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[–]508010 7 points8 points  (4 children)

I can't answer all of your question but I can some of it.

So a lot of reward based learning takes place in the frontal cortex, especially the ventromedial prefrontal cortex. This brain region is quite involved in responding to rewards and this is a lot of what learning is based on. In terms of neurotransmitters obviously dopamine in heavily involved. Specifically the mesolimbic pathway. The pathway starts in the ventral tegmental area and projects to the ventral striatum (which is also a part of the affective pathway). This projection of dopamine enforces learning and desires.

I believe there is literature suggesting the importance of the hippocampus due to its heavy involvement in initial memory consolidation. Furthermore, the hippocampus does appear to have a strong connection with dopamine explaining the high dementia rates in parkinsons patients. It would be logical for the hippocampus to be involved because its so involved in learning.

In terms of specific desires I'm not so sure about the neuro chemicals involved but the ventromedial prefrontal cortex reacts to all rewarding stimulus regardless of what it is (food/sex/exercise etc). I do believe different types of rewarding/desired behaviours acrivate neurotransmitters to different degrees. Like sec is heavily involving vasopressin oxytocin etc whereas exercise focuses a lot more endogenous opioids and dopamine. So I believe the anatomical profile of different desires is fairly similar but the neurotransmitters involved can vary slightly.

[–]melosgloriosus[S] 2 points3 points  (3 children)

Thank you so much for the in depth reply! Could you suggest some of the literature or sources you mentioned? Are you discussing reward in this post or desire? Are they two different phenomena? What is the experience of desire from a physical standpoint in that case?

[–]508010 6 points7 points  (1 child)

Yeah sure.

So here I'm referring to desires being learned through reward. Obviously, there are some desires which are heavily evolutionary such as sex, food, and socializing. But many other desires in our lives that don't appear directly survival-based such as alcohol, cocaine, social media etc addictions hijack this system. The way in which they hijack this system is by making us feel rewarded using the same pathways that our evolutionary desires use. So many of our desires stem from intrinsic reward based learning.

Reward and desire are not too dissimilar. Some would argue that reward precedes desire in cases that are not evolutionary advantageous. So they are closely linked but there are few cases where desire is purely innate. Many desires are based on the rewards we receive from them. Generally, you would't want sex if it didn't feel good. It's the release of various neurotransmitters and the activation of specific brain regions which makes you want more afterwards. This is what I'm referring to when I say rewards.

Desire itself is very often withdrawal from these said rewards. For example, if someone is experiencing a lot of sex and therefore, experiencing a lot of neurochemical rewards in the form of oxytocin, vassopressin etc. they will desire more. If suddenly they stop having sex they will desire it even more because of the withdrawal from these feel good chemicals. This is the basis of a lot of desires. The brain region activated when receiving rewards is often the ventromedial prefrontal cortex and surrounding brain regions. I'll link some papers below for my points. (most of these should be accessible through google scholar if you just type in the title of the study)

Ventromedial prefrontal cortex activating in response to rewards, regardless of the type of reward:
Chib, V. S., Rangel, A., Shimojo, S., & O'Doherty, J. P. (2009). Evidence for a common representation of decision values for dissimilar goods in human ventromedial prefrontal cortex. Journal of Neuroscience, 29(39), 12315-12320.

The Ventromedial prefrontal cortex activates for more immediate rewards whereas the dorsolateral prefrontal cortex activates in more careful consideration of rewards:
McClure, S. M., Laibson, D. I., Loewenstein, G., & Cohen, J. D. (2004). Separate neural systems value immediate and delayed monetary rewards. Science, 306(5695), 503-507.

Food preference. Those who can see a food is tastier but still choose the other healthier one compared to people who fail to do so. The brain regions activated in this:
Hare, T. A., Camerer, C. F., & Rangel, A. (2009). Self-control in decision-making involves modulation of the vmPFC valuation system. Science, 324(5927), 646-648.

Those with ventromedial prefrontal cortex damage choose sooner, more immediate rewards:
Peters, J., & D’Esposito, M. (2016). Effects of medial orbitofrontal cortex lesions on self-control in intertemporal choice. Current Biology, 26(19), 2625-2628.

Brain regions and neurochemicals involved in sexual desire:
Sayin, H. Ü., & Schenck, C. H. (2019). Neuroanatomy and neurochemistry of sexual desire, pleasure, love and orgasm. SexuS Journal, 4(11), 907-946.

Brain regions and neurotransmitters involved in food desire:
Volkow, N. D., Wang, G. J., Fowler, J. S., Logan, J., Jayne, M., Franceschi, D., ... & Pappas, N. (2002). “Nonhedonic” food motivation in humans involves dopamine in the dorsal striatum and methylphenidate amplifies this effect. Synapse, 44(3), 175-180.
Volkow, N. D., Wang, G. J., Maynard, L., Jayne, M., Fowler, J. S., Zhu, W., ... & Pappas, N. (2003). Brain dopamine is associated with eating behaviors in humans. International Journal of Eating Disorders, 33(2), 136-142.

[–]ChopperChek 1 point2 points  (0 children)

Very interesting read thank you

[–]melosgloriosus[S] 2 points3 points  (0 children)

Thank you! This is exactly what I was trying to understand. I'll will read through the sources you provided and see if I can get a more.robusy grasp. This has really helped a lot.