Stochastic descent optimisation in Matlab

Using the Adam optimiser

21st February, 2017

Stochastic gradient descent is a powerful tool for optimisation, which relies on estimation of gradients over small, randomly-selected batches of data. This approach is efficient (since gradients only need to be evaluated over few data points at a time) and uses the noise inherent in the stochastic gradient estimates to help get around local minima. This is a Matlab implementation of a recent powerful SGD algorithm.

Putting vision into context

And adding context to vision

21st December, 2015

This optical illusion shows how strongly the context of a visual scene influences what we see, and how that context can sometimes mislead us. The three people in the picture are exactly the same size. However, because our brain judges the size of an object based on its perceived distance, the person at the back seems to be further away and therefore appears larger.

Our brain does not faithfully interpret visual information, but instead uses a complex mixture of prior experience and context to shape our perception of the world. We described a pathway in the brain for this contextual information, from the mouse thalamus to visual cortex.

Thalamus conveys diverse contextual information to layer 1 of visual cortex

Poster at SfN 2015

17th October, 2015

Sensory perception depends on context. Many models emphasise cortical feedback as the source of contextual modulation. However, higher-order thalamic nuclei, such as the pulvinar, interconnect with many cortical and subcortical areas, suggesting a role for the thalamus in providing sensory and behavioral context — yet the nature of the signals conveyed to cortex by higher-order thalamus remains poorly understood.

The brain's social network

Nerve cells interact like friends on Facebook

4th February, 2015

Neurons in the brain are wired like a social network, report researchers from Biozentrum, University of Basel. Each nerve cell has links with many others, but the strongest bonds form between the few cells most similar to each other.

SlackMatlab

Matlab integration for Slack

19th November, 2014

Basic integration to send notifications to Slack from Matlab, via an Incoming Webhooks integration. Sending message attachments along with a notification is supported.