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As a graduate student working with Justin Gardner one of my major projects has been to look at how we can use contrast and coherence to understand how the brain "reads out" from sensory representations during perceptual decision making. This project is now published in two parts, first a paper outlining the framework we used to quantify how sensory representations of contrast and coherence are encoded in the brain, and second a paper looking at how "readout" is performed.

A quantitative framework for motion visibility in human cortex

Birman, D., & Gardner, J. L. (2018). A quantitative framework for motion visibility in human cortex. Journal of neurophysiology.

Link to paper:

Flexible readout of stable cortical representations support motion visibility perception

Using the sensitivity maps that we built in the first part of this project we then looked to understand how readout of motion visibility perception is performed. This manuscript is in preparation and will be presented at SFN 2018 in the session Visual Motion II on Sunday Nov 4, 1:00PM-5:00PM.

with Justin Gardner at Gardner Lab; Code; Stim; Data

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The point of no return in vetoing self-initiated movements

In 2013 I lived in Berlin and worked in the lab of John-Dylan Haynes on this project.

We have an intuition that we "commit" to a decision at a specific moment. Despite this intuition early neuroscience researchers found that brain activity becomes predictive of our intentions far in advance, sometimes up to 10 seconds. In this experiment we showed that in reality the point of no return, after which an action is guaranteed to happen, occurs only about 200 ms before motor activity. Until the point of no return the brain has not committed with no possibility of cancelling.

Birman, D.*, Schultze-Kraft, M.*, Rusconi, M., Allefeld, C., Görgen, K., Dähne, S., ... & Haynes, J. D. (2015). The point of no return in vetoing self-initiated movements. Proceedings of the National Academy of Sciences, 201513569. *Equal author contribution. at hayneslab

Link to paper:

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I am very interested in the idea of building better models to link human and non-human animal behavior as a way of better connecting physiological data from different model systems. We got interested in this project while looking at a set of monkey physiology data where the order of task training turned out to be critical to interpreting the results.

Comparing monkey and human learning

Birman, D., & Gardner, J. L. (2016). Parietal and prefrontal: categorical differences?. Nature neuroscience, 19(1), 5-7. at Gardner Lab.

Link to paper:

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Cognitive neuroscience tutorials

Let's face it. We're awful at teaching cognitive neuroscience! When you learn about physics you get to play with kinetics, electricity, magnetism, and thermodynamics. When you learn about chemistry you get to blow things up! But for some reason we seem to think that students will get excited if we show them pictures and movies about psychology and call it a day.

In my time at Stanford I've invested a lot of work into building playful brain simulation tutorials about cognitive neuroscience. These tutorials help students re-discover classic experiments about the visual system. Brain.js (below) is the new interface to all of these -- but I keep a list of older tutorials here.

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Brain.js

Brain.js is the core simulation environment I have been working on. A demo version is available which allows you to record from V1 and MT (currently a WIP).

I'll be presenting Brain as a dynamic poster at SFN 2018. Come find me Saturday 1:00pm-5:00pm!

Teaching

Cognitive Neuroscience

PSYCH 50: Introduction to cognitive neuroscience Winter 2019, Winter 2018, Winter 2017, Winter 2016

Instructor: Justin Gardner
Head TA: Dan Birman
2019 TAs: TBA
2018 TAs: Akshay Jagadeesh, Minyoung Lee, Guillaume Riesen, Jon Walters, Undergraduate TAs: Emma Master, Stephanie Zhang, Kawena Hirayama, Henry Ingram, Storm Foley
2017 TAs: Minyoung Lee, Lior Bugatus, Zeynep Enkavi, Mona Rosenke, Guillaume Riesen
2016 TAs: Anna Khazenzon, Natalia Velez, Anthony Stigliani, Rosemary Le

NEPR 207: Cognitive neuroscience - first year seminar for neuroscience graduate students Spring 2018, Spring 2017, Spring 2016

Instructors: Russ Poldrack, Justin Gardner
TA: Dan Birman

Statistics

PSYCH 252: Methods for behavioral and social sciences Fall 2016

Instructors: Ewart Thomas, Benoit Monin
TAs: Dan Birman, Stephanie Gagnon, Robert Hawkins

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Rock Climbing

Vertical rescue Spring 2018, Winter 2018, Spring 2012, Spring 2011

Sport leading and rappelling (clinics) Fall 2018 (x2), Spring 2018, Winter 2018

Crack climbing (clinics) Fall 2017

Winter camping Spring 2012, Spring 2011, Spring 2010

Multipitch climbing: Red Rock Spring 2012

Multipitch climbing: Shawangunks Fall 2011