Unless otherwise noted, all talks are Wednesdays 12:30–2:30 in Ross Hall S421. Some talks will be held remotely on Zoom. In these cases, the Zoom link will be emailed to all students and faculty from Cognitive Science and Philosophy. If you're affiliated with York but not in one of those groups, and want to receive the Zoom links, email cogs@yorku.ca from your York email address.
Speaker Series 2023-2024
September 20
Blake Richards (McGill University)
Sequential Predictive Learning is a Unifying Theory for Hippocampal Functions
The mammalian hippocampus contains spatially tuned cells and can generate offline simulations for the purposes of recall, planning, and long-term memory formation. The hippocampus has also been shown to engage in prediction of upcoming events, and spatially tuned cells emerge in recurrent neural networks trained to predict, suggesting a potential link between prediction, spatial tuning, memory, and offline simulation. However, a unifying theory is still lacking. Here, we show that predictive learning of egocentric sensory inputs and the presence of spatially-tuned cells do not guarantee the ability to engage in offline simulations or recall recent locations. Offline simulations only emerged when networks used recurrent connections and head-direction information to predict multiple steps into the future, which promoted the formation of a continuous attractor manifold in which population activity reflected the spatial topology of the environment. Specifically, these networks generated realistic trajectories from noise and were able to replay recently experienced locations. Finally, a multi-step predictive algorithm inspired by sequential spiking in the hippocampus led to faster and more efficient learning. Altogether, our results demonstrate how continuous attractors can emerge in neural networks engaged in sequential predictive learning, which provides a unifying theory for hippocampal functions and hippocampal-inspired approaches to artificial intelligence.
October 4
Yang Xu (University of Toronto)
Discovering Shared Knowledge of Human Lexical Creativity
A defining property of the human lexicon is the creative use of words to express multiple meanings through word meaning extension (WME). Such lexical creativity is manifested across languages and at different timescales, ranging from historical evolution of word meanings to child language development. I describe work exploring the idea that different manifestations of WME might build on a common cognitive foundation: a shared repertoire of knowledge grounded in human experience. Taking a computational approach, I show that models drawing on multiple sources of information such as associativity, visual perception, and taxonomy, can jointly predict patterns of word meaning extension observed across languages and in speech errors made by young children. These findings suggest a unified view of human lexical creativity that connects the evolutionary products of phylogeny across languages with the fleeting products of individual ontogeny. I discuss the implications of this work toward understanding the cognitive mechanisms in the creative construction of the lexicon.
October 25
Carrie Branch (University of Western Ontario)
Sexual Selection, Female Choice, and Cognitive Adaptation in a Food-Caching Bird
Environmental gradients often create different selective pressures among populations and may drive local adaptation. Along mountain slopes, heterogeneity occurs rapidly and predictably, resulting in local adaptions on a rather small spatial scale. Mountain chickadees are food-caching birds that inhabit a continuous elevation gradient associated with predictable variation in winter climate, such that birds living at higher elevations experience harsher winter conditions compared to their lower elevation counterparts. These birds use spatial cognition to recover their food stores and survive winter. Previous research shows that individuals at higher elevations exhibit superior cognitive abilities and associated brain morphology compared to their lower elevation counterparts. During my talk, I will present evidence for evolution by natural selection on the spatial cognitive abilities of mountain chickadees inhabiting these differentially harsh winter climates and the role females play in maintaining local adaptation.
November 8
Lily Hu (Yale University)
Does Calibration Mean What They Say It Means; Or, The Reference Class Problem Rises Again
Discussions of statistical criteria for fairness commonly convey the normative significance of calibration within groups by invoking what risk scores “mean.” On the Same Meaning picture, group-calibrated scores “mean the same thing” (on average) across individuals from different groups and accordingly, guard against disparate treatment of individuals based on group membership. My contention is that calibration guarantees no such thing. Since concrete actual people belong to many groups, calibration cannot ensure the kind of consistent score interpretation that the Same Meaning picture implies matters for fairness, unless calibration is met within every group to which an individual belongs. Alas only perfect predictors may meet this bar. The Same Meaning picture thus commits a reference class fallacy by inferring from calibration within some group to the “meaning” or evidential value of an individual’s score, because they are a member of that group. Furthermore, the reference class answer it presumes is almost surely wrong. I then show that the reference class problem besets not just calibration but all group statistical facts that claim a close connection to fairness. Reflecting on the origins of this error opens a wider lens onto the predominant methodology in algorithmic fairness based on stylized cases.
Winter 2024
January 17
Christina Starmans (University of Toronto)
How Temptation Makes Us Moral
We often know the right thing to do, but also feel tempted to do the wrong thing—to cheat on our taxes or our spouses, lie to avoid trouble, or skip out on an obligation. How do these struggles with temptation affect our moral judgments?
In this talk I will review a series of studies examining how both adults and young children reason about inner conflict and temptation. These studies find that in most cases, adults judge that someone who has acted morally in the face of temptation deserves more moral credit than someone who acted morally but was never tempted to be immoral. Conversely, children (aged 38 years) give more moral credit to the person who was never tempted to act immorally. I’ll discuss some theories for how children’s moral intuitions come to match those of adults and argue that these developmental changes may help us understand certain puzzles in adults’ moral reasoning.
January 31
Robert Geirhos (Google DeepMind)
Do Machines See the World Like Humans?
From ChatGPT to models that generate images from a text description, today’s deep learning models are more powerful than ever and increasingly reach human-level performance on challenging tasks. But do machines see the world like humans, or completely differently? I will discuss recent advances in comparing machine and human vision, focusing on the task of recognizing objects from images. After a broader introduction to the area, I’ll talk about our recent work on using generative, rather than discriminative, models for recognizing objects from images. These models show four intriguing emergent properties: they recognize objects by shape rather than texture, achieve near human-level accuracy even on heavily distorted images, make more human-like errors, and they understand certain perceptual illusions. This indicates that even though machines don’t fully see the world like humans, the gap is narrowing year by year, sometimes even month by month.
February 14
Daniel Munro (York University)
Conspiracy Theories and the Epistemic Power of Narratives
The truth can be emotionally painful or otherwise difficult to confront. We often try to distract ourselves from ugly truths by retreating to familiar, comforting stories (think: a classic rom-com you’ve seen a dozen times, or a cookie-cutter true crime documentary that ends with justice being served). Such stories can do us a lot of good. However, this talk explores a darker side of our tendency to use comforting narratives as a way of avoiding difficult truths. I argue that false conspiracy theories are often packaged as part of such emotionally comforting narratives. Furthermore, I argue that this way of packaging and disseminating conspiracy theories can make people more likely to believe them, since it gives conspiracy theories a greater ring of truth than the facts. My account of conspiracy narratives helps to bring out some more general considerations about the power of narratives for misleading people into believing falsehoods.
March 6
Dora Biro (University of Rochester)
Collective knowledge in animal groups: From the ‘Wisdom of the Crowd’ to cultural evolution
Living in groups poses a range of challenges and opportunities, in which individual perceptual and cognitive powers can be pooled to give rise to complex collective outcomes. For example, how animals travelling in groups collectively perceive, map, and orient through space addresses enduring questions in animal navigation and collective decision-making, while regional variation in groups’ behavioural “traditions” underscores the profound influence of the social context on the emergence and maintenance of learnt behaviour. I will illustrate these examples with research in avian and primate study systems to highlight how, in combination with laboratory and field experimentation, a range of biologging technologies (on-board GPS, head-mounted sensors, accelerometers) and other remote sensing and data processing techniques (camera traps, AI-based automated video analysis) can now provide us with varied novel insights into animal behaviour. These are related both to basic processes of perception and cognition (learning and memory), and to more complex collective outcomes such as collective problem-solving, collective vigilance, the ‘wisdom of the crowd’, and the cultural accumulation of collective knowledge. These insights have important implications for our understanding not only of the psychological machinery that underlies animals’ ability to cope with specific problems posed by their environment, but also of their capacity to adapt when these environments undergo rapid change.