Welcome

I am a computational neuroscientist based in Tübingen, Germany.

My goal is to understand how neural systems – both biological and artificial – perform visual perception.

Learn more about my research and my publications.

Advertisements

Paper on one-shot segmentation at ICML

Our paper on one-shot segmentation in clutter has been accepted to ICML. In this paper, we tackle a one-shot visual search task: based on a single instruction example (the red Φ in the image below), the goal is to find the same letter in a cluttered image that consists of many letters (left) and segment it. This task is pretty hard for computer vision systems, because the image clutter consists of other letters (i.e. very similar statistics), the letters can have arbitrary colors, are drawn by different people, transformed by affine transformations, and have not been seen during training.

MaskNet

Continue reading

Welcome Mara & Max

Marissa Weis and Max Günthner have started their Master’s thesis projects on March 1st. Mara will be working on image processing using foveated image representations. Max will be investigating nonlinearities in neural responses in primary visual cortex using techniques to visualize convolutional neural networks.

Review on texture and art with deep neural networks

Our review on “Texture and Art with Deep Neural Networks” (free version) has been published online and will appear in the October issue of Current Opinion in Neurobiology.

In the review, written by Leon Gatys, Matthias Bethge and myself, we discuss recent advances in texture synthesis using Convolutional Neural Networks (CNNs) that were motivated by visual neuroscience and have led to a substantial advance in image synthesis and manipulation in computer vision. We also discuss how these advanecs can in turn inspire new research in visual perception and computational neuroscience.

Preprint of paper on human texture perception available

Our psychophysical evaluation of our CNN-based texture model is now available on bioRxiv. In the study led by Tom Wallis, we compared our recent parameteric model of texture appearance (CNN model) that uses the features encoded by a deep convolutional neural network (VGG-19) with two other models: the venerable Portilla and Simoncelli model (PS) and an extension of the CNN model in which the power spectrum is additionally matched.

textures.jpg

Continue reading

More control in style transfer

We just put a preprint on arXiv describing a number of improvements to the style transfer algorithm we developed a while ago. These new features include spatial control, color control and scale control.

style-transfer

Spatial control: applying different styles to different parts of the image (panel b).

Color control: transferring only the style of a painting, but keeping the colors of the original photograph (panel c). You can find additional examples in our blog post on blog.deepart.io.

Scale control: combine small-scale features of one style with large-scale features of another.

New paper out in Science

Fig6DWe have a new paper published today in Science. Xiaolong Jiang in Andreas Tolias’ lab at Baylor College of Medicine recorded, labeled, and classified over 1600 neurons in mouse visual cortex and characterized their connectivity. Based on his remarkable work we discovered three simple connectivity rules that capture most of the structure of the connectivity matrix:

  1. There are two master regulators with distinct input profiles.
  2. Interneuron-selective interneurons are neither self-inhibitory nor locally recruited.
  3. Pyramidal-neuron-targeting interneurons are self-inhibitory and locally recruited.

The paper has already attracted some media attention on Popular MechanicsThe Scientist and some German news outlets.

Pro-Test Germany founded

11223967_503227913165999_856660535330262984_nWe recently founded Pro-Test Germany, a non-profit organization by young scientists with the goal of communicating and educating about the need of using animals in research.

Whether or not we should use animals in research is a controversial question. While it is clear to a neuroscientist like myself that we need animal research to make progress in basic research and medicine, it may not be as obvious to someone who has never done science or even met a scientist.

Unfortunately, in Germany the public dispute on this topic has been dominated by animal rights activists with extreme views. Scientists, on the other hand, have mostly preferred to do their work instead of engaging with the public. After the recent events in Tübingen that forced Max Planck director Nikos Logothetis to give up his work with macaque monkeys, it has become clear to many of us that this needs to change. Scientists have to speak up, get out there, and talk about their work: What do we do? Why do we do it? Why is it necessary? How does it help society? To help answering these questions for everybody, we started Pro-Test Germany. We will have a website, be active on social media and have public actions in Tübingen. Visit our website or Facebook page and stay tuned!