Spatial chromatic contrast sensitivity in natural scenes

• Applicant: Dr. Martin Giesel
• Subject Area: General, Cognitive and Mathematical Psychology
• Term: from 2010 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 169885164

It has been suggested that the visual system is optimized for the processing of natural images (Barlow, 1961). In most previous studies on contrast sensitivity simple stimuli such as gratings have been used. This is based on the idea that responses to more complex stimuli can be inferred from the responses to these basic stimuli. More recent studies have shown that both the local and the global properties of complex scenes determine performance in detection and discrimination tasks. This has important implications for the location where the signals from complex scenes are processed in the visual system. Contrast sensitivity has been investigated for dierent types of achromatic modulations of grayscale images of natural scenes. However, it has been shown that color plays an important role in the detection, identication, and remembrance of objects within naturalistic scenes (Gegenfurtner & Rieger, 2000; Hansen & Gegenfurtner, 2009; Zaidi & Bostic, 2008). Therefore, it is an articial reduction of the information that is available in these scenes if the scenes are conned to their achromatic variations. Here, we propose experiments in which we plan to measure contrast sensitivity for chromatic and achromatic modulations within images of natural scenes.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Qasim Zaidi