A limen is the point where an input becomes strong enough to generate a response or the point where sensory stimulus enters conscious awareness. Nervous systems exist to direct movement. Obviously, they can do slightly more than that but if they can't or don't act on the outside world then they aren't much use. However, movement can occur with very little neural hardware. Bees have tiny little poppy seed size brains and they manage to communicate direction and distance. Ants also have tiny brains which work pretty well but they can also be made to walk themselves to death if their scent trails lead in a circle. Brains have to navigate the real world with all of its infinite complexity and much of what they're doing in more complex organisms is balancing competing impulses. You here a sound in the forest: flee or wait? The organism that always flees will run itself to exhaustion and the organism that always waits will soon be eaten. Between the two there is some happy medium but it's a moving target. This only gets more complicated when dealing with social groups. Challenge the alpha for status or accept the status quo? Chickens have peanut sized brains and they have no trouble knowing where they are in the pecking order. Brains get more complex to support more and more complex chains of behaviors but the pyramid is still built from the bottom and at the fulcrum of the interplay between perception and behavior is limens.
Limens can include anything from the itch that itches just enough to scratch it to the flicker of movement that gets a glance to the tone of voice that sees punches thrown. The second definition is actually a subset of the first unless you subscribe to a very weird view of thought and it's roll in behavior. Thoughts aren't exactly separate from the outside world; they show up in MRI scans and are upstream from a lot of actions. Their exact roll in behavior and causality is debatable but that they have one really isn't. It's a bit weird to me that limen isn't more common in discourse because it's really useful in describing behaviors. Maybe this is just a matter of it taking time for language to catch up to psychology or maybe people have more of an aversion to describing consciousnesses in mechanistic terms than I do.
IRON NODER XV: LAST SECOND BARE BONES IRON NODER FREAKOUT!