Abstract. In an effort to quantify message complexity in such a way that predictions regarding the moment-to-moment cognitive and emotional processing of viewers would be made, Lang and her colleagues devised the coding system information introduced (or ii). This coding system quantifies the number of structural features that are known to consume cognitive resources and considers it in combination with the number of camera changes (cc) in the video, which supply additional cognitive resources owing to their elicitation of an orienting response. This study further validates ii using psychophysiological responses that index cognitive resource allocation and recognition memory. We also pose two novel hypotheses regarding the confluence of controlled and automatic processing and the effect of cognitive overload on enjoyment of messages. Thirty television advertisements were selected from a pool of 172 (all 20 s in length) based on their ii/cc ratio and ratings for their arousing content. Heart rate change over time showed significant deceleration (indicative of increased cognitive resource allocation) for messages with greater ii/cc ratios. Further, recognition memory worsened as ii/cc increased. It was also found that message complexity increases both automatic and controlled allocations to processing, and that the most complex messages may have created a state of cognitive overload, which was received as enjoyable by the participants in this television context.