Fig 1.
Behavioral data are depicted separately for low (blue), and highly (red) susceptible participants in control (CON), distraction (DIS), hypnosis (HYP), and simulation (SIM). (A) Histograms of hit rates showing the percentage of subjects in each of the five mutually exclusive hit rate classes (0≤25≤50≤75≤100%). (B) Grandaverage receiver operating characteristic (ROC) curves in the four conditions. Circles mark the empirical true positive (hit) rates plotted against false positive (false alarm) rates of each subject. Shaded areas indicate the 95% CI. A curve above the dotted diagnol represents a discrimination better than random. (C) Probability density function (PDF) and scatter plot of estimated d-primes. Vertical lines and boxes mark the mean and interquartile range (difference between 75th and 25th percentiles) of estimated d-primes, respectively. (D) Line plot of d-prime (mean ± within-subject standard error). (E) Target response time (mean ± within-subject standard error). (F) Loudness rating of target, standard, and distractor stimuli (mean ± within-subject standard error).
Fig 2.
(A) Grandaverage waveforms and 95% C.I. in control (CON), distraction (DIS), hypnosis (HYP), and simulation (SIM) for target, distractor, and standard at the posteriocentral electrode 29 for low (blue, n = 24) and highly susceptible (red, n = 24) participants. The grey rectangle marks the P3b time window (320–470 ms) used for statistical analysis of P3b amplitudes at sensor-level. (B) Topographical maps of scalp voltage at the peak latency of the target N1 (100 ms) and P3b (400 ms) depicted for condition and stimulus-type across all subjects. (C) Focused contrasts within the Topography-by-Time-Cluster-Analysis to disentangle the interaction of condition by stimulus-type. There were no significant amplitude differences for the distractor between DIS and HYP as well as HYP and SIM, and for the Standard between CON and DIS and between CON and SIM. The summary statistic scalp-time images were thresholded at p < .001 (uncorrected) with FWE correction at cluster-level, p < .0017 (two-tailed, Bonferroni-adjusted, n = 15), based on random field theory. The statistical parametric maps (SPMs) are displayed as Maximum Intensity Projection (MIP) of the 3D (scalp x time) summary statistic image. Blue dots mark the electrode sites. post = posterior; ant = anterior.
Fig 3.
N1 and P3b amplitudes (mean ± within-subject standard error) at electrode E8 (Fz) and E29 (Pz), respectively, of high (red) and low (blue) susceptible participants in response to target (dotted line), distractor (dashed), and standard (solid) stimuli in the four experimental conditions: Control (CON), distraction (DIS), hypnosis (HYP), and simulation (SIM).
Fig 4.
Source-level effects of the auditory Three-Stimulus-Oddball paradigm during the P3b window (320–470 ms) in control (CON) for the target (A), distractor (B), and standard (C).
The cortical images show sources that were significantly different from zero (one-sample t-test). The labeled brain structures refer to the cluster peaks. l = left; r = right; MTG = middle temporal gyrus; FP = frontal pole; SPL = superior parietal lobule LOC = lateral occipital cortex; OFG = occipital fusiform gyrus; SFG = superior frontal gyrus; PoG = postcentral gyrus; cOP = central opercular cortex. The summary statistic images of the cortical mesh were thresholded at uncorrected p = .001 with FWE correction at cluster-level, p = .05, based on random field theory.
Fig 5.
Source-level effects of the auditory Three-Stimulus-Oddball paradigm during the P3b window (320–470 ms) in the control (CON), distraction (DIS), hypnosis (HYP), and simulation (SIM) condition.
(A/C) Statistical comparison (t-contrast) of Target > Standard (top row) and Target > Distractor (bottom row) for source activities within the P3b window in the CON, DIS, HYP and SIM. The cortical images show sources that were significantly more activated following processing of target as compared to standard stimulus. The labeled brain structures refer to the cluster peaks. l = left; r = right; MFG = middle frontal gyrus; MTG = middle temporal gyrus; PCu = precuneous; OFG = occipital fusiform gyrus; PrG = precentral gyrus. The summary statistic images of the cortical mesh were thresholded at uncorrected p = .001 with FWE correction at cluster-level, p = .05, based on random field theory. (B/D) Parameter estimates (β-value, 90% C.I.) of target, distractor and standard in CON, DIS, HYP, and SIM for sources located within cluster peaks of the left and right hemisphere (see Fig 5A, top row) where sources in question are located. Values of source strength are expressed as root mean square (RMS, in arbitrary units). Grey rectangle marks the P3b window.
Fig 6.
Effect size () of statistical comparison (t-contrast) of control (CON) vs. distraction (DIS), CON vs. hypnosis (HYP), and CON vs. simulation (SIM) for processing of target stimulus.
The comparisons of DIS vs. SIM and HYP vs. SIM were not significant. (A) The cortical mesh images show sources that were significantly less activated in HYP, DIS and SIM compared to CON following processing of target. PCu = precuneous; PrG = precentral gyrus; OFG = occipital fusiform gyrus. The summary statistic images of the cortical mesh were thresholded at uncorrected p = .001 with FWE correction at cluster-level, p = .0045 (one-sided, Bonferroni), based on random field theory. r = right, l = left. (B) The grandaverage cluster source waveforms (across subjects, n = 48) are based on the average of source waveforms within the respective clusters found in Fig 5A (CON > SIM) for the three Stimulus-Types in CON (black), HYP (red), DIS (grey), and SIM (blue). Source strength is expressed as root mean square (RMS, in arbitrary units). Grey rectangle marks the P3b window (320–470 ms).