Cognitive Science Colloquium

Spring 2013

All meetings take place on Thursdays, 3.30-5.30 pm in Bioscience Research Building 1103, unless otherwise noted.

January 31George Alvarez (Psychology, Harvard).

Title: What are visual representations, and why can't I have more of them?
Abstract: Philosophers, cognitive scientists, and neuroscientists tend to have very different ideas about how to define a representation. I certainly won’t
settle this issue in my talk, but I hope to provide data that informs how we think about visual representations, and why we cannot have more of them at
once. I will focus on temporary information buffers (attention and working memory), and argue that these buffers have a two-dimensional “map”
architecture where individual items compete for cortical real estate. This competitive format leads to capacity limits that are flexible, set by the nature of
the content and their locations within the physically delimited cortical space. Using visual spatial attention and visual memory as case studies, I will
suggest that these competitive maps are a widespread architecture that limits cognitive capacity across broader domains, and that this map architecture
has important implications for how define visual representations.

February 14Marie Coppola (Psychology, UConn).

Title: Which aspects of language and cognition depend on linguistic input? Insights from homesign gesture systems
Abstract: Researchers in the cognitive sciences have long debated the relationships between linguistic input and language structure, as well as the relationships between language and cognition. Homesign systems offer a unique window into these relationships. Homesigns are gesture systems developed by deaf individuals who are not exposed to conventional sign or spoken language input. Homesign systems exhibit a number of linguistic properties, but appear to lack others, which depend on access to a linguistic model and/or interaction within a language community. I will present evidence for structure in homesign from a variety of levels of linguistic analysis, including phonology and discourse structure. I will also discuss the cognitive consequences (or lack thereof) of linguistic (but not social) deprivation, particularly with respect to number cognition. Finally, I will present results suggesting that the linguistic structure in homesign systems is not entirely driven by communication factors.

March 7 — Chris Kennedy talk postponed due to weather.

March 28  — Chandra Sripada (Philosophy & Psychiatry, Michigan).

Title: Moral responsibility: Philosophical analyses, psychological experiments
Abstract: Consider the case, due to the philosopher Harry Frankfurt, of an unwilling addict: “[He] hates his addiction and always struggles desperately, although to no avail, against its thrust. He tries everything that he thinks might enable him to overcome his desires for the drug. But these desires are too powerful for him to withstand, and invariably, in the end, they conquer him.” (Frankfurt 1971.) There is a strong intuition that the addict is not morally responsible for using the drug. But why? The answer to this question divides two major philosophical approaches to moral responsibility. Ability views focus on the addict’s ability (or lack thereof) to regulate his actions across a range of relevant scenarios. Very roughly, to be morally responsible for an action, the person must be able to issue the action when there is sufficient reason to do so, and withhold the action when there is sufficient reason not to. Attributability views, in contrast, say the addict is not responsible for using the drug because his action does not express his self. That is, since the addict’s own fundamental values and principles repudiate the action, the action does not reflect the person who he truly is, and he is not responsible for it.
            In this talk, I propose and defend a version of an attributability approach to moral responsibility called the Self-Expression account. (A strictly philosophical statement and defense of the view is available here.) Part of my defense of the view relies on traditional methods—analysis of concepts and appeals to intuitions about hypothetical cases. Other lines of evidence are drawn from empirical methods.  These include surveys of folk intuitions, studies that utilize systematic manipulations, and covariational techniques such as structural equation modeling.

April 4Sheng He (Psychology, Minnesota).

Title: Binocular rivalry, visual awareness, and attention
Abstract: When two different images are presented to the two eyes at the corresponding retinal locations, observers often experience binocular rivalry - alternating perception of the two images.  In a number of behavioral and neuroimaging experiments using binocular rivalry as a tool, we showed that object category information is available in the brain from the suppressed images, and observers' spatial attention could be guided by certain types of invisible images. With a frequency-tagged SSVEP measure, we also demonstrated that when attention was diverted away from the competing stimuli, binocular rivalry ceased and interocular competition remain unresolved.

April 11 — Chris Kennedy (Linguistics, University of Chicago).

Title: Vagueness, Imprecision, and Tolerance
Abstract: When I say “the theater is packed tonight” or “there are a lot of people in the theater tonight,” my utterance leaves a certain amount of uncertainty about the actual number of people in the theater. The same uncertainty is usually present when I say “the theater is full tonight” (even if the number of seats in the theater is known) or “there are 1000 people in the theater tonight.” In all cases, this can be traced back to the fact that we use and interpret utterances like these tolerantly:  small differences in the actual number of people in the theater typically do not affect our willingness either to make these utterances or to accept a speaker's utterance of them. However, there is an important difference between the two sets of utterances: "the theater is full" and "there are 1000 people in the theater" can be used or understood in a way that is fully precise, but "the theater is packed" and "there are a lot of people in the theater" cannot be so used or understood. This distinction — the possibility of “natural precisifications” — is one of several empirical properties that distinguish vague terms like 'packed' and 'a lot' from (potentially) imprecise ones like 'full' and '1000'. 

The central theoretical question is how to account for these and other empirical differences while at the same time explaining why both kinds of expressions can be tolerant. Does the shared property of tolerance indicate that both vague and imprecise expressions have the same core semantic analysis (one in which all meanings are fundamentally tolerant); or does the difference in precisification reflect a core semantic distinction that is sometimes blurred by use? My goal in this talk is to present some arguments in favor of the latter position.  I will begin by providing linguistic and experimental evidence which argues in favor of a distinction between vagueness as a fundamentally semantic phenomenon and imprecision as a fundamentally pragmatic one. I will then argue that any reasonable pragmatic model of imprecision is one that will give rise to the phenomenological properties associated with tolerance, for exactly the same reasons that the semantic features of vague terms give rise to these properties.

April 18Robert Boyd (Anthropology, Arizona State University).

Title: Is causal reasoning necessary for cultural adaptation?
Abstract: Human populations are able to rapidly acquire knowledge and technology specific to a wide range of environments.  The received explanation for this fact is that humans are better than other animals at causal reasoning.  In this talk, I present theoretical work that shows that gradual cultural evolution can lead to the rapid evolution of complex technologies without causal understanding, and some empirical results that suggest some aspects of the design of traditional houses in a Fiji are not understood by Fijian house builders.

May 2 — Liz Brannon (Psychology & Neuroscience, Duke).

Title:  Foundations for symbolic mathematics: development and evolution of our primitive number sense
Abstract: Adult humans quantify, label, and categorize almost every aspect of the world with numbers.  The ability to use numbers is one of the most complex cognitive abilities that humans possess and is often held up as a defining feature of the human mind.  In my talk I will present a body of data that demonstrates that there are strong developmental and evolutionary precursors to adult mathematical cognition that can be uncovered by studying human infants and nonhuman primates. Developmental data and controversies will be discussed in light of comparative research with monkeys and other animals allowing us to see both parallels and discontinuities in the evolutionary and developmental building blocks of adult human cognition.  Implications for education will be explored by describing a) a longitudinal study exploring the relationship between infants’ number sense and later developing mathematical cognition in childhood and b) a set of training studies exploring the link between primitive number sense and symbolic mathematics.