Neuronal representation of music during musicogenic epilepsy

It has been shown earlier that deep aesthetic appreciation of music can induce an altered state of consciousness, a phenomenon often referred to as musicogenic epilepsy. The change in EEG, during such a state, has been characterized by large number of spikes, symptomatic to epilepsy, along, with changes in background EEG. The fractal dimension of EEG was found to reduce during this (epoch) period. Morphological variations in ECG, causing a possible sympathetic burst on autonomic system (ANS), has also been reported. In the present study, the neural representation of the music, causing change in the state of mind, has been found out using a biophysically defensible model of auditory processing. This involves analysis, transduction and reduction in the cochlear mechanism generating the auditory spectrum. The latter is again taken as input to the response function (RF) of the neuron and the output of this filter is the neuronal representation of the input signal (music). This cortical representation turns out to be a ripple, i.e. near-sinusoid on the log-frequency axis, indicating a broad-based spike in the time domain. This might have deeper implications on the study of altered state of consciousness because spikes in EEG and the 'clouding' of consciousness (say during grandmal/petitmal epilepsy) are established phenomena.