Received: by alpheratz.cpm.aca.mmu.ac.uk id XAA13626 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Fri, 17 Aug 2001 23:41:19 +0100 From: <joedees@bellsouth.net> To: memetics@mmu.ac.uk Date: Fri, 17 Aug 2001 17:43:55 -0500 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Re: Spoiled Reward-Pathway Hypothesis Message-ID: <3B7D57DB.28568.6D61FE@localhost> In-reply-to: <998065363.3b7d44d349869@rugth1.phys.rug.nl> References: <998048139.3b7d018bf3ed3@rugth1.phys.rug.nl> X-mailer: Pegasus Mail for Win32 (v3.12c) Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
On 17 Aug 2001, at 18:22, Philip Jonkers wrote:
> The Spoiled Reward System Hypothesis
>
> Susan Blackmore makes a solid case in defending and describing
> the hypothesis of the emergence of humans' big brains as a result of
> cultural and biologically coupled evolution, she refers to this
> process as gene-meme co-evolution.
>
> The original biological function of the reward pathway (RP)
> - running from a brain stem ventral tegmental area (VTA)
> via the nucleus accumbens (NA) to the prefrontal cortex -
> is to issue feelings of reward for fulfillment of actions aimed to
> warrant or enhance chances of survival such as eating, drinking and
> reproduction. Without the RP organisms would lose interest in life and
> be rendered incapable of maintaining self-support as life-saving or
> reproductive activities would not be re-inforced by the act of reward.
> Therefore, the RP is the motivator designed to maximize chances of
> survival and as such, maintain biological evolution.
>
> With the arrival of culture and its (initial) biologically
> advantageous and useful role in survival, the RP had to take up an
> additional task of rewarding actions aimed at developing and
> maintaining culture. I contend that the gene-meme co-evolution could
> not have been sustained if such actions were not accompanied by
> emissions of feelings of rewards to its partakers. The RP was obliged
> to take up the dual task of rewarding biological as well as cultural
> actions. Therefore, in humans, the RP is the built-in motivator of
> both genetic and memetic evolution. The main objective of life,
> survival, was supplemented with a myriad of cultural sub-objectives,
> some of which are only remotely related to survival at best (such as
> art, music, dance). Together with the increase in brain size it seems
> plausible then, that the RP gained in size simultaneously. At present
> stage of brain evolution, by serving parties of biology and culture,
> it is plausible also to assume that the RP is used to receive many
> stimuli. Compared to non-human organisms one might say that the human
> brain RP is spoiled.
>
> In healthy human beings the RP serves its role well by providing
> sufficient satisfaction from performing regular healthy biological and
> cultural actions (such as work, school, sports and so on). Since the
> resources on this planet are limited however, not everyone gets the
> opportunity to derive sufficient satisfaction and pleasure from such
> beneficial activities. After all, scarcity of resources forced
> competitive selection necessary to fuel evolution in the first place.
> The unfortunate people with a lack of healthy supply of satisfaction
> are still left with a spoiled RP inherently craving for stimuli.
>
> To satisfy themselves (by satifying their spoiled RPs) they have the
> tendency to seek pleasure and reward in artificial and most of the
> times harmful means. The consensus now is that drugs, gambling,
> compulsive sex and eating all have in common to stimulate the RP. This
> is where the risk of addiction kicks in. Needless to say, addiction is
> wide-spread and highly prevalent among all layers of the population
> (e.g. work can become addictive too). The mentioned surrogate means
> stimulate the release of dopamine. Normally this NT/hormone is
> necessary for re-inforcing healthy behavior by helping to memorizing
> it. (Dopamine has a stabilizing role on memory.) Unfortunately, the
> above mentioned artificial means have a similar effect and increase
> the risk of addiction by re-inforcing the corresponding unhealthy
> behavior thus making recurrence probable. NB Bear with me that I just
> started out in neuroscience so I might fall a little short on
> accuracy.
>
> In conclusion, I contend that the wide-spread prevalence of addictive
> behavior is an artifact of the meme-gene co-evolution of the brain
> (and in particular the RP).
>
> Anyone, any comments?
>
> Consistent with the ideas presented above, addiction in animals living
> in a natural environment is very improbable. Does anybody know of
> cases reporting animal addictive behavior?
>
In studies of addiction performed upon chimpanzees, 'junkie
monkeys' eagerly extende their arms for their daily fix; rats would
push a lever which electrostimulated the pleasure centers in their
brains rather than other levers that fed them, to the point of
starvation, and other such results were reported with the
dispensation of cocaine to rats.
>
> Philip.
>
> ===============================================================
> This was distributed via the memetics list associated with the
> Journal of Memetics - Evolutionary Models of Information Transmission
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>
===============================================================
This was distributed via the memetics list associated with the
Journal of Memetics - Evolutionary Models of Information Transmission
For information about the journal and the list (e.g. unsubscribing)
see: http://www.cpm.mmu.ac.uk/jom-emit
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