UC Berkeley

The amount of sensory input received by the human brain far surpasses its capacity for conscious processing. Attention serves to gate incoming inputs to enable the receiver to select aspects of the environment for further processing based on its relevance to higher-level goals. When attention is impaired, behavior goes awry, and this often has serious consequences. While it is clear that attentional processes are critical for humans’ ability to interact effectively with the environment, the lack of a clear and conclusive definition of attention itself has, at times, impeded research progress on attention in the neural and behavioral sciences.

In this dissertation, I examine the construct of human attention from both empirical and theoretical standpoints. In Chapter 1, I provide an introduction to the concept of attention, including diverging definitions. I also articulate the urgency of obtaining a clearer understanding of the neurocognitive processes that support attention. Chapter 2 presents an empirical study of a specific type of attention, known as visual search. The study uses rare intracranial recordings in humans to present evidence consistent with the view that visual search, a classical attention behavior, may need to be reinterpreted as navigation in visual space. In Chapter 3, I present a theoretical discussion of the distinctions and similarities between attention and expectation, including interpretational pitfalls in experimental designs aiming to directly compare the two. Chapter 4 provides closing thoughts with emphasis on future directions for this field of research.