Inter-regional delays fluctuate in the human cerebral cortex
Poster No:
2376
Submission Type:
Abstract Submission
Authors:
Joon-Young Moon1,2, Charles Schroeder3, Kathrin Müsch4, Christopher Honey4
Institutions:
1Sungkyunkwan University, Suwon-si, Gyeonggi-do, Korea, Republic of, 2Institute for Basic Science (IBS), Suwon-si, Gyeonggi-do, Korea, Republic of, 3Nathan S. kline Institute for Psychiatric Research, Orangeburg, NY, 4Johns Hopkins University, Baltimore, MD
First Author:
Joon-Young Moon
Sungkyunkwan University|Institute for Basic Science (IBS)
Suwon-si, Gyeonggi-do, Korea, Republic of|Suwon-si, Gyeonggi-do, Korea, Republic of
Sungkyunkwan University|Institute for Basic Science (IBS)
Suwon-si, Gyeonggi-do, Korea, Republic of|Suwon-si, Gyeonggi-do, Korea, Republic of
Co-Author(s):
Introduction:
In electric signals such as field-potentials measured across regions of the human brain, parietal signals have a tendency to phase-lead signals in temporal and frontal cortex, while waves of activity propagates along parieto-temporal pathways. In order to better understand the functional properties of such large-scale pattern of signal flow, we asked: (i) are inter-regional delays stable or variable over time? (ii) do the patterns of signal propagation co-vary with endogenous cortical rhythms? (iii) do the patterns of signal flow vary with external stimulus properties?
Methods:
We recorded electrocorticographic signals from the lateral cortical surface of 10 human participants as they listened to a 7-minute auditory narrative. In sliding 2-second windows, we identified inter-regional delays by computing the cross-correlation of voltage signals between nearby electrode pairs. For each time window, and for electrodes and electrode-pairs, we identified the time delay of maximal inter-electrode correlation from raw voltage signals, the power for different bands, and the mean broadband high-frequency power. We designed a computational model for the inter-regional flows using a Stuart-Landau coupled oscillator model, with structural topology based on human cortical anatomy.
Results:
i) Inter-regional Latencies Vary Across Time: Consistent with prior reports [1, 2], we found that the auditory pathway exhibited a gradient of delays, with posterior temporal regions leading anterior temporal regions on average. However, the latencies between stages of auditory processing were not stable, but fluctuated over time. Two distinct electrophysiological states were evident from data: one with longer inter-channel latencies ("propagating state"), and the other shorter latencies ("synchronized state").
ii) Latencies Correlates with Alpha Power Bursts: Latencies were longer during bursts of alpha power (propagating state) and were shorter during bursts of broadband power (synchronized state), consistent with models in which alpha oscillations regulate corticocortical interactions (van Kerkoerle et al., 2014). The inter-regional delays were mostly endogenous, as the correlation between responses under repeated stimulus was weak. Altogether, the changes in inter-regional latencies are not a random process, and reliably track features of the endogenous dynamics.
iii) Global Latencies Changes between States: The transitions between synchronized and propagating states generalizes beyond the auditory pathway to the parietal, temporal and sensorimotor cortex. We observed that global latency patterns change between the synchronized state and the propagating state. When auditory drive was strong the latencies between many areas were reduced, and when auditory drive was absent the latencies increased.
iv) Coupled Oscillator Model Reproduces Both States: We were able to reproduce the inter-regional correlation and delay pattern, by varying the coupling-strength between oscillators in the Stuart-Landau oscillator model, indicating that the large-scale dynamic shifts may be regulated by overall shifts in the efficacy of inter-regional influence.
ii) Latencies Correlates with Alpha Power Bursts: Latencies were longer during bursts of alpha power (propagating state) and were shorter during bursts of broadband power (synchronized state), consistent with models in which alpha oscillations regulate corticocortical interactions (van Kerkoerle et al., 2014). The inter-regional delays were mostly endogenous, as the correlation between responses under repeated stimulus was weak. Altogether, the changes in inter-regional latencies are not a random process, and reliably track features of the endogenous dynamics.
iii) Global Latencies Changes between States: The transitions between synchronized and propagating states generalizes beyond the auditory pathway to the parietal, temporal and sensorimotor cortex. We observed that global latency patterns change between the synchronized state and the propagating state. When auditory drive was strong the latencies between many areas were reduced, and when auditory drive was absent the latencies increased.
iv) Coupled Oscillator Model Reproduces Both States: We were able to reproduce the inter-regional correlation and delay pattern, by varying the coupling-strength between oscillators in the Stuart-Landau oscillator model, indicating that the large-scale dynamic shifts may be regulated by overall shifts in the efficacy of inter-regional influence.
Conclusions:
Altogether, the data and models suggest that human cortical dynamics reliably transition between synchronized states (associated with increase of broadband power) and propagating states (associated with bursts of alpha-band power). These coupling dynamics may reflect a cortex-wide modulation of the relative influence of top-down and bottom-up signals in the human cerebral cortex [4].
Modeling and Analysis Methods:
EEG/MEG Modeling and Analysis 2
Novel Imaging Acquisition Methods:
EEG 1
Perception, Attention and Motor Behavior:
Perception: Auditory/ Vestibular
Keywords:
Cognition
Computational Neuroscience
Cortex
ELECTROCORTICOGRAPHY
Modeling
Somatosensory
Other - brain network
1|2Indicates the priority used for review
Provide references using author date format
2. Zhang, H., Watrous, A. J., Patel, A., & Jacobs, J. (2018), Theta and Alpha Oscillations Are Traveling Waves in the Human Neocortex. Neuron. 98, 1269-1281.e4.
3. van Kerkoerle, T., Self, M. W., Dagnino, B., Gariel-Mathis, M.-A., Poort, J., van der Togt, C., & Roelfsema, P. R., (2014), Alpha and gamma oscillations characterize feedback and feedforward processing in monkey visual cortex, PNAS 111, 14332-14341.
4. Moon, J.-Y., Müsch, K., Schroeder, C. E., Honey, C. J. (2023)., Inter-regional delays fluctuate in the human cerebral cortex, bioRxiv, doi:10.1101/2022.06.01.494224, to be published in eLife.