Event:

Visual perception is an active process: we constantly move our eyes, head, and body to fully perceive the world around us. Research over the last century has yielded incredible insight into how neurons in the visual system process information, yet our understanding is largely limited to conditions of passive rather than active vision. This is primarily due to the fact that experiments are traditionally performed under physically restrictive conditions that prevent the natural sensory consequences of movement (e.g. head-restrained animals presented with isolated stimuli). How does visual processing occur under ethological conditions, where animals freely explore complex visual environments in a goal-dependent manner? We addressed this question by performing visual physiology in freely moving mice, recording the activity of more than 100 V1 neurons while measuring the visual input with a head-mounted camera. In addition to mapping spatiotemporal receptive fields in freely moving animals, we found that V1 neurons jointly code for eye and head position - a coding scheme useful for performing retinocentric-to-egocentric reference frame transformations. We also found that V1 neurons fire in a sequence around saccadic eye movements according to increasing spatial frequency preference, consistent with coarse-to-fine models of visual scene processing. To address how these phenomena relate to goal-directed behavior, ongoing work in the lab is focused on the neural circuits and coding underlying visual distance estimation. Together, we are moving toward a greater understanding of how our visual systems operate under real-world conditions.