You are hiking and see a long, thin object on the path. You instantly jump back in fear, but a moment later you realize it is just a stick. Which statement best analyzes this two-part reaction by describing the role of the brain's primary sensory relay center?

While walking in the woods, you suddenly see a long, curved shape on the path ahead and immediately jump back in fear. A moment later, you realize it is just a fallen tree branch and you calm down. Which of the following neurological explanations best accounts for this two-part sequence of reaction and re-evaluation?