12 Sep 2017
September 12, 2017

Howard Eichenbaum (1947–2017)

In The News

A wonderful tribute to Howard Eichenbaum by Mike Hasselmo and Chantal Stern.  You will be missed, Howard.

http://science.sciencemag.org/content/357/6354/875

And they show the same independence between the visual hemifields that we saw in primates.

Balakhonov, D., & Rose, J. (2017). Crows Rival Monkeys in Cognitive CapacityScientific Reports7.

For further reading:

Buschman,T.J., Siegel, M., Roy, J.E. and Miller, E.K. (2011) Neural substrates of cognitive capacity limitations. Proceedings of the National Academy of Sciences. 108(27):11252-5. View PDF »

Miller, E.K. and Buschman, T.J. (2015)  Working memory capacity: Limits on the bandwidth of cognition. Daedalus, Vol. 144, No. 1, Pages 112-122. View PDF »

Kornblith, S., Buschman, T.J., and Miller, E.K. (2015)  Stimulus load and oscillatory activity in higher cortex. Cerebral Cortex. Published online August 18, 2015  doi: 10.1093/cercor/bhv182. View PDF »

Driscoll et al tracked parietal cortex neurons over one month after mice learned and practiced a navigation task.  The activity of individual neurons changed but information on the population level was stable.  This is a nice demonstration of “mixed selectivity” in individual neurons and further evidence that the functional unit of the brain is neural ensembles, not individual neurons.

Driscoll, L. N., Pettit, N. L., Minderer, M., Chettih, S. N., & Harvey, C. D. (2017). Dynamic reorganization of neuronal activity patterns in parietal cortexCell.

For further reading:
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 »

When you search for something do you simply hold a static template of it in mind.  Apparently not.  Your search template waxes and wanes, waxing with the anticipated moment of search.  When the template is strong, your eyes move less.

Olmos-Solis, K., van Loon, A. M., Los, S. A., & Olivers, C. N. (2017). Oculomotor measures reveal the temporal dynamics of preparing for search. Progress in Brain Research.

A study using a combination of TMS and FMRI to asses functional connectivity.

Hawco, C., Armony, J. L., Daskalakis, Z. J., Berlim, M. T., Chakravarty, M. M., Pike, G. B., & Lepage, M. (2017). Differing Time of Onset of Concurrent TMS-fMRI during Associative Memory Encoding: A Measure of Dynamic ConnectivityFrontiers in Human Neuroscience11, 404.

Working memory for different items in a sequence is prioritized by how much attention is paid to the item at encoding.

Jafarpour, A., Penny, W., Barnes, G., Knight, R. T., & Duzel, E. (2017). Working Memory Replay Prioritizes Weakly Attended EventseNeuro4(4), ENEURO-0171.

Context-dependent attractor dynamics can underlie mental flexibility.

Tajima, S., Koida, K., Tajima, C. I., Suzuki, H., Aihara, K., & Komatsu, H. (2017). Task-dependent recurrent dynamics in visual cortex. eLife6, e26868.

Marc Howard reviews “time cells” in the brain.  Time cells show Weber-fraction like decreases in accuracy the further in the past you go.  Interestingly, these cells keep track of time even when tasks do not require it.  You can’t escape time.

Howard, M. W. Memory as perception of the past: Compressed time in mind and brain.

 

 

Miller Lab postdoc Mikael Lunqvist won a NARSAD Young Investigator Grant.  Congrats, Mikael!

Read Mikael’s recent paper to see what the fuss is all about:
Lunqvist, M., Rose, J., Herman, P, Brincat, S.L, Buschman, T.J., and Miller, E.K. (2016) Gamma and beta bursts underlie working memory.  Neuron, published online March 17, 2016. View PDF »

Info about NARSAD grants:
https://www.bbrfoundation.org/grants-prizes/grants

Here’s Mikael:

Mikael Lundqvist

Increased theta synchrony between the prefrontal cortex and hippocampus when subjects encoded unexpected study items.  This is further evidence that theta-band (6-10 Hz) oscillations orchestrate communication between these brain areas.

Gruber, M. J., Hsieh, L. T., Staresina, B., Elger, C., Fell, J., Axmacher, N., & Ranganath, C. (2017). Theta Phase Synchronization Between The Human Hippocampus And The Prefrontal Cortex Supports Learning Of Unexpected InformationbioRxiv, 144634.

For further reading:

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