GEMME2 · What is it worth looking at? Exploratory oculomotor behaviour and the brain efficiency in selecting a perceptual target
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2006-04-01 → 2008-03-31
- EU contribution
- €158,219
- Participants
- 1
- Scheme
- EIF
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Results in brief
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.
Data: CORDIS, © European Union
Project objective
Humans explore their visual surroundings by means of rapid shifts of eye-gaze, or saccades, in order to align the higher acuity region of the retina, the fovea, with regions of interest in the scene. The quality and the type of visual information that is processed by our visual system depends fundamentally on the orientation of our gaze.In turn, the mechanisms to guide the orientation of the eyes in the space rely on the overall visual input as well as on higher-level cognitive factors (i.e. the intention to look for something in particular).Such intimate interaction between a high-resolution optical system and the oculomotor system has evolved into the highly efficient mechanisms of active vision: as a whole this system is a remarkable model system to understand sensorimotor integration in human and other primates.An integrate approach to active vision is actually the broad goal of the proposed scientific project. Moreover, our project investigates in a robust, quantitative way the strategy used by the brain to select a perceptual target for privileged processing through gaze redirection. Target selection, indeed, is the primary focus of Selective Attention research, one of the cutting-edge fields in the modern Neurosciences.We will investigate in particular the low level mechanisms of guidance of eye movements, focusing on the relationship between the simple features extracted at the early stages of vision (in the retina, LGN and primary visual cortex) and the motor-preparation mechanisms that lock the saccadic system onto a particular target.We are ultimately interested in understanding the basis of human free exploration of the visual environment and evaluate its efficiency for the purposes of information optimisation.The project will comprise a series of behavioural experiments on human volunteers, whose eye movements will be recorded and analysed. Furthermore statistical analysis and modelling of data will constitute a major part of the research.
Original text from CORDIS.
Participants
- UNIVERSITE DE LA MEDITERRANEE · MARSEILLECoordinatorCity levelFrance
Links
Data: CORDIS, © European Union