Fast Optical Response of Cortical Neurons to Visual Stimulation

Aim of this researh is the identification of a non invasive methodology to detect the fast NIRS signal during visual stim- ulation. We based our studies on Gratton and Steinbrink works on fast NIRS identification and we focalized our atten- tion on how to increase the signal to noise ratio. The first step was to develop a visual stimulus for maximize neuronal activity in according to the hypercolumn model of Hebel and Wiesel; afterwards, using flexible and low-cost instruments, LEDs and Photodiode, and developing a new head support for this devices, we set the basies for a flexible instrumental de- sign to identified NIRS signal, leaving the possibility to im- prove mathematical algorithms for epocs extraction and signal analysis for later time.