Megan and I discuss her work using metacognition as a way to study subjective awareness, or confidence. We talk about using computational and neural network models to probe how decisions are related to our confidence, the current state of the science of consciousness, and her newest project using fMRI decoded neurofeedback to induce particular brain states in subjects so we can learn about conscious and unconscious brain processing.

Notes:

• Visit Megan's cognitive & neural computation lab.
• Twitter: @meganakpeters
• The papers we discuss or mention:
  • Human intracranial electrophysiology suggests suboptimal calculations underlie perceptual confidence
  • Tuned normalization in perceptual decision-making circuits can explain seemingly suboptimal confidence behavior.

Mazviita and I discuss the growing divide between prediction and understanding as neuroscience models and deep learning networks become bigger and more complex. She describes her non-factive account of understanding, which among other things suggests that the best predictive models may deliver less understanding. We also discuss the brain as a computer metaphor, and whether it's really possible to ignore all the traditionally "non-computational" parts of the brain like metabolism and other life processes.

Show notes:

• Her website.
• Outside color website (with links to more of her publications)
• Her book Outside Color: Perceptual Science and the Puzzle of Color in Philosophy.
• Papers we discuss or mention:
  • Prediction Versus Understanding in Computationally Enhanced Neuroscience.
  • Your brain is like a computer: function, analogy, simplification.
  • Charting the Heraclitean Brain: Perspectivism and Simplification in Models of the Motor Cortex.

Patrick and I mostly discuss his path from a technician in the then nascent Jim DiCarlo lab, through his graduate school and two postdoc experiences, and finally landing a faculty position, plus the culture and issues in academia in general. We also cover plenty of science, like the role of eye movements in the study of vision, the neuroscience (and concept) of attention, what Patrick thinks of the deep learning hype, and more.

But, this is a special episode, less about the science and more about the experience of an academic neuroscience trajectory/life. Episodes like this will appear in Patreon supporters' private feeds from now on.

Show notes:

• His pre-lab website university page.
• Twitter: @mayo_lab.
• Here’s the paper he recommends to understand attention:
  • Attention can be subdivided into neurobiological components corresponding to distinct behavioral effects.

Brad and I discuss his battle-tested, age-defying cognitive model for how we learn and store concepts by forming and rearranging clusters, how the model maps onto brain areas, and how he's using deep learning models to explore how attention and sensory information interact with concept formation. We also discuss the cognitive modeling approach, Marr's levels of analysis, the term "biological plausibility", emergence and reduction, and plenty more.

Notes:

• Visit Brad’s website.
• Follow Brad on twitter: @ProfData.
• Related papers:
  • Levels of Biological Plausibility.
  • Models in search of a brain.
  • A non-spatial account of place and grid cells based on clustering models of concept learning.
  • Abstract neural representations of category membership beyond information coding stimulus or response.
  • Ventromedial prefrontal cortex compression during concept learning.
  • The Costs and Benefits of Goal-Directed Attention in Deep Convolutional Neural Networks
  • Learning as the unsupervised alignment of conceptual systems.

David and I discuss the latest efforts he and his Elemental Cognition team have made to create machines that can understand stories the way humans can and do. The long term vision is to create what David calls "thought partners", which are virtual assistants that can learn and synthesize a massive amount of information for us when we need that information for whatever project we're working on. We also discuss the nature of understanding, language, the role of the biological sciences for AI, and more.

• Dave’s business Elemental Cognition.
• The paper we discuss:
  • To Test Machine Comprehension, Start by Defining Comprehension.

Rodrigo and I discuss concept cells and his latest book, NeuroScience Fiction. The book is a whirlwind of many of the big questions in neuroscience, each one framed by of one of Rodrigo’s favorite science fiction films and buttressed by tons of history, literature, and philosophy. We discuss a few of the topics in the book, like AI, identity, free will, consciousness, and immortality, and we keep returning to concept cells and the role of abstraction in human cognition.

Notes:

• Rodrigo's lab website: Centre for Systems Neuroscience at the University of Leicester, UK
• His book:
  • NeuroScience Fiction: From "2001: A Space Odyssey" to "Inception," How Neuroscience Is Transforming Sci-Fi into Reality―While Challenging Our Beliefs About the Mind, Machines, and What Makes us Human.
• Papers we discuss or mention:
  • Concept cells: the building blocks of declarative memory functions.
  • Neural representations across species.
  • Searching for the neural correlates of human intelligence.
• Talks:
  • Concept cells and their role in memory - Part 1 and Part 2

In this second part of my conversion with Paul (listen to the first part), we continue our discussion about how to understand brains as feedback control mechanisms - controlling our internal state and extending that control into the world - and how Paul thinks the key to understanding intelligence is to trace our evolutionary past through phylogenetic refinement.

• Paul's lab website.
• (A few of) his papers we discuss or mention:
  • Resynthesizing behavior through phylogenetic refinement.
  • Navigating the affordance landscape: Feedback control as a process model of behavior and cognition.
  • Neural Mechanisms for Interacting with a World Full of Action Choices.
• Books Paul recommends about these topics:
  • The Ecological Approach to Visual Perception by Gibson.
  • Brains Through Time: A Natural History of Vertebrates by Striedter and Northcutt.
  • The Neurobiology of the Prefrontal Cortex: Anatomy, Evolution, And The Origin Of Insight by Passingham and Wise.
  • The Evolution of Memory Systems: Ancestors, Anatomy, and Adaptations by Murray, Wise, and Graham.
  • The ancient origins of consciousness:How the brain created experience by Feinberg and Mallatt.
  • Catching Ourselves in the Act: Situated Activity, Interactive Emergence, Evolution, and Human Thought by Hendriks-Jansen.
• In case, like me, you didn’t know what an amphioxus is… here you go.

In this first part of our conversation, Paul and I discuss his approach to understanding how the brain (and intelligence) works. Namely, he believes we are fundamentally action and movement oriented - all of our behavior and cognition is based on controlling ourselves and our environment through feedback control mechanisms, and basically all neural activity should be understood through that lens. This contrasts with the view that we serially perceive the environment, make internal representations of what we perceive, do some cognition on those representations, and transform that cognition into decisions about how to move. From that premise, Paul also believes the best (and perhaps only) way to understand our current brains is by tracing out the evolutionary steps that took us from our single celled first organisms all the way to us - a process he calls phylogenetic refinement.

• Paul's lab website.
• (A few of) his papers we discuss or mention:
  • Resynthesizing behavior through phylogenetic refinement.
  • Navigating the affordance landscape: Feedback control as a process model of behavior and cognition.
  • Neural Mechanisms for Interacting with a World Full of Action Choices.
• Books Paul recommends about these topics:
  • The Ecological Approach to Visual Perception by Gibson.
  • Brains Through Time: A Natural History of Vertebrates by Striedter and Northcutt.
  • The Neurobiology of the Prefrontal Cortex: Anatomy, Evolution, And The Origin Of Insight by Passingham and Wise.
  • The Evolution of Memory Systems: Ancestors, Anatomy, and Adaptations by Murray, Wise, and Graham.
  • The ancient origins of consciousness:How the brain created experience by Feinberg and Mallatt.
  • Catching Ourselves in the Act: Situated Activity, Interactive Emergence, Evolution, and Human Thought by Hendriks-Jansen.
• In case, like me, you didn’t know what an amphioxus is… here you go.

Thomas and I discuss the role of recurrence in visual cognition: how brains somehow excel with so few “layers” compared to deep nets, how feedback recurrence can underlie visual reasoning, how LSTM gate-like processing could explain the function of canonical cortical microcircuits, the current limitations of deep learning networks like adversarial examples, and a bit of history in modeling our hierarchical visual system, including his work with the HMAX model and interacting with the deep learning folks as convolutional neural networks were being developed.

Show Notes:

• Visit the Serre Lab website.
• Follow Thomas on twitter: @tserre.
• Good reviews that references all the work we discussed, including the HMAX model:
  • Beyond the feedforward sweep: feedback computations in the visual cortex.
  • Deep learning: the good, the bad and the ugly.
• Papers about the topics we discuss:
  • Complementary Surrounds Explain Diverse Contextual Phenomena Across Visual Modalities.
  • Recurrent neural circuits for contour detection.
  • Learning long-range spatial dependencies with horizontal gated-recurrent units.

Galit and I discuss the independent roles of prediction and explanation in scientific models, their history and eventual separation in the philosophy of science, how they can inform each other, and how statisticians like Galit view the current deep learning explosion.

• Galit's website.
• Follow her on twitter: @gshmueli.
• The papers we discuss or mention:
  • To Explain or To Predict?
  • Predictive Analytics in Information Systems Research.