Title Information
Type of Resource (primo): dissertations
Name: Personal
Name: Personal
Name: Personal
Name: Personal
Name: Personal
Name: Corporate
Origin Information
Physical Description
Note: thesis: Thesis (Ph. D.)--Brown University, 2024
Genre (aat): theses
Abstract: Neocortical circuits respond with distinct sensitivity to unexpected ‘deviant’ stimuli, an amplification mechanism widely regarded as crucial for sensory processing. Despite extensive characterization of stimulus-evoked neural responses and the ensembles of neurons that underlie these responses, the process by which neural circuits dynamically differentiate between static and changing stimulus features (i.e., deviance detection, DD)—a process essential to an animal’s ability to interact with and recognize patterns in its environment—remains largely unknown. Here, I employed computational neural modeling and theoretical analysis to explore how a local patch of neocortex (i.e., a neocortical column) gets activated by afferent drive and how recurrent dynamics between neuron types within the column contribute to sensory encoding, specifically in service of DD. Through the development and use of a biophysically-detailed computational model that bridges from microscale cellular and circuit-level neurophysiology phenomena (e.g., measured invasively in rodents) to macroscale phenomena measured non-invasively in humans, I found that local inhibition plays a unique and critical role in shaping the neocortical column’s response to sensory afferent drive. Specifically, I discovered distinct spatiotemporal patterns of afferent drive that allows the neurons of a neocortical column to produce different types of somatosensory evoked responses (in this case, due to non-nociceptive versus nociceptive stimuli). These patterns of afferent drive provided excitation to a wide swath of cells in a local neocortical column yet were found to leverage specialized targeting of layer-specific inhibitory interneurons to modulate the dynamics and stability of emergent electrophysiology signals in a stimulus-specific manner. I further developed a dynamical system theory for the generation of experimentally observed measures of deviance-driven shifts in neural tuning. With a number of corollary predictions that can be tested in future in vivo studies, I show that ensemble priming viacompetitive inhibition acts as a local mechanism for sensory context storage and DD that does not require specialized input from other brain areas—a novel theoretical paradigm that resolves previously confounding aspects of sensory encoding and predictive processing in the neocortex.
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00872004")
Subject
Subject
Language
Record Information