does Neuroscience Need More Behavior?
Episode 20: Studies on the State of Science 
Episode 23: What Can Neuroscience Say about Consciousness?



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) 

Wednesday, November 29, 2017

Episode 27: The Concept of Coding - Part 2

In the second part of our discussion on the concept of coding, we get into specific examples of what could count as the "neural code". In particular, we talk rate vs temporal coding along with examples of each in different organisms. We then get into the use of coding as a metaphor. How does it influence thought & experiments? Is an "action" or "process" metaphor a better alternative? We also discuss why language is the wrong metaphor for the neural code and the relationship between metaphors & formal mathematical systems. To illustrate the tension between a coding framework versus an action/process framework, we discuss a concrete example where the same finding is explained two different ways: do orientation-selective cells in primary visual cortex arise from sparse coding principles or is it just what happens when you train a system to do vision?

We read:
Neural Representation and the Cortical Code
Is coding a relevant metaphor for the brain?

You can also listen to Part 1 of this discussion.

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, October 31, 2017

Episode 26: The Concept of Coding - Part 1

The concept of "coding," along with language referencing it, is abundant in neuroscience whether describing sensory systems, cognition, or motor control. The notion that neurons encode information is so core to neuroscience it is almost difficult to imagine the field without it. In the first part of this two-part discussion on coding, we talk about the origins of the coding concept. We start with some of the early experimental work that demonstrated the most basic response properties of neurons. We then delve into a conference report from the 60's that summarized the state of the field at that time and find it (depressingly?) relevant for today. In particular, the focus at that time on coding as only an imperfect metaphor is contrasted with its perhaps outsized role in modern work. We ask things like: When is the metaphor working, and when is it stretched beyond recognition? What qualities does a code need to have to be a candidate for the "neural code"? and If there is a neural code, who's reading it out? By the end, Grace freaks out about how abstract "information processing" is, and Josh and Conor claim the whole world is just one big information processing machine.

We read:
Neurosciences Research Program report on Neural Coding

And mentioned:
List of recommended readings on coding
Spikes
Our fMRI episode

Upcoming readings for Part 2:
Neural Representation and the Cortical Code
Is coding a relevant metaphor for the brain?

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) 

Sunday, October 1, 2017

Episode 25: What Can Eye Movements Tell Us About The Mind?

You move your eyes several times a second, making choices about what to attend to without even noticing. That is a lot of behavioral data that scientists could use to understand underlying computations, preferences, memories, and intentions. On this episode, we talk about just such endeavors to understand cognition by monitoring eye movements. Eye movements are a comparatively easy thing to measure (though as we discuss, some of the older methods seemed like torture devices), and can be used in a wide range of settings: in animals and babies, in the lab or in the wild. In this episode, Josh regals us with tales of using a modern eye-tracking device at a conference, and we talk about the basic findings you can discover from that and exactly how surprising or interesting they are. We then get into how tasks influence eye movements and the many forms of memory that eye movements can measure, including differences between novices and experts. We top it all off with a delightful study about looking at porn, and some speculations about how eye-tracking could be used in the future. 
We read:

Eye movements in natural behavior

Worth a Glance: Using Eye Movements to Investigate the Cognitive Neuroscience of Memory

Sex differences in viewing sexual stimuli: An eye-tracking study in men and women

A Breadth-First Survey of Eye Tracking Applications 

And watched some cool eye-tracking videos!
What Does a Pianist See? 
The Science of Dating


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, August 28, 2017

Episode 24: Social Neuroscience Research

For this episode, special guest Nancy Padilla (E5: Neural Oscillations) returns to talk about a topic she now studies: social neuroscience. We get into the methods this rather new field uses to probe the neural processes behind social interaction, including the inherent difficulties in studying such a complex subject. We go from special pathways for bottom-up social processing such as smells and facial recognition to ideas about theory of mind and cooperation. In the process, we hit on the mirror neuron system, simultaneous dual-brain recordings, and the role of philosophy in the field. Two common questions throughout are: (1) are humans unique amongst animals? and (2) is social processing unique amongst neuroscience topics? Ultimately, we try to discover if social neuroscience is greater than the sum of its parts.

We read:
Conceptual Challenges and Directions for Social Neuroscience

Brain Basis of Human Social Interaction: From Concepts to Brain Imaging

Brain-to-Brain coupling: A mechanism for creating and sharing a social world

And mentioned:
Episode 10: Brain Size

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) 

Wednesday, July 26, 2017

Episode 23: What Can Neuroscience Say About Consciousness?

For this episode, we try to de-thorn one of the thorniest topics in neuroscience: consciousness! Starting with the (not so) simple task of defining the c-word, we first lay out our own definitions but end up relying on the work of philosopher David Chalmers (easy and hard problems of consciousness, philosophical zombies). Then, after establishing the myriad of reasons why science can't actually study consciousness, we get into its attempts to do so. Specifically, we talk about studies on anaesthesia and the role of optical illusions in probing conscious perception. After that we go through a laundry list of all kinds of theories/models of consciousness put forth by neuroscientists, psychologists, and (ugh) physicists. Throughout, Josh complains about people saying they have "heightened consciousness",  Conor advocates a lot of drug use (for science), and we discuss the politics of urination. If you're confused by any of this, no worries, Conor is too.

We read:
Scholarpedia: Neuronal Correlates of Consciousness
Scholarpedia: Models of Consciousness 

Neural Correlates of Consciousness (sensory paper by Rees)

Neural correlates of consciousness during general anesthesia using functional magnetic resonance imaging (fMRI)


And mentioned:
20 Years of ASSC: are we ready for its coming of age? (thanks to @tweetsatpreet for pointing us to this journal)


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)