to anyone who could gather Pepsi bottle caps that spelled out the words "Pepsi Challenge". See also Cola Wars New Coke Pepsi Cool Cans Pepsi Stuff References Further reading Koenigs, M., Tranel, D. (2008). Prefrontal cortex damage abolishes brand-cued changes in cola preference. Social Cognitive and Affective Neuroscience, 3, 1–6. Pronko, N.H., Herman, D.T. (1950). Identification of cola beverages. IV. Postscript. Journal of Applied Psychology, 34, 68–69. Cola PepsiCo advertising campaigns Advertising campaigns Metaphors referring to food and drink 1975 introductions Business rivalries