In a post on Killzone, James Scott Bell says you can streamline your writing by putting your stimulus-response transactions in the right order. In other words, make sure your characters actions and responses are produced by a cause, not the other way around.
As an example, Bell shares this sentence: I lit a cigarette and shoved it in my mouth.
“Pretty obvious, isn’t it?” he says. “The action is backwards. You shove a nail in the mouth before you light it.” The principle of stimulus-response requires that when you have a stimulus, your character should respond. Conversely, if you want your character to respond, you have to show the stimulus first.
No: Bob hit the dirt, hearing the explosion.
Yes: Bob heard the explosion. He hit the dirt.
Notice that the stimulus and response are adjacent. Bob does not have time to notice his surroundings, remember his dead family, or consider his future before he hits the dirt.
Sometimes the connection is more complicated. The reader can easily make the connection between explosion and hit the dirt, but other stimulus-response strings need more information. If your protagonist picks up her mail and goes inside screaming and crying, your reader is going to feel like they missed something, Bell says. In this case, the stimulus wasn’t opening the mailbox, but opening a piece of mail, but the reader does not know this.
You can clarify complex stimulus-response strings with a sentence or two of narrative. In some cases, describing a character’s internal considerations before the response can be effective. While the response isn’t immediate, the deliberation will clue your reader into the reasoning behind it.
The stimulus-response effect can also work with your inciting incident – which Bell prefers to call The Disturbance and the Doorway of No Return. This concept can also help you structure stronger scenes and sequels. “After a scene ends in ‘disaster’ (as most scenes should) the character has an emotional beat that roughly follows this pattern: emotion, analysis, decision,” Bell explains. “You control pace largely through emotional beats. If you want to keep a fast pace, the beat can be short—even just one line of internal thought. Or it can be skipped altogether and implied—we see in the subsequent action what went on inside the character. When the emotion is strong, you can spend time on it.”
