Frequency and period as a function of delay.

<p><b>A</b>: Oscillation frequency . <b>B</b>: Period . The analytical estimate under small-delay approximation (see <i>Methods</i>) is displayed as a solid line; results of numerical simulations of the dynamics (1) as dots (). Simulations were performed for homogeneous coupling with within-pair coupling , between-pair coupling strength , and distributed delays ; see text for details. The presence of between-pair coupling and even heterogeneity in coupling, , did not yield qualitatively different results.</p

Anatomical connectivity matrix and resulting functional connectivities as a function of delay distribution.

<p><b>A</b>: Sparse neuroanatomical coupling matrix serving as structural connectivity (connections are given in yellow). <b>B</b>: Structure-function correlation . <b>C</b>: Overall synchronizability . Between-pair coupling strength appears on the horizontal axis; while blue, red, and black lines correspond to respectively. Note that an increase in delay distribution width increased synchronizability due to increased , but the accompanying higher variance decreased structure-function correspondence as predicted by (3). <b>D-F</b>: Corresponding spatial synchronization matrices for delay distributions , and respectively (). Color coding is displayed in the most right panel; only excitatory nodes are shown.</p

Structural connectivity in the case of two coupled pairs of excitatory/inhibitory neural masses.

<p><b>A</b>: Homogeneous coupling with coupling matrix . <b>B</b>: Inhomogenous coupling using the coupling matrix . In both cases excitatory/inhibitory-pairs have a symmetric ‘internal’ coupling with strength but the coupling between these pairs differs. In A the between-pair coupling is homogeneous at strength whilst in B the between-pair coupling may differ across pairs; i.e. it is randomly chosen from a certain distribution with the constraint that inhibitory units map (on average) with negative and excitatory with positive coupling strength. See text for more details and <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003736#pcbi-1003736-g007" target="_blank">Figs 7</a> and <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003736#pcbi-1003736-g008" target="_blank">8A</a> for the more complicated coupling schemes employed below.</p

Phase distributions in the presence of inhomogeneous coupling .

<p><b>A</b>: Strong coupling (). <b>B</b>: Weak coupling (). As predicted by the phase derivation (9), inhomogeneity in the coupling matrix resulted in similar behavior as a distribution in delays; compare <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003736#pcbi-1003736-g005" target="_blank">Figs 5A and 5C</a> with panels Fig. 6A and 6B respectively. For reasonably weak coupling we found a widening of the phase distribution equivalent to the case with homogeneous coupling. Again, an increase in coupling strength resulted in a concentration of .</p

Phase distributions for weak coupling () and equal delays.

<p><b>A</b>: Vanishing delay (). <b>B</b>: Fixed finite delay . <b>C</b>: Fixed finite delay . As for strong coupling we found synchronized solutions in the weak coupling case . In addition solutions were also present. The number of clusters did depend on the delay value . That is, altering the delay from to caused a switch in stability between these two solutions. Since for the two clusters within an -group only showed a small phase difference, we conjecture that is close to the critical value of this bifurcation parameter.</p

Phase distributions for different coupling strengths and distributed delays.

<p><b>A</b>: , . <b>B</b>: , . <b>C</b>: , . The effect of a delay distribution and consequently the presence of centroid phase values manifested itself as a widening of the phase distribution compared to the constant delay cases in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003736#pcbi-1003736-g004" target="_blank">Fig 4</a>. Narrow delay distributions with , i.e. the were randomly drawn from a uniform distribution over the interval , yielded comparably narrow phase distributions located around two narrow peaks (peaks representing the - and -populations; (A)). Increasing the width of the delay distribution to (B) had a very similar effect as lowering the coupling strength (C): in both cases the phase distribution widened substantially.</p

Data_Sheet_1_Accounting for Stimulations That Do Not Elicit Motor-Evoked Potentials When Mapping Cortical Representations of Multiple Muscles.PDF

The representation of muscles in the cortex can be mapped using navigated transcranial magnetic stimulation. The commonly employed measure to quantify the mapping are the center of gravity or the centroid of the region of excitability as well as its size. Determining these measures typically relies only on stimulation points that yield motor-evoked potentials (MEPs); stimulations that do not elicit an MEP, i.e., non-MEP points, are ignored entirely. In this study, we show how incorporating non-MEP points may affect the estimates of the size and centroid of the excitable area in eight hand and forearm muscles after mono-phasic single-pulse TMS. We performed test-retest assessments in twenty participants and estimated the reliability of centroids and sizes of the corresponding areas using inter-class correlation coefficients. For most muscles, the reliability turned out good. As expected, removing the non-MEP points significantly decreased area sizes and area weights, suggesting that conventional approaches that do not account for non-MEP points are likely to overestimate the regions of excitability.</p

Subjective and Normative Mean Valence Rating Scores on a Scale Ranging From 1 (Very Pleasant) to 9 (Very Unpleasant).

<p>Subjective and Normative Mean Valence Rating Scores on a Scale Ranging From 1 (Very Pleasant) to 9 (Very Unpleasant).</p

Examples of ten motor evoked potentials (MEPs) recorded in a resting abductor pollicis brevis (APB) muscle during one condition in a single subject.

<p>The vertical lines at 0 ms indicates when a single pulse of TMS was fired.</p

Subjective and Normative Mean Arousal Rating Scores on a Scale Ranging From 1 (Very Calm) to 9 (Very Excited).

<p>Subjective and Normative Mean Arousal Rating Scores on a Scale Ranging From 1 (Very Calm) to 9 (Very Excited).</p