With the advent of video as an art form, artists began to capture the fleeting interval between an action and its effect. As time-based work evolved, art was no longer confined to the tradition of stop-action records used by painting and sculpture. 'Action < > Reaction' highlights five videos that examine this causal relationship and document the evolution of video over four decades. Artists include Bruce Nauman, Ana Mendieta, Peter Fischli, David Weiss and Bill Viola.