Perceptual suboptimality: Bug or feature?

Rahnev & Denison (R&D) argue that whether people are "optimal" or "suboptimal" is not a well-posed question. We agree. However, we argue that the critical question is why humans make suboptimal perceptual decisions in the first place. We suggest that perceptual distortions have a normative explanation - that they promote efficient coding and computation in biological information processing systems.