How do spatiotemporal patterns of spiking activity influence the computations in local and remotely-connected neural populations? Which features of local field potentials reflect these computations? Can we track changes in these neural dynamics with learning?

Studying changes in neural activity across neural ensembles in the behaving primate brain requires specialized tools and techniques. We have developed several indwelling recording solutions that have allowed us to sample multiple areas with linear arrays. We’ve used these arrays with closed-loop stimulation and with wireless recording in freely-behaving macaques.

Relevant publications:

  • Talakoub O, Lewis CM, Fries P, Zinke W, Womelsdorf T,  and Hoffman KL Tuning of hippocampal and neocortical oscillations with vigilance state in freely-behaving macaques. (pending).
  • Hussin AT, Leonard TK and Hoffman KL Sharp-wave ripple features in macaques depend on behavioral state and cell-type specific firing. (accepted pending minor revisions)
  • Montefusco-Siegmund R, Leonard TK and Hoffman KL (2017) Hippocampal gamma-band synchrony and pupillary responses index memory during visual search. Hippocampus 27(4)p. 425-434. doi: 10.1002/hipo.22702
  • Sayegh PF, Gorbet DJ, Hawkins KM, Hoffman KL, Sergio LE (2017) The Contribution of Different Cortical Regions to the Control of Spatially Decoupled Eye–Hand Coordination. Journal of Cognitive Neuroscience doi:10.1162/jocn_a_01111
  • Talakoub O, Gomez Palacio-Schjetnan A, Popovic MR, Valiante TA, Hoffman KL (2016) Closed-loop interruption of hippocampal ripples through fornix stimulation in non-human primates. Brain Stimulation DOI: 10.1016/j.brs.2016.07.010
  • Leonard TK, Mikkila J, Gerrard JL, Kaping D, Patel S, Eskandar E, Womelsdorf T, Hoffman KL. (2015) Sharp wave ripples during visual exploration in the primate hippocampus. The Journal of Neuroscience 35(44):14771-14782  doi: 10.1523/JNEUROSCI.0864-15.2015
  • Hoffman KL, McNaughton BL (2002) Coordinated reactivation of distributed memory traces in primate neocortex. Science 297:2070-3.
  • Turesson HK, Logothetis NK, Hoffman KL (2012) Category-selective phase coding in the superior temporal sulcus. Proceedings of the National Academy of Sciences. doi:10.1073/pnas.1217012109
  • Gothard KM, Hoffman KL, Battaglia F, McNaughton BL (2001) Dentate gyrus and CA1 ensemble activity during spatial reference frame shifts in the presence and absence of visual input. Journal of Neuroscience 21(18):7284-92.
  • Hoffman KL, Dragan MC, Leonard TK, Micheli C, Montefusco-Siegmund R, Valiante TA (2013) Saccades during visual exploration align hippocampal 3-8 Hz rhythms in human and non-human primates. Frontiers in Systems Neuroscience 7:43. doi: 10.3389/fnsys.2013.00043
  • Bartlett AM, Ovaysikia S, Logothetis NK and Hoffman KL (2011) Saccades during object viewing modulate oscillatory phase in the superior temporal sulcus. Journal of Neuroscience 31(50):18423-18432. doi:10.1523/JNEUROSCI.4102-11.2011
  • Hoffman KL and Logothetis NK (2009) Cortical mechanisms of sensory learning and object recognition. Philosophical Transactions of the Royal Society B (364) 321-329.
  • Sayegh PF, Hawkins KM, Neagu B, Crawford JD, Hoffman KL, and Sergio LE (2014) Decoupling the actions of the eyes from the hand alters beta and gamma synchrony within SPL. Journal of Neurophysiology.