Livingstone Logo

Carlos Ramon Ponce, M.D., Ph.D.

Postdoctoral Fellow at the Livingstone Laboratory

Education and Training


Carlos_Education_Logos
Ponce and others 2008




Neuroscience Primer
for Rotating Lab Students


Paris sculpture





         Research Interests
   
Carlos en Xochimilco
About me





EDUCATION / TRAINING

INSTITUTION AND LOCATION

DEGREE

MM/YY

FIELD OF STUDY

University of Utah
 
Harvard Graduate School of Arts and Sciences
 
Harvard-M.I.T. Health Sciences and Technology Program, Harvard Medical Schoo
B.S.



 Ph.D.

 
M.D.

06/2001

 

06/2008

 

06/2010

Biology and chemistry

 

Neurobiology

 

Medicine

POST-GRADUATE POSITIONS

INSTITUTION AND LOCATION


MM/YY POSITION
  Massachusetts General Hospital

2010 - 2012
Pathology resident

Research Interests

Many years back, a relative once asked me - how could we know if our perceptions of colors were the same? Is it possible that his subjective impression of blue was the same that others experienced as red? My cousin, a Mexican immigrant trained as an electrician, had never taken a philosophy course. Qualia and zombies did not preoccupy him. Yet a brief gaze inward and he swiftly joined  the ranks of those who have been captured by the ageless puzzles of the brain. I had stepped into that crowd not long before, and have remained an enthusiastic student every since.

I am interested in how billions of electrically–active cells form our thoughts and behavior. Although a robust understanding of this problem requires the study of processes at the level of the synapse, single cells, cellular networks and experimental psychology, I have anchored my daily work to the activity of single cells and neuronal networks in the visual cortex.

Decades of investigations of the visual cortex have revealed  the existence of a set of semi-parallel, hierarchical cellular circuits that process information across multiple cortical areas. Neurons in the primary visual cortex (V1) actively represent specific features of the visual scene and project their outputs to different cells in the occipital, temporal and parietal lobes. The recipient cells generally demonstrate different functional responses - some concerned with shape, others with motion, color/wavelength, depth/binocular disparity. The visual scene is thus broken down across different domains of information, reflected by these different channels.

My graduate thesis work explored how different channels combine information at the level of a single neuron. Motion–sensitive cells in area MT (V5) receive concurrent inputs from multiple antecedent areas (its largest inputs arise from V1, V2 and V3). We found that distinct features of motion analyzed in MT, such as direction and depth, are disproportionately represented by different input pathways (binocular disparity, or depth, depends heavily on the inputs of V2 and V3 cells; but direction of motion is well–sustained by V1 inputs alone). The speed of moving objects is also computed by two complementary pathways: the representation of higher speeds in area MT depend significantly on the input of V2 and V3 cells.

After undertaking some pathology training, I have begun a new project exploring the ventral stream of the macaque brain, which subserves the analysis of object shape. I am excited to explore a new aspect of the fascinating visual brain.


Publications

Ponce CR, Hunter JN, Pack CC, Lomber SG, Born RT. (2011) Contributions of indirect pathways to visual response properties in macaque middle temporal area MT. J. Neurosci. Mar 9; 31(10):3894-903.

Ponce CR, Lomber SG, Born RT. (2008) Integrating motion and depth via parallel pathways. Nat Neurosci. 2008 Feb; 11(2):216-23.

Born RT, Pack CC, Ponce CR, Yi S. (2006) Temporal evolution of 2-dimensionaldirection signals used to guide eye movements. J Neurophysiol. Jan;95(1):284-300.

Ponce CR, Born RT. (2008) Stereopsis. Curr Biol. Sep 23;18(18):R845-50.

Educational resources

David_Hubel_Image


David Hubel's Eye, Brain and Vision. A wonderful introduction to modern systems neuroscience, by one of its earliest and most distinguished pioneers. The book is entirely available in Dr. Hubel's website.





More resources on the way...




About me

I was born in Chihuahua, Mexico, and grew up in a farm in central Mexico. Part of my family moved to the United States in the late eighties, and I joined them in 1991. I attended high school and college in Salt Lake City, Utah.

In my non-laboratory time, I enjoy reading and holding extended discussions with friends about politics, philosophy, morality, temperament and personality or the latest electronic gadget. If current company allows it, I will happily discuss comic books, popular TV shows and movies. An obsession with Americana? Sure...I'm a naturalized citizen now, but I was and will always be a wide–eyed immigrant at heart...

For more info, please visit my Google Plus page.