The hippocampus: Beyond recognition memory

The hippocampus has long been appreciated as crucial for long-term memory processes, and both neuropsychological studies and neuroimaging studies have placed particular emphasis on the role of the hippocampus in recognition memory. However, an impressive body of recent evidence suggests a crucial role for the hippocampus in a multitude of disparate tasks and functions beyond the standard definition of long-term memory and the recognition memory tasks with which hippocampal-dependent performance has so often been measured. The list includes everything from aspects of visual perception, language processing, and problem solving, to neuropsychiatric disorder, motivation, and more. So broad is the range of domains with which the hippocampus has recently been associated that one might wonder: “What does the hippocampus NOT do!” But, this hippocampal promiscuity is in stark contrast to the relatively small set of neurocomputational and neurobiological mechanisms typically ascribed to the hippocampus, including, for example, pattern separation and relational binding. In this Research Topic, researchers who examine hippocampal function in a variety of experimental circumstances attempt to document the range of hippocampal functionalities and to explicate how the hippocampus contributes to the wide variety of tasks that suffer due to its damage. By juxtaposing the various cognitive and behavioral phenomena related to hippocampal function, as well as various accounts of how and why the hippocampus is important for these disparate phenomena, we hope to advance overarching frameworks for hippocampal function. These frameworks must be broad enough to explain why the hippocampus is crucial for so much, yet finely tuned enough to honor the widely accepted functional specializations of the hippocampus. Striking this balance is no easy task, and this collection of articles will serve as a critical and formative step in this endeavor.