Functional Changes in Brain Activity Using Hypnosis: A Systematic Review.

Hypnosis has proven a powerful method in indications such as pain control and anxiety reduction. As recently discussed, it has been yielding increased attention from medical/dental perspectives. This systematic review (PROSPERO-registration-ID-CRD42021259187) aimed to critically evaluate and discuss functional changes in brain activity using hypnosis by means of different imaging techniques. Randomized controlled trials, cohort, comparative, cross-sectional, evaluation and validation studies from three databases-Cochrane, Embase and Medline via PubMed from January 1979 to August 2021-were reviewed using an ad hoc prepared search string and following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A total of 10,404 articles were identified, 1194 duplicates were removed and 9190 papers were discarded after consulting article titles/abstracts. Ultimately, 20 papers were assessed for eligibility, and 20 papers were included after a hand search (ntotal = 40). Despite a broad heterogenicity of included studies, evidence of functional changes in brain activity using hypnosis was identified. Electromyography (EMG) startle amplitudes result in greater activity in the frontal brain area; amplitudes using Somatosensory Event-Related Potentials (SERPs) showed similar results. Electroencephalography (EEG) oscillations of θ activity are positively associated with response to hypnosis. EEG results showed greater amplitudes for highly hypnotizable subjects over the left hemisphere. Less activity during hypnosis was observed in the insula and anterior cingulate cortex (ACC).

Current neuroscientific research database findings of brain activity changes after hypnosis.

Using multi-modal brain imaging techniques we found pronounced changes in neuronal activity after hypnotic trance induction whereby state changes seem to occur synchronously with the specific induction instructions. In clinical patients, hypnosis proved to be a powerful method in inhibiting the reaction of the fear circuitry structures. The aim of the present paper is to critically discuss the limitations of the current neuroscientific research database in the light of a debate in defining relevant hypnotic constructs and to suggest ideas for future research projects. We discuss the role of hypnotic suggestibility (HS), the impact of hypnotic inductions and the importance of the depth of hypnotic trance. We argue that future research on brain imaging studies on the effects of hypnosis and hypnotherapy should focus on the analysis of individual cross-network activation patterns. A most promising approach is to simultaneously include physiological parameters linked to cognitive, somatic, and behavioral effects.

Caries treatment in a four-year-old boy using hypnosis - a case report.

This clinical case report demonstrates the successful application of hypnosis in an anxious four-year-old boy in whom two primary molars were treated with a composite filling. The almost 16-minute pediatric dental treatment was performed without complications and without interruptions. It could be shown that hypnosis can be used for the pediatric dental treatment of decayed primary tooth lesions. In the specific individual case hypnosis was not only used adjuvant but as an alternative to local anesthesia. A dental anxiety reducing effect and an elimination of pain perception were observed, so that the treatment was possible without anesthesia. It was also found that the communication and rapport between the practitioner and the four-year-old child were improved using hypnosis. There is still a need for high quality studies on the numerous positive effects that hypnosis has on pediatric dental treatment.

FUNCTIONAL CHANGES IN BRAIN ACTIVITY AFTER HYPNOSIS: Neurobiological Mechanisms and Application to Patients with a Specific Phobia-Limitations and Future Directions.

Studies of brain-plasticity changes in hypnosis using functional magnetic resonance imaging (fMRI), positron-emission-tomography (PET) and electroencephalography (EEG) were reviewed. The authors found evidence in those studies that hypnosis is a powerful and successful method for inhibiting the reaction of the fear circuitry structures. Limitations of the studies were critically discussed, and implications for future research were made. The authors are currently using a portable fNIRS apparatus to integrate the scanning device into real life situations in medical practice. Their aim is to disentangle the neuronal mechanisms and physiological correlates in patients with severe fear of medical treatments when directly confronted with anxiety-provoking stimuli and to assess the effects of a brief hypnosis. Drawing on evidence from several technological modalities, neuroimaging and physiological studies pave the road to a better scientific understanding of neural mechanisms of hypnosis.

Spatial characteristics of spontaneous and stimulus-induced individual functional connectivity networks in severe disorders of consciousness.

BACKGROUND: Functional connectivity (fcMRI) analyses of resting state functional magnetic resonance imaging (fMRI) data revealed substantial differences between states of consciousness. The underlying cause-effect linkage, however, remains unknown to the present day. The aim of this study was to examine the relationship between fcMRI measures and Disorders of Consciousness (DOC) in resting state and under adequate stimulation. METHODS AND FINDINGS: fMRI data from thirteen patients with unresponsive wakefulness syndrome, eight patients in minimally conscious state, and eleven healthy controls were acquired in rest and during the application of nociceptive and emotional acoustic stimuli. We compared spatial characteristics and anatomical topography of seed-based fcMRI networks on group and individual levels. The anatomical topography of fcMRI networks of patients was altered in all three conditions as compared with healthy controls. Spread and distribution of individual fcMRI networks, however, differed significantly between patients and healthy controls in stimulation conditions only. The exploration of individual metric values identified two patients whose spatial metrics did not deviate from metric distributions of healthy controls in a statistically meaningful manner. CONCLUSIONS: These findings suggest that the disturbance of consciousness in DOC is related to deficits in global topographical network organization rather than a principal inability to establish long-distance connections. In addition, the results question the claim that task-free measurements are particularly valuable as a tool for individual diagnostics in severe neurological disorders. Further studies comparing connectivity indices with outcome of DOC patients are needed to determine the clinical relevance of spatial metrics and stimulation paradigms for individual diagnosis, prognosis and treatment in DOC.

Influence of owners' attachment style and personality on their dogs' (Canis familiaris) separation-related disorder.

Previous research has suggested that owners' attitude to their family dogs may contribute to a variety of behaviour problems in the dog, and authors assume that dogs with separation-related disorder (SRD) attach differently to the owner than typical dogs do. Our previous research suggested that these dogs may have an insecure attachment style. In the present study we have investigated whether owners' attachment style, personality traits and the personality of the dog influence the occurrence of SRD in the dog. In an internet-based survey 1508 (1185 German and 323 Hungarian) dog-owners filled in five questionnaires: Demographic questions, Separation Behaviour Questionnaire (to determine SRD), Human and Dog Big Five Inventory and Adult Attachment Scale. We found that with owners' higher score on attachment avoidance the occurrence of SRD in the dog increases. Dogs scoring higher on the neuroticism scale were more prone to develop SRD. Our results suggest that owners' attachment avoidance may facilitate the development of SRD in dogs. We assume that avoidant owners are less responsive to the dog's needs and do not provide a secure base for the dog when needed. As a result dogs form an insecure attachment and may develop SRD. However, there may be alternative explanations of our findings that we also discuss.

Functional changes in brain activity after hypnosis in patients with dental phobia.

Visiting the dentist is often accompanied by apprehension or anxiety. People, who suffer from specific dental phobia (a disproportional fear of dental) procedures show psychological and physiological symptoms which make dental treatments difficult or impossible. For such purposes, hypnosis is often used in dental practice as an alternative for a number of treatments adjuvant or instead of sedation or general anaesthetics, as medication is often associated with risks and side effects. This is the first study to address the effects of a brief dental hypnosis on the fear processing structures of the brain in dental phobics using functional magnetic resonance imaging (fMRI). 12 dental phobics (DP; mean 34.9years) and 12 healthy controls (CO; mean 33.2years) were scanned with a 3T MRI whole body-scanner observing brain activity changes after a brief hypnotic invervention. An fMRI event-related design symptom provocation task applying animated audio-visual pseudorandomized strong phobic stimuli was presented in order to maximize the fearful reactions during scanning. Control videos showed the use of familiar electronic household equipment. In DP group, main effects of fear condition were found in the left amygdala and bilaterally in the anterior cingulate cortex (ACC), insula and hippocampu (R

Designing rehabilitation programs for neglect: could 2 be more than 1+1?

Unilateral neglect is a multimodal neuropsychological disorder that has puzzled scientists for a long time. Many interventions have been developed, but only a handful has proven to be effective. This review examines whether applying different therapeutic techniques in combination will increase therapeutic benefits. Studies were reviewed where therapies are applied sequentially or in combination with other techniques. The results indicate that combining different interventions leads to increased general improvement compared with other noncombined designs, even when the number of treatment sessions is not constant. Practical and theoretical aspects of different treatments are discussed. The combined approach to treatment may have direct relevance to disorders other than neglect. This report introduces a new classification scheme for different interventions with the aim of facilitating more focused therapy. Finally, suggestions are made as to what the focus of future studies of neglect therapy should be and how therapeutic benefits might be maximized.

Analysis of electrophysiological state patterns and changes during hypnosis induction.

Hypnosis can be seen as a guided induction of various states of consciousness. This article details a time-series analysis that visualized the electrophysiological state changes during a session as a correlate to the instructions. Sixty-four channels of EEG and peripheral physiological measures were recorded in 1 highly susceptible subject. Significant state changes occurred synchronously with specific induction instructions. Some patterns could be physiologically explained, such as sensorimotor desynchronization over the right hemispheric hand area during left arm levitation. There was a highly significant increase in broadband activity during the stepwise trance induction that may point to a deep hypnotic state. This study provides illustrated proof for the detectability of physiological state changes as correlates to different states of awareness, consciousness, or cognition during hypnosis.

Strength in numbers: combining neck vibration and prism adaptation produces additive therapeutic effects in unilateral neglect.

Unilateral neglect is a multifaceted disorder. Many authors have, for this reason, speculated that the best treatment for neglect will involve combinations of different therapeutic techniques. Two well-known interventions, neck vibration (NV) and prism adaptation (PA), have often been considered to be among the most effective treatments for neglect. Here, two experiments were performed to explore possible additive benefits when these interventions are used in combination to treat chronic neglect. Both experimental groups received NV for 20 minutes, while the second group received simultaneous PA. The effects of treatment were measured with a time-restricted and feedback-based visual search task, which has previously been found to abolish the beneficial effects of PA, and with standard neglect tests. Baseline and intervention measures were performed on separate days. Findings for both groups indicated improved visual search following intervention, but the patients that underwent the combined intervention (NVPA) showed clear improvements on visual search paper and pencil neglect tests unlike the NV-only group. Overall, our results suggest that PA strengthens the effects of NV and that feedback-based tasks do not abolish the beneficial effects of PA, when NV is applied simultaneously. The results support the view that the most effective treatment for neglect will involve the combination of different treatments.

Prism adaptation improves visual search in hemispatial neglect.

Visuomotor prism adaptation has been found to induce a lateral bias of spatial attention in chronic hemispatial neglect patients. Here, two experiments were conducted to explore the effects of 10 degrees prism adaptation on visual search tasks and standard visual inattention tests. Baselines and intervention effects were measured on separate days for all patients. The first experiment explored whether prism adaptation affects performance on a time restricted visual search task (maximum 3500ms presentation followed by visual and auditory feedback). No positive effects of prism adaptation were found on accuracy in visual search nor on traditional neglect tests. These results accord well with previous studies showing that increased cognitive load can lead to prism de-adaptation or unchanged performance following prism adaptation. Response times in visual search became faster following intervention but this was not the case for the standard neglect tests. In the second experiment, the same single-featured search task was used, but the participants had unlimited search time and received no feedback on their response. This time, the patients showed accuracy improvements in visual search and all four on regular neglect tests. Therapeutic effects lasted for at least 90-120min. Response times on all tasks became faster after prism adaptation. The results are consistent with studies showing effects of prism adaptation on neuropsychological neglect tests and other attentional tasks that are not speeded or time restricted, where feedback is not provided, or are performed following non-feedback-based tasks. The current findings show that prism adaptation improves visual search in neglect and that these beneficial effects can disappear with feedback.

Reduced ventrolateral fMRI response during observation of emotional gestures related to the degree of dopaminergic impairment in Parkinson disease.

Recent findings point to a perceptive impairment of emotional facial expressions in patients diagnosed with Parkinson disease (PD). In these patients, administration of dopamine can modulate emotional facial recognition. We used fMRI to investigate differences in the functional activation in response to emotional and nonemotional gestures between PD patients and age-matched healthy controls (HC). In addition, we used PET to evaluate the striatal dopamine transporter availability (DAT) with [(11)C]d-threo-methylphenidate in the patient group. Patients showed an average decrease to 26% in DAT when compared to age-corrected healthy references. Reduction in the DAT of the left putamen correlated not only with motor impairment but also with errors in emotional gesture recognition. In comparison to HC, PD patients showed a specific decrease in activation related to emotional gesture observation in the left ventrolateral prefrontal cortex (VLPFC) and the right superior temporal sulcus. Moreover, the less DAT present in the left putamen, the lower the activation in the left VLPFC. We conclude that a loss of dopaminergic neurotransmission in the putamen results in a reduction of ventrolateral prefrontal access involved in the recognition of emotional gestures.

Lateralization of hippocampal activation differs between left and right temporal lobe epilepsy patients and correlates with postsurgical verbal learning decrement.

We addressed the question whether lateralization of memory-related medial temporal lobe (MTL) activity in medial temporal lobe epilepsy (MTLE) patients is determined by pathology or sex, differentiating between two MTL subregions implicated in visuospatial memory as regions-of-interest (ROI) - the hippocampus (Hc) and the parahippocampal place area (PPA). We further assessed the relation between lateralization of hippocampal activation and postsurgical memory decline regarding performance in standardized neuropsychological tests of verbal and visuospatial learning. Functional magnetic resonance imaging (fMRI) data were acquired from unilateral MTLE patients performing an object location memory task in a virtual environment. Individual lateralization indices (LI) based on memory-related brain activation patterns were calculated for each subject and ROI. Correlational analyses were computed between pre- to postsurgical changes in learning and asymmetry in hippocampal activation. Results revealed that lateralization of hippocampal, memory-related activity in patients with MTLE was determined by the side of seizure focus, not sex. Laterality of activation in the PPA was neither influenced by side of pathology nor sex. Lateralization of hippocampal activation was significantly correlated with decline in verbal learning after surgery. We were able to demonstrate that asymmetry of hippocampal fMRI-activation in unilateral MTLE patients is determined by the side of seizure focus, thus indicating the relative functional integrity of the hippocampi. This is corroborated by the finding that greater activation of the to-be-resected hippocampus leads to stronger verbal memory decline after surgery.

Differential effect of side of temporal lobe epilepsy on lateralization of hippocampal, temporolateral, and inferior frontal activation patterns during a verbal episodic memory task.

The encoding of verbal stimuli elicits left-lateralized activation patterns within the medial temporal lobes in healthy adults. In our study, patients with left- and right-sided temporal lobe epilepsy (LTLE, RTLE) were investigated during the encoding and retrieval of word-pair associates using functional magnetic resonance imaging. Functional asymmetry of activation patterns in hippocampal, inferior frontal, and temporolateral neocortical areas associated with language functions was analyzed. Hippocampal activation patterns in patients with LTLE were more right-lateralized than those in patients with RTLE (P<0.05). There were no group differences with respect to lateralization in frontal or temporolateral regions of interest (ROIs). For both groups, frontal cortical activation patterns were significantly more left-lateralized than hippocampal patterns (P<0.05). For patients with LTLE, there was a strong trend toward a difference in functional asymmetry between the temporolateral and hippocampal ROIs (P=0.059). A graded effect of epileptic activity on laterality of the different regional activation patterns is discussed.

Hippocampal functional connectivity reflects verbal episodic memory network integrity.

Using functional magnetic resonance imaging during a verbal memory task, we investigated correlations of signal fluctuations within the hippocampus and ipsilateral frontal as well as temporal areas in temporal lobe epilepsy patients. Declarative memory abilities were additionally examined before and after temporal lobe epilepsy surgery. A significant difference exists in functional connectivity between patients whose mnemonic functions deteriorated and those who remained stable or improved. Univariate analyses showed significantly higher preoperative coupling between the hippocampus and Brodmann area 22 for the group that decreased in verbal learning. We suggest greater coupling to reflect higher functional network integrity. Postoperatively reduced learning ability in patients with higher preoperative coupling underlines the importance of hippocampal interaction with cortical areas for successful memory formation.

Differences between subtypes of children with ADHD and simple attentional difficulties during an initial assessment.

OBJECTIVE: To examine differences between subtypes of children with attention-deficit/hyperactivity disorder (ADHD), simple attentional difficulties and situational ADHD during an initial assessment. METHOD: In a single-centre study examination data of 205 children who had an initial assessment between January 1, 2002 and December 31, 2003 were retrospectively analyzed. The groups of children were compared with respect to their history features, neuromotor deficits, neuropsychological performance, and comorbid behavioural and developmental deficits by standardized test procedures and questionnaires. RESULTS: Children with ADHD more frequently have a positive family history of attentional symptoms than non-ADHD children. There is no difference between these groups with respect to the associated behavioural problems. Children classified as ADHD show more neuromotor problems and neuropsychological deficits than children with non-ADHD attentional problems. Children with ADHD subtype hyperactive/impulsive demonstrate better neuropsychological performance than children with subtypes inattentive and combined. Children with situational home-only or school-only ADHD show no clear differences in neuromotor behaviour, comorbid problems or neuropsychological performance. CONCLUSIONS: There are clear neuropsychological differences between children who fulfil the classification criteria of The Diagnostic and Statistical Manual of Disease, Fourth Revision (DSM-IV) for ADHD and children who are confronted daily with attentional difficulties, but do not fulfil the criteria for ADHD. In contrast, differences in behavioural comorbidities were not found, nor were differences found between home-only and school-only ADHD children.

Neuropsychological impairment in obsessive-compulsive disorder--improvement over the course of cognitive behavioral treatment.

A large body of studies demonstrates mild cognitive dysfunction in patients with Obsessive Compulsive Disorder (OCD). Few trials have investigated whether this dysfunction can be improved by treatment. Thirty unmedicated inpatients with OCD were administered a comprehensive neuropsychological test battery before and after 12 weeks of cognitive behavioral therapy (CBT). Thirty-nine carefully matched healthy controls were tested twice within the same interval. At baseline, patients exhibited significant impairments on several tests which normalized at follow-up. A significant group x time interaction was found for tests of nonverbal memory, set shifting and flexible, self guided behavior. Major responders improved significantly more than minor responders on the Rey-Osterrieth Figure immediate and delayed recall. Results suggest that cognitive dysfunction in OCD can improve in the course of treatment. We hypothesize that particularly cognitive behavioral treatment enables OCD patients to think and act in a more flexible way that helps them to develop more effective cognitive strategies.

Learning in trance: functional brain imaging studies and neuropsychology.

This study examined the fundamental question, whether verbal memory processing in hypnosis and in the waking state is mediated by a common neural system or by distinct cortical areas. Seven right-handed volunteers (25.4 years, sd 3.1) with high-hypnotic susceptibility scores were PET-scanned while encoding/retrieving word associations either in hypnosis or in the waking state. Word-pairs were visually presented and highly imaginable, but not semantically related (e.g. monkey-street). The presentation of pseudo-words served as a reference condition. An emission scan was recorded after each intravenous administration of O-15 water. Encoding under hypnosis was associated with more pronounced bilateral activations in the occipital cortex and the prefrontal areas as compared to learning in the waking state. During memory retrieval of word-pairs which had been previously learned under hypnosis, activations were found in the occipital lobe and the cerebellum. Under both experimental conditions precuneus and prefrontal cortex showed a consistent bilateral activation which was most distinct when the learning had taken place under hypnosis. In order to further analyze the effect of hypnosis on imagery-mediated learning, we administered sets of high-imagery word-pairs and sets of abstract words. In the first experimental condition word-pair associations were presented visually. In the second condition it was found that highly hypnotisable persons recalled significantly more high-imagery words under hypnosis as compared to low-hypnotisables both in the visual and auditory modality. Furthermore, high-imagery words were also better recalled by the highly hypnotisable subjects during the non-hypnotic condition. The memory effect was consistently present under both, immediate and delayed recall conditions. Taken together, the findings advance our understanding of the neural representation that underlies hypnosis and the neuropsychological correlates of hypnotic susceptibility.

PET imaging of the basal ganglia.

The present chapter reviews PET imaging in basal ganglia disorders; Parkinson's disease is used as a model of these disorders because the neurochemical pathobiology of this disease is well known and great advances in the imaging area have been achieved. Other basal ganglia disorders including Tourette's syndrome, dystonia, Huntington's chorea and Wilson's disease are also dealt with. With PET and SPECT techniques, the whole integrative dopaminergic network of neurons can be studied, which plays an important role in differential diagnostics. Furthermore, pharmacological effects of medication can be visualized and the role of stereotaxic neurosurgery can be evaluated. Finally, functional imaging gives clues about the prognosis and rehabilitation aspects of the basal ganglia disorders.