Final Activity Report Summary - SEEING SPACE (Seeing Space: A Virtual Reality Lab for the study of visual spatial attention and eye movements) There is currently converging evidence from lesion, behavioural and neuroimaging studies supporting a distinction between perception and action in far and near space. These studies led to the notion of different reference frames that are used for perceiving and interacting with the three-dimensional world around us, namely to an 'egocentric' viewer-centred system and an 'allocentric' environment-centred system of coordinates. The SEEING SPACE programme aimed at the creation of an Electroencephalography-virtual reality (EEG-VR) unit for the study of spatial perception. The use of VR appeared to be ideally suited for the study of three-dimensional space perception. It could offer a realistic three-dimensional representation of space, fully controlled by the experimenter. SEEING SPACE focussed on the study of space perception and eye movement control in three-dimensional space. Emphasis was drawn on the temporal aspects of ongoing processes as elucidated by the EEG patterns of cortical activation. This field of research, namely the study of depth perception and vergence eye movements was almost entirely unexplored in humans, despite its major importance in everyday life, visual ergonomics and frequent pathologies affecting perception and safe action in space. During the course of SEEING SPACE, a new EEG system was purchased and installed, along with the appropriate software for visual stimulus delivery and data processing. An interface with the existing VR system was developed in order to deliver appropriate time stamps regarding the onset of objects of interest in the VR environment. The goal of this project part was to provide a platform which would allow for the use of virtual stimuli in the same way as conventional stimuli were used in two-dimensional computer displays for EEG and behavioural experiments. Using the new experimental setup, eye movements in different directions and depths, such as saccades, vergence and combined eye movements, were evaluated. We found that vergence movements were associated with a higher degree of variability when virtual stimuli were used compared to conventional stimuli, i.e. Light-emitting diodes (LEDs) in real space. This was probably because of the lack or variability of vergence accommodation in the virtual environment. Using EEG recordings, the cortical activity related to visual processing of elementary stimuli in far and near space was investigated. Preliminary results suggested the activation of different networks by near and far stimuli after 100 ms. The new EEG-VR unit could be used, after the project completion, to perform a wide range of experiments regarding human three-dimensional spatial perception. Apart from spatial perception, different brain functions as well as pathology could be evaluated in the future, such as navigation and locomotion, which were difficult to assess in the real three-dimensional world but were controllable and feasible in a VR environment. Most importantly, SEEING SPACE provided a pool of convergence between neuroscience and engineers and allowed for interdisciplinary interaction and collaboration, which proved to be the basis of scientific excellence in Europe.
