Do you remember where you read that? I read in a neuroscience paper today that dopamine's primary effect is alertness rather than a particular pleasureable sensation. Makes sense in terms of what you've posted [too little and one could be subject to Alzheimer's; also the other side: too much and the result is attentional overload]. I'll try to backtrack to the link to the paper I referred to.
Steve had written:
Obviously a staggering gap. How do we then remain functionally oriented to the environment and our own situation in it moment by moment? It has to be accounted for, imo, by the 'subconscious mind', an aspect of the consciousness complex that is finally being recognized and taken up in neuroscience. The subconscious clearly absorbs and maintains immense amounts of information from the environment and from our experience in the world -- affectivity, feeling, sense of significance, sense of interconnection -- in and with our environment. The question is becoming to what extent the subconscious mind processes and collates (correlates) what it receives and remembers . . . re-members, reconnects, puts back together . . . and how that integration is manifested at times to conscious awareness. Of course it's in 'para-normal experiences' such as telepathy, precognition, strokes of genius and insight, mediumship, etc., that we see the subconscious in action. And of course these experiences are so abnormal and anomalous that science has thus far refused to study them. That will probably change.