We consider a decision maker (DM) who, before taking an action, seeks information by allocating her limited attention dynamically over different news sources that are biased toward alternative actions. Endogenous choice of information generates rich dynamics: The chosen news source either reinforces or weakens the prior, shaping subsequent attention choices, belief updating, and the final action. The DM adopts a learning strategy biased toward the current belief when the belief is extreme and against that belief when it is moderate. Applied to consumption of news media, observed behavior exhibits an "echo-chamber" effect for partisan voters and a novel "anti echo-chamber" effect for moderates. DDMs, which lead to a continuous belief process, are more suitable for the problem of learning the properties of a data-generating process from a sequence of samples, as in clinical trials, or for the analysis of statistical information. Poisson models, which lead to discontinuous updating, are useful to model the discovery of individual pieces of information that are very informative, as is common in the political 10 Since the belief is a martingale, we have λαDividing by dt and letting dt → 0 yields (2.1).11 These examples are similar in spirit to Suen (2004) and Burke (2008), except that information is not costly in these models, which leads to a different characterization. In particular, dynamics has no significant effect in these models, in contrast to the point made here.