Final Activity Report Summary - GEMME2 (What is it worth looking at? Exploratory oculomotor behaviour and the brain efficiency in selecting a perceptual target)
It is said that 'The eyes are the mirror of the soul.' With this EIF-funded project we have intended to explore this concept in a scientifically rigorous way: what does the observation of eye movements teach us about the functioning of the brain? And more in particular: what kind of strategy is implemented by our brain to select a visual target as the goal of a gaze shift? Given an extremely rich visual input, the optimal strategy for our visuo-oculomotor system is to make an intelligent selection of the important information while ignoring the rest. Every time we move our eyes in order to direct our gaze to a particular object (which happens very often, indeed, about three times per second!), our brain does actually face a decision-making problem, which can be very complex.
Thanks to this EIF-funded project I have been able to investigate several aspects of this imporant cognitive issue. First, I have characterised the dynamic interaction between the mechanisms of selection of an oculomotor target and those responsible for the pure perceptual selection (which are referred to as covert-attention mechanisms). Second, I have analysed in detail a situation in which the oculomotor system is transiently induced in error when tracking an extended moving object (edge-orthogonal bias): interestingly, this error turns out to be the outcome of a sort of 'best-guess' strategy in a situation in which only intrinsically ambiguous information is available. Finally, I have addressed the complex question of how the information carried by different visual features is integrated to extract a map of visual saliency and the corresponding oculomotor target. In particular, I have investigated the relative importance of luminance and colour in the target-selection mechanisms.
Overall, my results contribute to clarify the dynamic and complex interaction between visual perception, cognitive processing and oculomotor control. These behavioural results provide important hints and testable predictions about the neuronal substrate of the visuo-oculomotor target selection mechanisms (and of their possible impairements, under pathological conditions). In addition, at the theoretical level, they indicate that a valid conceptual framework to understand the visuo-cognitive-oculomotor interaction is the decision-making theory.
Thanks to this EIF-funded project I have been able to investigate several aspects of this imporant cognitive issue. First, I have characterised the dynamic interaction between the mechanisms of selection of an oculomotor target and those responsible for the pure perceptual selection (which are referred to as covert-attention mechanisms). Second, I have analysed in detail a situation in which the oculomotor system is transiently induced in error when tracking an extended moving object (edge-orthogonal bias): interestingly, this error turns out to be the outcome of a sort of 'best-guess' strategy in a situation in which only intrinsically ambiguous information is available. Finally, I have addressed the complex question of how the information carried by different visual features is integrated to extract a map of visual saliency and the corresponding oculomotor target. In particular, I have investigated the relative importance of luminance and colour in the target-selection mechanisms.
Overall, my results contribute to clarify the dynamic and complex interaction between visual perception, cognitive processing and oculomotor control. These behavioural results provide important hints and testable predictions about the neuronal substrate of the visuo-oculomotor target selection mechanisms (and of their possible impairements, under pathological conditions). In addition, at the theoretical level, they indicate that a valid conceptual framework to understand the visuo-cognitive-oculomotor interaction is the decision-making theory.