The Time-Course of Visual Categorizations: You Spot the Animal Faster than the Bird

Abstract

BackgroundSince the pioneering study by Rosch and colleagues in the 70s, it is commonly agreed that basic level perceptual categories (dog, chair…) are accessed faster than superordinate ones (animal, furniture…). Nevertheless, the speed at which objects presented in natural images can be processed in a rapid go/no-go visual superordinate categorization task has challenged this “basic level advantage”.Principal FindingsUsing the same task, we compared human processing speed when categorizing natural scenes as containing either an animal (superordinate level), or a specific animal (bird or dog, basic level). Human subjects require an additional 40–65 ms to decide whether an animal is a bird or a dog and most errors are induced by non-target animals. Indeed, processing time is tightly linked with the type of non-targets objects. Without any exemplar of the same superordinate category to ignore, the basic level category is accessed as fast as the superordinate category, whereas the presence of animal non-targets induces both an increase in reaction time and a decrease in accuracy.Conclusions and SignificanceThese results support the parallel distributed processing theory (PDP) and might reconciliate controversial studies recently published. The visual system can quickly access a coarse/abstract visual representation that allows fast decision for superordinate categorization of objects but additional time-consuming visual analysis would be necessary for a decision at the basic level based on more detailed representations.

Scene gist categorization by pigeons.

“…However, there was some indication of superior performance in the natural-manmade group under processing time challenges (see Figure 5). This mirrors the results with human participants, where categorical distinctions between two members of the same superordinate category are more difficult than distinctions between members of two different superordinate categories, particularly with shorter processing times Loschky & Larson, 2010;Mace et al, 2009). …”

The speed and accuracy of material recognition in natural images

“…We replicated the advantage of superordinate object categorization over basic-level object categorization (Mace et al, 2009) and demonstrated that material classification was more similar to basic-level than to superordinate object categorization. The speed of categorization under these ultra-short presentation times was crucially mediated by our normalization procedure.…”

“…Mace, Joubert, Nespoulous, and Fabre- Thorpe (2009) reported increased reaction times in a go/no-go task if the target represented a basic-level category rather than a superordinate category. Thus, varying the level of abstraction in the objects should result in a variation of task difficulty.…”

Les catégories d'odeurs en sont-elles vraiment ?

“…Le niveau de base est, en conséquence, le niveau le plus élevé (le plus abstrait) où les membres des catégories ont des formes globales perçues de façon similaire et où, du même coup, les catégories entre elles sont le mieux différenciées. Pour cette raison, il est réputé être le niveau d'entrée privilégié dans la catégorie, même si cela semble moins vrai pour des membres atypiques de celle-ci (Murphy & Brownell 1985) ou dans le cas de la catégorisation visuelle (Macé et al 2009). Il représente donc un optimum du point de vue de l'efficacité cognitive de la catégorisation.…”