Does the brain know the physics of specular reflection?

Andrew Blake, Heinrich Bulthoff

Research output: Contribution to journalArticle

156 Citations (Scopus)


IMAGES of artificial and natural scenes typically contain many highlights generated by mirror-like reflection from glossy surfaces. Until recently, computational models of visual processes have tended to regard highlights as obscuring the structure of the underlying scene. The truth is that, on the contrary, highlights are rich in local geometric information. Here we report that the three-dimensional appearance of a highlight on a computer-simulated stereoscopic curved surface affects observers' judgment of surface gloss. We also show that the 3-D appearance of a highlight affects the perception of surface curvature - that is, it can force an ambiguous convex-concave figure to change state. We thus conclude that human visual analysis seems to employ a physical model of the interaction of light with curved surfaces, a model firmly based on ray optics and differential geometry.

Original languageEnglish
Pages (from-to)165-168
Number of pages4
Issue number6254
Publication statusPublished - 1990 Jan 11
Externally publishedYes


ASJC Scopus subject areas

  • General

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