Sentience and qualia

An objective (scientific) look at the biological world tells us some animals are sentient, others less so to the extent that many animals function entirely by programmed response (reflex).

What is sentience?  Well it is an intervention between an incoming sense experience and its being acted upon via the animal "experiencing" the sensation via a "qualia" and emotional associations.  A phototropic organism moves toward a light source but does not "experience" light -- it just responds that way automatically.  A sentient organism experiences the light and, if it likes it, moves toward it ("likes" -- an emotion).

This is "the great mystery" of neurology -- whence the qualia of experience and the associated emotional qualia?  It is a far better arrangement for reactions than evolved reflexes, which tend to be automatic and hence take a long time to change and are basically inflexible (an ant given a certain pheromone does a certain thing, and other organisms can take advantage and for a while fool the ants).  An emotional reaction is more flexible and permits learning without genetic evolution.

Some work has identified the evolution of certain neurochemicals and their pathways (those associated with emotions such as pleasure for reinforcing a behavior and displeasure for discouraging it) as marking the appearance of sentience in the animal world -- something which, if true, would imply that the dinosaurs, mammals and birds (and probably the "mammal like reptiles" that preceded these) were sentient but that other reptiles, amphibians, fish, and invertebrates are not, although similar pathways evolved independently have been identified in some cephalopods.