Cognitive Science Colloquium
All meetings take place on Thursdays, 3.30-5.30 pm in Bioscience Research Building 1103, unless otherwise indicated.
September 6 — Anjan Chatterjee (Neuroscience, Penn).
Title: Disembodying cognition: Spatial perception, thought, and language
Abstract: Embodied cognition is an idea in high fashion. Concepts are postulated to entail simulations of sensory experiences or reenactments of motor behavior with instances of these concepts. I will argue that strong versions of embodied cognition are untenable. The choice between a purely symbolic and a fully embodied cognition obscures a more realistic question: what does it mean for cognition to be “grounded” in perception and action and still permit abstraction? This kind of question has a rich history in neurology dating back to the 19th century. Spatial perception, thought, and language offers a continuum within which to consider the disembodying of cognition. Using fMRI and patient studies I will discuss ways in which actions are extracted from actors, thinking about object properties is shifted to object relations, and richly textured perceptions are reduced to schematic analog representations. I will also present data to suggest that analog behavioral effects need not arise from reenactments as typically conceived.
September 13 — Iris Berent (Psychology, Northeastern).
Title: The Phonological Mind
Abstract: Human weave phonological patterns instinctively. We form phonological patterns at birth; like songbirds, we do so spontaneously, even in the absence of an adult model, and we impose phonological design not only on our natural linguistic communication but also on invented cultural technologies—reading and writing. Why are humans—young and mature—compelled to generate phonological patterns? And how can phonological patterns be intimately grounded in their sensorimotor channels (oral or manual) while remaining partly amodal, fully productive and abstract? In this talk, I suggest that the phonological grammar is a specialized algebraic system of core knowledge. It encompasses algebraic, grammatical constraints that are universal, but its adaptive design is shaped by phonetic triggers that operate in ontogeny and phylogeny. I evaluate this hypothesis against domain-general associationist explanations in light of behavioral, neuroimaging and linguistic studies that gauge the design of the phonological mind and its capacity for discrete infinity.
September 20 — Susan Gelman (Psychology, Michigan).
Title: Origins of Essentialist Reasoning
Abstract: Essentialism is the idea that items have an underlying reality that explains their manifest appearance and determines their identity. I argue that essentialism is an early cognitive bias. Young children's concepts reflect a deep commitment to essentialism, and this commitment leads children to look beyond the obvious in many converging ways: when learning words, generalizing knowledge to new category members, reasoning about the insides of things, contemplating the role of nature versus nurture, and constructing causal explanations. I consider two puzzles that this phenomenon raises: How are essentialist beliefs transmitted? And: What is the scope of essentialist reasoning?
October 4 — Nelson Cowan (Psychology, University of Missouri-Columbia).
Title: Measuring the Contents of the Conscious Human Mind
Abstract: I will address the basic question of how much a person can think about at one time, and how the contents of the conscious mind might be measured. In 1956 George A. Miller, a founding cognitive psychologist who died recently, suggested that the amount of information that one can recall from a just-presented list is fixed at about seven meaningful units, or chunks. Two critically important issues about this working memory capacity limit were left unresolved, however: (1) how one can reliably measure meaningful units, and (2) how much of the information is retrieved from the conscious mind as opposed to a more automatic type of memory. Our laboratory has advanced the understanding of these issues in recent years using a combination of methods including dual-task experimentation, brain imaging, mathematical modeling, and child developmental research. I will review the evidence and suggest that the mental faculty that is limited in capacity, to about 3 or 4 chunks in normal adults, is the focus of attention.
October 18 — Steven Dakin (Institute of Ophthalmology, University College London).
Title: Do humans have a distinct sense of visual number?
Abstract: There is current interest in how we are able to make an estimate of the approximate number of objects in a scene: existing evidence suggests that we may have a dedicated "visual number" sense that may even be linked to mathematical ability. In this talk I will present evidence from my lab that, contrary to this position, human sense of number is not independent of our sense of space/distance and that our ability to estimate one depends on the other. This implicates a common perceptual mechanism, and we describe one candidate based on the operation of neurons in the primary visual areas. This rather simple model can explain a range of perceptual phenomena associated with approximate number estimation.
November 15 — Felix Warneken (Psychology, Harvard).
Title: The origins of human altruistic behavior in ontogeny and phylogeny
Abstract: It is often assumed that humans are inherently selfish, and cultural norms and practices have to override these tendencies to enable altruistic behavior. Specifically, young children are thought to be driven mainly by immediate selfish motivations, acquiring altruistic behaviors through the internalization of social norms or being rewarded for socially desired behavior. Moreover, it has been argued that our closest evolutionary relatives are motivated by selfish interests alone, not caring about the needs of others. This comparative evidence would lend further support for the notion that human-unique cultural factors are foundational. However, I present recent work with young children and chimpanzees that indicates that human altruism might have deeper roots in ontogeny and phylogeny. I will summarize these studies to entertain the possibility that human altruism is not due to cultural practices alone, but reflects a biological predisposition that we might share with our closest evolutionary relatives.
November 29 — Bob Frank (Linguistics, Yale).
Title: Computation and Grammar: Restrictiveness in Semantics
Abstract: There is a tradition of linguistic research starting with the earliest work in generative grammar that aims to employ notions of computational restrictiveness (e.g, generative capacity, parsing complexity, etc.) to explain general properties of human language. When such work is successful, it provides theoretical simplification as well as a means for understanding (as opposed to stipulating) why human grammars are structured as they are. This tradition has been applied widely in the linguistic domains of syntax and phonology, increasingly so in recent years, and I will briefly review the progress that has been made. In contrast, there has been little work attempting such computational explanation in the domain of semantics. I will report on a line of research that attempts to do just this. Specifically, I will show how a "synchronous" extension of Tree Adjoining Grammar, a computationally weak, mildly context-sensitive, grammar formalism, provides a simple, restrictive, and arguably empirically satisfying theory of the correspondence between surface syntax and logical form.