Eiselt and Nieder trained monkeys to make greater/less than judgments to line lengths and dot numerosities.  They compared neural activity in the prefrontal cortex (PFC), anterior cingulate (AC), and premotor cortex (PMC).  The greatest proportion of greater/less than rule neurons were found in the PFC.  Further, only the PFC had neurons that were “generalists”; they signaled the greater/less than rules for both judgments.  Neurons in other areas were specialized for one judgment or the other.

This is consistent with our work showing that a large proportion of PFC neurons are multifunction, mixed selectivity neurons.  They may be key in providing the computational power for complex, flexible behavior.  For further reading see:

Rigotti, M., Barak, O., Warden, M.R., Wang, X., Daw, N.D., Miller, E.K., & Fusi, S. (2013) “The importance of mixed selectivity in complex cognitive tasks”. Nature, 497, 585-590,  doi:10.1038/nature12160. View PDF

Cromer, J.A., Roy, J.E., and Miller, E.K. (2010) Representation of multiple, independent categories in the primate prefrontal cortex. Neuron, 66: 796-807. View PDF »

About the Author


The Miller Lab uses experimental and theoretical approaches to study the neural basis of the high-level cognitive functions that underlie complex goal-directed behavior. ekmillerlab.mit.edu