Neglect patients exhibit egocentric or allocentric neglect for the same stimulus contingent upon task demands

Hemispatial Neglect (HN) is a failure to allocate attention to a region of space opposite to where damage has occurred in the brain, usually the left side of space. It is widely documented that there are two types of neglect: egocentric neglect (neglect of information falling on the individual?s left side) and allocentric neglect (neglect of the left side of each object, regardless of the position of that object in relation to the individual). We set out to address whether neglect presentation could be modified from egocentric to allocentric through manipulating the task demands whilst keeping the physical stimulus constant by measuring the eye movement behaviour of a single group of neglect patients engaged in two different tasks (copying and tracing). Eye movements and behavioural data demonstrated that patients exhibited symptoms consistent with egocentric neglect in one task (tracing), and allocentric neglect in another task (copying), suggesting that task requirements may influence the nature of the neglect symptoms produced by the same individual. Different task demands may be able to explain differential neglect symptoms in some individuals

Statistical properties of seismicity of fault zones at different evolutionary stages

We perform a systematic parameter space study of the seismic response of a large fault with different levels of heterogeneity, using a 3-D elastic framework within the continuum limit. The fault is governed by rate-and-state friction and simulations are performed for model realizations with frictional and large scale properties characterized by different ranges of size scales. We use a number of seismicity and stress functions to characterize different types of seismic responses and test the correlation between hypocenter locations and the employed distributions of model parameters. The simulated hypocenters are found to correlate significantly with small L values of the rate-and-state friction. The final sizes of earthquakes are correlated with physical properties at their nucleation sites. The obtained stacked scaling relations are overall self-similar and have good correspondence with properties of natural earthquakes

How do you look?

How Do You Look? (2003-2006) was a Wellcome Trust funded project carried out jointly with Imperial College Computing Department (IC) and St Mary’s Hospital London. The role of Imperial College was confined to providing eye tracking equipment for the surgical part of the project. The project’s main thrust was to apply to laparoscopic surgery the research methodology we had developed over the years with artists. This consisted in observing the surgeon’s eye movements in order to understand his eye-hand strategies and, on this basis, devise ways of teaching surgery trainees. A training DVD “General Eye Movement Catalogue (GEMC)” 2003 was produced and presented at 12th European Conference on Eye Movements, Dundee 2003 “Visual Search in Parallel Environments – eye-hand coordination in minimal access surgery”. The results were also presented in an invited lecture in Tampere University, Finland “A Painter’s Eye – observing an expert in Visual Perception” March 2004. During the course of the project, Sir Professor Ara Darzi was eye tracked and filmed performing laparoscopic cholysystectomy (gall bladder extraction) which, to our knowledge, constitutes a world first which, in all likelihood, will remain for some time the only available reference on the subject of eye-hand coordination in real-world keyhole surgery. The U.K. touring exhibition, film, and dedicated website [www.howdoyoulook.co.uk], opened in an art gallery (Dulwich Picture Gallery London) and progressed to its final venue, a medical institute (Hunterian Museum London) where it was accompanied by a series of lectures including "Many look but few see – Leonardo da Vinci" by Francis Wells FRCS