Format

Send to

Choose Destination
PLoS One. 2012;7(12):e51471. doi: 10.1371/journal.pone.0051471. Epub 2012 Dec 10.

Animal detection precedes access to scene category.

Author information

1
Université de Toulouse, UPS, CerCo, Toulouse, France ; CNRS, UMR 5549, Toulouse, France ; Cognitive, Linguistic and Psychological Science, Brown University, Providence, Rhode Island, United States of America.

Abstract

The processes underlying object recognition are fundamental for the understanding of visual perception. Humans can recognize many objects rapidly even in complex scenes, a task that still presents major challenges for computer vision systems. A common experimental demonstration of this ability is the rapid animal detection protocol, where human participants earliest responses to report the presence/absence of animals in natural scenes are observed at 250-270 ms latencies. One of the hypotheses to account for such speed is that people would not actually recognize an animal per se, but rather base their decision on global scene statistics. These global statistics (also referred to as spatial envelope or gist) have been shown to be computationally easy to process and could thus be used as a proxy for coarse object recognition. Here, using a saccadic choice task, which allows us to investigate a previously inaccessible temporal window of visual processing, we showed that animal - but not vehicle - detection clearly precedes scene categorization. This asynchrony is in addition validated by a late contextual modulation of animal detection, starting simultaneously with the availability of scene category. Interestingly, the advantage for animal over scene categorization is in opposition to the results of simulations using standard computational models. Taken together, these results challenge the idea that rapid animal detection might be based on early access of global scene statistics, and rather suggests a process based on the extraction of specific local complex features that might be hardwired in the visual system.

PMID:
23251545
PMCID:
PMC3518465
DOI:
10.1371/journal.pone.0051471
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center