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Seeing the movement: our visual brain at work

By on Feb 18, 2017 in Vision | 2 comments

Having discussed how painters tackled the problem of representing motion in art, we can, therefore, ask ourselves the following question: how is this type of information processed in our brain? On a different occasion, we will describe the stream of visual information from the retina via the lateral geniculate nucleus (LGN) to the posterior pole of the occipital lobe, which contains the primary visual cortex (V1). From V1, information flows along two channels: a ventral pathway extending towards the temporal lobe and a more dorsal pathway, that projects towards the parietal lobe (see figure below). The ventral stream of information is mainly concerned with establishing identities and building categories of visual objects. Running in an anterior direction from the occipital lobe, neurons lying along this pathway are selectively activated by increasingly more complex visual stimuli....

Light music for the masses: a story of LEDs

By on Jan 28, 2017 in Vision | 0 comments

Optics: fast and furious imaging With optics coming of age and its widespread use in biomedical sciences, scientists invest substantial efforts in new imaging technologies. The aim is to reconcile versatility, performance and cost issues. Developments take place in the design of new molecules with expanded capabilities (e.g., increased resistance to photodamage, exquisite sensitivity to excitation frequency, chemical stability). But they also pursue the engineering of more flexible sensors and stimulators with improved performance (e.g. higher quantum efficiency detectors, higher signal-to-noise ratios and the choice of selectable wavelengths of excitation with narrower bandwidths). Being able to quickly switch across different stimulation wavelengths while keeping them as narrow as possible is of great value for the experimenter. The optical properties of most materials largely depend...