Final answer:
The theme conveyed is the interplay between madness and heightened senses in "The Tell-Tale Heart," showcasing the unreliability and intense anxiety of the narrator.
Step-by-step explanation:
The theme conveyed in the excerpt from "The Tell-Tale Heart" by Edgar Allan Poe is that of madness intertwined with over-acuteness of the senses. The narrator vehemently denies being mad while paradoxically exhibiting symptoms of acute anxiety and madness, such as heightened sensory perceptions, obsessive thoughts, and illogical rationalizations for committing murder. This theme reflects Poe's exploration of the human psyche and the fine line between sanity and insanity as the narrator's reliability is undermined by their own admissions and the intense emotions conveyed in the text.