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Figure 2 | BMC Neuroscience

Figure 2

From: The BOLD response and the gamma oscillations respond differently than evoked potentials: an interleaved EEG-fMRI study

Figure 2

Evoked potentials and event-related oscillations for each electrode and for all the subjects. The upper part presents three different views of the average electrode position relative to the areas with BOLD activation (threshold p ≤ 0.001, 100 voxels, Target-related activation – red, Target-related deactivation – green, and rare Distractor (Novel) activation – blue). It is provided for better appreciation of electrical signals, considering fMRI activation. The lower part displays the evoked potentials (EPs) and event-related oscillations (EROs) for each electrode, for the 5 subjects. For C3, Cz, C4, Pz, the "no-smoking" symbol, which is an instance of Novels (blue), yielded larger EPs than Targets (red). Distractors are represented in gray. For all the electrodes, the reverse is true as far as EROs are concerned, with significantly more oscillations around 300–400 ms, regarding Targets. In the case of EPs, signals have been plotted from -325 to +625 ms and the voltage range was kept constant from -9 to +9 μV. The shaded region around 474 ms corresponds to the response time and its standard deviation. The statistics for the comparison of Target-related and Novel-related EPs are computed every 10 ms, between 100 ms and 600 ms, and represented by the gray and black stars above the curves (1 star for pnc ≤ 0.05, 2 starsfor pnc ≤ 0.01). The time-cluster significance, corrected for multiple comparison is indicated by the color of the stars: black if above pc ≤ 0.05, gray if not significant at the corrected time-clusterlevel. The set level is given for each electrode by the number of stars beside the electrode label (1 star for p ≤ 0.05, 2 stars for p ≤ 0.01). For EROs, only the statistics comparing Targets and Novels is given for the 24- to 44-Hz band, and between -320 to 600 ms. The solid and dotted black lines correspond to the response time and standard deviation, respectively. The color code for the statistics is shown on the upper right hand side, and represents the cumulative p distribution stated in percent. Cold colors code for a higher Novel-related power level, and hot colors code for greater Target-related power intensity. Regions above the .05 and .01 thresholds are contoured in black (notice that the numbers 1, 5, 95 and 99 represent the cumulative p values stated in percent).

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