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http://www.umn.edu/urelate
612-624-6868
Fall 2011 Colloquia
Thursdays 4:00-5:30pm N119 Elliott Hall
Sept. 15
Angus MacDonald, III, Psychology
How intrinsic connectivity can contribute to the sadly neglected neurometrics of functional imaging
Functional neuroimaging, particularly fMRI, has frequently used small-sample sizes and tasks with unknown psychometric properties. This proclivity has reduced the reliability of these findings, detracting from their capacity to provide a strong foundation for studying individual differences and psychopathology. A corrective approach may derive from the finding that intrinsic connectivity networks within the brain at rest, identified using independent components analysis (ICA), reflect activation patterns from evoked fMRI paradigms. For example, a connectivity network including right dorso- and ventrolateral prefrontal, anterior cingulate and parietal cortices corresponded closely to a meta-analysis of regions evoked by inhibition tasks (Smith, et. al., 2009). I will describe work extending these discoveries into the domain of individual differences, including development and personality. This work has examined the retest reliability, covariance structure, and convergent and divergent validity of ICA-derived intrinsic connectivity networks. I will then conclude with a roadmap of the analyses needed to establish the connectivity network approach as a cumulative science for understanding the neural basis of individual differences and psychopathology, highlighting the cautionary principles necessary to avoid neurometric false positives.
Suggested readings:
- Angela R. Laird, et al. (in press) Behavioral Interpretations of Intrinsic Connectivity Networks, Journal of Cognitive Neuroscience 1:16
- Stephen M. Smith, et al. (2009) Correspondence of the brain's functional architecture during activation and rest.PNAS 13040:13045 106 31
Sept. 22
Michael K. Lee, Department of Neuroscience
Monoaminergic neurodegeneration in mouse models of Alzheimer's disease
Alzheimer disease (AD), the most common age-caused degeneration disease, is characterized by cerebral Aβ deposition, tau pathology, and neurodegeneration. While Aβ related abnormalities are thought to be early and essential factor in AD, lack of neurodegeneration with Aβ pathology alone in animal models have questioned the overall amyloid hypothesis of AD. However, our analysis of monoaminergic neurotransmitter system in APPswe/PS1ΔE9 mouse model of AD deposition shows progressive loss of monoaminergic axons with cortical Aβ deposition. Initial loss of axons are followed by profound (~50%) loss of monoaminergic neurons that project to cortex in midbrain (DA neurons in VTA) and brain stem (5-HT neurons in raphe, NA neurons in locus coeruleus/LC).
Degeneration of these neurons occur without signs of tau pathology or accumulation of intracellular Aβ. Thus, exposure of axons to Aβ deposition can cause progressive neurodegeneration via the "dying back" process in vivo. Consistent with involvement of these neurotransmitter systems in emotional behaviors, advanced stages of monoaminergic neurodegeneration is associated with presence of aggressive behavior, a significant non-cognitive clinical complications associated with AD. Our results show that extracellular Aβ pathology/abnormalities is sufficient to cause progressive neurodegeneration, including profound loss of neuronal cell bodies. In addition to understanding the mechanisms of neurodegeneration, our model will allow us to understand the biological basis of non-cognitive dysfunction in AD.
Suggested reading:
- John R. Cirrito, et al. (2011) Serotonin signaling is associated with lower amyloid-β levels and plaques in transgenic mice and humans, PNAS
- Ying Liu, et al. (2008) Amyloid Pathology Is Associated with Progressive Monoaminergic Neurodegeneration in a Transgenic Mouse Model of Alzheimer's Disease, J Neuroscience, 28 (51):13805-13814
Sept. 29
Bob Meisel, Neuroscience
Random Musings on a Career in Sex Research
Sexual behavior in animals historically has been thought of as a stereotypical behavior along the lines of a reflex or fixed action pattern. This view has obscured the role of experience (broadly defined) in regulating and modifying patterns of sexual behavior. This talk will focus on an array of experiential factors affecting sexual behavior in rodents with a focus on neural mechanisms of plasticity resulting from repeated sexual activity.
- Robert L. Meisel, Amanda J. Mullins (2006) Sexual experience in female rodents: Cellular mechanisms and functional consequences, Brain Research 1126 56:65
Oct 6
Stephen Engel, Psychology
Novel Mechanisms of Long Term Visual Adaptation
In order to optimize perception, neurons in the visual system adapt to the current environment. Laboratory studies of adaptation have been limited to short durations, however. In this talk, I will cover recent work using novel altered reality technology to study effects of adaptation induced over up to 8 hours. Subjects lived in a visual world where contrast at a narrow range of orientations was removed. Deprivation increased perceptual sensitivity to the missing orientation, and effects grew stronger as adaptation durations grew longer. This increase could be due to either 1) a single mechanism controlling adaptation that gained strength over time, or 2) long-term mechanisms that became active following longer-term exposure. To distinguished between these possibilities, we used a short-term "deadaptation" procedure, which eliminated aftereffects of long-term adaptation. Continued testing, however, revealed their striking spontaneous recovery. This pattern strongly suggests that adaptation was maintained in a novel long-term mechanism, while deadaptation affected short-term mechanisms . To control adaptation, the visual system learns about the current environment, and general principles of learning may be useful for understanding and manipulating this process.
- Konrad P Kording, Joshua B Tenenbaum & Reza Shadmehr (2007) The dynamics of memory as a consequence of optimal adaptation to a changing body, Nature Neuroscience 10, 6
- Peng Zhang, Min Bao, Miyoung Kwon, Sheng He, and Stephen A. Engel (2009) Effects of Orientation-Specific Visual Deprivation Induced with Altered Reality, Current Biology 19, 1956–1960
Oct. 13
Adam JohnsonAssistant Professor, Psychology Department, Bethel University
Exploring space and memory in the hippocampus
We argue that exploratory behavior and its neural substrates can be understood as information foraging. The decision processes associated with information foraging suggest two different patterns of foraging behavior. Undirected or random information foraging leads to greater time spent exploring or sampling from unexpected or novel stimuli in the environment. Directed information foraging leads to specific sampling behavior that emphasizes highly informative aspects of a task or environment. We argue that undirected information foraging is dependent on high level sensory association areas such as the perirhinal cortex for object recognition tasks while directed information foraging is dependent on the hippocampus. We provide a theoretical account of recollection-based novelty preference on the E-maze version of the what/where/which task (Eacott et al., 2005; Easton et al., 2009) and an account of VTE behavior and its development with experience (Tolman, 1939, 1948). We further explain how a covert form of directed information foraging could be used to explain VTE-like dynamics (Johnson and Redish, 2007; Gupta et al., 2011) and map-switching dynamics (Jackson and Redish, 2007; Fenton et al., 2010; Kelemen and Fenton, 2010) observed in hippocampal place cell activity. Finally, we show how directed information foraging and its associated hippocampal dynamics could be used to understand temporally variable memory consolidation and the time-limited dependence of the hippocampus (Maviel et al., 2004; Tse et al., 2007).
- Easton A, Zinkivskay A, Eacott MJ (2009) Recollection is impaired, but familiarity remains intact in rats with lesions of the fornix. Hippocampus 19(9):837–843
- Tse D, Langston RF, Kakeyama M, Bethus I, Spooner PA, Wood ER, Witter MP, Morris RGM (2007) Schemas and memory consolidation. Science 316(5821):76–82.
Oct. 20
CCS Fall Institute: "Music, Language, Brain"
Maroon & Gold Room, McNamara Alumni Center
9:00-4:30 PM .
View program and registration.
Oct 27
Hooi Ling Soh, Institute of Linguistics, CLA
The syntax and semantics of change
A central goal of research in Linguistics is to understand the nature of our linguistic knowledge and how we acquire such knowledge. Part of the answer involves determining which part of our linguistic knowledge is innate and which is acquired through exposure to the language in our environment. Research addressing this question has focused on determining what is universally true about human languages, on the assumption that linguistic universals are potential candidates for innate linguistic knowledge. My recent work attempts to clarify our linguistic capabilities relating to the expressions of change by focusing on the following three questions: (i) How is the concept of change represented linguistically; (ii) What are the different types of change that may be distinguished; (iii) Is there any general principle regarding how change is expressed across languages? In this talk, I present results from my work on Mandarin Chinese that suggest that there are (at least) two types of change that languages distinguish, and that there may be a general principle relating the position of the change marker in a sentence with the type of change expressed.
- Soh, Hooi Ling (2009). Speaker presupposition and Mandarin Chinese sentence final –le: A unified analysis of the "change of state" and the "contrary to expectation" reading. Natural Language and Linguistic Theory 27(3): 623-657.
Nov 10
Mark Collier, Philosophy (UMN Morris)
Hume's Ethics: A Cognitive Science Perspective
Hume's moral psychology receives a surprising amount of support from recent work in cognitive science. The first half of this talk examines his account of justice conventions. Hume maintains that considerations of strategic rationality are not sufficient to explain how trust is established between impulsive and shortsighted agents; we only manage to participate in social exchange, on his account, because (most of us) have developed an emotional aversion to cheating. This sentimentalist proposal might sound like wishful thinking, but it is consistent with recent work in experimental game theory and neuroeconomics. The second half investigates Hume's theory of moral imagination. Hume embraces a hybrid account of sympathy: our concern for the pain and suffering of those around us depends on associative mechanisms, whereas our capacity to adopt the moral point of view depends on cognitive principles of the imagination. This distinction is bolstered by recent work on affective mirroring and cognitive pretense. It should appeal to contemporary researchers, then, who are interested in the psychological foundations of morality.
- Justice. Hume's Treatise of Human Nature, Book Three, Part Two, Section Two ("Of the origin of justice and property"). [11 pages] Mark Collier: "Hume's Natural History of Justice", in C. Taylor and S. Buckle (Eds.) Hume and the Enlightenment, 2011, 131-142.
- Morality. Hume's Treatise of Human Nature, Book Three, Part Three, Section One ("Of the origin of the natural virtues and vices"). [11 pages] Mark Collier: "Hume's Theory of Moral Imagination", History of Philosophy Quarterly, 27, 2010, 255-273.
Matt ChafeeDec 8
Sashank Varma, Educational Psychology
Memory for Text: Exemplar and Prototype Representations Drive Script-Based Comprehension
Prior knowledge is critical for discourse comprehension. For example, when reading a story that takes place in a restaurant, knowledge of (1) the people (e.g., waitresses) and props (e.g., menus) that are typically involved and (2) the canonical sequence of actions enables causal inferences about why the current action happened and predictive inferences about what action happen next. Such knowledge is classically thought to be encapsulated in large structures called "schemas" or "scripts". Surprisingly, our theoretical understanding of how scripts are represented and how they are applied during comprehension is grounded in models of memory that date to the 1970s, and that are quite different from contemporary models. The current research addresses this gap. Three experiments apply paradigms from the memory literature – in particular, the study of concepts and categories – to investigate script-based comprehension. The results are important for discourse comprehension. They are also important for memory research. Texts are richer stimuli than those of typical memory experiments, and raise novel questions such as how people make incremental categorizations when the features of a stimulus are revealed over time.