Antonyms for the term "most imperceptive" could include "most perceptive," "most discerning," "most observant," and "most attentive." These terms suggest a high level of awareness and sensitivity to detail, which stands in contrast to the lack of perception implied by the original term. Other antonyms might include "most astute," "most insightful," and "most intuitive," all of which suggest the ability to understand complex ideas quickly and accurately. In general, these antonyms point toward a more positive outlook on perception and the ability to understand the world around us.