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Abstract

We used a recognition memory paradigm to assess the influence of color
information on visual memory for color images of natural scenes.
During the presentation phase 48 images of natural scenes were
presented on a CRT for exposure durations between 50 and 1000 msec
followed by a random noise mask. Half of the images were presented in
color and half in black white. In the subsequent query phase the
same 48 images were intermixed with 48 new images and the subjects had
to indicate which of the images they had already seen during the
presentation phase. We found that performance increased with exposure
duration. However, independent of exposure duration subjects performed
5-10 better for colored than for black white images, even for
exposure durations as short as 50 msec. This effect cannot be due to
contrast differences in the images since a second experiment showed
little effect of contrast once the images were suprathreshold. Further
experiments showed that performance worsened when images were
presented in color and tested in black white, or vice versa.
Performance was not impaired for a comparison group of 31 color
deficient observers (17 protanopes and 14 deuteranopes), whose
recognition performance was also better for colored than for black
white images. We conclude that color information plays an important
role in the early and fast processing of visual images. Both sensory
and cognitive factors seem to contribute to the superior recognition
of color images. Finally, color-deficient observers appear to be able
to compensate for their reduced chromatic information range when
viewing and analyzing complex scenes.