Understanding the role of color in object representation: Evidence for multiple levels of interaction

This thesis examines the role of color in object representation using a variant of the Stroop paradigm (Stroop, 1935). In a series of experiments, observers were presented with pictures of a variety of color-diagnostic objects (objects that have a strong association with a specific color or colors, e.g. banana with the color yellow) that appeared either in their typical colors or in non-typical colors. In addition, objects were presented lexically, in the form of a written word in these same two conditions. Using color naming, color matching, and recognition memory tasks a significant difference in reaction time was found between the typical and non-typical conditions for both picture and word presentations. This difference suggests that color plays an important role in object representation. Moreover, the difference between the two conditions sometimes occurred in one direction (e.g. RT for the typical condition was shorter) and in other times it occurred in the opposite direction (e.g. RT for the non-typical condition was shorter). These findings suggest that color knowledge interacts with object representation in multiple levels, depending on the access level triggered by the stimulus as well as the response type.