Life Sciences Commons^™

Dynamics Of Alpha Control: Preparatory Suppression Of Posterior Alpha Oscillations By Frontal Modulators Revealed With Combined Eeg And Event-Related Optical Signal, Kyle E. Mathewson, Diane M. Beck, Tony Ro, Edward L. Maclin, Kathy A. Low, Monica Fabiani, Gabriele Gratton

Publications and Research

We investigated the dynamics of brain processes facilitating conscious experience of external stimuli. Previously, we proposed that alpha (8–12 Hz) oscillations, which fluctuate with both sustained and directed attention, represent a pulsed inhibition of ongoing sensory brain activity. Here we tested the prediction that inhibitory alpha oscillations in visual cortex are modulated by top–down signals from frontoparietal attention networks. We measured modulations in phase-coherent alpha oscillations from superficial frontal, parietal, and occipital cortices using the event-related optical signal (EROS), a measure of neuronal activity affording high spatiotemporal resolution, along with concurrently recorded EEG, while participants performed a visual target detection …

Age-Related Aspects Of Mirror-Use By Bottlenose Dolphins (Tursiops Truncatus), Rachel A. Morrison

Dissertations, Theses, and Capstone Projects

Bottlenose dolphins are neuroanatomically different and evolutionarily divergent from primates yet they exhibit mirror self-recognition (MSR), a rare cognitive ability in non-human animals. This research investigated the developmental and age-related aspects of MSR in this species. During a longitudinal study, a social group of bottlenose dolphins at the National Aquarium, Baltimore, MD were exposed to a mirror and their behavioral responses were recorded to: 1) further confirm the presence of MSR in this species, 2) determine the age of emergence of MSR and 3) draw comparisons with data documenting the emergence of this ability in humans and great ape species. …

The Effects Of Environmental Enrichment On Abstinence And Relapse Using An Animal Conflict Model, Joshua Alan Peck

Dissertations, Theses, and Capstone Projects

Heroin addiction is a significant health and societal problem for which there is no effective and well-accepted long-term behavioral or pharmacological treatment. Therefore, strategies that prolong heroin abstinence should be the primary focus of heroin treatment research. There is promising evidence that environmental enrichment may indeed support drug abstinence in animals using the reinstatement model of abstinence and relapse. The current studies used an animal conflict model that captures the aversive consequences of drug seeking (as are typical in humans, e.g., arrest, incarceration, job loss, and strained social relationships) to test the effects of environmental enrichment on heroin abstinence, prolonged …

Executive Dysfunction And Reward Dysregulation: Interactions In Drug Addiction, Kristen Paula Morie

Dissertations, Theses, and Capstone Projects

Cocaine addiction is a serious public health hazard, and contributes to disastrous outcomes for individuals who suffer from it. Addiction is accompanied by an inability to control one's own behavior, and a preoccupation with cocaine at the expense of other rewarding pursuits. Previous research has suggested that difficulties with executive function and reward processing may underlie these problems, but the extent to which each contributes to addiction severity, or how these two factors may interact, remains to be elucidated. By using event related potential (ERP) measures in combination with information about self-reported anhedonia over three experiments, we set out to …

Psychic Collapse And Traumatic Defense: How The Mind Mediates Trauma Living In The Body, Patricia Kim Yoon

Dissertations, Theses, and Capstone Projects

The aim of this exploratory study was to link psychoanalytic theories of trauma and its impact on the mind with psychobiological research of how trauma lives in the body. The study has expanded on prior research (Cramer, 2003) to evidence that defense mechanisms do in fact moderate the relationship between stress and physiological response, and that there are likely individual differences in physiological response to traumatic stress. This study goes further to identify the psychological concomitants of these individual differences within an adult population exposed to potentially traumatic events (PTEs), and their proclivity for using different defense mechanisms. Defense use …

Mental Representations, Social Exclusion, And Neurobiological Processes In Borderline Personality Disorder: A Multi-Level Study, Jeffrey K. Erbe

Dissertations, Theses, and Capstone Projects

Borderline Personality Disorder (BPD) is an ongoing public health crisis. Poor developmental quality of differentiation-relatedness of object representations and attachment insecurity have been clinically and empirically demonstrated as core patterns of intrapsychic and interpersonal dysfunction in this particular form of personality pathology. Differentiation-relatedness (D-R), which involves a complementary relationship between intrapsychic autonomy and interpersonal relatedness, has been shown to be a significant aspect of internal psychic experience that relates directly to external relationship patterns, including characteristic response to interpersonal interactions and has been a specific target for treatment of BPD. Specifically, individuals with BPD have shown lower developmental quality of …

Biological Motion Processing In Typical Development And In The Autism Spectrum, Aaron Krakowski

Dissertations, Theses, and Capstone Projects

Biological motion (BM) analysis and interpretation is a fundamental process of human neurocognition that has been only minimally explored neurophysiologically. In addition to its importance in understanding the underlying roots and development of social cognition, BM processing is a prime candidate domain for exploring the underlying etiology of social cognitive disorders such as the autism spectrum.

In an initial experiment, typical adults observed BM point-light displays of a human actor (UM) as well as their spatially scrambled counterparts (SM), in both an unattended distractor task as well as an explicit attention task. Results showed a neurophysiological response manifested as three …

Behavioral And Neuroanatomical Abnormalities In Pleiotrophin Knockout Mice, Jason W. Krellman, Henry H. Ruiz, Veronica A. Marciano, Bracha Mondrow, Susan D. Croll

Publications and Research

Pleiotrophin (PTN) is an extracellular matrix-associated protein with neurotrophic and neuroprotective effects that is involved in a variety of neurodevelopmental processes. Data regarding the cognitive-behavioral and neuroanatomical phenotype of pleiotrophin knockout (KO) mice is limited. The purpose of this study was to more fully characterize this phenotype, with emphasis on the domains of learning and memory, cognitive-behavioral flexibility, exploratory behavior and anxiety, social behavior, and the neuronal and vascular microstructure of the lateral entorhinal cortex (EC). PTN KOs exhibited cognitive rigidity, heightened anxiety, behavioral reticence in novel contexts and novel social interactions suggestive of neophobia, and lamina-specific decreases in neuronal …

Supraspinal And Spinal Mechanisms Of Morphine-Induced Hyperalgesia, Caroline A. Arout

Dissertations, Theses, and Capstone Projects

Morphine is the most prominent pharmacological treatment for moderate to severe pain in both acute and chronic paradigms. However, morphine notoriously elicits a paradoxical state of increased pain sensitivity known as hyperalgesia that complicates its use in clinical application. Research over the past three decades has reported that morphine-induced hyperalgesia is dose- and sex-dependent, and likely involves the synchronous activity of several neural networks beyond the opioid system. Whereas systemic, supraspinal, and spinal administration of morphine all cause hyperalgesia that is differentially reversible by N-methyl-D-aspartate receptor (NMDAR) antagonists or melanocortin-1 receptor (MC1R) antagonists, it is unknown as to whether or …

Direct Control Of Visual Perception With Phase-Specific Modulation Of Posterior Parietal Cortex, Andrew Jaegle, Tony Ro

Publications and Research

We examined the causal relationship between the phase of alpha oscillations (9–12 Hz) and conscious visual perception using rhythmic TMS (rTMS) while simultaneously recording EEG activity. rTMS of posterior parietal cortex at an alpha frequency (10 Hz), but not occipital or sham rTMS, both entrained the phase of subsequent alpha oscillatory activity and produced a phase-dependent change on subsequent visual perception, with lower discrimination accuracy for targets presented at one phase of the alpha oscillatory waveform than for targets presented at the opposite phase. By extrinsically manipulating the phase of alpha before stimulus presentation, we provide direct evidence that the …

The Neurodevelopment Of Basic Sensory Processing And Integration In Autism Spectrum Disorder, Alice Brown Brandwein

Dissertations, Theses, and Capstone Projects

This thesis presents three studies that together explore the neurophysiological basis for the sensory processing and integration abnormalities that have been observed in autism spectrum disorder (ASD) since the disorder was first described over half a century ago. In designing these studies we seek to fill a hole that currently exists in the research community‟s knowledge of the neurodevelopment of basic multisensory integration -- both in children with autism and as well as in those with typical development. The first study applied event related potentials (ERPs) and behavioral measures of multisensory integration to a large group of healthy participants ranging …

Using Otoacoustic Emissions To Evaluate Efferent Auditory Function In Humans, Simon Henin

Dissertations, Theses, and Capstone Projects

The auditory system continually adapts to changes in the acoustic environment over short periods of time. This fine-tuning of its dynamics is mediated in part by the medial olivocochlear (MOC) bundle, a neural feedback loop which aids in the regulation of cochlear micro-mechanics. The ability to measure the response of the MOC system in humans may provide significant insight into unique cochlear functions, such as its sharp frequency selectivity and wide dynamic range. In humans the efferent system can be investigated non-invasively using otoacoustic emissions (OAEs). However, how OAEs can best be used to evaluate efferent function, the pitfalls associated …

On The Role Of Neuronal Oscillations In Auditory Cortical Processing, Monica Noelle O'Connell

Dissertations, Theses, and Capstone Projects

Although it has been over 100 years since William James stated that "everyone knows what attention is", its underlying neural mechanisms are still being debated today. The goal of this research was to describe the physiological mechanisms of auditory attention using direct electrophysiological recordings in macaque primary auditory cortex (A1). A major focus of my research was on the role ongoing neuronal oscillations play in attentional modulation of auditory responses in A1.

For all studies, laminar profiles of synaptic activity, (indexed by current source density analysis) and concomitant firing patterns in local neurons (multiunit activity) were acquired simultaneously via linear …

Neurophysiological Bases Of Frequency Discrimination In Children With Auditory Processing Disorder Or Specific Language Impairment, Christine Rota-Donahue

Dissertations, Theses, and Capstone Projects

The purpose of this study was to determine if 10-12 year old children with Auditory Processing Disorder (APD) or Specific Language Impairment (SLI) could discriminate three different frequency changes behaviorally and electrophysiologically. Behavioral frequency discrimination and event-related potentials were examined using a 1000Hz pure tone base frequency. Typically developing children and children with APD or SLI differed in in their detection of frequency changes: behavioral results were below chance level and the MMN amplitude was smaller in the impaired population. Slight differences between children with APD and children with SLI were also found that might shed light on the controversy …

A Kinder, Gentler Dopamine. . . Highlighting Dopamine's Role In Behavioral Flexibility, Jeff A. Beeler, Roshan Cools, Monica Luciana, Sean B. Ostlund, Giselle Petzinger

Publications and Research

No abstract provided.

Nest Destruction Elicits Indiscriminate Con- Versus Heterospecific Brood Parasitism In A Captive Bird, Rachel C. Shaw, William E. Feeney, Mark E. Hauber

Publications and Research

Following nest destruction, the laying of physiologically committed eggs (eggs that are ovulated, yolked, and making their way through the oviduct) in the nests of other birds is considered a viable pathway for the evolution of obligate interspecific brood parasitism. While intraspecific brood parasitism in response to nest predation has been experimentally demonstrated, this pathway has yet to be evaluated in an interspecific context. We studied patterns of egg laying following experimental nest destruction in captive zebra finches, Taeniopygia guttata, a frequent intraspecific brood parasite. We found that zebra finches laid physiologically committed eggs indiscriminately between nests containing conspecific eggs …