Do rodents have one?  The answer is not straightforward.  Marie Carlén reviews the data for us.

Carlén, M. (2017). What constitutes the prefrontal cortex?Science358(6362), 478-482.

Interesting new results from Charan Ranganath and crew.  They show changes in oscillatory dynamics in humans as they learn new visuomotor associations.  There was a decrease in theta and an increase in alpha oscillations, much as has been seen in animals.

Clarke, A., Roberts, B. M., & Ranganath, C. (2017). Neural oscillations during conditional associative learningbioRxiv, 198838.

For further reading:
Loonis, R.F, Brincat, S.L., Antzoulatos, E.G., and Miller, E.K. (2017) A meta-analysis suggests different neural correlates for implicit and explicit learning. Neuron. 96:521-534  View PDF

Brincat, S.L. and Miller, E.K. (2015)  Frequency-specific hippocampal-prefrontal interactions during associative learning.  Nature Neuroscience. Published online 23 Feb 2015 doi:10.1038/nn.3954. View PDF »

Brincat, S.L. and Miller, E.K (2016) Prefrontal networks shift from external to internal modes during learning  Journal of Neuroscience. 36(37): 9739-9754, 2016 doi: 10.1523/JNEUROSCI.0274-16.2016. View PDF

There were clear differences.

Viswanathan, P., & Nieder, A. (2017). Comparison of visual receptive fields in the dorsolateral prefrontal cortex (dlPFC) and ventral intraparietal area (VIP) in macaques. European Journal of Neuroscience.

Press release for our new paper in Neuron: Brain waves reflect different types of learning

Lindsay, G.W., Rigotti, M., Warden, M.R., Miller, E.K., and Fusi, S. (2017) Hebbian Learning in a Random Network Captures Selectivity Properties of Prefrontal CortexJournal of Neuroscience.  6 October 2017, 1222-17; DOI:   View PDF

A Meta-Analysis Suggests Different Neural Correlates for Implicit and Explicit Learning
Roman F. Loonis, Scott L. Brincat, Evan G. Antzoulatos, Earl K. Miller
Neuron, 96(2): p521-534, 2017.

Preview by Matthew Chafee and David Crowe:
Implicit and Explicit Learning Mechanisms Meet in Monkey Prefrontal Cortex

Parthasarathy et al found that a distractor stimulus caused neural representations in the prefrontal cortex to morph into a different pattern but while still retaining information about the item in memory.  This was due to mixed selectivity neurons.  By contrast, the FEF had less mixed selectivity and the distractor caused it to lose information.  Nice.

Mixed selectivity morphs population codes in prefrontal cortex
Aishwarya Parthasarathy, Roger Herikstad, Jit Hon Bong, Felipe Salvador Medina, Camilo Libedinsky & Shih-Cheng Yen
Nature Neuroscience (2017)

For further reading about mixed selectivity:
Fusi, S., Miller, E.K., and Rigotti, M. (2016) Why neurons mix: High dimensionality for higher cognition.  Current Opinion in Neurobiology. 37:66-74  doi:10.1016/j.conb.2016.01.010. View PDF »
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 »

American Academy of Arts and Sciences. Induction Ceremony October 7, 2017.
The American Academy of Arts and Sciences is of the nation’s most prestigious honorary societies, the academy is also a leading center for independent policy research. Members contribute to academy publications, as well as studies of science and technology policy, energy and global security, social policy and American institutions, the humanities and culture, and education.

Tomorrow, we say good bye to a great scientist and a great person.  I am going to miss you, Howard.

Remembering Howard Eichenbaum


Feb 14-17, 2018 in Washington, DC.  See you there!

INS Washington DC 2018