Getting real — sensory processing of natural stimuli

Normal sensory experience rarely presents us with isolated bars, gratings, or other stimuli that have shaped our knowledge of sensory representations. Instead, typical input adheres to certain statistical regularities, which make it ‘natural’ and cannot be adequately modeled by linear superposition of simple stimuli. Natural stimuli necessitate a paradigm shift with a focus on downstream processing. This shift currently follows three main lines: quantification of the information a downstream area can read out (decoding); describing a representation as the optimization of computational principles with respect to natural input (normative approach); understanding the sensory representation as optimal for the systems’ tasks and intended actions (behavioral context). The interaction between representational levels, intermediate-level features, and bidirectional coupling through attention are key elements for sensory processing.