You will find references to over 300 other authors that have contributed to understanding the Neurobiological Correlates of Gratitude as "the healthiest of all human emotions." (Zig Ziglar)
The most recent superb summary article Published 11/19/2019 written by Madhuleena Roy Chowdhury online @https://positivepsychology.com/neuroscience-of-gratitude/: The Neuroscience of Gratitude and How it Affects Anxiety & Grief
The Marvelous "Neural Correlates of Gratitude" by Glenn R. Fox, Jonas Kaplan, Hanna Damasio, Antonio Damasio: Frontiers in Psychology 2015;6:1491 @https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4588123/
Daniel Dewey's Ted Talk on the Safe use of AI @https://www.youtube.com/watch?v=CK5w3wh4G-M
And of course Gratitude has become one of Oprah Winfrey's favorite subjects on her Super Soul Sunday.
Please refer again to my Pod Cast #37 @Emotional Anatomy: Intelligent Design / Exploding Awareness I @https://anchor.fm/emotional-anatomy