Neuroscience and Neurobiology Commons^™

Towards A Unified Computational Model Of Contextual Interactions Across Visual Modalities, David A. Mély, Thomas Serre

MODVIS Workshop

The perception of a stimulus is largely determined by its surrounding. Examples abound from color (Land and McCann, 1971), disparity (Westheimer, 1986) and motion induction (Anstis and Casco, 2006) to orientation tilt effects (O’Toole and Wenderoth, 1976). Some of these phenomena have been studied individually using monkey neurophysiology techniques. In these experiments, a center stimulus is typically used to probe a cell’s classical “center” receptive field (cRF), whose activity is then modulated by an annular “surround” (extra-cRF) stimulus. While this center-surround integration (CSI) has been well characterized, a theoretical framework which unifies these different phenomena across visual modalities is lacking. …

A Conceptual Framework Of Computations In Mid-Level Vision, Jonas Kubilius, Johan Wagemans, Hans P. Op De Beeck

MODVIS Workshop

The goal of visual processing is to extract information necessary for a variety of tasks, such as grasping objects, navigating in scenes, and recognizing them. While ultimately these tasks might be carried out by separate processing pathways, they nonetheless share a common root in the early and intermediate visual areas. What representations should these areas develop in order to facilitate all of these higher-level tasks? Several distinct ideas have received empirical support in the literature so far: (i) boundary feature detection, such as edge, corner, and curved segment extraction; (ii) second-order feature detection, such as the difference in orientation or …

Binocular 3d Motion Perception As Bayesian Inference, Martin Lages, Suzanne Heron

MODVIS Workshop

The human visual system encodes monocular motion and binocular disparity input before it is integrated into a single 3D percept. Here we propose a geometric-statistical model of human 3D motion perception that solves the aperture problem in 3D by assuming that (i) velocity constraints arise from inverse projection of local 2D velocity constraints in a binocular viewing geometry, (ii) noise from monocular motion and binocular disparity processing is independent, and (iii) slower motions are more likely to occur than faster ones. In two experiments we found that instantiation of this Bayesian model can explain perceived 3D line motion direction under …

A Binocular Model For Motion Integration In Mt Neurons, Pamela M. Baker, Wyeth Bair

MODVIS Workshop

Processing of visual motion by neurons in MT has long been an active area of study, however circuit models detailing the computations underlying binocular integration of motion signals remains elusive. Such models are important for studying the visual perception of motion in depth (MID), which involves both frontoparallel (FP) visual motion and binocular signal integration. Recent studies (Czuba et al. 2014, Sanada and DeAngelis 2014) have shown that many MT neurons are MID sensitive, contrary to the prevailing view (Maunsell and van Essen, 1983). These novel data are ideal for constraining models of binocular motion integration in MT. We have …

A Critical Evaluation Of Computational Mechanisms Of Binocular Disparity Processing, Junkyung Kim, David A. Mély, Thomas Serre

MODVIS Workshop

The past decades of research in visual neuroscience have generated a large and disparate body of literature on the computation of binocular disparity in the primary visual cortex. Models have been proposed to describe specific phenomena, yet we lack a theoretical framework which is grounded in neurophysiology and also explains the effectiveness of disparity computation. Here, we examine neural circuits that are thought to play an important role in the computation of binocular disparity. Starting with the binocular energy model (Ohzawa et al. 1990), we consider plausible extensions which include suppressive mechanisms from units tuned to different phase disparities (Tanabe …

Modeling Shape Representation In Area V4, Wyeth Bair, Dina Popovkina, Abhishek De, Anitha Pasupathy

MODVIS Workshop

Our model builds on a convolutional-style neural network with hierarchical stages representing processing steps in the ventral visual pathway. It was designed to capture the translation-invariance and shape-selectivity of neurons in area V4. The model uses biologically plausible linear filters at the front end, normalization and sigmoidal nonlinear activation functions. The max() function is used to generate translation invariance.

A Recurrent Multilayer Model With Hebbian Learning And Intrinsic Plasticity Leads To Invariant Object Recognition And Biologically Plausible Receptive Fields, Michael Teichmann, Fred H. Hamker

MODVIS Workshop

Much effort has been spent to develop biologically plausible models for different aspects of the processing in the visual cortex. However, most of these models are not investigated with respect to the functionality of the neural code for the purpose of object recognition comparable to the framework of deep learning in the machine learning community.
We developed a model of V1 and V2 based on anatomical evidence of the layered architecture, using excitatory and inhibitory neurons where the connectivity to each neuron is learned in parallel. We address learning by three different mechanisms of plasticity: intrinsic plasticity, Hebbian learning with …

A Computational Model To Account For Dynamics Of Spatial Updating Of Remembered Visual Targets Across Slow And Rapid Eye Movements, Yalda Mohsenzadeh, J. Douglas Crawford

MODVIS Workshop

Despite the ever-changing visual scene on the retina between eye movements, our perception of the visual world is constant and unified. It is generally believed that this space constancy is due to the brain’s ability of spatial updating. Although many efforts have been made to discover the mechanism underlying spatial updating across eye movements, still there are many unanswered questions about the neuronal mechanism of this phenomenon.

We developed a state space model for updating gaze-centered spatial information. To explore spatial updating, we considered two kinds of eye movements, saccade and smooth pursuit. The inputs to our proposed model are: …

A Model Of Repetitive Microsaccades, Coupled With Pre-Microsaccadic Changes In Vision, Is Sufficient To Account For Both Attentional Capture And Inhibition Of Return In Posner Cueing, Ziad M. Hafed, Xiaoguang Tian

MODVIS Workshop

When a cue is presented at a location, orienting efficacy towards that location is improved relative to other locations (“attentional capture”), but only briefly; a mere few hundred milliseconds later, orienting incurs large costs. These costs have been classically termed “inhibition of return” (IOR), alluding to voluntary, cognitive strategies avoiding perseverance at one location. However, despite this popular hypothesis, the origins of both attentional capture and IOR remain elusive. Here we show that both of these phenomena can be accounted for by a single concept of oculomotor rhythmicity, and one that involves the entire gamut of saccadic activity including microsaccades. …

Object Recognition And Visual Search With A Physiologically Grounded Model Of Visual Attention, Frederik Beuth, Fred H. Hamker

MODVIS Workshop

Visual attention models can explain a rich set of physiological data (Reynolds & Heeger, 2009, Neuron), but can rarely link these findings to real-world tasks. Here, we would like to narrow this gap with a novel, physiologically grounded model of visual attention by demonstrating its objects recognition abilities in noisy scenes.

To base the model on physiological data, we used a recently developed microcircuit model of visual attention (Beuth & Hamker, in revision, Vision Res) which explains a large set of attention experiments, e.g. biased competition, modulation of contrast response functions, tuning curves, and surround suppression. Objects are represented by …

Modeling Visual Features To Recognize Biological Motion: A Developmental Approach, Giulio Sandini, Nicoletta Noceti, Alessia Vignolo, Alessandra Sciutti, Francesco Rea, Alessandro Verri, Francesca Odone

MODVIS Workshop

In this work we deal with the problem of designing and developing computational vision models – comparable to the early stages of the human development – using coarse low-level information.

More specifically, we consider a binary classification setting to characterize biological movements with respect to non-biological dynamic events. To this purpose, our model builds on top of the optical flow estimation, and abstract the representation to simulate the limited amount of visual information available at birth. We take inspiration from known biological motion regularities explained by the Two-Thirds Power Law, and design a motion representation that includes different low-level features, …

Recent Studies On Nutrition And Parkinson’S Disease Prevention: A Systematic Review, Ann Gaba

Publications and Research

Introduction: Parkinson’s disease (PD) is a chronic progressive movement disorder, affecting primarily people over sixty years of age. With aging populations, some estimates indicate as many as nine million people will be impacted by this disease by 2030. Thus it is imperative to identify means of prevention, delay of onset, and management of symptoms. Many elements of diet and nutrition have been investigated to accomplish these goals. This review will examine recent studies of potential diet and nutrition factors and PD incidence.

Methods: A PubMed Search was conducted using the keywords “Parkinson, prevention and nutrition”, and “Parkinson, prevention, and diet.” …

The Short And Long-Term Effects Of Chronic Ketamine During Adolescence On Object Recognition Memory In Rats, William Hardin

Seton Hall University Dissertations and Theses (ETDs)

Prior research has demonstrated that ketamine causes deficits in object recognition and location memory following both acute and chronic administration (Pitsikas & Boultadakis, 2009; Venãncio et al., 2011). Although it is well established that abuse of many different kinds of drugs during the critical developmental period of adolescence can lead to impairments in cognition later in adulthood (Gilpin et al., 2012; Wagner et al., 2010), no research has investigated the effects of chronic ketamine administration during adolescence and its effects on behavior in adulthood. With recent research establishing that chronic ketamine during adolescence produces late-onset alterations in electrophysiology during adulthood …

Multimodal Inputs And Modularity Of The Inferior Colliculus Prior To Audition., Joseph A. Balsamo

Senior Honors Projects, 2010-2019

A fully functional nervous system requires assimilation of sensory modalities to adequately interpret stimuli and determine appropriate motor responses. Two such regions responsible for multimodal integration are found in the auditory system, the cochlear nucleus (CN) and the inferior colliculus (IC). The lateral cortex of the IC (LCIC) in particular receives a diverse multimodal input array to discrete modular/extramodular zones. Staining for certain neurochemicals, including GAD, a marker for GABAergic neurons, reveal this compartmentalized LCIC organization. The present study utilizes fluorescent anterograde tracttracing techniques to determine the development of a somatosensory brainstem projection from the spinal trigeminal nucleus (Sp5), to …

The Effect Of Taste On Swallowing Function, Rachel Mulheren

Dissertations, 2014-2019

This study investigated the effects of taste on swallowing frequency and cortical activation in the swallowing network. The effects of salivary flow and taster status were also examined, along with genetic taster status. The effects of a 3ml bolus compared sour, sour with slow infusion, sweet, water, and water with infusion. Swallowing frequency was significantly higher 0-15 seconds after bolus delivery than 16-30 seconds. Swallowing frequency was higher in the sour conditions, whereas sweet and water did not differ. Functional near-infrared spectroscopy recordings measured changes in blood oxygenation (HbO) in the right and left hemispheres in the premotor, S1 and …

Identification Of Three Novel Genes, Ppk12, Ppk23, And Ppk25, Involved In Noxious Cold Detection In Drosophila, Benjamin Williamson

Masters Theses, 2010-2019

The reflexive response and perception of pain (nociception) is an evolutionarily conserved process in animals. Pain can be a major health concern and current treatments often prove insufficient, especially in regards to chronic pain. Greater understanding of the molecular processes underlying pain sensation could lead to new and more effective treatments. The aim of this study is to investigate the molecular mechanisms of cold nociception in Drosophila melanogaster. A specific subset of peripheral sensory neurons (Class III dendritic arborization (da) neurons), are implicated in Drosophila larvae’s response to noxious cold.

Previous literature has implicated a variety of ion channel families, …

Sleep Deprivation And Voluntary Alcohol Consumption In Adolescent Rats, Sancho N. Sequeira

Masters Theses, 2010-2019

Alcohol is one of the most common psychoactive drugs, and has been used by humans for thousands of years. Research has focused on the effects of alcohol on sleep, however recent trends in the literature have taken a more bidirectional approach to the relationship between alcohol and sleep. This research investigates the effects of chronic, partial sleep deprivation on alcohol consumption. Twelve adolescent Sprague Dawley rats had free access to two bottles at all times, one containing water and one containing a 7% alcohol and water solution. Sleep deprivation was achieved by using a forced exercise wheel. All rats were …

Physical Feature Encoding And Word Recognition Abilities Are Altered In Children With Intractable Epilepsy: Preliminary Neuromagnetic Evidence, Maria Pardos, Milena Korostenskaja, Jing Xiang, Hisako Fujiwara, Ki H. Lee, Paul S. Horn, Anna Byars, Jennifer Vannest, Yingying Wang, Nat Hemasilpin, Douglas F. Rose

Center for Brain, Biology, and Behavior: Faculty Publications

Objective evaluation of language function is critical for children with intractable epilepsy under consideration for epilepsy surgery. The purpose of this preliminary study was to evaluate word recognition in children with intractable epilepsy by using magnetoencephalography (MEG). Ten children with intractable epilepsy (M/F 6/4, mean ± SD 13.4 ± 2.2 years) were matched on age and sex to healthy controls. Common nouns were presented simultaneously from visual and auditory sensory inputs in “match” and “mismatch” conditions. Neuromagnetic responses M1, M2, M3, M4, and M5 with latencies of ∼100ms, ∼150ms, ∼250ms, ∼350ms, and ∼450ms, respectively, elicited during the “match” condition were …

Axonal Activity In Vivo: Technical Considerations And Implications For The Exploration Of Neural Circuits In Freely Moving Animals, Jeremy M. Barry

Dartmouth Scholarship

While extracellular somatic action potentials from freely moving rats have been well characterized, axonal activity has not. We have recently reported extracellular tetrode recordings of short duration waveforms (SDWs) with an average peak-trough duration less than 172μs. These waveforms have significantly shorter duration than somatic action potentials and tend to be triphasic. The present review discusses further data that suggests SDWs are representative of axonal activity, how this characterization allows for more accurate classification of somatic activity and could serve as a means of exploring signal integration in neural circuits. The review also discusses how axons may function as more …

Age-Dependent Breakdown Of The Blood Brain Barrier And Associated Changes In S100b Ko Mice, Eric V. Brown

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies play an important role in many autoimmune diseases. Recent research has shown that breakdown of the blood brain barrier (BBB) occurs concomitant to generation of brain reactive autoantibodies in many neurodegenerative diseases, which serve as biomarkers and drivers of pathology. SI00B, a calcium binding protein found most highly expressed in astrocytes which ensheathe the BBB, has many functions in neural development and signaling. Currently literature indicates that S100B KO mice develop normally, with no phenotypic abnormalities. Here, it is demonstrated that S100B KO mice seem to develop a chronic BBB breakdown similar to that seen in human neurodegenerative diseases. …

Behavioral And Neuroanatomical Outcomes Of Early And Late Preterm Hypoxic-Ischemic Injury And The Neuroprotective Effects Of Whole-Body Hypothermia: An Animal Model, Haley C. Garbus

University Scholar Projects

The overarching aims of this research were: first, to characterize the anatomical and behavioral effects of preterm hypoxic-ischemic (HI) injury in rodent models; and second, to explore the method of passively induced whole-body hypothermia as a neuroprotective intervention following HI. Clinical research of preterm injured infants has shown a large range of behavioral deficits, including delays in language learning, spatial and non-spatial memory, visual attention, and motor coordination. The current studies focused on these behavioral abnormalities, using HI rodent models. Specifically, we explored a model for early preterm HI (HI induced on postnatal day (P) 3 in rats), and compared …

An Exploratory High-Density Eeg Investigation Of The Misinformation Effect: Attentional And Recollective Differences Between True And False Perceptual Memories, John E. Kiat, Robert F. Belli

Department of Psychology: Faculty Publications

The misinformation effect, a phenomenon in which eyewitness memories are altered via exposure to post-event misinformation, is one of the most important paradigms used to investigate the reconstructive nature of human memory. The aim of this study was to use the misinformation effect paradigm to investigate differences in attentional and recollective processing between true and false event memories. Nineteen participants completed a variant of the misinformation paradigm in which recognition responses to true and misinformation based event details embedded within a narrative context, were investigated using high-density (256-channel) EEG with a 1-day delay between event exposure and test. Source monitoring …

Glycine Receptor Alpha Subunit (Glyra) Specific Inhibition Contributes To Ganglion Cell Signaling In Mouse Retina., Chi Zhang

Electronic Theses and Dissertations

In the retina, numerous types of neurons are wired together in a highly specific albeit complex pattern. This sophisticated retinal network allows extraction and encoding of more than 20 representations of the visual scene in its output neurons, the retinal ganglion cells (RGCs). Within the inner plexiform layer (IPL) of retina, glycine receptors (GlyRs) are expressed on different cell classes and modulate RGC visual activity to light onset (ON RGCs) and to light offset (OFF RGCs), for example, their temporal precision and gain control. There are four GlyR alpha subunits (GlyRα1-4) with differential expression patterns in IPL. Each mediates spontaneous …

Characterizing The Neuropeptide Pathways Between The Forebrain And The Pons., Ali Al-Magableh

Electronic Theses and Dissertations

Many current health problems including obesity, hypertension, stroke, heart disease, and type 2-diabetes can be attributed to diet. One powerful determinant of food selection is how good or bad a food 'tastes' (e.g. affective value), and is ranked highly by consumers as their top reason for choosing a food (e.g. preference). Learning plays an important role in the establishment and strengthening of food preference and, thus in guiding food choice and calories consumed. The basis of such learning is provided, in part, by limbic system modulation of gustatory neural processing at lower levels in the medulla and pons. I hypothesize …

Efficient In Vitro Development Of Photoreceptors From Human Pluripotent Stem Cells, Joseph C. Reynolds

Dissertations, Masters Theses, Capstones, and Culminating Projects

Degeneration of the rod and cone photoreceptors in the human retina is among the most common causes of blindness. Replacing these damaged photoreceptors may help to restore vision. Repairing the damaged retina relies on the insertion of new, healthy cells. Embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are two possible sources of photoreceptors to restore vision. Previous data shows that human ES cells and iPS cells can be differentiated into photoreceptors and transplanted into the eye to restore some vision. However, this process is inefficient, and costly. Here, we show a new method for inducing photoreceptor production …

Spike Field Coherence (Sfc) For Ripples In Rat Hippocampus, Pranav Singla

Honors Scholar Theses

The aim of this project was to determine coherence between two types of neural recordings which can be obtained from the rat hippocampus: spikes and local field potentials. Extracellular recording makes it possible to determine spiking activity from individual neurons in the vicinity of the recording electrode. Local field potential recording gives a combined activity of many neurons (thousands) at once to determine an overall picture of the coordination of the cells in real time. Here we examine the relationship between these two signals, focusing on place cells which spike at their maximal rate only at certain positions in physical …

Design, Programming, And User-Experience, Kaila G. Manca

Honors Scholar Theses

This thesis is a culmination of my individualized major in Human-Computer Interaction. As such, it showcases my knowledge of design, computer engineering, user-experience research, and puts into practice my background in psychology, com- munications, and neuroscience.

I provided full-service design and development for a web application to be used by the Digital Media and Design Department and their students.This process involved several iterations of user-experience research, testing, concepting, branding and strategy, ideation, and design. It lead to two products.

The first product is full-scale development and optimization of the web appli- cation.The web application adheres to best practices. It was …

Estrodial Effects On Age-Related Shifts In Learning And Memory: A Multiple Memory Systems Approach, Luis Castelan

Renée Crown University Honors Thesis Projects - All

Many findings from our lab and others suggest that circulating estrogens as well as estrogen replacement after ovariectomy influence cognitive performance. Young female rats trained during proestrus, when estrogens are high, or with acute estradiol (E2) administration after ovariectomy perform better on the hippocampus-sensitive place task but worse on the striatum-sensitive response task (Korol et al., 2004; Korol and Kolo, 2002). Behavioral neuroscience studies tend to use male rodent models to avoid the complexities of the female reproductive cycle, producing a gap in our knowledge about neural mechanisms of learning and memory in females. As a consequence, age-related effects of …

Differential Activation Of Microglia In An In Vitro Model Of Intracerebral Hemorrhage, Bhakti Patel

Renée Crown University Honors Thesis Projects - All

An in vitro model of intracerebral hemorrhage was established to examine the protective versus cytotoxic roles of microglia in the context of mild versus severe injury. Co-cultures of microglia, astrocytes, and granule neurons were prepared from the cerebellar cortex of neonatal rats, and grown in standard medium containing fetal bovine serum or, in some cases, a serum-free chemically defined medium. To mimic hemorrhagic stroke, co-cultures grown for 7-8 days in vitro were challenged with two different concentrations of the toxic blood product hemin, corresponding to a mild versus a severe brain bleed. Immunocyto-chemical, real-time RT-PCR, iron deposition, and cell survival …

An Exploration Of The Societal Impact Of Neuroethics In Scientific And General Communities, Katelyn Marie Edel

Renée Crown University Honors Thesis Projects - All

Neuroethics serves as a roadmap for maneuvering the difficult and often personal concerns that arise concurrently with advancements in neuroscience. It is important to consider these issues at present and to take a proactive, rather than reactive, approach towards assuaging fears and hesitations related to the quickening applications of neuroscience into the non-scientific community. This Capstone explores recent suggestions made by prominent scholars in the neuroethics field related to the integration of neuroscience into society. Three cogent issues in neuroscience are discussed, with a focus on the possible effects that neuroscientific advancements have on society. Using a framework of human …