Center For Mind, Brain, And Culture

Advancements in machine learning and data mining have already led to amazing breakthroughs in the natural sciences, including the unlocking of the human genome and the detection of subatomic particles. Such techniques promise to wield a similar impact on the study of mind. In my talk I will discuss how the large-scale structure of the human mental lexicon, roughly 50,000 words, can be recovered from billions of words at a level of resolution that includes the differentiation of word senses. Central to this effort are several machine learning and dimensionality reduction techniques, including deep learning, t-Distributed Stochastic Neighbor Embedding (t-SNE), and the clustering technique called GMeans. In addition to the extraction of the mental lexicon, I will discuss how an approach to topic modeling, based on neural networks, might be used to partially automate the process of theory generation. I also raise implications for research on physical and mental wellbeing. NEUROSCIENCE WORKSHOP: Dimensionality Red

The engineering and applied math communities often exploit the fact that natural stimuli have significant structure that lends itself well to dimensionality reduction. The efficient coding hypothesis for sensory neural coding postulates that stages of neural processing should sequentially make the representations more efficient by removing stimulus redundancies, and this is often expressed in the language of information theory. In this talk I will present our work exploring efficient coding models of vision based on dimensionality reduction, including sparsity, low-rank matrix factorizations and random projections. I will show that such approaches are able to account for many observed properties in visual cortex, including classical receptive fields, response properties based on nonclassical or nonlinear receptive fields, and properties of the inhibitory interneurons. NEUROSCIENCE WORKSHOP: Dimensionality Reduction Friday, October 30, 2015 Saturday, October 31, 2015

Animals perform a complex array of behaviors, from changes in body posture to vocalizations to other dynamic outputs. Far from being a disordered collection of actions, however, there is thought to be an intrinsic structure to the set of behaviors and their temporal and functional organization. In this talk, I will introduce a novel method for mapping the behavioral space of organisms. This method relies only upon the underlying structure of postural movement data to organize and classify behavior, eschewing ad hoc behavioral definitions entirely and effectively compressing the vast amounts of data being collected. Applying this method to videos of freely-behaving fruit flies (D. melanogaster), I will show that the organisms’ behavioral repertoire consists of a hierarchically-organized set of stereotyped behaviors. This hierarchical patterning results in the emergence of long time scales of memory in the system, providing insight into the mechanisms of behavioral control over that occur over seconds, minutes,

Most sensory, cognitive, and motor functions rely on the interaction among many neurons. To analyze the activity of many neurons together, many groups are now adopting advanced statistical methods, such as dimensionality reduction. In this talk, I will first describe how dimensionality reduction can be used in a closed-loop experimental setting to understand how learning is shaped by the underlying neural circuitry. Then, I will describe a novel latent variable model that extracts a subject's internal model during sensorimotor control. NEUROSCIENCE WORKSHOP: Dimensionality Reduction Friday, October 30, 2015 Saturday, October 31, 2015

I discuss two new studies that focus on general questions about the cognitive science and neural implementation of speech and language. I come to (currently) unpopular conclusions about both domains. Based on a first set of experiments, using fMRI and exploiting the temporal statistics of speech, I argue for the existence of a speech-specific processing stage that implicates a particular neuronal substrate that has the appropriate sensitivity and selectivity for speech (Overath et al. 2015). Based on a second set of experiments, using MEG, I show how temporal encoding can form the basis for more abstract, structural processing. The results demonstrate that, during listening to connected speech, cortical activity of different time scales is entrained concurrently to track the time course of linguistic structures at different hierarchical levels. Critically, entrainment to hierarchical linguistic structures is dissociated from the neural encoding of acoustic cues and from processing the predictability of incomi

Ritual is a puzzling aspect of behavior, as it involves obvious expenditures of effort, energy and resources without equally obvious payoffs. Evolutionary theorists have long proposed that such costly behaviors would not have survived throughout human history unless they conveyed certain benefits to their practitioners. But what might those benefits be, and how can they be operationalised and measured? This talk will present a series of studies that combined laboratory and field methods to explore the puzzle of ritualized behavior among humans. (October 1, 2015)

In 1993, Time magazine dubbed Miami “the Capital of Latin America.” At the time, Miami’s Hispanic / Latino population was at roughly 50% and was overwhelmingly Cuban-origin. In the ensuing two decades, Miami’s Hispanic / Latino population has continued to grow, reaching 65% in Miami-Dade County and 78% in the City of Miami in 2010. At the same time, the Cuban-origin share has fallen to below 50%. Both of these developments owe to the economic and political crises in Latin America in the 1990s and 2000s that brought unprecedented numbers of Colombians, Venezuelans, Peruvians, Dominicans, and other Spanish-speaking groups to South Florida. As a result of the socio-demographic changes, Miami is now both the most Latino large city in the U.S. (79%) and the most foreign-born (65%). It is also most likely to be the most bilingual large city in North America and the most dialectally-diverse Spanish speaking city in the world. The richness of the sociolinguistic landscape raises important questions about the ways in

Anthropology has a long history of investigating human variation with the goal of understanding the genetic, environmental, and epigenetic sources of variation existing within and between human populations. Yet the field has historically focused on variation from the neck down. In this discussion we identify inherent challenges to understanding the varieties of mental experience and explore several of the latest methodological advances that have helped researchers better address questions of human brain variation. (September 18, 2015)

People often choose larger future rewards over smaller immediate ones, but then abandon that choice before the future reward arrives. Examples include starting a diet but then not sticking to it, quitting smoking but then relapsing, and most new year's resolutions. Psychologists often explain such behavior by reference to fundamental limitations in human cognitive systems, such as limited willpower or self-control. I will argue for an alternative explanation, in which the failure to persist toward delayed outcomes arises from a rational reevaluation process regarding temporally uncertain delayed rewards. I will talk about our work showing the critical role of uncertainty in persistence towards future outcomes and examining how different forms of uncertainty are encoded in the brain and affect other neural representations during voluntary persistence. (September 24, 2015)

We will discuss our collaboration as co-teachers of a course called "Sleep in Science and Culture" and our consultations with each other since. We aim to show how a discussion between disciplines can help define what is normal and what is pathological, and the consequences of making those distinctions. (September 29, 2015)

In psychology (e.g., Schooler, 2011) and other fields (e.g., Jennions & Møller, 2001), there are reported cases of effect sizes declining over time. Later studies of a given phenomenon report smaller effect sizes than earlier studies. This decline suggests a publication bias toward large effects and regression to the mean. In the current study, we examine whether evidence exists for such a decline effect. In Study 1, we analyzed 3,488 effect sizes across 70 meta-analytic tables, which were drawn from 33 Psychological Bulletin articles (1980–2010). A multilevel analysis revealed no evidence of a linear or quadratic decline effect over time (indexed by publication year). In Studies 2 and 3, we examined 50 meta-analyses each from social psychology and clinical psychology. In both studies, the modal meta-analysis showed no correlation between effect size and publication year. The decline effect in psychology appears to be less prevalent than earlier anecdotal reports suggest. For replications, this finding su

In recent years, cultural sociologists have grown increasingly interested in psychology and some influential psychologists (e.g., Oishi et al 2009; Haidt 2012) have argued for closer connections to sociological theory and research. In this talk, I will outline some past and current work in which I have attempted to create bridges between sociology and psychology. I will also consider some concrete ways to improve interdisciplinary research on morality. (September 3, 2015) Sponsored by the Coalition of Graduate Sociologists (COGS) with support from the Department of Sociology and the CMBC.

A growing body of research points to a significant effect of bilingualism on cognitive outcomes across the lifespan. The main finding is evidence for the enhancement of executive control at all stages in the lifespan, with the most dramatic results being maintained cognitive performance in elderly adults and protection against the onset of dementia. These results shed new light on the question of how cognitive and linguistic systems interact in the mind and brain. I will review evidence from both behavioral and imaging studies and propose a framework for understanding the mechanism that could lead to the reported consequences of bilingualism and the limitation or absence of these effects under some conditions. (November 11, 2015) Sponsored by the CMBC with additional support from the Departments of Psychology, German Studies, French and Italian Studies, Russian and East Asian Languages and Cultures (REALC), Middle Eastern and South Asian Studies (MESAS), the Emory College Language Center (ECLC), the Program i

There has recently been an international surge of interest in building large brain models. The European Union's Human Brain Project (HBP) has received 1 billion euros worth of funding, and President Obama announced the Brain Initiative along with a similar level of funding. However the large scale models affiliated with both projects do not demonstrate how their generated complex neural activity relates to observable behaviour -- arguably the central challenge for neuroscience. I will present our recent work on large-scale brain modeling that is focussed on both biological realism and reproducing human behaviour. I will demonstrate how the model relates to both low-level neural data and high-level behavioural data. Finally, I will discuss applications of this research to understanding both the biological basis of cognition and building more advanced robots. [March 25, 2015]

Why is there some “religious stuff” in all human societies? A tempting answer is that religions are somehow grounded in evolved properties of human minds. Recently, some have even suggested that religion could have been selected for ensuring large-scale cooperation and prosocial behavior. Considering the empirical evidence leads to a more sober understanding of the evolutionary processes underpinning the emergence and spread of religious concepts and norms. The term “religion” misleadingly lumps together three very different kinds of social-cultural processes, unlikely to have spread in the same contexts. I propose to model the diffusion of religious concepts in terms of cultural epidemics based on universal cognitive dispositions, showing how some (not all) religious concepts can serve as recruitment devices in building coalitions. [March 24, 2015]

An essential feature of any society is the capacity of its members to distinguish one another from outsiders and reject outsiders on that basis. Some social insects and humans are able to form huge societies because their membership is anonymous—members aren’t required to distinguish all the other members as individuals for the society to remain unified. Societies are instead bonded by shared identity cues and signals, such as society-specific odors in ants and learned social labels in humans. I contrast this with societies of nonhuman vertebrates, which achieve a maximum of 200 members by the necessity that each member recalls every other member individually. The capacity to form an anonymous society is a complex trait that I will show could have arisen in our ancestors well before language. While there has been a perennial focus on the cooperative networks that emerge inside each society, identification with a clearly defined group of members, and not coop­eration or kinship as many experts assert, is the m

The language(s) that we know shape the way we process and represent the speech that we hear. Since real-world speech recognition almost always takes place in conditions that involve some sort of background noise, we can ask whether the influence of linguistic knowledge and experience on speech processing extends to the particular challenges posed by speech-in-noise recognition, specifically the perceptual separation of speech from background noise (Experiment Series 1) and the cognitive representation of speech and concurrent background noise (Experiment Series 2). In Experiment Series 1, listeners were asked to recognize English sentences embedded in a background of competing speech that was either English (matched-language, English-in-English recognition) or another language (mismatched-language, e.g. English-in-Mandarin recognition). Listeners were either native or non-native listeners of the target language (usually, English), and were either familiar or unfamiliar with the language of the to-be-ignored,

Collective memory—sometimes referred to as public memory, or social (or cultural) memory—is a term commonly used in the humanities. It posits the act of remembering as ineluctably linked to what the French sociologist Maurice Halbwachs (who is credited with elaborating the concept) called the “social frameworks” of memory such as family, class, ethnic, national or religious communities. Within these social frameworks, an individual’s recollection of events is shaped by the shared experience of that event as the group in question frames it. Cognitive scientists, on the other hand, speak in terms of personal memory, distinguishing among three types—procedural, semantic, and episodic—that enable individuals to register and recall a range of experiences. How do we go from the multiplicity of private, individual memories to the potential unity of collective memory? Inversely, can the collective memory of an event shared by a social group influence the way an individual recollects her experience of that same event?

The time seems right to rethink how the fields of cognitive psychology and computational neuroscience could take advantage of each other. Both fields make use of quantitative models, one of cognitive processes the other of brain processes. Since the brain ultimately supports cognitive processes one should think these levels of description should merge. Interestingly that has largely not happened yet. We will discuss possible approaches and areas of content where such overlap might become possible in the near future. [February 19, 2015]

Few would contest the claim that Shakespeare was a great poet and playwright. Less indisputable, perhaps, is the notion that he was also a great social theorist. By this, I'm not referring to theory in the weak sense of occasional philosophically nuanced comments by characters, or speeches with philosophical overtones. I mean that Shakespeare was a social theorist in the strong sense that, in addition to being powerful stories, his plays often are extended reflections on many of the classic issues of social thought. If I'm right about this, it raises an important question about literary technique and voice. Normally the analytical voice of the theorist is very different and in some sense in tension with the narrative voice of the dramatist or novelist. Reconciling the requirements of effective theoretical analysis and affecting dramatic narrative is a major challenge. This talk, adapted from my upcoming book on Shakespeare and social theory, deals with one important way in which Shakespeare accomplished this