What is episodic memory if it is a natural kind?
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Colloquially, episodic memory is described as “the memory of personally experienced events”. Even though episodic memory has been studied in psychology and neuroscience for about six decades, there is still great uncertainty as to what episodic memory is. Here we ask how episodic memory should be characterized in order to be validated as a natural kind. We propose to conceive of episodic memory as a knowledge-like state that is identified with an experientially based mnemonic representation of an episode that allows for a mnemonic simulation thereof. We call our analysis the Sequence Analysis of Episodic Memory since episodes will be analyzed in terms of sequences of events. Our philosophical analysis of episodic memory is driven and supported by experimental results from psychology and neuroscience. We discuss selected experimental results that provide exemplary evidence for uniform causal mechanisms underlying the properties of episodic memory and argue that episodic memory is a natural kind. The argumentation proceeds along three cornerstones: First, psychological evidence suggests that a violation of any of the proposed conditions for episodic memory amounts to a deficiency of episodic memory and no form of memory or cognitive process but episodic memory fulfills them. Second, empirical results support a claim that the principal anatomical substrate of episodic memory is the hippocampus. Finally, we can pin down causal mechanisms onto neural activities in the hippocampus to explain the psychological states and processes constituting episodic memory.
KeywordsEvents Neural sequences Replay Mental time travel Memory trace Mnemonic simulation
We thank Thomas Suddendorf for helpful discussions and Kevin Reuter for comments on the manuscript. This work was supported by a Grant (SFB 874, project B2) from the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) and a Grant from the Stiftung Mercator.
- Agster, K. L., Fortin, N. J., & Eichenbaum, H. (2002). The hippocampus and disambiguation of overlapping sequences. Journal of Neuroscience, 22, 5760–5768.Google Scholar
- Bieri, P. (1995). Why is consciousness puzzling? In T. Metzinger (Ed.), Conscious Experience (pp. 45–60). Paderborn: Schoening, Imprint Academic.Google Scholar
- Bischof, N. (1980). On the pyhlogeny of human morality. In G. S. Stent (Ed.), Morality as a biological phenomenon. Report of the Dahlem workshop on biology and morals (pp. 48–66). Berkeley: Universtity of California Press.Google Scholar
- Bischof-Köhler, D. (1985). Zur phylogenese menschlicher motivation [on the phylogeny of human motivation]. In L. H. Eckensberger & M. M. Baltes (Eds.), Emotion und reflexivität (pp. 3–47). München: Urban & Schwarzenberg.Google Scholar
- Boyd, R. (1999). Kinds, complexity and multiple realization. Philosophical studies, 95, 67–98. doi: 10.1023/a%253a1004511407133.
- Bragin, A., Engel, J., Wilson, C., et al. (1999). High-frequency oscillations in human brain. Hippocampus, 9, 137–142.Google Scholar
- Buckley, M. J., Booth, M. C., Rolls, E. T., & Gaffan, D. (2001). Selective perceptual impairments after perirhinal cortex ablation. Journal of Neuroscience, 21, 9824–9836.Google Scholar
- Cowan, N. (1995). Attention and memory. Oxford: Oxford University Press.Google Scholar
- Davidson, D. (1980). The logical form of action sentences. Essays on actions and events (pp. 105–121). Oxford: Clarendon Press. [orginally published in 1967].Google Scholar
- Eschenko, O., Ramadan, W., Mölle, M., Born, J., & Sara, S. J. (2008). Sustained increase in hippocampal sharp-wave ripple activity during slow-wave sleep after learning. Learning and Memory, 15(4), 222–228. doi: 10.1101/lm.726008.
- Goldman, A. I. (1986). Epistemology and cognition. Cambridge, MA: Harvard University Press.Google Scholar
- Hasselmo, M. E. (2012). How we remember: Brain mechanisms of episodic memory. Cambridge, MA: MIT Press.Google Scholar
- Jadhav, S. P., Kemere, C., German, P. W., & Frank, L. M. (2012). Awake Hippocampal Sharp-Wave Ripples Support Spatial Memory. Science, 336, 1454–1458. doi: 10.1126/science.1217230.
- Kahana, M. J., Howard, M. W., & Polyn, S. M. (2008). Associative retrieval processes in episodic memory. In J. H. Byrne (Ed.), Learning and Memory: A Comprehensive Reference (pp. 467–490). Oxford: Academic Press.Google Scholar
- Köhler, W. (1925). The mentality of apes. London: Routledge, Trench, Trubner & Co., Ltd.Google Scholar
- Kudrimoti, H. S., Barnes, C. A., & McNaughton, B. L. (1999). Reactivation of hippocampal cell assemblies: Effects of behavioral state, experience, and EEG dynamics. Journal of Neuroscience, 19, 4090–4101.Google Scholar
- Levy, W. B. W. (1996). A sequence predicting CA3 is a flexible associator that learns and uses context to solve hippocampal-like tasks. Hippocampus, 6, 579–590.Google Scholar
- Lewis, D. (1973). Counterfactuals. Oxford: Blackwell.Google Scholar
- Morris, R. G. (2001). Episodic-like memory in animals: Psychological criteria, neural mechanisms and the value of episodic-like tasks to investigate animal models of neurodegenerative disease. Philosophical Transactions of the Royal Society B: Biological Sciences, 356, 1453–1465. doi: 10.1098/rstb.2001.0945.CrossRefGoogle Scholar
- Müller, G. E., & Pilzecker, A. (1900). Experimentelle Beiträge zur Lehre vom Gedächtnis. Zeitschrift für Psychologie. Ergänzungsband, 1, 1–300.Google Scholar
- Nádasdy, Z., Hirase, H., Czurkó, A., et al. (1999). Replay and time compression of recurring spike sequences in the hippocampus. Journal of Neuroscience, 19, 9497–9507.Google Scholar
- Nadel, L., Samsonovich, A., Ryan, L., & Moscovitch, M. (2000). Multiple trace theory of human memory: computational, neuroimaging, and neuropsychological results. Hippocampus, 10, 352–368.Google Scholar
- O’Keefe, J., & Nadel, L. (1978). The Hippocampus as a Cognitive Map. Oxford: Clarendon Press.Google Scholar
- Pagin, P., & Westerståhl, D. (2010). Compositionality. In C. Maienborn, K. von Heusinger, & P. Portner (Eds.), Semantics: an international handbook of natural language meaning. Berlin: Mouton de Gruyter.Google Scholar
- Parsons, T. (1990). Events in the semantics of english. Cambridge: MIT Press.Google Scholar
- Pavlides, C., & Winson, J. (1989). Influences of hippocampal place cell firing in the awake state on the activity of these cells during subsequent sleep episodes. Journal of Neuroscience, 9, 2907–2918.Google Scholar
- Pianesi, F., & Varzi, A. C. (2000). Events and Event Talk: An Introduction. In J. Higginbotham, F. Pianesi, & A. C. Varzi (Eds.), Speaking of Events (pp. 3–47). New York, NY: Oxford University Press.Google Scholar
- Raffmann, D. (1995). On the Persistence of Phenomenology. In T. Metzinger (Ed.), Conscious Experience (pp. 293–308). Paderborn: Schöningh/Imprint Academic.Google Scholar
- Ramadan, W., Eschenko, O., & Sara, S. J. (2009). Hippocampal sharp wave/ripples during sleep for consolidation of associative memory. PloS ONE, 4(8). doi: 10.1371/journal.pone.0006697.
- Ribot, T. (1881). Les maladies de la mémoire. Paris: Germer Baillare.Google Scholar
- Ruchkin, D. S., Grafman, J., Cameron, K., & Berndt, R. S. (2003). Working memory retention systems: A state of activated long-term memory. Behavioral and Brain Science, 26, 709–728. discussion 728–77.Google Scholar
- Ryle, G. (1949). The concept of mind. London: Hutchinson & Company.Google Scholar
- Schacter, D. L. (2012). Constructive memory: Past and future. Dialogues in Clinical Neuroscience, 14, 7–18.Google Scholar
- Schacter, D. L. (2002). The seven sins of memory: How the mind forgets and remembers. New York: Houghton Mifflin.Google Scholar
- Skaggs, W., McNaughton, B., Wilson, M., & Barnes, C. (1996). Theta phase precession in hippocampal neuronal populations and the compression of temporal sequences. Hippocampus, 6, 149–172. doi: 10.1002/(SICI)1098-1063(1996)6:2%3C149:AID-HIPO6%3E3.0.CO;2-K.
- Suddendorf, T., & Corballis, M. C. (1997). Mental time travel and the evolution of the human mind. Genetic Social and General Psychology Monographs, 123, 133–167.Google Scholar
- Toth, J. P., & Hunt, R. R. (1999). Not one versus many, but zero versus any: Structure and function in the context of the multiple memory systems debate. In J. K. Foster & M. Jelicic (Eds.), Memory: Systems, process, or function? Debates in psychology (pp. 232–272). New York: Oxford University Press.Google Scholar
- Tulving, E. (1983). Elements of episodic memory. Oxford: Clarendon Press.Google Scholar
- Tulving, E. (1972). Episodic and semantic memory. In E. Tulving & W. Donaldson (Eds.), Organization of memory (pp. 381–402). New York: Academic Press Inc.Google Scholar
- Tulving, E. (1995). Organization of memory: Quo vadis. In M. Gazzaniga (Ed.), Cognitive neuroscience (pp. 839–847). Cambridge, MA: MIT Press.Google Scholar
- Vargha-Khadem, F., Gadian, D., Watkins, K., Connelly, A., Van Paesschen, W., & Mishkin, M. (1997). Differential effects of early hippocampal pathology on episodic and semantic memory. Science, 277, 376–380. doi: 10.1126/science.277.5324.376.
- Werning, M. (2005). Right and wrong reasons for compositionality. In M. Werning, E. Machery, & G. Schurz (Eds.), The compositionality of meaning and content (Vol. I: Foundational Issues, pp. 285–309). Frankfurt: Ontos Verlag.Google Scholar
- Werning, M. (2012). Non-symbolic compositional representation and its neuronal foundation: Towards an emulative semantics. In M. Werning, W. Hinzen, & E. Machery (Eds.), The Oxford handbook of compositionality (pp. 633–654). Oxford: Oxford University Press.Google Scholar
- Werning, M., Hinzen, W., & Machery, E. (2012). The Oxford handbook of compositionality. Oxford: Oxford University Press.Google Scholar
- Zola-Morgan, S., Squire, L. R., Amaral, D. G., & Suzuki, Wa. (1989). Lesions of perirhinal and parahippocampal cortex that spare the amygdala and hippocampal formation produce severe memory impairment. Journal of Neuroscience, 9, 4355–4370.Google Scholar