Science

Another week has passed. Can't really recall what I've been up to. Guess nothing too exciting, just work at the lab. I am figuring out what's the best way of recording head movements in our new setup. Using a search coil system seems to be most accurate. Here you put to orthogonal coils (of a couple of mm) on the mouse's head. If you then put the mouse in a Helmholtz cube frame in which two orthoganal uniform magnetic fields are present, you can measure the orientation of the coils (and thus of the mouses head) by recording the magnetically induced voltage from the coils. The voltage recorded depends on the amount of the magnetic field that passes through the coil, so a coil orthogonal to he direction of the magnetic field would have the highest induced voltage and a coil alligned with the magnetic field would have no induced voltage. In between every position is reresented by a gradient in voltage. I hope I explain this basic physics clear enough so someone will understand it... The problem with such a system is the uniform magnetic field that has to be created by a framework of three pairs of opposing coils. This configuration is called a Helmholtz cube or field coil and is not cheap. Our lab does not own a Helmholtz cube. So I'll gues we might have to abandon the ideal method for something else. We're also exploring the possibility of using gyroscopes, little sensors that record rotation in a way I will not try to explain. The problem with gyroscopes is that they will need a hand made circuitry of chips which will be an awful lot of work. We'll see what we'll use in the end. The good thing is that just recently two papers were published claiming that measuring the vestibulo collic reflex (stabilizing head position in space by compensating head movements) is a valid method of measuring the state of the vestibular system. This has great advantages over measuring the vestibulo ocular reflex (stabilizing the image on the retina by compensating eye movements) because, well mice just have pretty small eyes....

Furthermore I am trying to schedule the road to graduation. I got my working with animals licence course scheduled for december and I might do an online course on conscious and unconscious perception with the University of Amsterdam fom september to the end of november. This would only leave me with a thesis and a graduation presentation in the new year and I might be ready to start my job in march instead of april, which is benificial for all of us.

Well there's some interesting stuff coming up about volcanoes and birthday parties, but I guess I'd better put that in a new post because everybody will have stopped reading even halfway my explanation of a search coil system..