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Towards Understanding And Improving Speech Processing, Sonia Yasmin

Electronic Thesis and Dissertation Repository

This dissertation explores mechanisms for understanding and improving speech processing. First, I used EEG to investigate the acoustic and semantic processing of continuous naturalistic speech masked by multi-talker babble. I found that different features of the same speech signal are reflected in different aspects of the neural tracking response, which are themselves differentially affected by noise. These findings point to a complex relationship between speech intelligibility and neural speech encoding.

Next, I systematically reviewed the current advancements in speech enhancement technologies. I find that speech enhancement algorithms are limited in their generalizability to speech-noise (i.e., babble). I demonstrate that, for …

The Modulation Of Lfp Characteristics In The Freely Moving Common Marmoset, William Jm Assis

Electronic Thesis and Dissertation Repository

The hippocampus is a neural structure critical for navigation. Neurons in this region, along with others, create a functional network which generates large-amplitude modulations known as local field potential (LFP) activity. Prior LFP research has predominantly used rodent animal models, however recent studies have shown that frequencies associated with navigation in other mammals do not correlate to those of the rodent. We hypothesized that LFP characteristics in the common marmoset are modulated by the speed and axis of travel of the animal. Two marmosets were placed in a free moving 3-dimensional environment where movement and neurological activity were recorded. Results …

Characterizing The Cognitive And Emotional Effects Of Delta-9-Tetrahydrocannabinol In Distinct Hippocampal Sub-Regions, Dinat Khan

Electronic Thesis and Dissertation Repository

The objective of this study is to determine the potential differential effects of THC in the DH or VH sub-regions, as well as the upstream effects on PFC neuronal activity and oscillations. Rodents used for electrophysiology were infused with THC or vehicle in the DH or VH regions, combined with PFC recordings. Additionally, a battery of behavioural paradigms was performed. Deficits in short-term memory when THC was infused into both regions was observed, however working memory was impaired with VH infusions only. This could be due to THC-induced dysregulation in the PFC, as beta oscillations were significantly decreased selectively in …