title: Mechanism, function, and computation in neural systems.
abstract: What constitutes a "mechanism" of behavior? In this tribute to Jerry Hogan we examine how questions of behavioral mechanism can be reframed as causes and consequences of neural circuit activity. Drawing from our work on the hippocampus and the medial prefrontal cortex we discuss the inherent difficulties of characterizing the behavioral functions of circuits that are many synapses away from sensory reception and motor/visceral expression. We briefly review the advantages of reframing a region's functions according to its computations, while also distinguishing those computations from the algorithms by which they are achieved. As an example of how these ideas can be applied, we discuss why the hippocampus and medial prefrontal cortex may have overlapping roles in memory expression in spite of being very different circuits. The present analysis draws inspiration from David Marr, whose framework for describing neural systems can be compared with Aristotle's "causes." This article is part of a Special Issue entitled: In Honor of Jerry Hogan.
authors.affiliation: Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada M1C1A4; Department of Psychology, University of Toronto, Toronto, ON, Canada M5S3GM. Electronic address: nathan.insel@utoronto.ca.
authors.forename: Nathan
authors.initials: N
authors.lastname: Insel
authors.affiliation: Department of Psychology, University of Toronto, Toronto, ON, Canada M5S3GM; Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada M6G1X8; Institute of Medical Science, University of Toronto, Toronto, ON, Canada M5S1A8; Department of Physiology, University of Toronto, Toronto, ON, Canada M5S1A8. Electronic address: paul.frankland@sickkids.ca.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Frankland
mesh_terms: D000818:Animals; D001519:Behavior / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D008959:Models, Neurological; D009434:Neural Pathways / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology
keywords: Circuits; Hippocampus; Levels of analysis; Mechanism; Prefrontal cortex