Brown, S.A.B. Episodic Memory and Unrestricted Learning. Provisionally accepted at Philosophy of Science.
ABSTRACT: We use rich memories for particular events every day, for all kinds of tasks. Need to remember a recipe, a fun fact about a certain species, or what a city you've visited many times before is like? You might well proceed by recalling a particular occasion when you made the dish in question, learned about the species, or visited the city. Why? Isn't recalling all this irrelevant detail a waste of resources, and sometimes actively harmful, given that we also have forms of memory which incorporate information from multiple different episodes, have less distracting details, and do not require so much sophistication to store, access, and operate with? I argue that this question poses a deep problem for a number of accounts of the function of episodic memory.  I then draw on recent ideas in AI to show that we can answer this problem, and show a crucial role for episodic memory in intelligence generally, if we appreciate the role episodic memory can play in a special kind of learning. Whereas most kinds of learning have in principle limits to how much they can learn about the world, learning with access to episodic memory is unrestricted in this sense. If episodic memory is for unrestricted learning, we can give explanations of its use in a wide range of contexts which seem to have little in common, and to which other forms of memory seem at first glance to be better suited.

Brown, S. A. B. (2022). Inter-temporal rationality without temporal representation. Mind & Language, 1– 20. 

ABSTRACT: Recent influential accounts of temporal representation—the use of mental representations with explicit temporal contents, such as before and after relations, durations, and specific times—have sharply distinguished representation from mere sensitivity.  A common, important picture of intertemporal rationality is that it consists in appropriately trading off immediate and future rewards, to maximize total expected discounted utility across time.  By carefully analysing simple reinforcement learning algorithms, this paper shows that, given such notions of temporal representation and intertemporal rationality, it would be possible for an agent to achieve intertemporal rationality without temporal representation.  Therefore, either: the austere account of temporal representation is too demanding; the utility-maximizing account of intertemporal rationality is not demanding enough; or the relationship between intertemporal rationality and temporal representation is very different to what many have assumed.  


Brown, S. A. B. (2022) How much of a pain would a crustacean “common currency” really be?. Animal Sentience 32(23). doi:10.51291/2377-7478.1749

(Commentary on Crump, Andrew; Browning, Heather; Schnell, Alex; Burn, Charlotte; and Birch, Jonathan (2022) Sentience in decapod crustaceans: A general framework and review of the evidence.)

ABSTRACT:  We should be suspicious of the idea that experiencing pain could enable animals to trade off different motivations in a common currency.  It is not even clear that humans have a common motivational currency reflected in evaluative experience. Instead, pain may capture attention, inhibiting attention to competing motivations and needs, thereby making genuine trade-offs harder.  Our criteria for pain in invertebrates should be part of a more subtle theory of the relationship between pain and decision-making.


Phillips, I. and Brown, S. A. B. (2022). ‘Hakwan Lau’s In Consciousness We Trust’, British Journal of Philosophy of Science Review of Books.

Open Access Version

Brown, S. (2021). Positing numerosities may be metaphysically extravagant; positing representation of numerosities is not. Behavioral and Brain Sciences, 44, E183. doi:10.1017/S0140525X21001126

(Commentary on S. Clarke & J. Beck 'The Number Sense Represents (Rational) Numbers')

ABSTRACT: Clarke & Beck assume that ANS representations should be assigned referents from our scientific ontology.  However, many representations, both in perception and cognition, do not straightforwardly refer to such entities.  If we reject Clarke and Beck’s assumption, many possible contents for ANS representations besides number are compatible with the evidence Clarke & Beck cite. 

Published Version Paywall Free Version

Mazor, M., Brown, S., Ciaunica, A., Demertzi, A., Fahrenfort, J., Faivre, N., Francken, J.C., Lamy, D., Lenggenhager, B., Moutoussis, M., Nizzi, M.C., Salomon, R., Soto, D., Stein, T., & Lubianiker, N. (2022) The Scientific Study of Consciousness Cannot, and Should not, be Morally Neutral. Perspectives on Psychological Science.

ABSTRACT: Normative decisions about moral status are strongly coupled with beliefs and assumptions about consciousness. Questions about how we ought to treat different animals, such as which individuals deserve legal protections from invasive experiments, have often been thought to depend on issues such as which animals can experience their environment, feel pain and pleasure, or reflect on their own experience. The scientific study of consciousness has advanced our understanding of some of these empirical questions by revealing how these dimensions of consciousness vary in different states and animal species. Considering the tight link between consciousness and moral status, scientific discoveries in this field have direct implications for law and ethics. Given this link, the scientific community studying consciousness may face implicit pressure to carry out certain research programmes or interpret results in certain ways in order to justify current norms rather than challenge them. Finally, because the presence of consciousness largely determines moral status, the use of non-human animals in the scientific study of consciousness introduces a direct conflict between scientific relevance and ethics – the more scientifically valuable an animal model is for studying consciousness, the more difficult it becomes to ethically justify compromises to its well-being for consciousness research. Here we call for a discussion of the immediate ethical corollaries of the body of knowledge that has been accumulated, and for a more explicit consideration of the role of ideology and ethics in the scientific study of consciousness, including the question of animal models of consciousness.

Narratives, Reinforcement Learning, and Death in Other Animals

ABSTRACT: Is maximising utility all there is to life? Many philosophers argue that the narrative structure of one’s life can make a difference to how well it goes overall, over and above one’s total utility.   Indeed, they think that it can be rational to choose a lower-utility life because it has a better narrative. I argue that intuitions favouring this view are mistaken, while doing justice to the importance of narratives in human thinking and decision-making.  We can explain why we would intuitively — but mistakenly — favour narratively structured lives even if all that really matters is total utility.  And the resulting view avoids various thorny issues which arise for the pro-narrative view.  To explain away the intuitions, we should allow that in practice we cannot directly maximise utility, instead implicitly aiming at approximating utility maximisation through the use of imperfect cognitive tools, such as heuristics and reinforcement learning. We can then see that there are compelling reasons for such an approach to include heuristics favouring narratives amongst those tools.  This is because other methods for approximating utility maximisation, especially Reinforcement Learning, have well-known limitations in non-Markovian environments; and the very features of narratives which we seem to value in narratively structured lives also make narratives perfectly suited to helping us to maximise utility despite non-Markovian dynamics.  Yet we would expect such heuristics to misfire in the kinds of cases appealed to in support of the intrinsic importance of narratives.  One consequence is that one celebrated argument, according to which painless death is only a harm for those animals who can conceive of their lives in narrative terms, rests on a mistaken premise.


Temporal Competence and Temporal Representation

ABSTRACT: What is temporal representation—the use of mental representations with explicit temporal contents, such as before and after relations, durations, and specific times?  Many theories of representation and discussions of animals' behaviour with respect to time seem to imply that temporal representation is extremely widespread, as nearly all organisms are in some way temporally competent — that is, they produce behaviour at the right times given the dynamics of their environment.  However such temporal competence can usually be explained with very simple mechanisms, and describing them as 'representing' the temporal features in question does not add anything to simply describing those mechanisms. This has motivated some philosophers to give accounts of temporal representation which demand more of temporal representation than simple temporal competence.  However, I show that extant versions of such accounts are too demanding, and appear to be motivated by the demand for behaviour which can only be explained by positing temporal representation — a demand which, I argue, is impossible to satisfy given that there will always be explanations which describe the implementation of representational processes. I give an alternative account of temporal representation which shows how temporal representations can be explanatory while also avoids excessive demandingness. This alternative develops the thought that temporal representation allows for flexibility with respect to time.  To do this, I give a novel account of the relevant kind of flexibility, and then show how states which are coupled to a temporal feature X and which are apt to combine with other representational states ground that kind of flexibility. 
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Episodic Memory Across Species and Across Purposes: What Really Matters and Why 
ABSTRACT: A central part of human cognition is episodic memory: roughly, remembering events we personally experienced.  Which if any other animals enjoy the same kind of memory?  Decades of research suggests that many species, from rats to jays to cuttlefish, have states with some of the features of human episodic memory. Some non-human animals represent numerous unique features of individual events, including how long ago they occurred and the order in which sub-events occurred.  However, no other animal will have states with exactly the features of typical human episodic memories, any more than they will have skeletons exactly like humans’.  This raises a question: which features does an animal’s mental state need to possess to count as being an episodic memory, and which features of human episodic memory are merely features of human episodic memory?  There is little agreement on how to even go about answering this question — or similar questions which arise for many other important mental states and capacities.  The best approaches on the market are (i) to search for what if anything makes episodic memory a natural kind, and (ii) to adopt a form of pluralism on which what matters to episodic memory is largely determined by specific aims on particular occasions.  I argue that each of these approaches gets something right, but limits the theoretical use of a notion like ‘episodic memory’.  I then sketch an approach to determining which features are essential to a state’s counting as episodic memory, irrespective of species, which avoids the problems of the pluralist and natural kind approaches.  Roughly, this approach involves searching for sets of features which are jointly important to episodic memory’s broader contribution to intelligence. 
In Prep: Slides from June 2022 presentation. Please email for latest version of paper.

What If Anything is Semantic Memory Like in Non-Human Animals? 

ABSTRACT: Much of the literature on animal memory focuses either on conditioning and reinforcement learning, or on whether animals have episodic memory. This latter literature tends to assume that animals do have semantic memory, treating episodic memory as a more advanced, mysterious and interesting capacity. I argue that the assumption that other animals have semantic memory only makes sense on an understanding of semantic memory as merely involving memory for generics as opposed to particulars (with contents more like Lions are dangerous than Gary the gazelle was eaten by a lion). But the notion of semantic memory appealed to in human psychology mixes this conception of semantic memory with at least one other conception: memory in a language-like format.  On this alternative conception, it is much less clear which, if any, non-human animals have semantic memory. Furthermore, these points suggest that semantic memory does not form a natural kind at all: rather, it seems to lump together quite different forms of memory solely in virtue of their not being episodic.  I explore new theoretical and empirical questions which are opened up by asking about the different forms of semantic memory, which animals have them, and why they matter.

In Prep: Slides from July 2021 presentation. Please email for latest version of paper.

How To Get Rich From Inflation

ABSTRACT: How rich is our visual experience? We seem to have rich experience across our visual field. Yet we are surprisingly poor at tasks involving the periphery and areas of the visual field we are not attending to. Recently, Lau and collaborators have argued that an empirical phenomenon known as subjective inflation allows us to reconcile these phenomena. However, I argue that subjective inflation is consistent with multiple interpretations, with starkly different consequences for the richness of visual experience and for our theories of consciousness more broadly. What’s more, we have only weak reasons favouring any of these interpretations over the others. I provisionally argue for an interpretation on which subjective experience is genuinely rich, but in the periphery and unattended areas it is unreliable as a guide to the external world. This view has a further striking consequence: experience in the periphery is not just unreliable but unstable, constantly fluctuating from moment to moment. I argue that this consequence, while initially appearing unintuitive, is in fact plausible.

In Prep: Draft Poster Slides