Astral Codex Ten

ventral striatum

3 min read

ventral striatum

Article

ventral striatum is a recurring concept in the Astral Codex Ten archive, appearing 2 times across 2 issues between September 30, 2022 and October 31, 2022. The archive places it in contexts such as “the ventral striatum (aka nucleus accumbens)”; “NAc in the ventral striatum and medial OFC”. It most often appears alongside dopamine, fMRI, mesocortical pathway.

Metadata

  • Category: Concepts
  • Mention count: 2
  • Issue count: 2
  • First seen: September 30, 2022
  • Last seen: October 31, 2022

Appears In

Source Context

Recovered passages from the original issue text. When the raw archive preserved outbound links inside the source passage, they are listed directly under the quote.

Highlights From The Comments On Unpredictable Reward
September 30, 2022 · Original source
One neuroscientific perspective on this is that in order for dopamine to track reward prediction *error* (RPE), it is logically necessary that some other piece of neural circuitry track reward prediction *per se*, often called "value." Those of us who think that dopamine is computing RPE on a moment-by-moment basis (the first derivative of value; see Kim, Malik et al., Cell, 2020) therefore generally also believe that some other part of the brain, especially the ventral striatum (aka nucleus accumbens) and perhaps also the prefrontal cortex, maintains an estimate of value that gets updated by dopamine. And indeed, there are dozens of papers reporting that neural firing in these brain regions correlate with value over and above RPE.
That said, it is also true that (1) NAc neurons correlate strongly with value and also respond to some extent to rewards, predicted and unpredicted; (2) cocaine or amphetamine in the NAc (and another region of the ventral striatum called the olfactory tubercle), which dramatically elevate dopamine levels, elicit robust responses; and (3) in the context of the "liking vs. wanting" framework you allude to, Kent Berridge and others have argued that the NAc contains a "hedonic hotspot", along with closely linked regions like the prefrontal cortex and ventral pallidum. This is an operational definition meaning that when you infuse opioid receptor agonists into said region, the animals react with pleasure, and conversely if you lesion/block activity in these areas, they don't show these behaviors as much, or even start showing defensive behaviors.
Highlights From The Comments On Jhanas
October 31, 2022 · Original source
> H5: Jhanas should show increased activation compared to the rest state in the dopamine reward system of the brain (NAc in the ventral striatum and medial OFC). A broad range of external rewards stimulate this system (food, sex, beautiful music, and monetary awards), so extreme joy in jhana may be triggered by the same system (the VTA is also part of this system, but is too small to image with standard fMRI methods, but see [35] for successful imaging methods).