Journal: Scientific Reports

Article Title: Entrainment of local synchrony reveals a causal role for high-beta right frontal oscillations in human visual consciousness

doi: 10.1038/s41598-019-49673-1

Figure Lengend Snippet: Experimental task, TMS targeted cortical region and stimulation patterns. ( A ) Visual detection task performed by participants. After a period of fixation, a central cross became slightly larger (alert cue) to alert participants of an upcoming event. Then active/sham rhythmic/random TMS patterns were delivered to the right FEF region prior to the presentation of a visual target at the center of a right/left placeholder. Participants were requested to indicate whether they did or did not perceive a target and, if they did, where it appeared (no target perceived/target perceived on the right/target perceived on the left). Notice that in 20% of the trials (“catch trials”), no target was presented in any of the two placeholders. ( B ) Coronal, sagittal and axial T1-3D MRI sections from a representative participant generated by the frameless stereotaxic neuronavigation system showing the localization of the right FEF, stimulated in our experiment (Talairach coordinates X = 31, Y = −2, Z = 47 ). ( C ) Schematic representation of the temporal distribution of the 4-pulse bursts employed for the 30 Hz rhythmic and the random stimulation conditions. Contrasting the behavioral (visual detection sensitivity) and electrophysiological (EEG) impact elicited by these two patterns isolates the effects of 30 Hz FEF activity (only present in rhythmic bursts) from those induced by 4 TMS pulses delivered during a 100 ms interval (featured by both rhythmic and random bursts).

Article Snippet: It synchronized the presentation of visual stimuli on the computer screen, the pulses delivered by two biphasic repetitive TMS devices (SuperRapid, Magstim) attached to standard 70 mm figure-of-eight coils operated via a trigger-synchronization device (Master 8, A.M.P.I.), a remote gaze tracking capture system (Eyelink 1000, SR Research), and EEG recordings performed with TMS-compatible equipment (BrainAmp DC, BrainVision Recording Software, EasyCap and Ag/AgCl sintered ring electrodes, BrainProducts GmbH).

Techniques: Generated, Activity Assay

Journal: Scientific Reports

Article Title: Entrainment of local synchrony reveals a causal role for high-beta right frontal oscillations in human visual consciousness

doi: 10.1038/s41598-019-49673-1

Figure Lengend Snippet: Causal impact of right FEF stimulation on evoked high-beta oscillations. Evoked oscillations (25–35 Hz, [−199.5 66.5] ms, [−2 2] µV) for rhythmic (A) and random (B) active/sham stimulation patterns for each of the 60 EEG scalp electrodes (left column; the location of electrode FC2, i.e., the closest to the stimulated right FEF, is indicated with an open circle) and at FC2 (right column). Vertical black dotted lines delineate the epochs employed for the analyses (T1: Pre TMS, T2: TMS burst part 1; T3: TMS burst part 2 and T4: Visual Target). Blue and red colors respectively represent the sham and active TMS conditions. Notice progressive increases in the amplitude of high-beta evoked oscillations (25–35 Hz), reaching higher levels during rhythmic than random active patterns throughout the course of 4-pulse stimulation patterns followed by a rather abrupt decay after the last pulse of the burst. (C) Amplitude (mean and standard error) of evoked oscillations (25–35 Hz) for rhythmic and random active/sham stimulation patterns across the 4 time-windows of interest (T1: Pre TMS; T2: TMS burst part 1; T3: TMS burst part 2; and T4: Visual Target). Due to the complexity of representation of interaction effects, significant statistical results are not shown in the figure. Notice, however, that active rhythmic patterns caused higher amplitude increases of evoked oscillations than active random patterns (significant stimulation pattern x stimulation condition interaction). In addition, we found a progressive build-up of evoked oscillations along the course of the 4-pulse burst (amplitude T1 < T2 < T3), and a decay following the offset of the stimulation (T4 < T3, significant stimulation condition x time window interaction).

Article Snippet: It synchronized the presentation of visual stimuli on the computer screen, the pulses delivered by two biphasic repetitive TMS devices (SuperRapid, Magstim) attached to standard 70 mm figure-of-eight coils operated via a trigger-synchronization device (Master 8, A.M.P.I.), a remote gaze tracking capture system (Eyelink 1000, SR Research), and EEG recordings performed with TMS-compatible equipment (BrainAmp DC, BrainVision Recording Software, EasyCap and Ag/AgCl sintered ring electrodes, BrainProducts GmbH).

Techniques:

Journal: Scientific Reports

Article Title: Entrainment of local synchrony reveals a causal role for high-beta right frontal oscillations in human visual consciousness

doi: 10.1038/s41598-019-49673-1

Figure Lengend Snippet: Causal impact of right FEF stimulation on visual detection and relationship with entrained high-beta oscillations. ( A ) Group impact of active/sham rhythmic and random patterns delivered to the right FEF on the detection of near-threshold targets presented in the left or right visual fields (means and standard errors; statistical comparison: **p < 0.01). Importantly rhythmic (but not random) right FEF active stimulation which, according to EEG evidence (see Figs and ), increased high-beta power and inter-trial coherence, also increased visual detection sensitivity (d’) for targets displayed in the left visual hemifield. ( B ) Correlation plots between levels of high-beta entrainment (estimated through increases of amplitude of evoked oscillations between active and sham TMS) and visual detection gains (d’ active TMS - d’ sham TMS) with rhythmic (left) or random (right) active TMS patterns for targets presented in the left visual field. Green dots represent all participants (n = 14). Dark green crossed dots represent pools of participants (n = 11 for high-beta rhythmic TMS, n = 10 for random TMS) who experienced visual detection sensitivity (d’) increases with right FEF stimulation. For high-beta rhythmic TMS, a linear correlation with only the latter selected cohort of participants (black regression line) proved highly significant, whereas for random TMS, no correlation reached significance (***p < 0.001; n.s. non-significant).

Article Snippet: It synchronized the presentation of visual stimuli on the computer screen, the pulses delivered by two biphasic repetitive TMS devices (SuperRapid, Magstim) attached to standard 70 mm figure-of-eight coils operated via a trigger-synchronization device (Master 8, A.M.P.I.), a remote gaze tracking capture system (Eyelink 1000, SR Research), and EEG recordings performed with TMS-compatible equipment (BrainAmp DC, BrainVision Recording Software, EasyCap and Ag/AgCl sintered ring electrodes, BrainProducts GmbH).

Techniques: Comparison