What are some examples of naturalism in the story "An Occurrence at Owl Creek Bridge"?

In texts which rely on
a naturalist perspective, characters are often the pawns of natural forces beyond their own
control. Peyton Farquhar is certainly in a dire and dramatic situation, but the forces that
control it are not natural; they are, rather, social. He, a Southern secessionist, has been
captured and sentenced to death for attempting to burn a railroad bridge (we assume, based on
the information in Part II) held by the Union army during the American Civil War. As he falls to
his death, at the end of the noose, Farquhar feels that time is slowing down; as he listens to
the "ticking of his watch," he perceives that "The intervals of silence grew
progressively longer; the delays became maddening." Some instinctive or fundamental action
of his brainsomething that is natural to humans, then, that he cannot control (here is the
naturalism) is affecting his perception of reality. During this incredibly brief space of time,
a second or two perhaps, Farquhar actually imagines...