In France we tried to reproduce neuronal functions with the synthesiser and listened to the outcome. This was great fun and Stephen is a really talented supervisor. Since my thesis is on hemispheric specialization I choose one theory which tries to explain differences in hemispheric processing by splitting incomming signals into relative frequency bands. I will first start describing the theory and hope to get to the implementation level in the end. The double filtering by frequency theory by Ivry and Robertson states that information is processed different in both hemispheres. The right hemisphere sees more the global features of f.e. a scene whereas the left hemisphere is processing local features. In the theory information of incomming sensory signals is filtered by frequency and than splitted in different input modules differing in frequency and receptive field size.
I pick up this idea, simplified it and tried to construct possible mechanisms in the theory. This is only a beginning. The theory is more complex and has more computational levels but I will try to build it up step by step. So the steps described below have to be seen as a first draft for combining important elements which need to be defined in more detail in the future.
As a first step I use only the frequency splitting. I therefore feed the signal in a high pass and low pass filter [1]. Depending on the attentional bias ( if you like alpha waves) [3] a cubic function [2] with varying amplitude and period will sample the resulting data.
For integration of the signals strenght this two signals [4a] (one from the highpass, the other from the lowpass filter) will be each split into three signals which then have to cross a given threshold (1:3) [4b]. Depending on the threshold level the overshoots will lead to a saw wave [4c] with a longer attack phase for higher thresholds. At maximum of the saw wave a trigger signal (cubic) with amplitude 1 (low threshold overshoots) to 3 (high threshold overshoots) will be send for each splitted signal and will be combined again [4d]. Then again a threshold detection leads to signals which can be used as a trigger to inhibit the other hemisphere at the level of the integral function [5]. A possible method could be to raise the thresholds for the other hemisphere. This would impede f.e. the global feature to be processed and enables to focus on local features. (For meditation study to be tested in a model see also http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351800/)
