Quantitative lunch -- Dr. Dan Meliza (University of Virginia).

"In noisy environments, the human auditory system fills in speech sounds obscured by noise, a perceptual illusion known as phonemic (or auditory) restoration. The neural mechanisms allowing the brain to generate predictions that override ascending sensory information remain poorly understood. Using data from extracellular recordings of many neurons, we tested whether zebra finches (Taeniopygia guttata) exhibit patterns of activity consistent with the illusion of auditory restoration. We find that applying a linear decoder to occluded songs reveals the spectrotemporal structure of the missing syllables. Surprisingly, restoration occurs under anesthesia and for unfamiliar as well as familiar songs. These results show that circuit dynamics within the auditory system instantiate an internal model of the general structure of conspecific vocalizations that can fill in missing acoustic features in ambiguous stimuli, even in the absence of top-down attention."