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Full-Text Articles in Life Sciences
Understanding Object Motion Encoding In The Mammalian Retina., Victor Julian Depiero
Understanding Object Motion Encoding In The Mammalian Retina., Victor Julian Depiero
Electronic Theses and Dissertations
Phototransduction, transmission of visual information down the optic nerve incurs delays on the order of 50 – 100ms. This implies that the neuronal representation of a moving object should lag behind the object’s actual position. However, studies have demonstrated that the visual system compensates for neuronal delays using a predictive mechanism called phase advancing, which shifts the population response toward the leading edge of a moving object’s retinal image. To understand how this compensation is achieved in the retina, I investigated cellular and synaptic mechanisms that drive phase advancing. I used three approaches, each testing phase advancing at a …
Coupled Correlates Of Attention And Consciousness, Ravi Varkki Chacko
Coupled Correlates Of Attention And Consciousness, Ravi Varkki Chacko
McKelvey School of Engineering Theses & Dissertations
Introduction: Brain Computer Interfaces (BCIs) have been shown to restore lost motor function that occurs in stroke using electrophysiological signals. However, little evidence exists for the use of BCIs to restore non-motor stroke deficits, such as the attention deficits seen in hemineglect. Attention is a cognitive function that selects objects or ideas for further neural processing, presumably to facilitate optimal behavior. Developing BCIs for attention is different from developing motor BCIs because attention networks in the brain are more distributed and associative than motor networks. For example, hemineglect patients have reduced levels of arousal, which exacerbates their attentional deficits. More …
Electrophysiological Mechanisms For Preparing Control In Time, Jacqueline Rosemary Janowich
Electrophysiological Mechanisms For Preparing Control In Time, Jacqueline Rosemary Janowich
Psychology ETDs
Cognitive control is critical in guiding goal-directed behavior, preparing neural resources and adapting processing to promote optimal action in a given environment. According to the Dual Mechanisms of Control theory (Braver, 2012), control can be dichotomized into proactive and reactive modes of control, utilized reciprocally in ahead-of-time preparation versus last-minute, stimulus-evoked reaction. Although a substantial body of work has tested differences between proactive control and reactive control, the underlying assumption of proactive control as a unitary process has not been systematically investigated. Very little is known as to how or when proactive control is initiated, sustained, or implemented.
As time …
Shining Light On An Amygdala -- Brainstem Connection Important For Attention Processing, Jose Carlos Cano
Shining Light On An Amygdala -- Brainstem Connection Important For Attention Processing, Jose Carlos Cano
Open Access Theses & Dissertations
We are continuously being exposed to an exorbitant amount of sensory information, which should result overwhelming. However, the nervous system operates several intrinsic sensory filtering mechanisms that allow us to cope with such sensory cluttering and shape appropriate behavior. Sensorimotor gating is a pre-attentive neuronal filtering mechanism that gates superfluous sensory information, and orients attentional resources towards salient information processing. Its relevance becomes in individuals suffering from schizophrenia and several otherwise unrelated neuropsychiatric disorders where sensorimotor gating is impaired. To understand the neural impaired mechanisms, extensive research studies have focused on first identifying the neural substrates underlying sensorimotor gating. This …
The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback
The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback
Theses and Dissertations--Biology
The ketogenic diet is commonly used to control epilepsy, especially in cases when medications cannot. The diet typically consists of high fat, low carb, and adequate protein and produces a metabolite called acetoacetate. Seizure activity is characterized by glutamate excitotoxicity and therefore glutamate regulation is a point of research for control of these disorders. Acetoacetate is heavily implicated as the primary molecule responsible for decreasing glutamate in the synapse; it is believed that acetoacetate interferes with the transport of glutamate into the synaptic vesicles. The effects on synaptic transmission at glutamatergic synapses was studied in relation to the ketogenic diet …