Neurophysiological recordings from
ventral tegmental neurons
Wolfram Schultz and
colleagues have characterized
the physiological properties of
midbrain dopamine neurons in
behaving monkeys.
They recorded from VTA
neurons while monkeys
performed tasks in which
rewards could be learned to be
expected.  In these tasks,
visual stimuli predicted
rewards, but the animal did not
know the association between
stimulus and reward at the
beginning of the experiment.