A new scientific field is being born, one that seeks to understand which organisms have subjective states, what purpose theymight serve, and how distinct states of consciousness come about. Here, the Holy Grail is to provide a satisfactory, quantitative account for why select states of complicated, neuronal networks go hand-in-hand with experiences such as seeing blue, feeling pain, smelling a dog that's just come in from the rain, or of simply being.
Philosophers call these feelings and sensations that constitute the elements of consciousness "qualia." In contrast, most brain states are not directly associated with conscious sensations: We have almost no access to the structures that give rise to speech, to depth perception or color vision, to the rapid sequence of sensory-motor transformations necessary to play soccer, climb a rock wall, or return a tennis ball, let alone those influencing perspiration, heart rate, or the action of our immune systems. ...