Digital Commons Network^™

Visual Modulation Of Resting State Α Oscillations, Kelly Webster, Tony Ro

Publications and Research

Once thought to simply reflect passive cortical idling, recent studies have demonstrated that α oscillations play a causal role in cognition and perception. However, whether and how cognitive or sensory processes modulate various components of the α rhythm is poorly understood. Sensory input and resting states were manipulated in human subjects while electroencephalography (EEG) activity was recorded in three conditions: eyes-open fixating on a visual stimulus, eyes-open without visual input (darkness), and eyes-closed without visual input (darkness). We show that α power and peak frequency increase when visual input is reduced compared to the eyes open, fixating condition. These results …

From The Human To The Planetary: Speculative Futures Of Care, Miriam Ticktin

Publications and Research

This is largely a theoretical, speculative essay that takes on the question of what ‘care’ looks like at a moment when climate change is increasingly taking center stage in public and political discussions. Starting with two new practices, namely, humanitarian care for nonhumans and One Health collaborations, I seek to determine what forms of political care can incorporate the well-being of future generations and future iterations of the earth. After an exploration of One Health as an approach to planetary care, I ask what its parts enable us to think, despite its limitations; I focus on the new human-nonhuman assemblages …

Neural Correlates Of Decision Making Related To Information Security: Self-Control And Moral Potency, Robert West, Emily Budde, Qing Hu

Publications and Research

Security breaches of digital information represent a significant threat to the wellbeing of individuals, corporations, and governments in the digital era. Roughly 50% of breaches of information security result from the actions of individuals inside organizations (i.e., insider threat), and some evidence indicates that common deterrence programs may not lessen the insiders’ intention to violate information security. This had led researchers to investigate contextual and individual difference variables that influence the intention to violate information security policies. The current research builds upon previous studies and explores the relationship between individual differences in self-control and moral potency and the neural correlates …

Development And Sensory Experience Dependent Regulation Of Microglia In Barrel Cortex, Joshua C. Brumberg, John Kalambogias, Chia-Chien Chen, Safraz Khan, Titus Son, Carolyn Headlam, Cindy Lin

Publications and Research

The barrel cortex is within the primary somatosensory cortex of the rodent, and processes signals from the vibrissae. Much focus has been devoted to the function of neurons, more recently, the role of glial cells in the processing of sensory input has gained increasing interest. Microglia are the principal immune cells of the nervous system that survey and regulate the cellular constituents of the dynamic nervous system. We investigated the normal and disrupted development of microglia in barrel cortex by chronically depriving sensory signals via whisker trimming for the animals’ first postnatal month. Using immunohistochemistry to label microglia, we performed …

Alpha Oscillations And Feedback Processing In Visual Cortex For Conscious Perception, Tony Ro

Publications and Research

Variability in perception between individuals may be a consequence of different inherent neural processing speeds. To assess whether alpha oscillations systematically reflect a feedback pacing mechanism for cortical processing during visual perception, comparisons were made between alpha oscillations, visual suppression from TMS, visual evoked responses, and metacontrast masking. Peak alpha oscillation frequencies, measured through scalp EEG recordings, significantly correlated with the optimum latencies for visual suppression from TMS of early visual cortex. Individuals with shorter alpha periods (i.e., higher peak alpha frequencies) processed visual information faster than those with longer alpha periods (i.e., lower peak alpha frequencies). Moreover, peak alpha …

Epigenetic Modifications In Alzheimer’S Neuropathology And Therapeutics, Michelle Esposito, Goldie Libby Sherr

Publications and Research

Transcriptional activation is a highly synchronized process in eukaryotes that requires a series of cis- and trans-acting elements at promoter regions. Epigenetic modifications, such as chromatin remodeling, histone acetylation/deacetylation, and methylation, have frequently been studied with regard to transcriptional regulation/dysregulation. Recently however, it has been determined that implications in epigenetic modification seem to expand into various neurodegenerative disease mechanisms. Impaired learning and memory deterioration are cognitive dysfunctions often associated with a plethora of neurodegenerative diseases, including Alzheimer’s disease. Through better understanding of the epigenetic mechanisms underlying these dysfunctions, new epigenomic therapeutic targets, such as histone deacetylases, are being explored. Here …

Modeling Changes In Cellular Micro-Environment In Mild To Moderate Head Trauma, Xiangfu Zhang, Subhendra N. Sarkar Phd, Rt

Publications and Research

Our work aims to connect and model multiple small, inter-related tissue injuries as a consequence of mild traumatic brain injuries (mTBI). It has been shown that frontal and temporal lobes are vulnerable regions for brain traumatic injury. A brain injury from a blow or high-speed impact can cause undersurface of the frontal and temporal lobes to deform against the anterior and cranial fossae. This deformation can often trigger damage to the cerebral vasculature, which is ill-understood and can result in chronic damage to larger vessels over time. These physiological injuries can be manifested psychologically; such as patients’ sleep-wake disturbances. The …

Neural Indices Of Vowel Discrimination In Monolingual And Bilingual Infants And Children, Yan H. Yu, Carol Tessel, Henry Han, Luca Campanelli, Nancy Vidal, Jennifer Gerometta, Karen Garrido-Nag, Hia Datta, Valerie L. Shafer

Publications and Research

Objectives: To examine maturation of neural discriminative responses to an English vowel contrast from infancy to 4 years of age and to determine how biological factors (age and sex) and an experiential factor (amount of Spanish versus English input) modulate neural discrimination of speech.

Design: Event-related potential (ERP) mismatch responses (MMRs) were used as indices of discrimination of the American English vowels [ε] versus [I] in infants and children between 3 months and 47 months of age. A total of 168 longitudinal and cross-sectional data sets were collected from 98 children (Bilingual Spanish–English: 47 male and 31 female …

Synchronicity: The Role Of Midbrain Dopamine In Whole-Brain Coordination, Jeff A. Beeler, Jakob Kiskye Dreyer

Publications and Research

Midbrain dopamine seems to play an outsized role in motivated behavior and learning. Widely associated with mediating reward-related behavior, decision making, and learning, dopamine continues to generate controversies in the field. While many studies and theories focus on what dopamine cells encode, the question of how the midbrain derives the information it encodes is poorly understood and comparatively less addressed. Recent anatomical studies suggest greater diversity and complexity of afferent inputs than previously appreciated, requiring rethinking of prior models. Here, we elaborate a hypothesis that construes midbrain dopamine as implementing a Bayesian selector in which individual dopamine cells sample afferent …

Neuromeasure: A Software Package For Quantification Of Cortical Motor Maps Using Frameless Stereotaxic Transcranial Magnetic Stimulation, Michael B. Gerber, Alasdair C. Mclean, Samuel J. Stephen, Alex G. Chalco, Usman M. Arshad, Gary W. Thickbroom, Josh Silverstein, K. Zoe Tsagaris, Amy Kuceyeski, Kathleen Friel, Taiza E. G. Santos, Dylan J. Edwards

Publications and Research

The recent enhanced sophistication of non-invasive mapping of the human motor cortex using MRI-guided Transcranial Magnetic Stimulation (TMS) techniques, has not been matched by refinement of methods for generating maps from motor evoked potential (MEP) data, or in quantifying map features. This is despite continued interest in understanding cortical reorganization for natural adaptive processes such as skill learning, or in the case of motor recovery, such as after lesion affecting the corticospinal system. With the observation that TMS-MEP map calculation and quantification methods vary, and that no readily available commercial or free software exists, we sought to establish and make …

The Serial Blocking Effect: A Testbed For The Neural Mechanisms Of Temporal-Difference Learning, Ashraf Mahmud, Petio Petrov, Guillem R. Esber, Mihaela D. Iordanova

Publications and Research

Temporal-difference (TD) learning models afford the neuroscientist a theory-driven roadmap in the quest for the neural mechanisms of reinforcement learning. The application of these models to understanding the role of phasic midbrain dopaminergic responses in reward prediction learning constitutes one of the greatest success stories in behavioural and cognitive neuroscience. Critically, the classic learning paradigms associated with TD are poorly suited to cast light on its neural implementation, thus hampering progress. Here, we present a serial blocking paradigm in rodents that overcomes these limitations and allows for the simultaneous investigation of two cardinal TD tenets; namely, that learning depends on …

Influence Of Stimulus Intensity On Multimodal Integration In The Startle Escape System Of Goldfish, Camille Mcintyre, Thomas Preuss

Publications and Research

Processing of multimodal information is essential for an organism to respond to environmental events. However, how multimodal integration in neurons translates into behavior is far from clear. Here, we investigate integration of biologically relevant visual and auditory information in the goldfish startle escape system in which paired Mauthner-cells (M-cells) initiate the behavior. Sound pips and visual looms as well as multimodal combinations of these stimuli were tested for their effectiveness of evoking the startle response. Results showed that adding a low intensity sound early during a visual loom (low visual effectiveness) produced a supralinear increase in startle responsiveness as compared …

Commentary: Sugar Metabolism Regulates Flavor Preferences And Portal Glucose Sensing, Anthony Sclafani, Karen Acroff

Publications and Research

No abstract provided.

Cortical And Subcortical Contributions To Neuroplasticity After Repetitive Transspinal Stimulation In Humans, Lynda M. Murray, Anamul Islam Md., Maria Knikou

Publications and Research

The objectives of this study were to establish cortical and subcortical contributions to neuroplasticity induced by noninvasive repetitive transspinal stimulation in human subjects free of any neurological disorder. To meet our objectives, before and after 40 minutes of transspinal stimulation we established changes in tibialis anterior (TA) motor-evoked potentials (MEPs) in response to paired transcranial magnetic stimulation (TMS) pulses at interstimulus intervals (ISIs) consistent with I-wave periodicity. In order to establish to what extent similar actions are exerted at the spinal cord and motor axons, changes in soleus H-reflex and transspinal evoked potential (TEP) amplitude following transspinal and group Ia …

Changes In Functional Connectivity Following Treatment With Emotion Regulation Therapy, Matthew A. Scult, David M. Fresco, Faith M. Gunning, Conor Liston, Saren H. Seeley, Emmanuel Garcia, Douglas S. Mennin

Publications and Research

Emotion regulation therapy (ERT) is an efficacious treatment for distress disorders (i.e., depression and anxiety), predicated on a conceptual model wherein difficult to treat distress arises from intense emotionality (e.g., neuroticism, dispositional negativity) and is prolonged by negative self-referentiality (e.g., worry, rumination). Individuals with distress disorders exhibit disruptions in two corresponding brain networks including the salience network (SN)reflecting emotion/motivation and the default mode network (DMN) reflecting self-referentiality. Using resting-state functional connectivity (rsFC) analyses, seeded with primary regions in each of these networks, we investigated whether ERT was associated with theoretically consistent changes across nodes of these networks and whether these …