The Time Course of Natural Scene Processing Revisited: A Critical Test of Affordance-based Classifications
A study by Greene & Oliva (2009) evinced that a global-property categorization can be accomplished with significantly less presentation time than a basic-level categorization, implying that there exists a time during which a scene may be classified, for example, as built or natural but not yet as a forest or an ocean. Such results suggest that the perception of action-properties latent in the environment at an architectural or ecological scale may be privileged during early visual processing. However compelling, such data do not unequivocally demonstrate that the brain accomplishes such global-level categorization in either less time or with less effort, only that they can be accomplished with inchoate presentations.
To address this issue, researchers used the identical set of stimuli used by Greene & Oliva and employed a response-signal paradigm. Ten subjects individually completed two experimental sessions. Preliminary results revealed that compared to basic-level categorizations, global-level categorizations actually required longer amounts of processing time to reach equivalent levels of accuracy, although both were completed accurately with equivalent or shorter amounts of processing time when compared to lexical categorizations. This suggests, when interpreted in the context of earlier results, that affordance-based judgments may need less information yet paradoxically require more processing, thus laying the groundwork for additional studies involving direct measures of brain activity (e.g., fMRI, EEG). Such results demonstrate that complex real-world stimuli used in conjunction with quantitative experimental paradigms may simultaneously inform cognitive neuroscience, environmental psychology and architectural theory.