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Full-Text Articles in Neuroscience and Neurobiology

Agent Based Model Of Cavitation In Spinal Cord Injury, Rahma Ahmed Jan 2019

Agent Based Model Of Cavitation In Spinal Cord Injury, Rahma Ahmed

Senior Projects Spring 2019

Annually, approximately 375,000 people suffer from spinal cord injury (SCI) worldwide and many SCI patients develop secondary health conditions such as respiratory, cardiovascular, and urinary/bowel complications which negatively impact their daily lives. SCI occurs when there is damage to the spinal cord resulting in decreased motor functions, decreased sensory functions, or paralysis. Days to weeks after initial impact, the lesion (area of injury) continues to increase in size in a process called progressive cavitation which demyelinates axons and inhibits effective axonal regeneration. In an in vitro model of progressive cavitation, Fitch et al. showed that activated macrophages cause cavities to …


Parametrically Constrained Lightness Model Incorporating Edge Classification And Increment-Decrement Neural Response Asymmetries, Michael E. Rudd May 2016

Parametrically Constrained Lightness Model Incorporating Edge Classification And Increment-Decrement Neural Response Asymmetries, Michael E. Rudd

MODVIS Workshop

Lightness matching data from disk-annulus experiments has the form of a parabolic (2nd-order polynomial) function when matches are plotted against annulus luminance on log-log axes. Rudd (2010) has proposed a computational cortical model to account for this fact and has subsequently (Rudd, 2013, 2014, 2015) extended the model to explain data from other lightness paradigms, including staircase-Gelb and luminance gradient illusions (Galmonte, Soranzo, Rudd, & Agostini, 2015). Here, I re-analyze parametric lightness matching data from disk-annulus experiments by Rudd and Zemach (2007) and Rudd (2010) for the purpose of further testing the model and to try to constrain …


How Deep Is The Feature Analysis Underlying Rapid Visual Categorization?, Sven Eberhardt, Jonah Cader, Thomas Serre May 2016

How Deep Is The Feature Analysis Underlying Rapid Visual Categorization?, Sven Eberhardt, Jonah Cader, Thomas Serre

MODVIS Workshop

Rapid categorization paradigms have a long history in experimental psychology: Characterized by short presentation times and fast behavioral responses, these tasks highlight both the speed and ease with which our visual system processes natural object categories. Previous studies have shown that feed-forward hierarchical models of the visual cortex provide a good fit to human visual decisions. At the same time, recent work has demonstrated significant gains in object recognition accuracy with increasingly deep hierarchical architectures: From AlexNet to VGG to Microsoft CNTK – the field of computer vision has championed both depth and accuracy. But it is unclear how well …


Predicting Phase Resetting Due To Multiple Stimuli, Kelsey M. Vollmer, Davy C. Vanderweyen, Derek R. Tuck, Sorinel A. Oprisan Oct 2015

Predicting Phase Resetting Due To Multiple Stimuli, Kelsey M. Vollmer, Davy C. Vanderweyen, Derek R. Tuck, Sorinel A. Oprisan

Journal of the South Carolina Academy of Science

We generalized the phase resetting curve (PRC) to a more realistic case of neural oscillators receiving two or more inputs per cycle. The PRC tabulates the transient change in the firing period of a neuron due to an external perturbation, such as a presynaptic stimulus. We used a conductance-based model neuron to estimate experimentally the two-stimulus PRC and compared the results against our mathematical prediction based on the assumption of instantaneous recurrent stimulation. Within the limits of the recurrent stimulation assumptions, we found that the newly introduced prediction for the two-stimulus PRC matched experimental measurements. Our new results open the …


Rejection Positivity Predicts Trial-To-Trial Reaction Times In An Auditory Selective Attention Task: A Computational Analysis Of Inhibitory Control, Sufen Chen, Robert D. Melara Aug 2014

Rejection Positivity Predicts Trial-To-Trial Reaction Times In An Auditory Selective Attention Task: A Computational Analysis Of Inhibitory Control, Sufen Chen, Robert D. Melara

Publications and Research

A series of computer simulations using variants of a formal model of attention (Melara and Algom, 2003) probed the role of rejection positivity (RP), a slow-wave electroencephalographic (EEG) component, in the inhibitory control of distraction. Behavioral and EEG data were recorded as participants performed auditory selective attention tasks. Simulations that modulated processes of distractor inhibition accounted well for reaction-time (RT) performance, whereas those that modulated target excitation did not. A model that incorporated RP from actual EEG recordings in estimating distractor inhibition was superior in predicting changes in RT as a function of distractor salience across conditions. A …