Structural and functional cerebral correlates of hypnotic suggestibility

Little is known about the neural bases of hypnotic suggestibility, a cognitive trait referring to the tendency to respond to hypnotic suggestions. In the present magnetic resonance imaging study, we performed regression analyses to assess hypnotic suggestibility-related differences in local gray matter volume, using voxel-based morphometry, and in waking resting state functional connectivity of 10 resting state networks, in 37 healthy women. Hypnotic suggestibility was positively correlated with gray matter volume in portions of the left superior and medial frontal gyri, roughly overlapping with the supplementary and pre-supplementary motor area, and negatively correlated with gray matter volume in the left superior temporal gyrus and insula. In the functional connectivity analysis, hypnotic suggestibility was positively correlated with functional connectivity between medial posterior areas, including bilateral posterior cingulate cortex and precuneus, and both the lateral visual network and the left fronto-parietal network; a positive correlation was also found with functional connectivity between the executive-control network and a right postcentral/parietal area. In contrast, hypnotic suggestibility was negatively correlated with functional connectivity between the right fronto-parietal network and the right lateral thalamus. These findings demonstrate for the first time a correlation between hypnotic suggestibility, the structural features of specific cortical regions, and the functional connectivity during the normal resting state of brain structures involved in imagery and self-monitoring activity

Immediate implant loading: a comparison of trabecular metal and tapered screw-vent dental implants

Aims: The aim of the present study is to compare osteointegration and marginal bone loss of immediately loaded Trabecular Metal® and Tapered Screw-Vent® Dental Implants (Zimmer Dental Inc., Carlsbad, CA, USA). Methods: Eighty-seven (87) patients were selected and randomly divided into Group A and Group B. Twenty-six (26) patients were enrolled in Group A, and were rehabilitated using Zimmer Trabecular Metal Dental Implants®. Sixty-one (61) patients were enrolled in Group B, and were rehabilitated using Zimmer Tapered Screw-Vent Dental Implants®. Results: The mean value of marginal bone loss after one year was 0.44 ± 0.40 mm for Group A and 0.95 ± 0.62 mm for Group B (p<.003). Mean marginal bone loss after 18 months was 0.46 ± 0.42 mm for group A and 0.97 ± 0.65 mm for group B (p<.003). No TM implant was lost (Group A), whereas one TSV implant (Group B) was lost before osseointegration and was not included in the statistical analysis. Conclusion: Both Trabecular Metal and Tapered Screw-Vent dental implants showed satisfying levels of osteointegration and marginal bone loss; however, statistical analysis revealed a value significantly lower of marginal bone loss for TM. Thus, it may be deduced that when implants are immediately loaded, the average loss of marginal bone around the TM implants is lower than that of the Tapered Screw-Vent implants

Pain mirrors: Neural correlates of observing self or others' facial expressions of pain

Facial expressions of pain are able to elicit empathy and adaptive behavioral responses in the observer. An influential theory posits that empathy relies on an affective mirror mechanism, according to which emotion recognition relies upon the internal simulation of motor and interoceptive states triggered by emotional stimuli. We tested this hypothesis comparing representations of self or others' expressions of pain in nineteen young healthy female volunteers by means of functional magnetic resonance imaging (fMRI). We hypothesized that one's own facial expressions are more likely to elicit the internal simulation of emotions, being more strictly related to self. Video-clips of the facial expressions of each volunteer receiving either painful or non-painful mechanical stimulations to their right hand dorsum were recorded and used as stimuli in a 2 × 2 (Self/Other; Pain/No-Pain) within-subject design. During each trial, a 2 s video clip was presented, displaying either the subject's own neutral or painful facial expressions (Self No-Pain, SNP; Self Pain, SP), or the expressions of other unfamiliar volunteers (Others' No-Pain, ONP; Others' Pain, OP), displaying a comparable emotional intensity. Participants were asked to indicate whether each video displayed a pain expression. fMRI signals were higher while viewing Pain than No-Pain stimuli in a large bilateral array of cortical areas including middle and superior temporal, supramarginal, superior mesial and inferior frontal (IFG) gyri, anterior insula (AI), anterior cingulate (ACC), and anterior mid-cingulate (aMCC) cortex, as well as right fusiform gyrus. Bilateral activations were also detected in thalamus and basal ganglia. The Self vs. Other contrast showed signal changes in ACC and aMCC, IFG, AI, and parietal cortex. A significant interaction between Self and Pain [(SP vs. SNP) &gt; (OP vs. ONP)] was found in a pre-defined region of aMCC known to be also active during noxious stimulation. These findings demonstrate that the observation of one's own and others' facial expressions share a largely common neural network, but self-related stimuli induce generally higher activations. In line with our hypothesis, selectively greater activity for self pain-related stimuli was found in aMCC, a medial-wall region critical for pain perception and recognition

Pain Mirrors: Neural Correlates of Observing Self or Others’ Facial Expressions of Pain

Facial expressions of pain are able to elicit empathy and adaptive behavioral responses in the observer. An influential theory posits that empathy relies on an affective mirror mechanism, according to which emotion recognition relies upon the internal simulation of motor and interoceptive states triggered by emotional stimuli. We tested this hypothesis comparing representations of self or others’ expressions of pain in nineteen young healthy female volunteers by means of functional magnetic resonance imaging (fMRI). We hypothesized that one’s own facial expressions are more likely to elicit the internal simulation of emotions, being more strictly related to self. Video-clips of the facial expressions of each volunteer receiving either painful or non-painful mechanical stimulations to their right hand dorsum were recorded and used as stimuli in a 2 × 2 (Self/Other; Pain/No-Pain) within-subject design. During each trial, a 2 s video clip was presented, displaying either the subject’s own neutral or painful facial expressions (Self No-Pain, SNP; Self Pain, SP), or the expressions of other unfamiliar volunteers (Others’ No-Pain, ONP; Others’ Pain, OP), displaying a comparable emotional intensity. Participants were asked to indicate whether each video displayed a pain expression. fMRI signals were higher while viewing Pain than No-Pain stimuli in a large bilateral array of cortical areas including middle and superior temporal, supramarginal, superior mesial and inferior frontal (IFG) gyri, anterior insula (AI), anterior cingulate (ACC), and anterior mid-cingulate (aMCC) cortex, as well as right fusiform gyrus. Bilateral activations were also detected in thalamus and basal ganglia. The Self vs. Other contrast showed signal changes in ACC and aMCC, IFG, AI, and parietal cortex. A significant interaction between Self and Pain [(SP vs. SNP) &gt;(OP vs. ONP)] was found in a pre-defined region of aMCC known to be also active during noxious stimulation. These findings demonstrate that the observation of one’s own and others’ facial expressions share a largely common neural network, but self-related stimuli induce generally higher activations. In line with our hypothesis, selectively greater activity for self pain-related stimuli was found in aMCC, a medial-wall region critical for pain perception and recognition

Cognitive modulation of pain and predictive coding. Comment on "Facing the experience of pain: a neuropsychological perspective" by Fabbro and Crescentini

A commentary on the article \u201cFacing the experience of pain: A neuropsychological perspective\u201d by Fabbro and Crescentini, where the potential usefulness of adopting a predictive coding approach to understand pain perception is outlined

Histomorphometric Comparison of New Bone Formed After Maxillary Sinus Lift With Lateral and Crestal Approaches Using Periostal Mesenchymal Stem Cells and Beta-Tricalcium Phosphate: A Controlled Clinical Trial

The present study investigated clinical and histomorphometric data after sinus lift procedures performed with and without mesenchymal stem cells (MSCs) added to a graft. Twenty-four patients underwent maxillary sinus lift for implant placement. Twelve patients each were assigned to control (Group 1) and test (Group 2) groups. An MSC suspension was added to the graft used in patients of Group 2. Five of 12 patients in both groups underwent crestal-approach sinus lift with immediate implant placement, while seven patients received a lateral-approach sinus lift. The MSC suspension was obtained using the Rigenera protocol. Samples from the grafted site were evaluated, processed, and stained using three staining techniques 90 days after surgery. Histomorphometric analysis was performed using an imaging software (ImageJ). Two types of tissues were defined: Type 1 ‘mature bone’ and Type 2 ‘osteoid tissue’. The mean Type 1 tissue percentage was 27.24% in Group 1 and 44.45% in Group 2 (P &lt; 0.05). The mean Type 2 tissue percentage was 10.86% and 7.04% in Groups 1 and 2, respectively. The mean Type 1 tissue percentages for the crestal approach were 24.52% for Group 1 and 50.78% for Group 2, while the mean Type 1 tissue percentages for the lateral approach were 29.18% for Group 1 and 39.92% for Group 2. Patients treated with grafts containing MSCs showed 63.18% increased bone formation compared to those treated with grafts not containing MSCs (P &lt; 0.05). Although our data showed a positive trend in patients treated with MSCs, differences between subgroups were not significant (P &gt; 0.05)

Voluntary modulation of mental effort investment: an fMRI study

Abstract Mental effort is a common phenomenological construct deeply linked to volition and self-control. While it is often assumed that the amount of exertion invested in a task can be voluntarily regulated, the neural bases of such faculty and its behavioural effects are yet insufficiently understood. In this study, we investigated how the instructions to execute a demanding cognitive task either “with maximum exertion” or “as relaxed as possible” affected performance and brain activity. The maximum exertion condition, compared to relaxed execution, was associated with speeded motor responses without an accuracy trade-off, and an amplification of both task-related activations in dorsal frontoparietal and cerebellar regions, and task-related deactivations in default mode network (DMN) areas. Furthermore, the visual cue to engage maximum effort triggered an anticipatory widespread increase of activity in attentional, sensory and executive regions, with its peak in the brain stem reticular activating system. Across individuals, this surge of activity in the brain stem, but also in medial wall cortical regions projecting to the adrenal medulla, positively correlated with increases in heart rate, suggesting that the intention to willfully modulate invested effort involves mechanisms related to catecholaminergic transmission and a suppression of DMN activity in favor of externally-directed attentional processes

Hypnotic susceptibility explains differences in resting state functional connectivity

Introduction: Hypnotic susceptibility (HS) is a measurable cognitive trait defined as the generalized tendency to respond to hypnotic suggestions [1]. Very little is known about the neural bases of HS [2]. Our aim was to assess HS-related differences in resting state func tional c onnec tivity. Methods: N=35 healthy women (3 ambidextrous, 4 left-handed; age range 19-56 yrs, mean 36.9 yrs) partic ipated in the study. HS was assessed with the Stanford Hypnotic Susc eptibility Sc ale – Form A (SHSS:A), mental absorption with the T ellegen Absorption Sc ale (T AS) and trait anxiety with the State-T rait Anxiety Inventory Form Y (ST AI-Y2). Subjec ts were not in any way pre-selec ted for SHSS sc ore. T o measure spontaneous BOLD signal fluc tuations at rest, two runs of EPI sc ans were ac quired while subjec ts lay in the sc anner relaxed with eyes c losed (for eac h run: 200 volumes; T R 2 s; isometric voxel size 3.6 mm; 35 axial slic es without gap; matrix 80 x 63 voxels; FOV 286 x 229 mm; ac quisition time 7 min), using a 3T Philips Ac hieva MR sc anner. A T 1-weighted brain image (isotropic voxel size 0.5 mm) was ac quired for inter-subjec t alignment. EPI data were analysed using AFNI. Preproc essing inc luded the removal of physiologic al, white matter and hardware related noise using RET ROICOR and ANAT ICOR proc edures, lowpass filtering to remove frequenc ies >0.1 Hz, and 6-mm FWHM spatial smoothing. Seed-based func tional c onnec tivity (FC) was quantified as the z-transformed Pearson c orrelation with the seed signal (average BOLD signal within a sphere of 6mm radius). Seeds were plac ed (a) within key regions of the Default Mode Network (DMN) taken from the literature; (b) in the two areas (anterior c ingulate c ortex – ACC; dorsolateral prefrontal c ortex – DLPFC) desc ribed in Hoeft et al. [2]; and (c ) in 15 seeds ad-hoc plac ed along the c ingulate c ortex in eac h hemisphere. HS-related differenc es in FC were assessed by using SHSS sc ore as a between-subjec ts linear regressor to explain FC z-sc ores. Furthermore, some of the c lusters whic h resulted signific antly c onnec ted with the above mentioned seeds, e.g. orbitofrontal c ortex (OFC), were, in turn, used as seeds (d). Results: SHSS sc ores ranged from 0-10 (mean 3.6). Eighteen subjec ts had low (SHSS<4), 14 medium (SHSS=4-7) and 3 high SHSS sc ores (SHSS>7). SHSS was independent of age, educ ational level, handedness, trait anxiety and mental absorption. SHSS was positively c orrelated with FC (a) of DMN seeds, i.e., the right medial PFC, left posterior c ingulate c ortex (PCC) and left posterior insula with c erebellar foc i, and (b) of Hoeft et al.'s [2] ACC seed with c erebellar regions, and of right DLPFC with left OFC. When foc using on the c ingulate c ortex (c ), SHSS was positively c orrelated with FC of ACC with mid-c ingulate c ortex (MCC), of various seeds in the ACC and MCC with c erebellar foc i, and of MCC with bilateral OFC. SHSS was also positively c orrelated with FC of the OFC foc i (d) with a wide network of regions, inc luding MCC, bilateral DLPFC (see Fig. 1), pre- and postcentral gyri, superior temporal gyri and insula as well as cerebellum and contralateral precuneus (Fig. 2). Conclusions:Among healthy women, individuals with higher HS show higher resting state FC between OFC, DLPFC, cingulate cortex and cerebellum. Further researc h is needed to c onfirm these relationships in men, and to assess their cognitive correlates

Does anticipation of pain affect cortical nociceptive systems?

Anticipation of pain is a complex state that may influence the perception of subsequent noxious stimuli. We used functional magnetic resonance imaging (fMRI) to study changes of activity of cortical nociceptive networks in healthy volunteers while they expected the somatosensory stimulation of one foot, which might be painful (subcutaneous injection of ascorbic acid) or not. Subjects had no previous experience of the noxious stimulus. Mean fMRI signal intensity increased over baseline values during anticipation and during actual stimulation in the putative foot representation area of the contralateral primary somatosensory cortex (SI). Mean fMRI signals decreased during anticipation in other portions of the contralateral and ipsilateral SI, as well as in the anteroventral cingulate cortex. The activity of cortical clusters whose signal time courses showed positive or negative correlations with the individual psychophysical pain intensity curve was also significantly afected during the waiting period. Positively correlated clusters were found in the contralateral SI and bilaterally in the anterior cingulate, anterior insula, and medial prefrontal cortex. Negatively correlated clusters were found in the anteroventral cingulate bilaterally. In all of these areas, changes during anticipation were of the same sign as those observed during pain but less intense (similar to30-40% as large as peak changes during actual noxious stimulation). These results provide evidence for top-down mechanisms, triggered by anticipation, modulating cortical systems involved in sensory and affective components of pain even in the absence of actual noxious input and suggest that the activity of cortical nociceptive networks may be directly influenced by cognitive factors