Associate Professor, Department of Psychology
Ph.D. California Institute of Technology
Sc.B. Brown University
Research Interests: How local circuits in the auditory cortex encode and transform sensory information
Overview: We study how local circuits in the cerebral cortex encode and transform sensory information. We use the rodent auditory cortex as a model system to investigate how cellular and network properties shape cortical responses to a continuous and temporally complex stream of sensory data. Research in my laboratory combines aspects of both cellular, systems, and computational neuroscience, by using the tools of molecular biology and cellular physiology to address systems-level questions. By using a variety of electrophysiological approaches, in particular in vivo whole cell recording methods in combination with molecular manipulations, we are trying to identify the cellular and synaptic mechanisms with which cortical circuits process auditory information, leading ultimately to our perceptual experiences of acoustic streams, such as music and speech.
A Cortico-Collicular Amplification Mechanism for Gap Detection.
Cereb Cortex. 2020 Feb 14;:
Authors: Weible AP, Yavorska I, Wehr M
Auditory cortex (AC) is necessary for the detection of brief gaps in ongoing sounds, but not for the detection of longer gaps or other stimuli such as tones or noise. It remains unclear why this is so, and what is special about brief gaps in particular. Here, we used both optogenetic suppression and conventional lesions to show that the cortical dependence of brief gap detection hinges specifically on gap termination. We then identified a cortico-collicular gap detection circuit that amplifies cortical gap termination responses before projecting to inferior colliculus (IC) to impact behavior. We found that gaps evoked off-responses and on-responses in cortical neurons, which temporally overlapped for brief gaps, but not long gaps. This overlap specifically enhanced cortical responses to brief gaps, whereas IC neurons preferred longer gaps. Optogenetic suppression of AC reduced collicular responses specifically to brief gaps, indicating that under normal conditions, the enhanced cortical representation of brief gaps amplifies collicular gap responses. Together these mechanisms explain how and why AC contributes to the behavioral detection of brief gaps, which are critical cues for speech perception, perceptual grouping, and auditory scene analysis.
PMID: 32055848 [PubMed - as supplied by publisher]
Disruption of Early or Late Epochs of Auditory Cortical Activity Impairs Speech Discrimination in Mice.
Front Neurosci. 2019;13:1394
Authors: O'Sullivan C, Weible AP, Wehr M
Speech evokes robust activity in auditory cortex, which contains information over a wide range of spatial and temporal scales. It remains unclear which components of these neural representations are causally involved in the perception and processing of speech sounds. Here we compared the relative importance of early and late speech-evoked activity for consonant discrimination. We trained mice to discriminate the initial consonants in spoken words, and then tested the effect of optogenetically suppressing different temporal windows of speech-evoked activity in auditory cortex. We found that both early and late suppression disrupted performance equivalently. These results suggest that mice are impaired at recognizing either type of disrupted representation because it differs from those learned in training.
PMID: 31998064 [PubMed]