"It's almost as though, without sleep, the brain had reverted back to more primitive patterns of activity, in that it was unable to put emotional experiences into context and produce controlled, appropriate responses,"
They become bears.
When you consider that this would be added to the effects of lack of sleep I talked about a few days ago, it becomes a potentially deadly combination. Add anger and poor impulse control to the drunk-like effects and it is easy to imagine that lack of sleep can have a pervasive effect, probably a bigger effect than is usually really thought about.
Take driving while drowsy and throw in a little rage and consider the consequences. It isn’t much of a stretch to conjecture that impaired impulse control mixed with the poor judgment from drowsiness could contribute to violent action and escalation, as well.
Get good nights sleep and/or take a nap. It is good for you and good for the rest of us and your interactions with us.