A Phil-for-an-ill Blog

September 1, 2008

The Spoiled Reward Pathway Hypothesis II or Learning-Machines

I wrote this brain-quirk shortly after its predecessor. As with the its predecessor I also augmented this one a little also.

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Spoiled Reward-Pathway Hypothesis II or Learning-Machines

In this `Spoiled Reward-Pathway Hypothesis’ follow-up I will argue that our culture is responsible for giving us elevated dopamine brain levels. This makes us so liable to develop addictive behavior.

Susan Blackmore argued that we humans are meme-machines. On adopting the meme’s eye-view it is tempting to regard humans as mere instruments of memes, almost blindlessly replicating the culture-replicators.

Prior to replicating a meme, i.e. modifying and transmitting, you have to adopt or master the meme first. This process of acquisition is equivalent to learning or assimilating the contents of the meme (self-reflection, feedback, the works).
If the meme is viable for adoption, i.e. if it doesn’t clash with existing meme-plexes too much, this period may be as short as a few seconds, as with gossip-memes, or as long as a few years, as with scientific theory memes.

Anyway, my point is that humans should better be regarded as learning-machines rather than meme-machines in order to understand addiction. During our entire lifes our brain is designed to constantly try to acquire new memes, put them in the right meme-plexes, possibly modify them a little by interaction with exising memes (=`(creative) thinking’?) and pass them on to the next person. Therefore we are
literally constantly in the process of learning (about our culture). Compared with other animals this makes us humans unique; there’s simply no other animal who learns at such an intense level throughout its entire life as humans do.

I have this link to an interesting internet page in which Dr. Wightman and colleagues argue that `forebrain dopamine release is not necessary for the experience of reward or the maintenance of addictive behavior’. The paper says further: `the actions of dopamine may be most important in mediating expectation of reward or in processing novel stimuli.’ This suggests that dopamine fulfills a vital role in learning and hence meme-acquisition. If you want to read the entire article, go to:

http://www.med.unc.edu/alcohol/cenline/11_2_1.htm (now dead link, try this one instead: http://www.flyfishingdevon.co.uk/salmon/yea…theorydrugaddiction.htm )

The conclusion of Wightman and co-workers seems consistent with findings of Durstewitz and others that dopamine has a stabilizing function on the working-memory and thus improves memory tasks (mastery of memes?). For instance see:

http://www.bio.psy.ruhr-uni-bochum.de/cnl/dmstab.pdf

If the above reasoning is correct it seems plausible that humans possess higher functional dopamine levels than any other animal. The subconscious goal of exercising addictive behavior is to elevate dopamine levels in the brain. The brain of addicts might be engaged in trying to approach the naturally high dopamine levels already possessed by the normal `learning’ brain. Failure to learn (acquisition of memes) for whatever reason might predispose the brain to develop addictive behavior as a short-cut compensative means to stimulate dopamine release. In this sense we may blame our culture for our affinity to develop addictive behavior (i.e. dopamine craving).

Again, any comments?

Philip Jonkers.

Related reading:

1.The Meme-Machine
http://www.susanblackmore.co.uk/Books/Meme%20Machine/mmsynop.html
2.The Biological Basis of Addiction
http://www.addictionscience.net/ASNbiological.htm
3.Pleasure Systems in the Brain
http://www.addictionscience.net/ASNreport01.htm

http://cfpm.org/~majordom/memetics/2000/6278.html

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