In nearly all sensory pathways, sensory information propagates from the peripheral receptors to the thalamus before reaching the cortex. The thalamocortical circuit is a critical stage of processing where sensory encoding explodes in complexity, ultimately providing the computations necessary for interacting with our environment. Thalamic activity, and ultimately cortical processing, is strongly affected by fluctuating subthreshold membrane potential levels in the thalamus, or the thalamic state. Neurons in the thalamus have long been described as having distinct “modes” of firing, from tonic to burst, and the firing mode is modulated by the level of polarization of the membrane potential of these neurons. Although we have some knowledge of the firing modes induced by thalamic state, we do not have a clear understanding of how these firing modes affect the transmission of sensory information. Previous work in our lab has suggested that 'burst' firing may be indicative of a 'detect' mode while 'tonic' firing may be better suited for a 'discrimination' mode. In this work, I will comprehensively examine the role of imposed thalamic states on the encoding of somatosensory information by explicitly testing hypotheses about the relationship between firing mode and information transmission in the thalamocortical circuit. Furthermore, I will directly quantify the role of critical thalamic feedback regions in the modulation of thalamic state. This work will provide, for the first time, a thorough investigation of the mechanisms underlying thalamic state and the functional implications of dynamic encoding.