Neuronal Representation of Music During Musicogenic Epilepsy
Proceedings of the 20th Annual International Conference of the IEEE
Engineering in Medicine and Biology Society, (1998)Abstract
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