Representational Shifts Towards the Prototype in Memory for Hue

Representational shifts in memory have been a recent topic of interest and debate (Blanco & Gureckis 2012; Lupyan, 2008; Richler, Gauthier & Palmeri, 2011; Richler, Palmeri & Gauthier, 2012). Whether there are true systematic biases in memory due to a stimulus being labeled has been proposed and contested. The fundamental proposal that representations shift toward the prototype has not previously been demonstrated. In the present experiment, participants judged colored silhouettes by color category or by preference, then were asked to remember the hue of the original silhouette among five narrowly distinct options. By using the single dimension of hue, we are able to show prototypical representational shifts in memory for colored silhouettes after a few minutes. We did not observe a difference between color labeled and preference judged silhouettes, refuting the claim that labeling is the source of prototypical representational shifts.