The broad goal of this proposal is to study the processing of audiovisual (AV) information in communication. This is key to my long term goal of understanding how this contributes to emotion and social cognition. Recent findings dispute the traditional view that cortical sensory processing is isolated within each modality for at least the first several processing stages, suggesting instead that the senses are already merging at the inception of cortical processing. There is also recent evidence that primary cortical integration of sensory input from any source makes instrumental use of the ambient oscillatory activity, omnipresent in the local neuronal ensemble, and that this provides the means for non-auditory inputs to modulate the processing of auditory inputs in primary auditory cortex (A1). Along with their broader implications, these findings have specific import for my project. Coming from a background in physics, molecular biology and cellular neurophysiology, my objective in joining the Cognitive Neuroscience and Schizophrenia Division at the Nathan Kline Institute was to learn how to study neuronal ensemble physiology using combined local field potential (LFP), multiunit activity (MUA) and current source density (CSD) analysis, and how to translate information gleaned with these techniques to a more direct understanding of homologous brain processes occurring in humans. I also needed grounding in the key conceptual issues pertinent to studying neuronal ensemble oscillations with these and other methods in both animals and humans. My project will focus on AV integration during vocalization processing in A1. I will study activity in A1 while they discriminate changes in the A and V components of conspecific vocalizations. As part of my training, I will participate in regular discussions of theory and technique in human EEG/ERP studies. I have one Specific Aim: To define the physiological mechanisms by which neuronal processing of vocalizations is affected by viewing the """"""""speaker's"""""""" face. I will evaluate the hypothesis that vocalization-induced neuronal responses in A1 are amplified by coincident visual input using a novel """"""""oscillatory phase-modulation"""""""" mechanism that I will outline in the following section. In evaluating this hypothesis, I will also determine the extent to which AV interactions in A1 conform to the Temporal Contiguity and Inverse Effectiveness Principles of multisensory integration.
The findings contribute-to the understanding of the neural bases of communicative and social cognition dysfunctions that are prominent components of neuropsychiatric disorders such as autism and schizophrenia.
| Kajikawa, Yoshinao; Camalier, Corrie R; de la Mothe, Lisa A et al. (2011) Auditory cortical tuning to band-pass noise in primate A1 and CM: a comparison to pure tones. Neurosci Res 70:401-7 |
| Kajikawa, Yoshinao; Schroeder, Charles E (2011) How local is the local field potential? Neuron 72:847-58 |
