Cris Niell

Assistant Professor, Department of Biology
Member, ION

Ph.D. Stanford University
B.S. Stanford Univeristy

214 LISB


Research Interests: Function and development of neural circuits for visual processing

Overview: How do we make sense of the visual world around us? Our brain takes a pattern of photons hitting the retina and continually creates a coherent representation of what we see – detecting objects and landmarks rather than just perceiving an array of pixels. This image processing allows us to perform a range of visual tasks, such as recognizing a friend’s face, finding your way to the grocery store, and catching a frisbee. However, how these computational feats are achieved by the neural circuitry of the visual system is largely unknown. Furthermore, this circuitry is wired up by a range of cellular processes, such as arbor growth, synapse formation, and activity-dependent plasticity, and thus these developmental mechanisms effectively determine how we see the world.

Our research is focused on understanding how neural circuits perform the image processing that allows us to perform complex visual behaviors, and how these circuits are assembled during development. We use in vivo recording techniques, including high-density extracellular recording and two-photon imaging, along with molecular genetic tools to dissect neural circuits, such as cell-type specific markers, optogenetic activation and inactivation, tracing of neural pathways, and in vivo imaging of dendritic and synaptic structure. We have also implemented behavioral tasks for mice so we can perform quantitative pyschophysics to measure the animal’s perception, and we use theoretical models to understand general computational principles being instantiated by a neural circuit.


How Changes in White Matter Might Underlie Improved Reaction Time Due to Practice.

Cogn Neurosci. 2016 Apr 11;

Authors: Voelker P, Piscopo D, Weible A, Lynch G, Rothbart MK, Posner MI, Niell CM

Why does training on a task reduce the reaction time for performing it? New research points to changes in white matter pathways as one likely mechanism. These pathways connect remote brain areas involved in performing the task. Genetic variations may be involved in individual differences in the extent of this improvement. If white matter change is involved in improved reaction time with training, it may point the way toward understanding where and how generalization occurs. We examine the hypothesis that brain pathways shared by different tasks may result in improved performance of cognitive tasks remote from the training.

PMID: 27064751 [PubMed - as supplied by publisher]