University Relations

Spring 2016 Wednesdays, 12:00 - 1:00 pm, Elliott Hall S204


January 28 - Discussion topics chosen.


February 4 - "The cognitive revolution: a historical perspective" by George Miller.

Cognitive science is a child of the 1950s, the product of a time when psychology, anthropology and linguistics were redefining themselves and computer science and neuroscience as disciplines were coming into existence. Psychology could not participate in the cognitive revolution until it had freed itself from behaviorism, thus restoring cognition to scientific respectability. By then, it was becoming clear in several disciplines that the solution to some of their problems depended crucially on solving problems traditionally allocated to other disciplines. Collaboration was called for: this is a personal account of how it came about.


February 11 - "The crusade against multiple regression analysis" by Richard Nisbett

"A huge range of science projects are done with multiple regression analysis. The results are often somewhere between meaningless and quite damaging ... I hope that in the future, if I'm successful in communicating with people about this, that there'll be a kind of upfront warning in New York Times articles: These data are based on multiple regression analysis. This would be a sign that you probably shouldn't read the article because you're quite likely to get non-information or misinformation."


February 17 - "Whatever next? Predictive brains, situated agents, and the future of cognitive science" by Andy Clark

Brains, it has recently been argued, are essentially prediction machines. They are bundles of cells that support perception and action by constantly attempting to match incoming sensory inputs with top-down expectations or predictions. This is achieved using a hierarchical generative model that aims to minimize prediction error within a bidirectional cascade of cortical processing. Such accounts offer a unifying model of perception and action, illuminate the functional role of attention, and may neatly capture the special contribution of cortical processing to adaptive success. This target article critically examines this "hierarchical prediction machine" approach, concluding that it offers the best clue yet to the shape of a unified science of mind and action. Sections 1 and 2 lay out the key elements and implications of the approach. Section 3 explores a variety of pitfalls and challenges, spanning the evidential, the methodological, and the more properly conceptual. The paper ends (sections 4 and 5) by asking how such approaches might impact our more general vision of mind, experience, and agency.


February 24 - "Conceptual Development: The Case of Essentialism" by Susan A. Gelman and Elizabeth A. Ware

The article focuses on conceptual development in children. There are two primary components to psychological essentialism, which include the belief that certain categories are natural kinds and the belief that there is some unobservable property. Psychologists examine the psychological representations of concepts whereas philosophers have examined essentialism with the goal of addressing a range of issues such as psychological, semantic, and metaphysical. The study of essentialism in children provides insights into children's cognition and information regarding the roots of human concepts. Essentialism includes several component beliefs, including that categories have sharp, immutable boundaries, that category members share deep, nonobvious commonalities, and that category membership has an innate, genetic, or biological basis. Kamp and Partee suggest that categories are seen with absolutely sharp boundaries only in abstract domains. Essentialism does not require that categories be treated as absolute but essentialism is the claim that category boundaries are intensified. Essentialism emerges early and consistently, does not require formal schooling, and if anything may be even stronger in early childhood than later. The detailed studies of parental input to children about categories also suggest that parents do not provide explicit instruction about essentialist beliefs.


March - "Beyond the computer metaphor: Behavior as interaction" by Paul Cisek

Behavior is often described as the computation of a response to a stimulus. This description is incomplete in an important way because it only examines what occurs between the reception of stimulus information and the generation of an action. Behavior is more correctly described as a control process where actions are performed in order to affect perceptions. This closed-loop nature of behavior is de-emphasized in modern discussions of brain function, leading to a number of artificial mysteries. A notable example is the "symbol grounding problem". When behavior is viewed as a control process, it is natural to explain how internal representations, even symbols, can have meaning for an organism, and how actions can be motivated by organic needs.


March 9 - "Words and the world: Predictive coding and the language-perception-cognition interface" by Lupyan and Clark

Can what we know change what we see? Does language affect cognition and perception? The last few years have seen increased attention to these seemingly disparate questions, but with little theoretical advance. We argue that substantial clarity can be gained by considering these questions through the lens of predictive processing, a framework in which mental representations—from the perceptual to the cognitive—reflect an interplay between downward- flowing predictions and upward-flowing sensory signals. This framework provides a parsimonious account of how (and when) what we know ought to change what we see and helps us understand how a putatively high-level trait such as language can impact putatively low-level processes such as perception. Within this framework, language begins to take on a surprisingly central role in cognition by providing a uniquely focused and flexible means of constructing predictions against which sensory signals can be evaluated. Predictive processing thus provides a plausible mechanism for many of the reported effects of language on perception, thought, and action, and new insights on how and when speakers of different languages construct the same "reality" in alternate ways.


March 23 - "Cortical tracking of hierarchical linguistic structures in connected speech" by Nai Ding, Lucia Melloni, Hang Zhang, Xing Tian & David Poeppel

The most critical attribute of human language is its unbounded combinatorial nature: smaller elements can be combined into larger structures on the basis of a grammatical system, resulting in a hierarchy of linguistic units, such as words, phrases and sentences. Mentally parsing and representing such structures, however, poses challenges for speech comprehension. In speech, hierarchical linguistic structures do not have boundaries that are clearly defined by acoustic cues and must therefore be internally and incrementally constructed during comprehension. We found that, during listening to connected speech, cortical activity of different timescales concurrently tracked the time course of abstract linguistic structures at different hierarchical levels, such as words, phrases and sentences. Notably, the neural tracking of hierarchical linguistic structures was dissociated from the encoding of acoustic cues and from the predictability of incoming words. Our results indicate that a hierarchy of neural processing timescales underlies grammar-based internal construction of hierarchical linguistic structure.


March 30 - "The Neuroscience of Learning: Beyond the Hebbian Synapse" by Gallistel and Matzel

From the traditional perspective of associative learning theory, the hypothesis linking modifications of synaptic transmission to learning and memory is plausible. It is less so from an information-processing perspective, in which learning is mediated by computations that make implicit commitments to physical and mathematical principles governing the domains where domain-specific cognitive mechanisms operate. We compare the properties of associative learning and memory to the properties of long-term potentiation, concluding that the properties of the latter do not explain the fundamental properties of the former. We briefly review the neuroscience of reinforcement learning, emphasizing the representational implications of the neuroscientific findings. We then review more extensively findings that confirm the existence of complex computations in three information-processing domains: probabilistic inference, the representation of uncertainty, and the representation of space. We argue for a change in the conceptual framework within which neuroscientists approach the study of learning mechanisms in the brain.


April 6 - "Why cognitive science needs philosophy and vice versa" by Paul Thagard.

Contrary to common views that philosophy is extraneous to cognitive science, this paper argues that philosophy has a crucial role to play in cognitive science with respect to generality and normativity. General questions include the nature of theories and explanations, the role of computer simulation in cognitive theorizing, and the relations among the different fields of cognitive science. Normative questions include whether human thinking should be Bayesian, whether decision making should maximize expected utility, and how norms should be established. These kinds of general and normative questions make philosophical reflection an important part of progress in cognitive science. Philosophy operates best, however, not with a priori reasoning or conceptual analysis, but rather with empirically informed reflection on a wide range of findings in cognitive science.


April 13 - "Human-level concept learning through probabilistic program induction" by Lake et al.

People learning new concepts can often generalize successfully from just a single example, yet machine learning algorithms typically require tens or hundreds of examples to perform with similar accuracy. People can also use learned concepts in richer ways than conventional algorithms — for action, imagination, and explanation. We present a computational model that captures these human learning abilities for a large class of simple visual concepts: handwritten characters from the world's alphabets. The model represents concepts as simple programs that best explain observed examples under a Bayesian criterion. On a challenging one-shot classification task, the model achieves human-level performance while outperforming recent deep learning approaches. We also present several "visual Turing tests" probing the model's creative generalization abilities, which in many cases are indistinguishable from human behavior.


April 20 - "LSD modulates music-induced imagery via changes in parahippocampal connectivity" by Kaelen et al.

Psychedelic drugs such as lysergic acid diethylamide (LSD) were used extensively in psychiatry in the past and their therapeutic potential is beginning to be re-examined today. Psychedelic psychotherapy typically involves a patient lying with their eyes-closed during peak drug effects, while listening to music and being supervised by trained psychotherapists. In this context, music is considered to be a key element in the therapeutic model; working in synergy with the drug to evoke therapeutically meaningful thoughts, emotions and imagery. The underlying mechanisms involved in this process have, however, never been formally investigated. Here we studied the interaction between LSD and music-listening on eyes-closed imagery by means of a placebo-controlled, functional magnetic resonance imaging (fMRI) study. Twelve healthy volunteers received intravenously administered LSD (75 µg) and, on a separate occasion, placebo, before being scanned under eyes-closed resting conditions with and without music-listening. The parahippocampal cortex (PHC) has previously been linked with (1) music-evoked emotion, (2) the action of psychedelics, and (3) mental imagery. Imaging analyses therefore focused on changes in the connectivity profile of this particular structure. Results revealed increased PHC–visual cortex (VC) functional connectivity and PHC to VC information flow in the interaction between music and LSD. This latter result correlated positively with ratings of enhanced eyes-closed visual imagery, including imagery of an autobiographical nature. These findings suggest a plausible mechanism by which LSD works in combination with music listening.


April 27 - "Intelligent without design" by Kate Douglas

"A feather isn't just pretty: it's pretty useful. Strong, light and flexible, with tiny barbs to zip each filament to its neighbours, it is fantastically designed for flight. The mammalian eye, too, is a marvel of complex design, with its pupil to regulate the amount of light that enters, a lens to focus it onto the retina, and rods and cones for low light and colour vision – all linked to the brain through the optic nerve. And these are just the tip of the iceberg of evolution's incredible prowess as a designer. For centuries, the apparent perfection of such designs was taken as self-evident proof of divine creation. Charles Darwin himself expressed amazement that natural selection could produce such variety and complexity. Even today, creationism and intelligent design thrive on intuitive incredulity that an unguided, unconscious process could produce such intricate contraptions."


May 4 - "A Review of B.F. Skinner's Verbal Behavior" by Noam Chomsky (HTML version)

"A great many linguists and philosophers concerned with language have expressed the hope that their studies might ultimately be embedded in a framework provided by behaviorist psychology, and that refractory areas of investigation, particularly those in which meaning is involved, will in this way be opened up to fruitful exploration. Since this volume is the first large-scale attempt to incorporate the major aspects of linguistic behavior within a behaviorist framework, it merits and will undoubtedly receive careful attention. Skinner is noted for his contributions to the study of animal behavior. The book under review is the product of study of linguistic behavior extending over more than twenty years. Earlier versions of it have been fairly widely circulated, and there are quite a few references in the psychological literature to its major ideas.

"The problem to which this book is addressed is that of giving a "functional analysis" of verbal behavior. By functional analysis, Skinner means identification of the variables that control this behavior and specification of how they interact to determine a particular verbal response. Furthermore, the controlling variables are to be described completely in terms of such notions as stimulus, reinforcement, deprivation, which have been given a reasonably clear meaning in animal experimentation. In other words, the goal of the book is to provide a way to predict and control verbal behavior by observing and manipulating the physical environment of the speaker."

Updated May 9, 2016