Cognitive and Behavioral Neuroscience
- Founded
1986 - Seminar Number
603
For more than 100 years, comparative psychologists have sought to understand the evolution of human intelligence. New paradigms for studying cognitive processes in animals—in particular symbol use and memory—have, for the first time, allowed psychologists and neuroscientists to compare higher thought processes in animals and human beings. New imaging approaches have also facilitated exploring the neural basis of behavior and both animals and humans. Questions concerning the nature of animal and human cognition have defined the themes of this seminar whose members include specialists in cognition, ethology, philosophy and neuroscience.
Co-Chairs
Yaakov Stern
Professor of Neuropsychology, Columbia University, Taub Institute
ys11@columbia.edu
Herbert S. Terrace
Professor of psychology, Columbia
terrace@columbia.edu
Rapporteur
Gregory Jensen
Columbia University, Psychology
ggj2102@columbia.edu
Welcome
Meetings
| 10/25/2012 | Faculty House 4:00 PM |
The Neuroscience of the Winner Effect
|
|
Notes: "The fundamental concept in social science is Power, in the same sense in which Energy is the fundamental concept in physics." -Bertrand Russell, "The Impulse To Power" One of the most under-explored determinants of human behviour is a person’s position in a dominance hierarchy. Predicted mathematically in 1950 before it was finally demonstrated empirically in 1968, ‘The Winner Effect” is the phenomenon whereby an animal competing against an artificially weakened opponent is more likely to win a subsequent contest against a strong opponent, an effected mediated partly by increased testosterone and dopamine activity and long-lasting increased androgen receptor densities in the brain. Holding power over others is one manifestation of a dominance-based ‘winner effect’ and in humans even small amounts of power alter behavior significantly. As an example of the capacity of social and psychological variables to reshape the biology of the brain, this has important implications for understanding and treating a number of different disorders of the brain. |
||
| 11/29/2012 | Faculty House 4:00 PM |
Individual Differences in the Ability to Direct Auditory Attention
|
| Notes: Many young, healthy listeners are good at selectively attending to whatever sound is most relevant, a task that requires the brain to separate a sound mixture into distinct perceptual objects. However, a growing number of studies suggest that there are large differences in the ability to direct auditory attention, even in listeners who have normal auditory thresholds. In this talk, I will first explore how it is that "good" listeners are able to direct auditory attention to whatever source is most interesting at a given moment, drawing on results from both behavioral and neuro-imaging studies. Then I will describe emerging evidence that helps explain why some listeners have trouble in ordinary social settings, where multiple people interact across multiple conversations. Understanding these individual differences not only provides basic scientific insight into how listeners control auditory attention, but is clinically important for determining effective ways to aid communication in everyday settings. | ||
| 12/13/2012 | Faculty House 4:00 PM |
Attention and Arousal in the Monkey Parietal Cortex
|
|
Notes: The primate brain does not have enough resources to process the entire visual world at once. Visual attention is the mechanism by which the brain selects some objects for further analysis, and ignores others. Attention has two basic mechanisms – exogenous attention, in which salient objects in the environment that may be behaviorally irrelevant grab attention automatically – a bright flash of light, sudden motion. Endogenous attention is the selection of an object not because of its physical characteristics, but because the object is somehow behaviorally important. The selected object can be further analyzed perceptually, and it can also become the target for movement. The lateral intraparietal area of the brain analyzes far visual space, the part of the world we explore with our eyes using rapid eye movements called saccades. Neurons in this area receive bottom-up visual, and top-down motor and cognitive information and sum these signals to provide a priority map of the visual world. Visual attention, as measured by an improvement in perceptual threshold, is pinned to the peak of the priority map. Saccades are made to the peak of the priority map when they are appropriate. The priority map is sharpened by surround suppression and by surround stimulation decreasing the variability of neuronal responses The efficiency of visual selection is gated by a second, less specific arousal process, measurable in the baseline activity of neurons, which predicts the intensity of subsequent neuronal responses and the efficiency of performance. The baseline signal is nonspatial, and is not dependent upon specific spatial attention. It is inversely proportional to the monkey’s recent history of reward. |
||
| 01/24/2013 | Faculty House 4:00 PM |
Harnessing the Brain for Language and Music
|
| Notes: Language and music are central to what it means to be human. But where did they come from? In his new book "Harnessed", cognitive scientist Mark Changizi argues that language and music are in us not because we evolved for them, but, rather, because they evolved for us. Over history, language and music came to have the structure that our non-language and amusical brains could brilliantly absorb. In particular, language and music came to have the structures of the sounds in nature -- the sounds of, respectively, solid-object physical events and human movement -- just the sorts of sounds our brain had evolved to process. | ||
| 02/21/2013 | Faculty House 4:00 PM |
Stability in the Face of Change: Comprehension and Recall of Rapid Speech in Healthy Aging
|
| 03/28/2013 | Faculty House 4:00 PM |
Multimodal Neuroimaging of Perceptual Decision Making
|
| Notes: Advances in neural signal and image acquisition as well as in multivariate signal processing and machine learning are enabling a richer and more rigorous understanding of the neural basis of human decision-making. Decision-making is essentially characterized behaviorally by the variability of the decision across individual trials--e.g., error and response time distributions. To infer the neural processes that govern decision-making requires identifying neural correlates of such trial-to-trial behavioral variability. In this talk I will describe our efforts in utilizing signal processing and machine learning to enable single-trial analysis of neural signals acquired while subjects perform simple decision-making tasks. Our focus is on neuroimaging data collected noninvasively via electroencephalograpy (EEG) and functional magnetic resonance imaging (fMRI). I will describe the specific framework for extracting decision-relevant neural components from the neuroimaging data, the goal being to analyze the trial-to-trial variability of the neural signal along these component directions and to relate them to elements of the decision-making process. Finally I will discuss how single-trial analysis reveals aspects of the underlying decision-making networks that are unobservable using traditional trial-averaging methods. | ||
| 04/25/2013 | Faculty House 4:00 PM |
Towards a neuroscience of self-knowledge
|
| Notes: How do we know that we know? The neural basis of self-knowledge (also known as metacognition) is poorly understood. In particular, it is unknown why some individuals have accurate self-knowledge – their confidence in their abilities tends to be accurate – whereas others have less precise impressions of themselves. In my talk I will describe how the application of methods from psychophysics and decision-making provides new perspectives on metacognition. Dynamic models of decision-making allow us to make detailed predictions of subjective confidence, and compare these predictions against subjects’ behaviour. Drawing on functional magnetic resonance imaging (fMRI) data, I will describe how representations of confidence are integral to the decision process. However, variability in metacognition across individuals also reveals a general constraint in accessing and reporting subjective confidence. Convergent evidence from structural and functional MRI and transcranial magnetic stimulation (TMS) sheds light on the neural basis for this constraint on self-knowledge. |
