Temporal Dynamics of Conscious Access during Eye Movements

JOAQUIN NAVAJAS; JUAN E KAMIENKOWSKI; MARIANO SIGMAN

Congreso; II Joint Meeting of Neuroscience; 2010

Sociedad Argentina de Neurociencias

When looking at a scene we produce spontaneously a discrete sequence of brief fixations. Bits of information from all fixations are integrated to produce a coherent percept of the scene. This experiment was aimed to understand the temporal kernel of conscious access to information in a single fixation. Participants had to make a rapid sequence of three fixations: 1) to a point at the left side of the screen, 2) to the center and 3) to the right side of the screen. A stream of letters presented on the center commenced before participant?s gaze was directed to it and continued until their eyes reached the right side. They were asked to report the content of what they had seen. We could infer the temporal kernel of conscious access relative to the onset and offset of the fixation and whether sequential information could be buffered in a single fixation. This temporal window begins around 80ms from the fixation onset, revealing the existence of a refractory period locked to the beginning of the fixation. The kernel increased smoothly and reached a cutoff during the saccade. These results indicate that it is possible to acquire information from a visual scene not only during fixations but also during saccades, contrary to what was expected from the literature (i.e. saccadic suppression).