|Fabee Sinz||University Tübingen|
|Alexander Ecker||University of Tuebingen|
|Edgar Walker||Baylor College of Medicine|
|Erick Cobos||Baylor College of Medicine|
|Emmanouil Froudarakis||Baylor College of Medicine|
|Dimitri Yatsenko||Baylor College of Medicine|
|Jacob Reimer||Baylor College of Medicine|
|Andreas Tolias||Baylor College of Medicine|
To better understand the representations in visual cortex, the authors need to generate better predictions of neural activity in awake animals presented with their ecological input: natural video.
To better understand the representations in visual cortex, we need to generate better predictions of neural activity in awake animals presented with their ecological input: natural video. Despite recent advances in models for static images, models for predicting responses to natural video are scarce and standard linear-nonlinear models perform poorly. We developed a new deep recurrent network architecture that predicts inferred spiking activity of thousands of mouse V1 neurons simultaneously recorded with two-photon microscopy, while accounting for confounding factors such as the animal's gaze position and brain state changes related to running state and pupil dilation. Powerful system identification models provide an opportunity to gain insight into cortical functions through in silico experiments that can subsequently be tested in the brain. However, in many cases this approach requires that the model is able to generalize to stimulus statistics that it was not trained on, such as band-limited noise and other parameterized stimuli. We investigated these domain transfer properties in our model and find that our model trained on natural images is able to correctly predict the orientation tuning of neurons in responses to artificial noise stimuli. Finally, we show that we can fully generalize from movies to noise and maintain high predictive performance on both stimulus domains by fine-tuning only the final layer's weights on a network otherwise trained on natural movies. The converse, however, is not true.