c 2014 Alexander D. Morgan ALL RIGHTS RESERVED ON THE MATTER OF MEMORY: NEURAL COMPUTATION AND THE MECHANISMS OF INTENTIONAL AGENCY by ALEXANDER D. MORGAN A dissertation submitted to the Graduate School-New Brunswick Rutgers, The State University of New Jersey in partial fulfillment of the requirements for the degree of Doctor of Philosophy Graduate Program in Philosophy written under the direction of Frances Egan and Robert Matthews and approved by New Brunswick, New Jersey May 2014 ABSTRACT OF THE DISSERTATION On the Matter of Memory: Neural Computation and the Mechanisms of Intentional Agency by ALEXANDER D. MORGAN Dissertation Directors: Frances Egan & Robert Matthews Humans and other animals are intentional agents; they are capable of acting in ways that are caused and explained by their reasons. Reasons are widely held to be medi- ated by mental representations, but it is notoriously difficult to understand how the intentional content of mental representations could causally explain action. Thus there is a puzzle about how to `naturalize' intentional agency. The present work is motivated by the conviction that this puzzle will be solved by elucidating the neural mechanisms that mediate the cognitive capacities that are distinctive of intentional agency. Two main obstacles stand in the way of developing such a project, which are both manifestations of a widespread sentiment that, as Jerry Fodor once put it, \notions like computational state and representation aren't accessible in the language of neu- roscience". First, C. Randy Gallistel has argued extensively that the mechanisms posited by neuroscientists cannot function as representations in an engineering sense, since they allegedly cannot be manipulated by the computational operations required to generate structurally complex representations. Second, William Ramsey has argued that neural mechanisms in fact do not function as representations in an explanatory sense, since the explanatory role they play is more like that of a causal relay rather than an internal `stand-in' for external entities. ii I argue that the criticisms developed by Gallistel and Ramsey rest on a misap- plication of relevant theoretical notions from computer science, and an impoverished appreciation of the rich variety of mechanisms posited in contemporary neuroscience. My central argument, though, is that the conception of representation presupposed by those researchers, according to which representations have the same abstract structure as the external systems they represent, encompasses states in all sorts of systems, in- cluding mindless systems such as plants. Thus these `structural representations' are not distinctively cognitive representations, and although they play an important ex- planatory role in neuroscience and other disciplines, they cannot on their own elucidate the nature of intentional agency. I conclude by sketching some ways in which neuro- scientists are beginning to elucidate the representational mechanisms that do mediate distinctively cognitive capacities. Thus, by removing the obstacles put in place by Gallistel and Ramsey, this work clears a path toward the `naturalization' of agency in terms of neural mechanisms. iii Acknowledgements `But is it philosophy?' The interdisciplinary hothouse of the Philosophy Department at Rutgers has provided an intellectual climate that is inhospitable to that question. For that I'm grateful, as it has allowed me to work away on questions that I'm interested in without much regard for disciplinary boundaries. But now that I step out into the wider field of academic philosophy, I should perhaps ready myself to answer that question. I don't think that philosophy has a distinctive content, or even an especially distinctive methodology; after all, scientists also use thought experiments and seek to clarify concepts. One way of thinking about philosophy that I find appealing is in terms of the intellectual habits or dispositions of its practitioners | a philosophical temperament. I have in mind a certain driving curiosity about the general principles that underly the patterns we find in nature, a willingness to question cherished verities, and perhaps most importantly, an eagerness to engage with criticisms of one's own views. If this is what we mean by `philosophy', then I can think of no-one who is more deserving of the label `philosopher' than Randy Gallistel. Although I think that Randy is dead wrong about many things, my tentative attempts to explain why to him are never met with dismissiveness or defensiveness, but rather with good-humored explanations of why I am dead wrong. Randy's philosophical temperament, together with his keen wit and deep erudition, are an inspiration. I am grateful for his example. This dissertation grew out of a graduate seminar that I took with Randy, undoubt- edly the highlight of my many years at university, but the interests that led me to take iv that seminar, and the preparedness that allowed me to benefit from it, were fostered and developed by several outstanding undergraduate teachers. My exposure to the force of nature that is Kim Sterelny in some of my first philosophy courses at Victoria University propelled me along the path of attempting to understand the mind as a biological phenomenon from the perspective of empirically-informed philosophy. That path led me to the University of Auckland, where I tried to find my own way through the thickets of the various fields of cognitive science. I would have become lost were it not for the expert guidance of Professors Michael Corballis, Russell Gray, Justine Kingsbury, Sue Pockett, and Denis Robinson at crucial junctures, so to them I owe a deep debt of gratitude. I am especially indebted to Justine, whose encouragement and support was pivotal in allowing me to go on to pursue graduate studies at Rutgers. Upon arriving in an environment that was deceptively familiar from so many sit- coms and college movies, this itinerant Kiwi was immediately made to feel at home by the wonderful community of graduate students in the philosophy department at Rutgers | a community sizzling with intellectual energy, but in a way that manages to warm with companionship, rather than burn with competition. I'd like to offer my sincerest thanks to my many brilliant peers at Rutgers who kept this community alive: Luvell Anderson, Marcello Antosh, Josh Armstrong, Kate Devitt, Tom Donaldson, Richard Dub, Erik Hoversten, Alex Jackson, Michael Johnson, Karen Lewis, Kelby Mason, Sarah Murray, Meghan Sullivan, Jenny Nado, Iris Oved, Karen Shanton, Jenn Wang, and many others. Special thanks to E. J. Green, Gabe Greenberg, Lisa Mirac- chi, Ron Planer, and Will Starr, not only for their friendship, but also for discussions and comments that directly led to improvements in many sections of this work. The community at Rutgers is kept alive not only by the students, but also by the tireless efforts of the administrative staff. I would thus like to thank Pauline Mitchell, Susan Viola, and especially Mercedes Diaz, who has provided not only expert guidance along my somewhat circuitous path through the PhD program, but also invaluable v friendship along the way. Of course, Rutgers wouldn't be Rutgers were it not for the inspiring faculty there. Seminars with Martha Bolton, Andy Egan, Jerry Fodor, Lila Gleitman, Alvin Goldman, Peter Klein, Ernie Lepore, Jason Stanley, Steve Stich, and many others not only enriched my understanding of the content of philosophy and cognitive science, but provided exemplary models of how philosophy ought to be done. Of the members of the philosophy faculty at Rutgers, two deserve special men- tion. From the beginning, Frankie Egan and Bob Matthews have provided unflagging intellectual and moral support, even, and indeed especially, during some of my most difficult periods during the PhD program. As dissertation chairs, they have been ex- emplary, allowing me free rein to explore ideas independently, but always ready at hand to help me discipline those ideas when needed with their keen critical feedback. This dissertation would be a far shoddier specimen were it not for their guidance and inspiration. I also could not have asked for a better external committee member. Ever since I first contacted Gualtiero Piccinini out of the blue as a second-year graduate stu- dent, he has been incredibly supportive and generous with his time. His unparalleled knowledge of the history of computer science and theoretical neuroscience is reflected throughout this dissertation. Together with Randy Gallistel's inspirational influence, I feel privileged to have had such an outstanding dissertation committee. Since leaving Rutgers, I have had the wonderful good fortune to find myself amongst a group of brilliant philosophers in the Center for Integrative Neuroscience at the University of T¨ubingen,under the inspiring guidance of Hong Yu Wong. I'd like to thank my colleagues Chiara Brozzo, Eva Engels, Gregor Hochstetter, Elizabeth Irvine, Krisztina Orb´an,Ferdinand P¨ohlmann, Katia Samoilova, and Catherine Stinson for helping me feel at home in Germany, for contributing to such a pleasantly stimulating environment in which to do philosophy, and for feedback on several sections of this dissertation. I would especially like to thank Hong Yu for his exceptional warmth and generosity, which among other things have allowed me to complete the final stages of vi this dissertation in an environment largely free from distractions. Hong Yu's personal qualities are matched by his keen philosophical acuity, and