question about phrase, "in den Gehirnen"

[edmont]

In English we have expressions where the plural "brains" is used for a single person -- such as "She's got brains."  "He blew his brains out." 

In the following German sentence, from around 1919, is it possible the speaker is using Gehirnen in the same way?

Es ziehen Gedanken durch die Welt wie elecktrische Ströme und leuchten auf da und dort in den Gehirnen.

Thoughts run through the world like electric current and light up here and there in the brains.

Is he referring, so to speak to "one's brains"? Or is he speaking of distinct brains in distinct people? Thank you for any assistance.

[Keswick]

The "Gehirnen" here refers to the brains of many. Thoughts run through the world like electric current and light up here and there in the brains (of the people living in this world).

[edmont]

Keswick, thank you.