Neurosciences Commons^™

Ensembles Of Human Mtl Neurons "Jump Back In Time" In Response To A Repeated Stimulus, M. W. Howard, Indre Viskontas, K. H. Shankar, I. Fried

Psychology

Episodic memory, which depends critically on the integrity of the medial temporal lobe (MTL), has been described as ‘‘mental time travel’’ in which the rememberer ‘‘jumps back in time.’’ The neural mechanism underlying this ability remains elusive. Mathematical and computational models of performance in episodic memory tasks provide a specific hypothesis regarding the computation that supports such a jump back in time. The models suggest that a representation of temporal context, a representation that changes gradually over macroscopic periods of time, is the cue for episodic recall. According to these models, a jump back in time corresponds to a stimulus …

Discriminating Famous From Fictional Names Based On Lifetime Experience: Evidence In Support Of A Signal-Detection Model Based On Finite Mixture Distributions., Ben Bowles, Iain M Harlow, Melissa M Meeking, Stefan Köhler

Brain and Mind Institute Researchers' Publications

It is widely accepted that signal-detection mechanisms contribute to item-recognition memory decisions that involve discriminations between targets and lures based on a controlled laboratory study episode. Here, the authors employed mathematical modeling of receiver operating characteristics (ROC) to determine whether and how a signal-detection mechanism contributes to discriminations between moderately famous and fictional names based on lifetime experience. Unique to fame judgments is a lack of control over participants' previous exposure to the stimuli deemed "targets" by the experimenter; specifically, if they pertain to moderately famous individuals, participants may have had no prior exposure to a substantial proportion of the …

Distinct Patterns Of Functional And Effective Connectivity Between Perirhinal Cortex And Other Cortical Regions In Recognition Memory And Perceptual Discrimination., Edward B O'Neil, Andrea B Protzner, Cornelia Mccormick, D Adam Mclean, Jordan Poppenk, Anthony D Cate, Stefan Köhler

Brain and Mind Institute Researchers' Publications

Traditionally, the medial temporal lobe (MTL) is thought to be dedicated to declarative memory. Recent evidence challenges this view, suggesting that perirhinal cortex (PrC), which interfaces the MTL with the ventral visual pathway, supports highly integrated object representations in recognition memory and perceptual discrimination. Even with comparable representational demands, perceptual and memory tasks differ in numerous task demands and the subjective experience they evoke. Here, we tested whether such differences are reflected in distinct patterns of connectivity between PrC and other cortical regions, including differential involvement of prefrontal control processes. We examined functional magnetic resonance imaging data for closely matched …

Sex Differences In The Dopaminergic Regulation Of Courtship, But Not Pairing Behaviors In Zebra Finches, Erin Marie Lowrey

Wayne State University Theses

Dopamine is one of the key ingredients in the glue that cements social bonds in vertebrates. The D2 dopamine receptor has been implicated in the regulation of monogamous pair bonding in the prairie vole. While dopamine affects courtship behaviors in the male zebra finch, the behavioral role of dopamine acting at D2 receptors in both males and females deserves further attention. We hypothesized that the D2 receptor would regulate courtship and pairing behaviors in the male and female zebra finch. Sixteen males and females were tested using a repeated measures design. On day 1, the zebra finches were injected with …

Stroke Rehabilitation, Length-Of-Stay, And Re-Admission Rates: A Literature Review, Morgen Hagedorn

All Graduate Theses, Dissertations, and Other Capstone Projects

Stroke is shown to be a significant U.S. health problem with a profound impact on the nation’s rising healthcare costs (Hall, Levant, & DeFrances, 2012). Longer patient length-of-stay [LOS] and higher re-admission rates have brought consequences to healthcare systems as institutional budgets are unable to reconcile the additional services and the influx of healthcare demands. Through a comprehensive literature review, the author illustrates the general knowledge available on the stroke experience, on stroke care and rehabilitation, and on patient LOS and re-admission rates. The literature review is based on general medical research with a focus on the stroke population. The …

Increasing Parity Is Associated With Cumulative Effects On Memory, Laura M. Glynn

Psychology Faculty Articles and Research

BACKGROUND: The purpose of this investigation was to determine if reproductive experience is associated with cumulative effects on human memory performance during pregnancy and if these effects persist into the postpartum period.

METHODS: Verbal recall memory performance was assessed in 254 women four times during pregnancy and at 3 months postpartum. The relation between parity and memory function was evaluated with hierarchical linear modeling and analysis of covariance (ANCOVA).

RESULTS: The data indicate that the previously documented adverse effects of pregnancy on memory performance are compounded with successive pregnancies. During gestation and postpartum, multiparity was associated with poorer memory function, …

Sugar Consumption And Cognitive Aging In The Swedish Adoption/Twin Study Of Aging, Shyam Seetharaman

USF Tampa Graduate Theses and Dissertations

Abstract

Consumption of foods high in sugar content has been linked with the development of metabolic abnormalities such as cardiovascular disease and type II diabetes, major sources of global health concerns. Although the detrimental consequences of high intake of sugar on abnormal metabolic processes are established, it is not known how this association affects (or accelerates) cognitive aging.

The current project was based on data from the Swedish Adoption/Twin Study of Aging (SATSA) to test the hypothesis that high refined sugar intake contributes to accelerated trajectories of cognitive decline assessed longitudinally. Trajectories of cognitive change were assessed as a function …

Specific Contributions Of Ventromedial, Anterior Cingulate, And Lateral Prefrontal Cortex For Attentional Selection And Stimulus Valuation., Daniel Kaping, Martin Vinck, R Matthew Hutchison, Stefan Everling, Thilo Womelsdorf

Brain and Mind Institute Researchers' Publications

Attentional control ensures that neuronal processes prioritize the most relevant stimulus in a given environment. Controlling which stimulus is attended thus originates from neurons encoding the relevance of stimuli, i.e. their expected value, in hand with neurons encoding contextual information about stimulus locations, features, and rules that guide the conditional allocation of attention. Here, we examined how these distinct processes are encoded and integrated in macaque prefrontal cortex (PFC) by mapping their functional topographies at the time of attentional stimulus selection. We find confined clusters of neurons in ventromedial PFC (vmPFC) that predominantly convey stimulus valuation information during attention shifts. …

Empathy-Based Conservation: An Interdisciplinary Approach To Conservation Policy And Decision-Making, Kaitlyn Delashmutt

Department of Environmental Studies: Undergraduate Student Theses

In the late 20^th century, neuroscientists in Italy discovered a neuron in the brain capable of mentally mimicking the emotions derived from the actions of others (Rizzolatti and Craighero, 2004). It is the process that makes your elbow ache when someone else knocks their elbow on the counter or the uncontrollable smile that creeps up when someone smiles at you. No questions asked, people intuitively sense what others are feeling. The old school of thought was that humans deduced through logic and reason the actions of others and interpreted the emotions through a rational process (Carew et al, 2008). …

Paradoxical Reversal Learning Enhancement By Stress Or Prefrontal Cortical Damage: Rescue With Bdnf., Carolyn Graybeal, Michael Feyder, Emily Schulman, Lisa M Saksida, Timothy J Bussey, Jonathan L Brigman, Andrew Holmes

Brain and Mind Institute Researchers' Publications

Stress affects various forms of cognition. We found that moderate stress enhanced late reversal learning in a mouse touchscreen-based choice task. Ventromedial prefrontal cortex (vmPFC) lesions mimicked the effect of stress, whereas orbitofrontal and dorsolateral striatal lesions impaired reversal. Stress facilitation of reversal was prevented by BDNF infusion into the vmPFC. These findings suggest a mechanism by which stress-induced vmPFC dysfunction disinhibits learning by alternate (for example, striatal) systems.

Principles Of Sensorimotor Learning., Daniel M Wolpert, Jörn Diedrichsen, J Randall Flanagan

Brain and Mind Institute Researchers' Publications

The exploits of Martina Navratilova and Roger Federer represent the pinnacle of motor learning. However, when considering the range and complexity of the processes that are involved in motor learning, even the mere mortals among us exhibit abilities that are impressive. We exercise these abilities when taking up new activities - whether it is snowboarding or ballroom dancing - but also engage in substantial motor learning on a daily basis as we adapt to changes in our environment, manipulate new objects and refine existing skills. Here we review recent research in human motor learning with an emphasis on the computational …

Lateralization Of Emotion, Reaction Time, And Skin Conductance Responsiveness, Kimberley Erin Rose

Loma Linda University Electronic Theses, Dissertations & Projects

Bilateral presentations of brief (250 ms), unmasked emotional and neutral stimuli were examined in two experiments with primarily female samples. Reaction time and accuracy data were used to measure perception of emotion and skin conductance response (SCR) was used to measure experience of emotion. Both words and pictures were used to account for hemispheric differences in language and visuospatial dominance. Response time was faster to emotional pictures than words. Reaction time and speeded accuracy data did not support right hemisphere hypothesis (RHH) or valence hypothesis (VH) in the expected manner. Data suggested emotion caused greater interference under speeded conditions in …

The Levels Of Analysis Revisited., Scott A Macdougall-Shackleton

Brain and Mind Institute Researchers' Publications

The term levels of analysis has been used in several ways: to distinguish between ultimate and proximate levels, to categorize different kinds of research questions and to differentiate levels of reductionism. Because questions regarding ultimate function and proximate mechanisms are logically distinct, I suggest that distinguishing between these two levels is the best use of the term. Integrating across levels in research has potential risks, but many benefits. Consideration at one level can help generate novel hypotheses at the other, define categories of behaviour and set criteria that must be addressed. Taking an adaptationist stance thus strengthens research on proximate …

Emotional Reactivity And Regulation In Current And Remitted Depression: An Event Related Potential Study, Lauren M. Bylsma

USF Tampa Graduate Theses and Dissertations

Major Depressive Disorder (MDD) is thought to be characterized by emotion regulation deficits, including decreased use of adaptive strategies such as reappraisal, but little is known about the exact nature of these deficits and whether or not they are specific to the depressed mood state. The late positive potential (LPP) is a sustained positive deflection of the event-related potential (ERP) associated with responding to emotionally-valenced stimuli, and reappraisal strategies have been found to reduce LPP magnitude in response to emotional stimuli in healthy individuals, but this effect has not been examined in MDD. This study utilized ERPs to examine emotional …

Treating Trauma Survivors With Neurofeedback: A Grounded Theory Study Based On The Practices Of Experienced Mental Health Professionals, Christine L. Currie

Counseling & Human Services Theses & Dissertations

Neuroscience, the mental health field, and the concept of trauma as an underlying factor in mental and physical disorders have been inextricably linked since the inception of the mental health professions. Numerous quantitative studies have indicated that neurofeedback may be effective in ameliorating trauma symptoms; however, there is a paucity of research exploring the factors that produce those positive outcomes. The purpose of this qualitative grounded theory study was to explore the factors and processes that influence treatment outcomes when neurofeedback is used with trauma survivors. Thirty interviews were completed with ten experienced mental health and neurofeedback professionals identified through …

Prefrontal Cortex Deactivation In Macaques Alters Activity In The Superior Colliculus And Impairs Voluntary Control Of Saccades, Michael J. Koval, Stephen G. Lombar, Stefan Everling

Brain and Mind Institute Researchers' Publications

The cognitive control of action requires both the suppression of automatic responses to sudden stimuli and the generation of behavior specified by abstract instructions. Though patient, functional imaging and neurophysiological studies have implicated the dorsolateral prefrontal cortex (dlPFC) in these abilities, the mechanism by which the dlPFC exerts this control remains unknown. Here we examined the functional interaction of the dlPFC with the saccade circuitry by deactivating area 46 of the dlPFC and measuring its effects on the activity of single superior colliculus neurons in monkeys performing a cognitive saccade task. Deactivation of the dlPFC reduced preparatory activity and increased …

The Effect Of Dopamine Therapy On Ventral And Dorsal Striatum-Mediated Cognition In Parkinson's Disease: Support From Functional Mri., Penny A Macdonald, Alex A Macdonald, Ken N Seergobin, Ruzbeh Tamjeedi, Hooman Ganjavi, Jean-Sebastien Provost, Oury Monchi

Brain and Mind Institute Researchers' Publications

The central aim of our study was to elucidate functions mediated by the ventral and dorsal striatum, respectively, to better understand the cognitive effects of dopamine replacement in Parkinson's disease. We proposed that the ventral striatum underlies general learning of stimulus associations, whereas the dorsal striatum promotes integration of various influences on selecting. In Parkinson's disease, dopamine depletion is substantially less notable in the ventral relative to the dorsal striatum, and therefore greater improvements are expected for dorsal striatum-mediated functions with dopamine replacement. Using a simple selection task, we found that dopamine replacement impaired encoding and facilitation of consistent stimulus-stimulus …

Executive Function Profiles In Pediatric Traumatic Brain Injury, Erik Nelson Ringdahl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Traumatic brain injury is a common cause of disability and death among children in the United States. Insult to the frontal and temporal lobes are frequent in closed head brain injury. Cognitive deficits in a variety of domains are common sequelae of brain trauma. In many cases, trauma to the frontal and temporal lobe regions engender prominent deficits in higher-order cognitive processing, memory, and attention.

Higher-order cognitive processing, or Executive Functions are the grouping of cognitive processes necessary for organization of thoughts and activities, attending to the activities, prioritizing tasks, managing time efficiently, and making decisions (Alvarez & Emory, 2006; …

Differential Effects Of Dopaminergic Therapies On Dorsal And Ventral Striatum In Parkinson's Disease: Implications For Cognitive Function., Penny A Macdonald, Oury Monchi

Brain and Mind Institute Researchers' Publications

Cognitive abnormalities are a feature of Parkinson's disease (PD). Unlike motor symptoms that are clearly improved by dopaminergic therapy, the effect of dopamine replacement on cognition seems paradoxical. Some cognitive functions are improved whereas others are unaltered or even hindered. Our aim was to understand the effect of dopamine replacement therapy on various aspects of cognition. Whereas dorsal striatum receives dopamine input from the substantia nigra (SN), ventral striatum is innervated by dopamine-producing cells in the ventral tegmental area (VTA). In PD, degeneration of SN is substantially greater than cell loss in VTA and hence dopamine-deficiency is significantly greater in …

Negative Associations Between Corpus Callosum Midsagittal Area And Iq In A Representative Sample Of Healthy Children And Adolescents., Hooman Ganjavi, John D Lewis, Pierre Bellec, Penny A Macdonald, Deborah P Waber, Alan C Evans, Sherif Karama, The Brain Development Cooperative Group

Brain and Mind Institute Researchers' Publications

Documented associations between corpus callosum size and cognitive ability have heretofore been inconsistent potentially owing to differences in sample characteristics, differing methodologies in measuring CC size, or the use of absolute versus relative measures. We investigated the relationship between CC size and intelligence quotient (IQ) in the NIH MRI Study of Normal Brain Development sample, a large cohort of healthy children and adolescents (aged six to 18, n = 198) recruited to be representative of the US population. CC midsagittal area was measured using an automated system that partitioned the CC into 25 subregions. IQ was measured using the Wechsler …

Repeated Binge Pattern Ethanol Administration During Adolescence Or Adulthood: Long-Term Changes In Voluntary Ethanol Intake And Mesolimbic Dopamine Functionality In Male Rats, Antoniette Michelle Maldonado-Devincci

USF Tampa Graduate Theses and Dissertations

Binge alcohol consumption is a rising concern in the United States, especially among adolescents as during this developmental period alcohol use is usually initiated and has been shown to cause detrimental effects on brain structure and function. These findings have been established through the use of binge models in animals, where animals are repeatedly administered high doses of ethanol typically over a period of three or four days. While such work has examined the effects of a four-day and repeated three-day binge, there has been almost no work conducted aimed at investigating the long-term behavioral and neurochemical and/or functional consequences …

Neurochemical Effects Of Amyloid-Beta Oligomers In Rats, John J. Panos

Dissertations

Alzheimer’s disease is a progressive neurodegenerative disease characterized by memory loss and cognitive decline. Although the symptomology of Alzheimer’s disease is well defined, its precise etiology remains elusive. Animal models are invaluable for understanding the pathogenesis of this devastating disease. Knowledge of the neurochemical actions of amyloid-β oligomers in specific brain structures is essential for validating animal models of Alzheimer’s disease and for determining the most appropriate behavioral assays of memory. The specific aim of this project was to investigate the neurochemical effects of direct intracerebral infusion of amyloid-β oligomers in the rat. Experiment 1 investigated direct infusions of synthetic …

Failing To Ignore: Paradoxical Neural Effects Of Perceptual Load On Early Attentional Selection In Normal Aging, Taylor W. Schmitz, Frederick H.T. Cheng, Eve De Rosa

Brain and Mind Institute Researchers' Publications

We examined visual selective attention under perceptual load - simultaneous presentation of task-relevant and -irrelevant information - in healthy young and older adult human participants to determine whether age differences are observable at early stages of selection in the visual cortices. Participants viewed 50/50 superimposed face/place images and judged whether the faces were male or female, rendering places perceptible but task-irrelevant. Each stimulus was repeated, allowing us to index dynamic stimulus-driven competition from places. Consistent with intact early selection in young adults, we observed no adaptation to unattended places in parahippocampal place area (PPA) and significant adaptation to attended faces …

Chronic Spontaneous Activity Generated In The Somata Of Primary Nociceptors Is Associated With Pain-Related Behavior After Spinal Cord Injury, Supinder S Bedi, Qing Yang, Robyn J Crook, Junhui Du, Zizhen Wu, Harvey M Fishman, Raymond J Grill, Susan M Carlton, Edgar T Walters

Faculty, Staff and Student Publications

Mechanisms underlying chronic pain that develops after spinal cord injury (SCI) are incompletely understood. Most research on SCI pain mechanisms has focused on neuronal alterations within pain pathways at spinal and supraspinal levels associated with inflammation and glial activation. These events might also impact central processes of primary sensory neurons, triggering in nociceptors a hyperexcitable state and spontaneous activity (SA) that drive behavioral hypersensitivity and pain. SCI can sensitize peripheral fibers of nociceptors and promote peripheral SA, but whether these effects are driven by extrinsic alterations in surrounding tissue or are intrinsic to the nociceptor, and whether similar SA occurs …

Neural Reuse: A Fundamental Organizational Principle Of The Brain, Michael Anderson

Brain and Mind Institute Researchers' Publications

An emerging class of theories concerning the functional structure of the brain takes the reuse of neural circuitry for various cognitive purposes to be a central organizational principle. According to these theories, it is quite common for neural circuits established for one purpose to be exapted (exploited, recycled, redeployed) during evolution or normal development, and be put to different uses, often without losing their original functions. Neural reuse theories thus differ from the usual understanding of the role of neural plasticity (which is, after all, a kind of reuse) in brain organization along the following lines: According to neural reuse, …

Multiple Mechanisms Of Consciousness: The Neural Correlates Of Emotional Awareness., Jayna M Amting, Steven G Greening, Derek G V Mitchell

Brain and Mind Institute Researchers' Publications

Emotional stimuli, including facial expressions, are thought to gain rapid and privileged access to processing resources in the brain. Despite this access, we are conscious of only a fraction of the myriad of emotion-related cues we face everyday. It remains unclear, therefore, what the relationship is between activity in neural regions associated with emotional representation and the phenomenological experience of emotional awareness. We used functional magnetic resonance imaging and binocular rivalry to delineate the neural correlates of awareness of conflicting emotional expressions in humans. Behaviorally, fearful faces were significantly more likely to be perceived than disgusted or neutral faces. Functionally, …

Deficits In Attention To Emotional Stimuli Distinguish Youth With Severe Mood Dysregulation From Youth With Bipolar Disorder., Brendan A Rich, Melissa A Brotman, Daniel P Dickstein, Derek G V Mitchell, R James R Blair, Ellen Leibenluft

Brain and Mind Institute Researchers' Publications

Studying attention in the context of emotional stimuli may aid in differentiating pediatric bipolar disorder (BD) from severe mood dysregulation (SMD). SMD is characterized by chronic irritability, arousal, and hyper-reactivity; SMD youth frequently receive a BD diagnosis although they do not meet DSM-IV criteria for BD because they lack manic episodes. We compared 57 BD (14.4 +/- 2.9 years old, 56% male), 41 SMD (12.6 +/- 2.6 years old, 66% male), and 33 control subjects (13.7 +/- 2.5 years old, 52% male) using the Emotional Interrupt task, which examines how attention is impacted by positive, negative, or neutral distracters. We …

Living On Autopilot: How Your Brain Thinks For You, Andrea Stathopoulos '10

Honor Scholar Theses

One way in which humans are set apart from other animals is by our impressive intellectual capacities. Humans are commonly considered to be true masters of rational, conscious control over our actions. However, that feeling of control may be mostly illusory. Accumulating evidence suggests that unconscious cognitive processes can account for much of human behavior. Homeostasis is a clear example of the evolutionary benefit of automation, allowing valuable energy and limited attention to be diverted elsewhere. I instead want to focus on the automaticity of more complicated behaviors, ones that are typically thought to require a large amount of cognitive …

Motor Output Evoked By Subsaccadic Stimulation Of Primate Frontal Eye Fields., Brian D Corneil, James K Elsley, Benjamin Nagy, Sharon L Cushing

Brain and Mind Institute Researchers' Publications

In addition to its role in shifting the line of sight, the oculomotor system is also involved in the covert orienting of visuospatial attention. Causal evidence supporting this premotor theory of attention, or oculomotor readiness hypothesis, comes from the effect of subsaccadic threshold stimulation of the oculomotor system on behavior and neural activity in the absence of evoked saccades, which parallels the effects of covert attention. Here, by recording neck-muscle activity from monkeys and systematically titrating the level of stimulation current delivered to the frontal eye fields (FEF), we show that such subsaccadic stimulation is not divorced from immediate motor …

Theta-Activity In Anterior Cingulate Cortex Predicts Task Rules And Their Adjustments Following Errors, Thilo Womelsdorf, Kevin Johnston, Martin Vinck, Stefan Everling

Brain and Mind Institute Researchers' Publications

Accomplishing even simple tasks depend on neuronal circuits to configure how incoming sensory stimuli map onto responses. Controlling these stimulus-response (SR) mapping rules relies on a cognitive control network comprising the anterior cingulate cortex (ACC). Single neurons within the ACC convey information about currently relevant SR mapping rules and signal unexpected action outcomes, which can be used to optimize behavioral choices. However, its functional significance and the mechanistic means of interaction with other nodes of the cognitive control network remain elusive and poorly understood. Here, we report that core aspects of cognitive control are encoded by rhythmic theta-band activity within …