Cortical Dynamics & Perception
Overview of Our Research
My goal is to understand the neural mechanisms of perception. My specific focus is to understand how dynamics in the neocortex, changes in its operating characteristics on millisecond time scales, shape these processes. We study the mechanisms that generate these dynamics (for a recent review, see Moore et al., in press Cell) and their meaning for information processing.
This problem requires a multi-disciplinary approach, and we draw principles and techniques from neuroscience, computation, biology and bioengineering. As one example, we recently demonstrated that a specific cell type in the neocortex can drive emergence of the ‘gamma’ rhythm, an oscillation associated with attention and with enhanced perceptual performance (Cardin et al., 2009 Nature). This study leveraged biological techniques (targeted viral transduction in genetic models) and required integration of multiple forms of electrophysiological recording with laser stimulation (Cardin et al., 2010 Nature Protocols).
We have now developed optogenetic control in behaving animals (Ritt et al., 2009 Soc for Neuroscience Abstracts). This advance lets us further our studies of cell type specific mechanisms in awake animals, and lets us causally test the impact of these dynamics on detailed perceptual performance in head posted animals. We are beginning to combine this strategy—precise psychophysics with optogenetic control—with neural monitoring, including intracellular and extracellular recording and 2-photon imaging.
Related studies in my laboratory also benefit from an integrative view of biological systems in the brain. Specifically, we are testing the hypothesis that local vascular dynamics impact neocortical dynamics and, in so doing, impact sensory information processing (Moore and Cao, 2008 J Neurophys). In this work, we are also innovating new methods, developing means for precise spatio-temporal control of brain vasculature by optogenetic targeting of smooth muscle.
The vibrissa sensory system—and its ‘barrel’ cortex—is our model. This model provides a high-resolution sensory system in a mammal (mouse) where we can leverage advances in genetic engineering. In addition to our studies of dynamics in this system, we have contributed to basic understanding, including delineation of key dimensions of the natural vibrissa ‘scene’ (e.g., Ritt et al., 2008 Neuron) and discovery of 2 new feature maps in barrel cortex (Andermann et al., 2004 Neuron; Andermann and Moore, 2006 Nature Neurosci).
To directly make a translational connection between these model studies and human dynamics, we pursue targeted studies of humans performing perceptual tasks, using MEG to record macroscopic neocortical activity patterns. To bridge our human and animal work, we construct biophysically precise computational models of neocortex, based on our knowledge from rodent studies, that capture the human MEG signal (e.g., Jones et al., 2007 J Neurosci; Jones et al., 2009 J Neurophys). These studies are conducted in collaboration with Dr. Stephanie Jones of Massachusetts General Hospital.