  The scientific approach to understand the nature of consciousness revolves
around the study of human brain. Neurobiological studies that compare the
nervous system of different species have accorded highest place to the humans
on account of various factors that include a highly developed cortical area
comprising of approximately 100 billion neurons, that are intrinsically
connected to form a highly complex network. Quantum theories of consciousness
are based on mathematical abstraction and Penrose-Hameroff Orch-OR Theory is
one of the most promising ones. Inspired by Penrose-Hameroff Orch-OR Theory,
Behrman et. al. (Behrman, 2006) have simulated a quantum Hopfield neural
network with the structure of a microtubule. They have used an extremely
simplified model of the tubulin dimers with each dimer represented simply as a
qubit, a single quantum two-state system. The extension of this model to
n-dimensional quantum states, or n-qudits presented in this work holds
considerable promise for even higher mathematical abstraction in modelling
consciousness systems.
