The brain responds to stimuli, tactile and visual contradiction in delaying the processing of information that comes from the skin. A fly is laying on the right elbow. Slight itching, moving vision towards the elbow, identification of the intruder and its position and, finally, blow. This reaction is not as instantaneous as you can imagine. Indeed, the brain seems to delay affixed aware of the tactile perception, as reported a study in Current Biology Group for Research in Cognitive Neuroscience (Grnc) in Barcelona. The brain is often having to generate rapid responses integrating stimuli that produce information in contradiction: if, for example, the subject has crossed his arms and brings his right arm on the left side and left arm on the right side, his hands will be in a position that is reversed from the original location. In this case, the brain must be able to correctly integrate the information of the tactile stimulus (for example pinch) on the right hand, although the visual stimulus comes in fact from the left. To avoid mistakes the brain needs time to make a realignment of the information space of two different maps: that rof the body and one that covers everything else. To understand how the mechanism works, researchers have assessed the response of 32 university students to a series of visual and tactile stimuli. Each student has been subjected to 600 tests. "First we asked participants to cross the arms, so that the position of hands was in conflict with the anatomical position" says Salvador Soto-Faraco, one of the authors of the study, "we have stimulated one of two hands." Few tenths of a second later, a small light (visual stimulus) I had left or right. Both the tactile stimuli that those visual products were in a totally random. In addition, the flash of light could be generated 60 or 200 milliseconds after the tactile stimulus. In order to assess whether the time elapsed between the two stimuli does influence or not the answer.

Using functional magnetic resonance imaging, researchers have been able to associate a brain activation pattern to the memory of an image. According to a study in Nature. Reading the thoughts of other people is not yet possible, but scientists are working on it. One tool developed by Jack L. Gallant and collaborators at the University of Berkeley (California) is able to recognize an image that a person has just seen through his brain activity. Two of the authors of the study published in Nature - Kendrick Kay and Thomas Naselaris - were submitted in person by observing the experiment at random photographs from a group of 120 during brain scans using functional magnetic resonance (fMri). The results of fMri, combined with a mathematical model, have served to associate the images neuronal activity that a person has just had before our eyes.

Even a visual stimulus extremely short, less than millisecond, affects the decoding of information in the nervous system. The Ferrari of insects, the horsefly, a tiny acrobat who moves at high speed, has proved that even a very short visual stimulus (on the scale of milliseconds) affects decoding information in the nervous system. This was discovered by scientists in universities of Indiana, Princeton (New Jersey) and the Los Alamos National Laboratory (New Mexico), one of the largest multidisciplinary institutions in the world. A human being is unable to record the continuous change of scenery and should have a supra-sensory stimulation. But this is a fly: its nervous system processes information very quickly so that the insect can adapt to what he sees with a reaction time of 30 milliseconds. "During the flight," says Ruyter van Steveninck University of Indiana, "the horsefly must quickly analyze a number of complex information and, because of its ability to move rapidly, it is reasonable to think that the way it deciphers level sensory-motor data is optimal. We then decided to study its visual system to understand how his brain can order a continuous stream of very complex data in such an efficient way. "

The procedural memory remains imprinted in the chemical synapses. It is not the merit of a cell constant. When we drive a car or we tie a shoe knot, we store a series of gestures that are accessed faster and automatically whenever you need that action again. It is the so-called working memory or procedural memory, whose operation resembles that of cache memory of a computer, for example, allows us to more quickly open a website already visited. A study conducted by Gianluigi Mongillo of French Cnrs research, and Omri Barak and Misha Tsodyks the Weizmann Institute (Israel) would seem to refute the widespread belief that this type of memory is fixed thanks to a number of specific neurons. On the contrary, the procedural memory is recorded at the level of chemical changes in cells that remain after the transition pressure in nervous synapses (points of contact and communication between neurons).