Limited capacity model

Participating in the political process requires citizens to continuously process large amounts of highly complex information, but the human brain is only capable of attending to a small fraction of the information present in the environment at any given time. These limitations necessitate that individuals selectively allocate their attention among a nearly infinite number of messages simultaneously vying for attention. As such, understanding how, when, and why individuals direct their attention to political messages has long been a central point of inquiry in political communication research. In this entry, we review extant theories and models that articulate the capacity limitations on human attention and the factors that motivate individuals to allocate their attentional capacity to certain messages over others. We focus especially on aspects of the attentional process that deviate from assumptions of rationality, highlighting the relevance of these attentional biases for understanding political communication in an increasingly algorithmically-mediated media environment.