Working memory in color: an FMRI study

Abstract

Verbal names of colors used in daily life are essentially categorical in nature rather than a reference to the particular color of the object. Colors that cross the borders of color hue categories could be verbally coded, whereas colors within a single color category are likely difficult to be verbally coded due to the involvement of slight hue differences. A brain imaging study focused on colors in working memory in a domain-dependent dissociable brain has not been well known. Current study investigated the specific dissociated brain areas responsible for color memory under both verbal and visual coding, using functional magnetic resonance imaging (fMRI). Using n-back working memory paradigm, we hypothesized that colors that cross different categories would activate phonological loop more easily because colors having large hue differences could be more easily coded verbally, as in the case of color words, than colors within the same category with slight hue differences in which memory for adjacent colors could not rely on phonological loop. We found left- and right-frontoparietal network activations under cross-color/color-word conditions, and within condition, respectively.