Fig 1.
Mean and standard errors of pain, panel (a) and distress ratings, panel (b), respectively as measures of sensory-discriminative and affective-motivational components of pain, in high and low hypnotizable subjects (HHs and LHs).
Measures were obtained during three treatments (Control, Hypoalgesia, and Hyperalgesia) in waking and hypnosis conditions.
Table 1.
Statistics for Pain Rating, Distress Rating, N140 and P220 peak amplitudes.
Fig 2.
Mean amplitudes and standard errors of N140 peak amplitude (negative values) averaged across frontal (Fr), frontocentral (FrCe), central (Ce), centroparietal (CePa) and parietal (Pa) locations for the Hypoalgesia, Hyperalgesia, and Control treatments during waking and hypnosis conditions in high (top panel) and low (bottom panel) hypnotizable subjects (HHs and LHs).
The histogram in the top clearly shows that in HHs, during hypnosis, hyperalgesia, compared to the control treatment, induced an enhanced N140 negative peak at frontal, frontocentral, central, centroparietal, and parietal sites, while hypoalgesia had reduced N140 wave (positive values). The bottom panel shows that LHs did not exhibit significant N140 amplitude differences between treatments in both waking and hypnosis conditions
Fig 3.
SERPs of the most sensitive scalp sites (F3, FC3, and C3).
Significant peak differences between treatments for the N140 and P200 waves are displayed in the left side (*, p<.05).
Fig 4.
Averaged scalp topography of N140 wave (peaking at 140.5±6.2 ms within a time window of 130–160 ms) for Hyperalgesia, Control, and Hypoalgesia treatments in high (top-panel, first row) and low (bottom-panel, first row) hypnotizable participants (HHs and LHs) during waking (left panel) and hypnosis (right panel) conditions.
t-Test maps comparing the three treatments are shown in the second row of each top and bottom panel.
Fig 5.
Mean amplitudes and standard errors of P200 peak amplitude averaged across left and right-hemisphere and medium head side (L-Hem, R-Hem, and Mid) for the Hypoalgesia, Hyperalgesia, and Control treatments during waking and hypnosis conditions in high (top panel) and low (bottom panel) hypnotizable subjects (HHs and LHs).
Both top and bottom histograms clearly shows larger positive peaks in the midline compared to the left and right sides as well as in the midline compared to right side. The top panel shows that in HHs, the hyperalgesia treatment during hypnosis had higher P200 amplitudes than control treatment, while hypnotic hypoalgesia had smaller peaks. These differences disappeared in waking condition. The bottom panel shows that LHs did not exhibit significant P200 amplitude differences between treatments in both waking and hypnosis conditions
Fig 6.
Averaged scalp topography of P200 wave (peaking at 220.4±3.8 ms within a time window of 200–250 ms) to Control, Hyperalgesia, and analgesia treatments in high (top-panel, first row) and low (bottom-panel, first row) hypnotizable participants (HHs and LHs) during waking (left panel) and hypnosis (right panel) conditions.
t-Test maps comparing the three treatments are shown in the second row of each top and bottom panel.
Fig 7.
Significant activation waveforms of LORETA current source density (left) and anatomical maps (right) of the spatial local maximum of BA3, BA6, and BA24 pain-related cortical regions in both left and right hemisphere (LH and RH) after application of noxious electric pulses to the right middle finger, during waking-relaxation control treatment (coordinates are shown in Table 2).
Table 2.
Correlations of pain and distress ratings with the area under the curve of cortical Pain-ROIs of current densities to noxious electric stimuli applied to the middle finger of the right hand across all subjects (N = 20).
Table 3.
Multivariate regression analysis using area under the curve of pain-related BA3, BA6 and BA24 activation in the left hemisphere as predictors of pain and distress ratings in Waking condition (step-1) and after entering SHCS scores as a covariate (step-2).
Table 4.
Multivariate regression analysis using area under the curve of pain-related BA3, BA6 and BA24 activation in the left hemisphere as predictors of pain and distress ratings in Hypnosis condition (step-1) and after entering SHCS scores as a covariate (step-2).
Table 5.
Multivariate regression analysis of changes in pain-related BA3 activation of hypoalgesia and hyperalgesia vs control condition in the left and right hemisphere (LH and RH) in relation to the changes in pain ratings of treatments vs control (Step-1), and after entering SHCS scores as a covariate (step-2).
Fig 8.
sLORETA solutions modeling the distributed sources for the N140 wave (panel a) and for the P200 wave (panel b) in high hypnotizable participants (HHs) in waking and hypnosis conditions to Hyperalgesia, Control, and Hypoalgesia treatments.
Brodmann areas (BA) of estimated sorces (local maxima in yellow color) are reported under each brain map. HHs for Hyperalgesia compared to Control in hypnosis had increased activity (yellow) of N140 wave within middle and superior frontal gyri, anterior cingulate gyrus, and supramarginal gyrus (BA9,10,32,40,39; t-test map, right panel a), and increased activity of P200 wave in the superior (BA22), middle (BA37), inferior and superior temporal (BA19,13) gyri, and superior parietal lobule (BA7; t-test map, right panel b). HHs for Hypoalgesia showed reduced activity (blue) of N140 wave within medial and superior frontal gyri (BA9,8) paraippocampal gyrus (BA34) and postcentral gyrus (BA1; t-test map, right panel a), and reduced activity of P200 wave within middle and superior frontal gyri (BA9 and BA10), anterior cingulate (BA33), cuneus (BA19) and sub-lobar insula (BA13; t-test map, right panel b).
Fig 9.
sLORETA solutions modeling the distributed sources for the N140 wave (panel a) and for the P200 wave (panel b) in low hypnotizable participants (LHs) in waking and hypnosis conditions to Hyperalgesia, Control, and Hypoalgesia treatments.
Brodmann areas (BA) of estimated sorces (local maxima in yellow color) are reported under each brain map. T-tests for both N140 (panel a) and P200 (panel b) waves between Hyperalgesia vs Control and Hypoalgesia vs Control did not yield significant differences in both waking and hypnosis conditions.
Table 6.
Brodmann areas (BA) and Talairach coordinates (x, y, z) of statistically stronger cerebral activation for N140 wave in high and low hypnotizable subjects (HHs and LHs) during Hyperalgesia and Hypoalgesia compared to Control treatment.
Table 7.
Brodmann areas (BA) and Talairach coordinates (x, y, z) of statistically stronger cerebral activation for P200 wave in high and low hypnotizable subjects (HHs and LHs) during Hyperalgesia and Hypoalgesia compared to Control treatment.