Publications & Preprints

I. Raposo, I. C. Fiebelkorn, J. J. Lin, J. Parvizi, S. Kastner, R. T. Knight, A. Breska, Randolph Helfrich (2025). Human attention-guided visual perception is governed by rhythmic oscillations and aperiodic timescales. PLoS Biology.

Randolph Helfrich (2025). Orchestrating prefrontal cognitive control: The thalamus in command. Neuron.

G. Iwama, Randolph Helfrich (2025). Sensory and action neural tuning explains how priors guide human visual decisions. bioRxiv.

R. Kienitz, J. Martini, Randolph Helfrich (2025). Hexagonal modulation of theta rhythmic attentional sampling of visual space. bioRxiv.

K. B. Boroujeni, Randolph Helfrich, I. C. Fiebelkorn, N. Bentley, J. J. Lin, R. T. Knight, S. Kastner (2025). Fast attentional information routing via high-frequency bursts in the human brain. bioRxiv.

Z. R. Cross, Randolph Helfrich, A. W. Corcoran, A. J.O. Dede, M. J. Kohler, S. W. Coussens, L. Zou-Williams, M. Schlesewsky, G. M. Gaskell, R. T. Knight, I. Bornkessel-Schlesewsky (2025). Slow oscillation-spindle coupling predicts sequence-based language learning. The Journal of Neuroscience.

K. Machetanz, E. Weinbrenner, T. V. Wuttke, S. Ethofer, Randolph Helfrich, J. Kegele, S. Lauxmann, M. Alber, S. Rona, M. Tatagiba, H. Lerche, J. Honegger, G. Naros (2025). Connectome-based disentangling of epilepsy networks from insular stereoelectroencephalographic leads. Frontiers in Neurology.

J. Lendner, Randolph Helfrich (2024). Defining slow wave sleep without slow waves. Trends in Neurosciences.

J. Lendner, J. J. Lin, P. G. Larsson, Randolph Helfrich (2024). Multiple intrinsic timescales govern distinct brain states in human sleep. The Journal of Neuroscience.

M. Hahn, J. Lendner, M. Anwander, K. S.J. Slama, R. T. Knight, J. J. Lin, Randolph Helfrich (2024). A tradeoff between efficiency and robustness in the hippocampal-neocortical memory network during human and rodent sleep. Progress in Neurobiology.

M. Kopf, J. Martini, C. Stier, S. Ethofer, C. Braun, Y. L. Hegner, N. K. Focke, J. Marquetand, Randolph Helfrich (2024). Aperiodic activity indexes neural hyperexcitability in generalized epilepsy. eNeuro.

J. Martini, A. K. Solbakk, A. O. Blenkmann, A. Llorens, I. Funderud, S. Leske, P. G. Larsson, J. Ivanovic, R. T. Knight, T. Endestad, Randolph Helfrich (2024). Ramping dynamics and theta oscillations reflect dissociable signatures during rule-guided human behavior. Nature Communications.

I. Raposo, S. Szczepanski, K. Haaland, T. Endestad, A. K. Solbakk, R. T. Knight, Randolph Helfrich (2023). Periodic neglect after frontoparietal lesions provides causal evidence for rhythmic attention sampling. Current Biology.

Randolph Helfrich, R. T. Knight (2023). Neural recordings and time series analyses. The SAGE Handbook of Cognitive and Systems Neuroscience.

J. Lendner, Randolph Helfrich (2023). How can I run sleep and anesthesia studies with intracranial EEG?. Intracranial EEG for Cognitive Neuroscience.

J. Lendner, N. Niethard, B. A. Mander, F. van Schalkwijk, S. Schuh-Hofer, H. Schmidt, R. T. Knight, J. Born, M. P. Walker, J. J. Lin, Randolph Helfrich (2023). Human REM sleep recalibrates neural activity in support of memory formation. Science Advances.

J. Weber, G. Iwama, A. K. Solbakk, A. O. Blenkmann, P. G. Larsson, J. Ivanovic, R. T. Knight, T. Endestad, Randolph Helfrich (2023). Subspace partitioning in human prefrontal cortex resolves cognitive interference. PNAS.

F. van Schalkwijk, J. Weber, M. Hahn, J. Lendner, M. Inostroza, J. J. Lin, Randolph Helfrich (2023). An evolutionary conserved division-of-labor between hippocampal and neocortical sharp-wave ripples organizes information transfer during sleep. Progress in Neurobiology.

Randolph Helfrich, R. T. Knight, M. D'Esposito (2022). Methods to study human memory. Oxford Handbook of Human Memory.

Randolph Helfrich, R. T. Knight (2022). Making memories last: How sleep promotes neuroplasticity. Changing Brains: Essays on Neuroplasticity in Honor of Helen J. Neville.

Randolph Helfrich (2022). Human intracranial cognitive neurophysiology. Electrophysiological Recording Techniques, Neuromethods.

M. Hahn, K. Bothe, D. Heib, M. Schabus, Randolph Helfrich, K. Hoedlmoser (2022). Slow oscillation–spindle coupling strength predicts real-life gross-motor learning in adolescents and adults. eLife.

Randolph Helfrich, J. Lendner, R. T. Knight (2021). Aperiodic sleep networks promote memory consolidation. Trends in Cognitive Sciences.

J. Kam, Randolph Helfrich, A. K. Sobbak, T. Endestad, P. G. Larsson, J. J. Lin, R. T. Knight (2021). Top–down attentional modulation in human frontal cortex: Differential engagement during external and internal attention. Cerebral Cortex.

J. Lendner, Randolph Helfrich, B. Mander, L. Romundstad, J. J. Lin, M. Walker, P. G. Larsson, R. T. Knight (2020). An electrophysiological marker of arousal level in humans. eLife.

M. Hahn, D. Heib, M. Schabus, K. Hoedlmoser, Randolph Helfrich (2020). Slow oscillation-spindle coupling predicts enhanced memory formation from childhood to adolescence. eLife.

Randolph Helfrich, R. T. Knight (2019). Cognitive neurophysiology: Event-related potentials. Handbook of Clinical Neurology.

Randolph Helfrich, R. T. Knight (2019). Cognitive neurophysiology of the prefrontal cortex. Handbook of Clinical Neurology.

J. Winer, B. Mander, Randolph Helfrich, A. Maass, T. Harrison, S. Baker, R. T. Knight, W. Jagust, M. Walker (2019). Sleep as a potential biomarker of tau and beta-amyloid burden in the human brain. The Journal of Neuroscience.

Randolph Helfrich, A. Breska, R. T. Knight (2019). Neural entrainment and network resonance in support of top-down guided attention. Current Opinion in Psychology.

Randolph Helfrich, J. Lendner, B. Mander, H. Guillen, M. Paff, L. Mnatsakanyan, S. Vadera, M. Walker, J. J. Lin, R. T. Knight (2019). Bidirectional prefrontal-hippocampal dynamics organize information transfer during sleep in humans. Nature Communications.

Randolph Helfrich, I. C. Fiebelkorn, S. Szczepanski, J. J. Lin, J. Parvizi, R. T. Knight, S. Kastner (2018). Neural mechanisms of sustained attention are rhythmic. Neuron.

Randolph Helfrich, B. Mander, W. Jagust, R. T. Knight, M. Walker (2018). Old brains come uncoupled in sleep: Slow wave-spindle synchrony, brain atrophy, and forgetting. Neuron.

Randolph Helfrich (2017). The rhythmic nature of visual perception. Journal of Neurophysiology.

Randolph Helfrich (2017). Prefrontal cortex modulates posterior alpha oscillations during top-down guided visual perception. PNAS.

B. Ram, Randolph Helfrich (2017). Waves of perception. Frontiers for Young Minds.

K. Slama, Randolph Helfrich (2017). How does expectation shape object-based attentional selection?. The Journal of Neuroscience.

Randolph Helfrich, R. T. Knight (2016). Oscillatory dynamics of prefrontal cognitive control. Journal of Neuroscience.

Randolph Helfrich, C. Herrman, A. Engel, T. Schneider (2016). Different coupling modes mediate cortical cross-frequency interactions. Neuroimage.

Randolph Helfrich, H. Knepper, G. Nolte, M. Sengelmann, P. König, T. Schneider, A. Engel (2016). Spectral fingerprints of large-scale cortical dynamics during ambiguous motion perception. Human Brain Mapping.

Randolph Helfrich, H. Knepper, G. Nolte, M. Sengelmann, P. König, T. Schneider, A. Engel (2016). Entrainment of brain oscillations by transcranial alternating current stimulation. Current Biology.

E. Johnson, Randolph Helfrich (2016). How brain cells make memories. Frontiers for Young Minds.

C. Herrmann, D. Strübel, Randolph Helfrich, A. Engel (2016). EEG oscillations: From correlation to causality. International Journal of Psychophysiology.

Randolph Helfrich, H. Knepper, G. Nolte, D. Strüber, S. Rach, C. Herrmann, T. Schneider, A. Engel (2014). Selective modulation of interhemispheric functional connectivity by HD-tACS shapes perception. PLoS Biology.

Randolph Helfrich, T. Schneider (2013). Modulation of cortical network activity by transcranial alternating current stimulation. Journal of Neuroscience.

Randolph Helfrich, H. Becker, T. Haarmeier (2013). Processing of coherent visual motion in topographically organized visual areas in human cerebral cortex. Brain Topogr.