Scintillating lustre and brightness induced by radial lines

Area of Science:

• Visual perception
• Illusory brightness
• Psychophysics

Background:

• The Ehrenstein pattern typically elicits illusory brightness in central gray disks.
• Scintillating lustre, characterized by apparent lightening and shimmering, is observed in these gray disks.
• Both phenomena are contingent on the presence of radial inducing lines converging onto the gaps.

Purpose of the Study:

• To investigate the phenomenon of scintillating lustre in the Ehrenstein pattern.
• To determine the relationship between scintillating lustre and line-induced brightness enhancement.
• To explore the underlying visual mechanisms, potentially involving ON and OFF pathways.

Main Methods:

• Parametric variation of stimulus features, including line length, width, number, contrast, and gap size.
• Systematic observation and analysis of the scintillating lustre phenomenon.
• Comparison with established theories of visual gloss and brightness perception.

Main Results:

• Scintillating lustre strength covaries with the degree of line-induced brightness enhancement.
• The presence and configuration of radial lines are critical for both illusory brightness and scintillating lustre.
• Gray disks appear matte in the absence of radial lines, indicating their importance.

Conclusions:

• Scintillating lustre arises from the interaction between illusory brightness (increment) induced by radial lines and the physical decrement of a dark gray disk.
• The findings support the hypothesis that lustre results from a competition between the ON and OFF visual pathways.
• This study demonstrates a novel form of lustre independent of stereoscopic fusion, differing from Helmholtz's binocular gloss.