While some of the ideas pursued in the Active Perception Laboratory have a long history, their importance in visual perception has become apparent and susceptible to precise experimental analysis only recently. As researchers in the Active Perception Laboratory approached these research questions, an important obstacle to testing theoretical predictions was the incapability of precisely controlling retinal image motion during natural fixation. Traditional systems came with major technical limitations. For example, available techniques for retinal stabilization gave no access to the quality of the manipulation, which critically depended on how the subject executed complicated calibration procedures.

An important component of work in the Active Perception Laboratory has been the development of new tools and techniques for better measuring eye movements and manipulating visual input signals. Most notably, we have:

  • Developed a general-purpose system for gaze-contingent control display, which has opened the way to experiments not feasible with previous methods (Santini et al, 2007, read more).


  • Implemented new techniques for localizing the line of sight, which provide a precision improvement of more than one order of magnitude over standard methods (Poletti et al, 2013; supplemental material). Use of these methods has led to a new understanding of the functions of ocular drift and microsaccades.


  • Developed a new system for recording microscopic head movements (Aytekin and Rucci, 2012). Use of this system has shown that even small fixational head movements contribute significant depth information in the space nearby the observer.


  • We are currently working on the development of two high-resolution eye-trackers, a video-based digital Dual Purkinje Image system, and a redesigned coil system for high-precision head-free measurements.