Selim Onat

I am a neuroscientist working currently on how humans make generalizations based on what they have previously learnt. To do so, 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.

In the past, I have been working on how the nervous system processes natural scenes both at the electrophysiological and sensory-motor level. Since the times of Hubel and Wiesel, visual processing had been
overwhelmingly studied with artificial stimuli such as moving edges. However this type of stimuli suffer from an ecological validity problem, as they only rarely occur in real-life. We therefore investigated cortical processing during viewing of natural movies. This previous work focused on visual processing using mostly the technique of voltage-sensitive dye imaging and eye-tracking.

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.