Biology subjects

Gomez-Pilar, J.

Publications and source records attributed to Gomez-Pilar, J..

3 recordsLinked to original sources

bioRxiv2020

Intrinsic neural timescales related to sensory processing: Evidence from abnormal behavioural states

The brain exhibits a complex temporal structure which translates into a hierarchy of distinct neural timescales. An open question is how these intrinsic timescales are related to sensory or motor information processing and whether these dynamics have common patterns in different behavioural states. We address these questions by investigating the brains intrinsic timescales in healthy controls, motor (amyotrophic lateral sclerosis, locked-in syndrome), sensory (anaesthesia, unresponsive wakefulness syndrome), and progressive reduction of sensory processing (from awake states over N1, N2, N3). We employed a combination of measures from EEG resting-state data: auto-correlation window (ACW), power spectral density (PSD), and power-law exponent (PLE). Prolonged neural timescales accompanied by a shift towards slower frequencies were observed in the conditions with sensory deficits, but not in conditions with motor deficits. Our results establish that the spontaneous activitys intrinsic neural timescale is related to specifically sensory rather than motor information processing in the healthy brain. HighlightsO_LIEEG resting-state shows a hierarchy of intrinsic neural timescales. C_LIO_LISensory deficits as in disorders of consciousness lead to prolonged intrinsic neuraltimescales. C_LIO_LIClinical conditions with motor deficits do not show changes in intrinsic neural timescales.20 C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=156 SRC="FIGDIR/small/229161v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1893c45org.highwire.dtl.DTLVardef@d4176dorg.highwire.dtl.DTLVardef@4dfaa8org.highwire.dtl.DTLVardef@183621e_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2020

Temporal hierarchy converges with spatial hierarchy: Intrinsic neural timescales follow core-periphery organization

The human cortex exhibits intrinsic neural timescales that shape a temporal hierarchy. Whether this temporal hierarchy follows the spatial hierarchy of its topography namely the core-periphery organization remains an open issue. Using Magnetoencephalography data, we investigate intrinsic neural timescales during rest and task states; we measure the autocorrelation window in short (ACW-50) and, introducing a novel variant, long (ACW-0) windows. We demonstrate longer ACW-50 and ACW-0 in networks located at the core compared to those at the periphery with rest and task states showing a high ACW correlation. Calculating rest-task differences, i.e., subtracting the shared core-periphery organization, reveals task-specific ACW changes in distinct networks. Finally, employing kernel density estimation, machine learning, and simulation, we demonstrate that ACW-0 exhibits better prediction in classifying a regions time window as core or periphery. Overall, our findings provide fundamental insight into how the human cortexs temporal hierarchy converges with its spatial core-periphery hierarchy.

neuroscience↗

bioRxiv2020

Time meets space: brain dynamics drive spatial topography

Unlike the brains faster frequencies, the exact role of its more powerful infraslow frequencies (ISF, 0.01 - 0.1Hz) in information processing remains poorly understood. Do and how ISF process information? We investigate information processing and related temporal dynamics of ISF in resting and task state fMRI. To quantify information, we apply the Lempel-Ziv complexity (LZC), a measure of signal compression indexing information. The LZC is combined with direct measurement of the dynamics of ISF themselves, namely their power spectral density by median frequency (MF). We demonstrate the following: (I) topographical differences in resting state between higher- and lower-order networks, showing statistically lower LZC in the former; (II) task-related changes in LZC; (III) modulation of LZC associated with MF changes, with low and high MF resting-state values correlated with different degrees of LZC change. In sum, we provide evidence that ISF carry and process information as mediated through their temporal dynamics.

neuroscience↗