Martina Poletti (University of Rochester), “Active Foveal Vision” and Michele Rucci (University of Rochester), “Active Space-Time Encoding: The Inseparable Link Between Vision and Action”

Martina Poletti’s talk will focus on active foveal vision. Vision is an active process even at its finest scale in the 1-deg foveola, the visual system is primarily sensitive to changes in the visual input and it has been shown that fixational eye movements reformat the spatiotemporal flow to the retina in a way that is optimal for fine spatial vision. Using high-precision eye-tracking coupled with a system for gaze-contingent display capable of localizing the line of sight with arcminute precision, and an Adaptive Optics Scanning Light Ophthalmoscope (AOSLO) for high-resolution retinal imaging enabling retinal-contingent manipulations of the visual input, their results show that the need for active foveolar vision also stems from the non-uniformity of fine spatial vision across this region. Further, they show that the visual system is highly sensitive even to a small sub-foveolar loss of vision and fixation behavior is readjusted to compensate for this loss. Overall, the emerging picture is that of a highly non-homogenous foveolar vision characterized by a refined level of control of attention and fixational eye movements at this scale.

Michele Rucci’s talk explores how the human visual system constructs spatial representations. Unlike other sensory modalities, where spatial information must be inferred from incoming signals, vision begins with a sophisticated imaging system—the eye—that explicitly preserves spatial structure on the retina. This might suggest that human vision is primarily a passive spatial process, in which the eye simply transmits the retinal image to the cortex—much like uploading a digital photograph—to form a map of the scene. However, this analogy is misleading, as it overlooks the strong temporal sensitivity of visual neurons and contradicts theoretical models and experimental findings that examine vision in the context of natural motor behavior. Here, Michele Rucci will review recent evidence supporting active space-time encoding—the idea that, as with other senses, vision relies on motor strategies to encode spatial information in the temporal domain. This concept has important implications for understanding the normal functioning of the visual system, the effects of abnormal oculomotor behavior, and the development of visual prostheses.

This talk is part of course Olga Shurygina‘s course “Active Sensing,” a seminar on cutting-edge research on active sensory perception in humans and other mammals and realted advances in artificial agents’ abilities such as seeing, grasping, and navigating in space.

Photo created with DALL-E by Maria Ott.