Selim Onat

My main occupation is Neuroscience.

In the past, I have been interested on how the visual system processes natural scenes. To this end, I have recorded naturalistic movies using micro-cameras carried by cats while they were actively exploring a natural environment. I used these movies to train neuronal networks in an unsupervised manner and compared learnt features to the known properties of neurons in visual cortex. I also used these videos as stimuli during physiological recordings to gain insights on the principles of natural signal processing in the visual cortex.

Recently, I started working on how humans make generalizations based on what they have previously learnt. To this end, I am using a variety of methodologies including fMRI (1), autonomous (2), as well as eye-movement recordings (3). This research emanates from the well-established field of "stimulus generalization" following mainly the "lineage" of Hovland, Hull and Roger Shepard (4), and including the more recent computational work of Josua Tenenbaum (5). Furthermore, it integrates work on anxiety disorders, as it is believed that these mechanisms are impaired in people suffering from anxiety problems.

Great Night at the Night of Science in Hamburg 2017

During the Night of Science event in Hamburg, we (me, Lea Kampermann and Lukas Neugebauer) introduced the eye-tracking technique to our guests, and illustrated it with the classical change blindness experiment.

We explained the basics of the eye-tracking and illustrated it with a classical experiment in visual neurosciences, namely the phenomenon of change blindness. We received about 60 people, and recorded eye-movements from 10 volunteers. Below I prepared an animated GIF that shows both the images shown to volunteers and the location that are most fixated by one volunteers. Overall our efforts were rewarded as being the highest rated demo during the night in our department.

Nine images shown to ten volunteers during the Night of Science event in Hamburg. The animation above consists of 3 different images.  The first two consist of flickering images presented during the experiment to induce change blindness; and the last one is the semi-transparent fixation map showing locations that were most attended by all volunteers.

For more information on change blindness, there is probably no better source than Kevan O'Regan's webpage whose name is closely associated with this phenomenon. For preparing the demo, we actually used many of the images that were used in the original publication. Furthermore, his webpage provides also a rich and original source of information on vision and perception.