pp. Posting a series of messages that reflect one's current thoughts, ideas, passions, observations, readings, and other intellectual interests.
Other Forms
But the claim that Twitter is nothing but mindless inanities is just as wrong as the analogous claim for blogs — in fact it’s precisely the same claim, five years later. There are other things you can do with the technology — the technical terms are "lifecasting" [here’s what I had for dinner] vs. "mindcasting" [here’s a thought, a question, an observation, a link to something more substantial].
—Sean Carroll, “Twitter Agonistes,” Discover, April 23, 2009
Twitter, the micro-messaging service where users broadcast short thoughts to one another, has been widely labeled the newest form of digital narcissism. And if it's not self-obsession tweeters are accused of, it's self-promotion, solipsism or flat out frivolousness.

But naysayers will soon eat their tweets. There's already a vibrant community of Twitter users who are using the system to share and filter the hyper-glut of online information with ingenious efficiency. Forget what you had for breakfast or how much you hate Mondays. That's just lifecasting.

Mindcasting is where it's at.
—David Sarno, “On Twitter, mindcasting is the new lifecasting,” Los Angeles Times, March 11, 2009
2008 (earliest)
I teach journalism at NYU, write the blog PressThink, direct NewAssignment.Net, and try to grok new media. I don't do lifecasting but mindcasting on Twitter.
—Jay Rosen, “Twitter bio,” Twitter.com, May 19, 2008
NeuroSky has developed a cost effective bio sensor and signal processing system for the consumer market. …

Adding this technology to Justin.tv would allow viewers to get into the lifecaster's state of mind.
—“Justin.tv + NeuroSky: Not just lifecasting but also mindcasting,” Mindrosity, July 13, 2007