Julius Krumbiegel was awarded the Humboldt Prize 2020 for his Master’s thesis “Evidence for efference copies from combined eye-head gaze shifts”, an award that recognizing exceptional academic work by students. Congratulations for this outstanding and well-deserved achievement!
In his work, Julius investigated the ability of human observers to maintain a sense of spatial locations in the world as they execute large-scale, unconstrained saccadic gaze shifts. These large saccades are quick movements (<100 ms) that coordinate the eyes and the head to get an object of interest in the far periphery into the center of gaze. As the retina moves with each saccade, the visual system is thought to keep track of object locations in space via an updating mechanism that associates these spatial locations with of the changing retinal locations as the eyes move. It remains unknown whether the visual system updates its internal representation of space in the face of large-scale movements the same way it does for smaller saccades, during which the head remains still. Julius’ thesis presents evidence for the existence of a precise updating mechanism for saccades involving head movements.
Studying combined eye-head gaze shifts is extremely intricate as it involves (1) the precise measurements of the position of the head in space and the position of the eye in the head, (2) the geometrical analysis of these positions and their combination into a world-centered reference frame (to determine the current gaze position), (3) a custom-made, but highly standardized, protocal for the calibration of this system to a given observer, and (4) the timely, gaze-contingent updating of the target locations displayed (i.e., movement and fixation targets) during experimental trials within no more than a few milliseconds. To isolate the role of an efference copy in keeping track of spatial locations—as opposed to visual landmarks, for instance—all of these components had to work in complete darkness. So a large part of Julius’ work consisted of building from scratch and validating an LED rig that allowed him to display a large array of stimulus locations in the absence of any visual distractions or landmarks.
Julius was a student at the Berlin School of Mind and Brain. He joined our lab as a student research assistant in 2017, and is now PhD student in Helen Blank’s group at the Medical Center Hamburg-Eppendorf (UKE). He is also a talented photographer.
The official announcement [in German] is here.