I've been very interested in the roles of dopamine for some time now
ever since I read that it may be more related to motivation than to
pleasure (as previously believed). It also seems to increase attention
to a given task as the dopamine level increases. On top of all of
this, it seems to be essential to goal-directed behavior.
What are everybody's thoughts as to the functions of dopamine?
By the way, if dopamine isn't specifically related to pleasure (but to
the pursuit of pleasure), why is it so pleasant to be in a motivated,
goal-directed state? I did a quick search in this group and one person
a long time ago noted that he thought it was due to increased blood
flow in the brain brought upon by in increases in dopamine.