Fight, Flight, Freeze, Fawn, Float

We used to say what happens when the saber-toothed tiger chases us?  Meaning, back in the way old days of human development, when someone’s life felt threatened, as in, when being pursued by the terrors of that time, we’d be worrying about tigers, the big ones with sharp and long canine teeth.

This helps with visualizing fear in the context of understanding fight/flight/freeze/fawn/float.  In other words, when we feel or sense fear our brain and bodies respond in predictable ways.

No more tigers (mostly) but our fears and our responses are very much present.

So, what about our response to current-day fears?  What is really going  on in our brain and, in particular, out brain stem?