Digital Commons Network^™

Prior Experience As A Stimulus Category Confound: An Example Using Facial Expressions Of Emotion, Leah H. Somerville, Paul J. Whalen

Dartmouth Scholarship

Facial expressions of emotion represent a stimulus set widely used to assess a broad range of psychological processes. However, a consideration of systematic differences between expression categories, other than differences relating to characteristics of the expressions themselves, has remained largely unaddressed. By collecting experience rankings in a large sample of undergraduates, we observed that the amount of reported experience individuals have had with different facial expressions of emotion systematically differed between all expression categories. These findings shed light on the potential for identifying confounds inherent to comparing some stimulus categories and, in this case, may aid in the interpretation of …

Interval Timer Control Of Puberty In Photoinhibited Siberian Hamsters, Ho Park Jin, Alexander S. Kauffman, Matthew J. Paul, Matthew P. Butler, Annaliese K. Beery, Ruth M. Costantini, Irving Zucker

Neuroscience: Faculty Publications

Puberty, which is markedly delayed in male Siberian hamsters (Phodopus sungorus) born into short day lengths, is controlled by an interval timer regulated by the duration of nocturnal melatonin secretion. Properties of the interval timer were assessed by perturbing normal patterns of melatonin secretion in males gestated and maintained thereafter in 1 of 2 short day lengths, 10 h light/day (10L) or 12L. Melatonin secretion of short-day hamsters was suppressed by constant light treatment or modified by daily injection of propranolol to mimic nocturnal melatonin durations typical of long-day hamsters. Constant light treatment during weeks 3 to 5 induced early …

In Situ Muscle Power Differs Without Varying In Vitro Mechanical Properties In Two Insect Leg Muscles Innervated By The Same Motor Neuron, Anna N. Ahn, Kenneth Meijer, Robert J. Full

All HMC Faculty Publications and Research

The mechanical behavior of muscle during locomotion is often predicted by its anatomy, kinematics, activation pattern and contractile properties. The neuromuscular design of the cockroach leg provides a model system to examine these assumptions, because a single motor neuron innervates two extensor muscles operating at a single joint. Comparisons of the in situ measurements under in vivo running conditions of muscle 178 to a previously examined muscle (179) demonstrate that the same inputs (e.g. neural signal and kinematics) can result in different mechanical outputs. The same neural signal and kinematics, as determined during running, can result in different mechanical functions, …

The Effects Of Category Overlap On Information-Integration And Rule-Based Category Learning, Shawn W. Ell, Gregory F. Ashby

Psychology Faculty Scholarship

Three experiments investigate whether the amount of category overlap constrains the decision strategies used in category learning, and whether such constraints depend on the type of category structures used. Experiments 1 and 2 used a category learning task requiring perceptual integration of information from multiple dimensions (information-integration task) and Experiment 3 used a task requiring the application of an explicit strategy (rule-based task). In the information-integration task, participants used perceptual-integration strategies at moderate levels of category overlap, but explicit strategies at extreme levels of overlap – even when such strategies were sub-optimal. In contrast, in the rule-based task, participants used …

Using Literature And Innovative Assessments To Ignite Interest And Cultivate Critical Thinking Skills In An Undergraduate Neuroscience Course, Eileen Lynd-Balta

Biology Faculty/Staff Publications

Science education reform initiatives emphasize 1) the value of concepts over facts; 2) the benefits of open-ended, inquiry-based problem-solving rather than protocols leading to a single correct answer; and 3) the importance of a multidisciplinary approach to teaching that is not confined by departmental boundaries. Neuroscientists should be at the forefront of this movement by the very nature of the discipline we study. Neuroscience is a relatively new field that integrates diverse subjects (anatomy, physiology, pharmacology, molecular biology, computer science, and psychology) and experimental advances are constantly changing and expanding our understanding of brain function. How can we convey this …

Dissociation Of Automatic And Strategic Lexical-Semantics: Functional Magnetic Resonance Imaging Evidence For Differing Roles Of Multiple Frontotemporal Regions, Brian T. Gold, David A. Balota, Sara J. Jones, David K. Powell, Charles D. Smith, Anders H. Andersen

Neuroscience Faculty Publications

Behavioral research has demonstrated three major components of the lexical-semantic processing system: automatic activation of semantic representations, strategic retrieval of semantic representations, and inhibition of competitors. However, these component processes are inherently conflated in explicit lexical-semantic decision tasks typically used in functional magnetic resonance imaging (fMRI) research. Here, we combine the logic of behavioral priming studies and the neurophysiological phenomenon of fMRI priming to dissociate the neural bases of automatic and strategic lexical-semantic processes across a series of three studies. A single lexical decision task was used in all studies, with stimulus onset asynchrony or linguistic relationship between prime and …

Medial Prefrontal Activity Differentiates Self From Close Others, Todd F. Heatherton, Carrie L. Wyland, C. Neil Macrae, Kathryn E. Demos, Bryan T. Denny, William M. Kelley

Dartmouth Scholarship

No abstract provided.

Focal Putamen Lesions Impair Learning In Rule-Based, But Not Information-Integration Categorization Tasks, Shawn W. Ell, Natalie L. Marchant, Richard B. Ivry

Psychology Faculty Scholarship

Previous research on the role of the basal ganglia in category learning has focused on patients with Parkinson’s and Huntington’s Disease, neurodegenerative diseases frequently accompanied by additional cortical pathology. The goal of the present study was to extend this work to patients with basal ganglia lesions due to stroke, asking if similar changes in performance would be observed in patients with more focal pathology. Patients with basal ganglia lesions centered in the putamen (6 left side, 1 right side) were tested on rule-based and information-integration visual categorization tasks. In rule-based tasks, it is assumed that participants can learn the category …

Prenatal Cocaine Exposure Alters Alpha2 Receptor Expression In Adolescent Rats, Rosemarie M. Booze, David R. Wallace, Janelle M. Silvers, Barbara J. Strupp, Diane M. Snow, Charles F. Mactutus

Neuroscience Faculty Publications

BACKGROUND: Prenatal cocaine exposure produces attentional deficits which to persist through early childhood. Given the role of norepinephrine (NE) in attentional processes, we examined the forebrain NE systems from prenatal cocaine exposed rats. Cocaine was administered during pregnancy via the clinically relevant intravenous route of administration. Specifically, we measured alpha2-adrenergic receptor (alpha2-AR) density in adolescent (35-days-old) rats, using [3H]RX821002 (5 nM).

RESULTS: Sex-specific alterations of alpha2-AR were found in the hippocampus and amygdala of the cocaine-exposed animals, as well as an upregulation of alpha2-AR in parietal cortex.

CONCLUSION: These data suggest that prenatal cocaine exposure results in a persistent alteration …

Cyclooxygenase-2 Mediates Microglial Activation And Secondary Dopaminergic Cell Death In The Mouse Mptp Model Of Parkinson's Disease, Rattanavijit Vijitruth, Mei Liu, Dong-Young Choi, Xuan V. Nguyen, Randy L. Hunter, Guoying Bing

Neuroscience Faculty Publications

BACKGROUND: Accumulating evidence suggests that inflammation plays an important role in the progression of Parkinson's disease (PD). Among many inflammatory factors found in the PD brain, cyclooxygenase (COX), specifically the inducible isoform, COX-2, is believed to be a critical enzyme in the inflammatory response. Induction of COX-2 is also found in an experimental model of PD produced by administration of 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

METHOD: COX-2-deficient mice or C57BL/6 mice were treated with MPTP to investigate the effects of COX-2 deficiency or by using various doses of valdecoxib, a specific COX-2 inhibitor, which induces inhibition of COX-2 on dopaminergic neuronal toxicity and …

Fms-Like Tyrosine Kinase 3 Ligand Recruits Plasmacytoid Dendritic Cells To The Brain, James Curtin, Gwendalyn King, Carlos Barcia, Chunyan Liu, Francois Hubert, Carole Guillonneau, Regis Josien, Ignacio Anegon, Pedro Lowenstein, Maria Castro

Articles

The lack of professional afferent APCs in naive brain parenchyma contributes to the systemic immune ignorance to Ags localized exclusively within the brain. Dendritic cells (DCs) appear within the brain as a consequence of inflammation, but no molecular mechanisms accounting for this influx have been described. In this study we demonstrate that Fms-like tyrosine kinase 3 ligand (Flt3L) recruits plasmacytoid DCs (pDCs; >50-fold; p < 0.001) to the brain parenchyma. These pDCs expressed IFN-alpha, the hallmark cytokine produced by pDCs, indicating recruitment and activation in situ of bona fide pDCs within the brain parenchyma. Flt3L did not increase the numbers of conventional DCs, macrophages, or B, T, NK, NKT, or microglial cells within the brain. Our data demonstrate that Flt3L reconstitutes a crucial afferent component of the immune response, namely, professional APCs within the brain parenchyma, and this could counteract the intrinsic systemic immune ignorance to Ags localized exclusively within the brain.

Effects Of Lesions Of The Bed Nucleus Of The Stria Terminalis, Laterual Hypothalamus, Or Insular Cortex On Conditioned Taste Aversion And Conditioned Odor Aversion, Christopher T. Roman, Nino Nebieridze, Aristides Sastre, Steve Reilly

Scholarship and Professional Work – COPHS

The effects of permanent forebrain lesions on conditioned taste aversions (CTAs) and conditioned odor aversions (COAs) were examined in 3 experiments. In Experiment 1, lesions of the bed nucleus of the stria terminalis had no influence on CTA or COA acquisition. Although lesions of the lateral hypothalamus induced severe hypodipsia in Experiment 2, they did not prevent the acquisition of CTAs or COAs. Finally, in Experiment 3, lesions of the insular cortex retarded CTA acquisition but had no influence on COA acquisition. The implications of these findings are discussed with regard to the forebrain influence on parabrachial nucleus function during …

Neuronal Pentraxins Mediate Synaptic Refinement In The Developing Visual System, Lisa Bjartmar, Andrew Huberman, Erik Ullian, Rene Renterıa, Xiaoqin Liu, Weifeng Xu, Jennifer Prezioso, Michael Susman, David Stellwagen, Caleb Stokes, Richard Cho, Paul Worley, Robert Malenka, Sherry Ball, Neal Peachey, David Copenhagen, Barbara Chapman, Masaru Nakamoto, Ben Barres, Mark Perin

Biology Faculty Publications

Neuronal pentraxins (NPs) define a family of proteins that are homologous to C-reactive and acute-phase proteins in the immune system and have been hypothesized to be involved in activity-dependent synaptic plasticity. To investigate the role of NPs in vivo , we generated mice that lack one, two, or all three NPs. NP1/2 knock-out mice exhibited defects in the segregation of eye-specific retinal ganglion cell (RGC) projections to the dorsal lateral geniculate nucleus, a process that involves activity-dependent synapse formation and elimination. Retinas from mice lacking NP1 and NP2 had cholinergically driven waves of activity that occurred at a frequency similar …

Axon Guidance Autonomy And Tensional Requirement For Synaptic Function: Is Learning A Forced Response?, Scott Siechen

Natural Science Faculty

Individual neurons extend multiple processes whose growth cones exhibit different responses to their environment. In culture, detached growth cones display guidance autonomy, contain mRNA for cytoskeletal and other axonal components, and are capable of synthesizing protein locally. However, the extent to which growth cone's autonomy contributes to its pathfinding function within the complex in vivo environment is unknown. Here, we show that detached axonal growth cones from identified Drosophila motoneurons maintain balanced filopodial activities as they extend, navigate and target postsynaptic partner cells normally. After detachment, the growth cones continue to synthesize the synaptic vesicle protein Synaptotagmin but, upon contacting …

Broad, Deep And Indirect: The Potential Influence Of Neuroscience In Law, Amanda C. Pustilnik

Faculty Scholarship

No abstract provided.

Sex Differences In The Anatomical And Functional Organization Of The Periaqueductal Gray-Rostral Ventromedial Medullary Pathway In The Rat: A Potential Circuit Mediating The Sexually Dimorphic Actions Of Morphine, Dayna R. Loyd, Anne Z. Murphy Phd

Neuroscience Institute Faculty Publications

Previous studies have demonstrated that morphine, administered systemically or directly into the PAG, produces a significantly greater degree of antinociception in males in comparison to females. As the midbrain periaqueductal gray (PAG) and its descending projections to the rostral ventromedial medulla (RVM) constitute an essential neural circuit for opioid-based analgesia, the present studies were conducted to determine if sex differences in the anatomical organization of the PAG-RVM pathway, and its activation during persistent inflammatory pain, could account for sex-based differences in opioid analgesia. In the rat, retrograde tracing was combined with Fos immunocytochemistry to investigate sexual dimorphism in the organization …

Center For Behavioral Neuroscience: A Prototype Multi-Institutional Collaborative Research Center, Kelly R. Powell, H. Elliott Albers

Neuroscience Institute Faculty Publications

The Center for Behavioral Neuroscience was launched in the fall of 1999 with support from the National Science Foundation, the Georgia Research Alliance, and our eight participating institutions (Georgia State University, Emory University, Georgia Institute of Technology, Morehouse School of Medicine, Clark-Atlanta University, Spelman College, Morehouse College, Morris Brown College). The CBN provides the resources to foster innovative research in behavioral neuroscience, with a specific focus on the neurobiology of social behavior. Center faculty working in collaboratories use diverse model systems from invertebrates to humans to investigate fear, aggression, affiliation, and reproductive behaviors. The addition of new research foci in …

Effects Of Gesture+Verbal Treatment For Noun And Verb Retrieval In Aphasia, Anastasia M. Raymer, Floris Singletary, Amy Rodriguez, Maribel Ciampitti, Kenneth M. Heilman, Leslie J. Gonzalez Rothi

Communication Disorders & Special Education Faculty Publications

Links between verbs and gesture knowledge suggest that verb retrieval may be particularly amenable to gesture+verbal training (GVT) in aphasia compared to noun retrieval. This study examines effects of GVT for noun and verb retrieval in nine individuals with aphasia subsequent to left hemisphere stroke. Participants presented an array of noun and verb retrieval deficits, including impairments of semantic and/or phonologic processing. In a single-participant experimental design, we investigated effects of GVT for noun and verb retrieval in two counterbalanced treatment phases. Effects were evaluated in spoken naming and gesture production to pictured objects and actions. Spoken naming improvements associated …

An Optimal Brain Can Be Composed Of Conflicting Agents, Adi Livnat, Nicholas Pippenger

All HMC Faculty Publications and Research

Many behaviors have been attributed to internal conflict within the animal and human mind. However, internal conflict has not been reconciled with evolutionary principles, in that it appears maladaptive relative to a seamless decision-making process. We study this problem through a mathematical analysis of decision-making structures. We find that, under natural physiological limitations, an optimal decision-making system can involve “selfish” agents that are in conflict with one another, even though the system is designed for a single purpose. It follows that conflict can emerge within a collective even when natural selection acts on the level of the collective only.

Word Association Tests Of Associative Memory And Implicit Processes: Theoretical And Assessment Issues, Alan W. Stacy, Susan L. Ames, Jerry L. Grenard

CGU Faculty Publications and Research

Word association is one of the most commonly used measures of association in cognitive science. These tests have been used to infer association parameters in normative studies, to derive cues and primes used in diverse paradigms (semantic priming, cued recall, illusory memory), to test implicit memory in experimental studies, and to suggest the operation of implicit processes in nonexperimental work. This chapter briefly outlines some of the historical routes and current controversies about association and summarizes basic cognitive research applying associative tests. The authors then describe benefits and limitations of the tests, as well as implications for theory and interventions …

Glucocorticoid Hormone Levels Increase With Group Size And Parasite Load In Cliff Swallows, Samrrah A. Raouf, Linda C. Smith, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown

School of Biological Sciences: Faculty Publications

Animals often cope with adverse events by releasing glucocorticoid hormones, which in turn promote increased energy assimilation. In captive animals, crowding also leads to increased glucocorticoid activity, probably because of increased levels of social competition. We investigated how group size and ectoparasite infestations affected endogenous levels of the glucocorticoid hormone, corticosterone, in colonial cliff swallows, Petrochelidon pyrrhonota, in southwestern Nebraska, USA. Parasites were removed from some colonies by fumigating nests. Baseline levels of corticosterone in breeding adults varied significantly with whether parasites were present, colony size (measured by total number of active nests at a site), and nesting stage. …

Social Software, Groups, And Governance, Michael J. Madison

Articles

Formal groups play an important role in the law. Informal groups largely lie outside it. Should the law be more attentive to informal groups? The paper argues that this and related questions are appearing more frequently as a number of computer technologies, which I collect under the heading social software, increase the salience of groups. In turn, that salience raises important questions about both the significance and the benefits of informal groups. The paper suggests that there may be important social benefits associated with informal groups, and that the law should move towards a framework for encouraging and recognizing them. …

Behavioural Genetics In Criminal Cases: Past, Present And Future, Nita A. Farahany, William Bernet

Faculty Scholarship

Researchers studying human behavioral genetics have made significant scientific progress in enhancing our understanding of the relative contributions of genetics and the environment in observed variations in human behavior. Quickly outpacing the advances in the science are its applications in the criminal justice system. Already, human behavioral genetics research has been introduced in the U.S. criminal justice system, and its use will only become more prevalent. This essay discusses the recent historical use of behavioral genetics in criminal cases, recent advances in two gene variants of particular interest in the criminal law, MAOA and SLC6A4, the recent expert testimony on …

The Effect Of Handling Time On Temporal Discounting In Two New World Primates, Alexandra G. Rosati, Jeffrey R. Stevens, Marc D. Hauser

Center for Brain, Biology, and Behavior: Faculty and Staff Publications

Foraging decisions in nonhuman animals often require choosing between small, immediate food rewards and larger, more delayed rewards. Faced with such choices, animals typically discount or devalue the future quite strongly. Although discounting studies often focus on delays to reward access, other temporal intervals contribute to foraging rate, and thus may potentially influence discounting levels. Here, we examine the effect of handling time, the time required to process and consume food, on discounting in cottontop tamarins, Saguinus oedipus, and common marmosets, Callithrix jacchus, two species that differ in levels of temporal discounting. We presented subjects with a discounting task under …

Associative Memory In Three Aplysiids: Correlation With Heterosynaptic Modulation, Brian A. Hoover, Hoang Nguyen, Laura Thompson, William G. Wright

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Much recent research on mechanisms of learning and memory focuses on the role of heterosynaptic neuromodulatory signaling. Such neuromodulation appears to stabilize Hebbian synaptic changes underlying associative learning, thereby extending memory. Previous comparisons of three related sea-hares ( Mollusca, Opisthobranchia) uncovered interspecific variation in neuromodulatory signaling: strong in Aplysia californica, immeasureable in Dolabrifera dolabrifera, and intermediate in Phyllaplysia taylori. The present study addressed whether this interspecific variation in neuromodulation is correlated with memory of associative ( classical conditioning) learning. We differentially conditioned the tail-mantle withdrawal reflex of each of the three species: Mild touch to one side of the tail …