We are honoured to have two prestigious speakers for our plenary sessions at ECVP 2012:
Sunday 2nd September 2012 at 17.00, David Burr (University of Florence)
Constructing stable spatial maps of the world
To interact rapidly and effectively with our environment, our brain needs access to a neural representation – or map – of the spatial layout of the external world. However, the construction of such a map poses major challenges to the visual system, given that the images on our retinae depend on where the eyes are looking, and shift each time we move our eyes, head and body to explore the world. Much research has been devoted as to how the stability is achieved, with the debate often polarizing between the utility of spatiotopic maps (that remain solid in external coordinates), as opposed to transiently updated retinotopic maps. Our research suggests that the visual system uses both strategies to maintain stability. fMRI, motion-adaptation and saccade-adaption studies demonstrate and characterize spatiotopic neural maps within the dorsal visual stream, maps that are updated by eye-movement signals to remain solid in external rather than retinal coordinates. However, the updating is not immediate, but takes up to 500 ms to complete. To solve the immediate problems created by individual saccades, there seems to exist a separate system that bridges each saccade with neural units that are “transiently spatiotopic”. These units prepare for the effects of saccades with a shift of their receptive fields before the saccade starts, then relaxing back into their standard position during the saccade, compensating for its action. Psychophysical studies investigation localization of stimuli flashed briefly around the time of saccades characterize quantitatively these neural mechanisms, and show how they serve to integrate information across saccades. The two systems – one rapid, transitory and high-resolution, the other slow, permanent and low-resolution – cooperate to keep the world stable as we move our head and eyes, and provide a stable world-centered map to guide interactions with our environment.
Monday 3rd September 2012 at 17.00, Giacomo Rizzolatti (University of Parma)
Rank Prize Lecture.
The mirror mechanism: a neural mechanism to understand others
Primates, and humans in particular, are exquisitely social species whose survival critically depends on their ability to understand what others do and feel. In my talk I will first describe the general properties of a neural mechanism – the mirror mechanism- that allows individuals to understand the actions done by others. This mechanism produces, in the brain of the viewer, the representation of the observed action in a motor format. Because the observing individuals know the outcome of their motor representations, they are able to achieve, through the mirror mechanism a direct knowledge of what the others do and feel. In the second part of my talk I will show that, while individual mirror neurons code the “what” of a given motor act (e.g. grasping), their “chained” organization enables the observer to infer the “why” of it (e.g. grasping-for-eating”), that is to read the agent’s motor intention. I will show then that the mirror mechanism exists also for emotion. In this case the mirror mechanism is localized in a circuit that includes the insula. I will conclude discussing some social implications of these data.