Hypnosis Research Articles

Q-EEG map of parietal and frontal lobes out of brain waves recording during dental hypnosis practice

Introduction: A patient with fear and anxiety is a common case to deal with for a dentist, therefore, dental hypnosis has been widely used to ease this situation. In a hypnotized state, the human brain may easily accept any suggestion. This is projected in the brain waves. Electroencephalograph (EEG) is a brain wave recording device, reflecting several states of consciousness. Beta for conscious, alpha and theta for subconscious, and delta for sleep. Dental hypnosis puts down beta waves to alpha or theta. Quantitative Electroencephalography (Q-EEG) or brain mapping is a comprehensive analysis of (Electroencephalography, EEG) in a colored topographic map, reflecting the brain's electrical activity. The objective of this article was reporting the parietal and frontal lobes activity during dental hypnosis based on the Q-EEG mapping. Methods: The research applied a quantitative research method using observatory study. The sample was taken with an accidental sampling method, with inclusion criteria, patients with dental anxiety and exclusion criteria was patients with special need and high level of dental anxiety. Data of the EEG records was taken in January-March 2018, and processed after in Pramita laboratorium Bandung. Results: Parietal lobe affected more during the inducement than temporal lobe. During dental hypnosis, the hypnotic markers (theta and alpha states) observed from the EEG were found to be more reactive. Conclusion: Dental hypnosis effects can be observed easily using Quantitative Electroencephalography method. Dental hypnosis affects brainwaves and brain mapping which indicate relaxations of brain waves especially on parietal lobes.

Frank, Ludwig. Die psychokathartische Behandlung nervöser Störungen. (Psychoneurosen-Thymopathieri). Verlag Georg Thieme. Leipzig. 1927. IV + 208

Frank proposes to call psychoneuroses thymopathies, because psychoneuroses and all related diseases are disorders of the affective sphere of a quite definite nature. These are dynamic disorders of affective life, consisting mainly in the phenomena of the repression of affects, their accumulation and accumulation in the subconscious, their desire to move from the subconscious to the superconscious and the delay of this process due to the "internal resistance" (innerer Widerstand), displacing those striving for the release of affects back into the subconscious. With regard to the treatment of such dynamic disorders of the affective sphere, Frank considers psycho-cathartic treatment to be the most appropriate. The active principle of psychocatarsis is the awareness and secondary experience of affective excitations accumulated for various reasons in the subconscious. This is achieved in a hypnotic state of half-sleep, when the consciousness is narrowed only so much that the internal resistance falls, the delays disappear and there is a free reaction of the affects accumulated in the subconscious with the passive participation of superconscious attention. Having responded to the restrained affects and realizing those initial experiences with which painful symptoms are associated, the b-oh recovers.

THE INFLUENCE OF HYPNOSIS ON CRIMINAL LIABILITY

“Sleep. Your eyelids are getting heavy. Sleep. Watch the swinging object. Concentrate. When you awake you will be completely under my power.” These words are familiar language to almost all of us, from images of the popular media, of a hypnotist attempting to place a subject in a hypnotic state. This subject has proved to be a source of fascination for many, and a source of intense debate in both psychological theory and jurisprudence for over two centuries, largely because of one controversial issue: can a person be induced to commit acts which are against his or her normal prudence and moral standards by means of hypnosis (or its historical antecedent, mesmerism)? The mysterious power of hypnotic coercion has moreover been absorbed into the popular consciousness, as reflected by the issue frequently featuring in fiction. For a single telling example, note the words of the villainous Baron Gruner to Sherlock Holmes: “You have heard of post-hypnotic suggestion, Mr Holmes? Well you will see how it works, for a man of personality can use hypnotism without any vulgar passes or tomfoolery.” The notoriety of hypnotic techniques is no doubt in no small measure due to accounts of sexual coercion of hypnotized subjects, as evidenced in the 1976 New South Wales Supreme Court case of R v Palmer, where a lay hypnotist was convicted on charges of rape, attempted rape and indecent assault. Evidence that this threat has been regarded as real by the courts even though no such case has arisen in South African law emerges from the declaring undesirable under the Publications and Entertainment Act 26 of 1963 of the magazine “True Men” for the publication of an article entitled “Amateur Hypnotism … Ruins 50 Girls a Week”. Gibson notes that “the idea that one person can dominate the will of another by occult or arcane means” goes back to the dawn of history, and is founded in pre-scientific ideas about magic and witchcraft. It has furtherbeen suggested by Gibson that in the present day, “hypnosis” has become a construct which has replaced “witchcraft” in the context of an accused performing criminal acts through an agent by means of coercion (perhaps this statement applies to both Anglo-American and European systems, less so to SA where witchcraft is as yet still a significant issue). This process has been aided by the proliferation of myths which have come to be established surrounding the notion of hypnosis in the public mind. The myths include: that hypnosis is done to the subject (as opposed to being self-induced); that it involves a battle of wills, with the stronger party (the Svengali-like hypnotist) winning over the weaker one; that the hypnotist must be a charismatic person; that hypnotic subjects are foolish or weak; that the hypnotist has unlimited power over the subject; that hypnosis is equivalent to sleep or loss of consciousness; that hypnosis is dangerous and destructive of the will; that hypnosis is a cure-all; that hypnosis confers special powers on subjects; that the hypnotic trance is irreversible; that hypnosis is fakery or sham behaviour; that hypnosis is a “truth serum” and that there are people who cannot be hypnotized. The law is not immune to these myths, and hypnotism has yet to be formally categorized in the general principles of criminal law. The search for a clear and rational explanation of the nature of hypnosis has further not beenassisted by the differing theories which have been offered in this regard. As will be indicated later, the courts (rather unsurprisingly) have also found difficulty with the concept.

Suggested visual blockade during hypnosis: Top-down modulation of stimulus processing in a visual oddball task.

Several theories of hypnosis assume that responses to hypnotic suggestions are implemented through top-down modulations via a frontoparietal network that is involved in monitoring and cognitive control. The current study addressed this issue re-analyzing previously published event-related-potentials (ERP) (N1, P2, and P3b amplitudes) and combined it with source reconstruction and connectivity analysis methods. ERP data were obtained from participants engaged in a visual oddball paradigm composed of target, standard, and distractor stimuli during a hypnosis (HYP) and a control (CON) condition. In both conditions, participants were asked to count the rare targets presented on a video screen. During HYP participants received suggestions that a wooden board in front of their eyes would obstruct their view of the screen. The results showed that participants’ counting accuracy was significantly impaired during HYP compared to CON. ERP components in the N1 and P2 window revealed no amplitude differences between CON and HYP at sensor-level. In contrast, P3b amplitudes in response to target stimuli were significantly reduced during HYP compared to CON. Source analysis of the P3b amplitudes in response to targets indicated that HYP was associated with reduced source activities in occipital and parietal brain areas related to stimulus categorization and attention. We further explored how these brain sources interacted by computing time-frequency effective connectivity between electrodes that best represented frontal, parietal, and occipital sources. This analysis revealed reduced directed information flow from parietal attentional to frontal executive sources during processing of target stimuli. These results provide preliminary evidence that hypnotic suggestions of a visual blockade are associated with a disruption of the coupling within the frontoparietal network implicated in top-down control.

Electrophysiological Features of Hypnotic State in Healthy Volunteers

Aim: Hypnosis is treated as a state of mind. An individual depending on his/her social and psychological features follows suggestions and applies the requirements concerning time and space. With the advancement in brain-imagining techniques, viewing neuropsychological features of hypnosis has become a possibility. This article investigates the neuropsychological properties of hypnosis. The present study examines the electrophysiological features of the hypnotic minds of healthy individuals. This study aims to detect whether there is a change in and, if yes, in what region of suggestible individuals' minds during hypnosis. Materials and Methods: In this study, 34 highly suggestive individuals were selected out of 150 healthy individuals and were subjected to multidimensional Iowa suggestibility scale inventory and electroencephalogram (EEG). Due to technical problems during EEG, 24 data could be used cleanly. Using a correlational design, 34 healthy, suggestive individuals between the ages of 18–55 were included in the study. These participants have gone through an EEG procedure using the oddball paradigm. EEG and oddball were administered to 17 participants with and without hypnosis. Seventeen participants were administered without and with hypnosis. Twenty-four participants whose data was clear were included in the analyses. Results: When the groups were compared, it was seen that there was no significant difference in P300, P200, and P100 activities. There was also no significant difference in N200 and N100 activities. Conclusions: In this study the authors administered oddball paradigm with hypnosis and without hypnosis. The authors do not report any differences between conditions in terms of enterprise resource plannings. Although there was no statistically significant difference in this experimental design, studies with new and different designs should be continued.

Linear and Nonlinear Quantitative EEG Analysis during Neutral Hypnosis following an Opened/Closed Eye Paradigm

Hypnotic susceptibility is a major factor influencing the study of the neural correlates of hypnosis using EEG. In this context, while its effects on the response to hypnotic suggestions are undisputed, less attention has been paid to “neutral hypnosis” (i.e., the hypnotic condition in absence of suggestions). Furthermore, although an influence of opened and closed eye condition onto hypnotizability has been reported, a systematic investigation is still missing. Here, we analyzed EEG signals from 34 healthy subjects with low (LS), medium (MS), and (HS) hypnotic susceptibility using power spectral measures (i.e., TPSD, PSD) and Lempel-Ziv-Complexity (i.e., LZC, fLZC). Indeed, LZC was found to be more suitable than other complexity measures for EEG analysis, while it has been never used in the study of hypnosis. Accordingly, for each measure, we investigated within-group differences between rest and neutral hypnosis, and between opened-eye/closed-eye conditions under both rest and neutral hypnosis. Then, we evaluated between-group differences for each experimental condition. We observed that, while power estimates did not reveal notable differences between groups, LZC and fLZC were able to distinguish between HS, MS, and LS. In particular, we found a left frontal difference between HS and LS during closed-eye rest. Moreover, we observed a symmetric pattern distinguishing HS and LS during closed-eye hypnosis. Our results suggest that LZC is better capable of discriminating subjects with different hypnotic susceptibility, as compared to standard power analysis.

Different roles of T-type calcium channel isoforms in hypnosis induced by an endogenous neurosteroid epipregnanolone

BackgroundMany neuroactive steroids induce sedation/hypnosis by potentiating γ-aminobutyric acid (GABAA) currents. However, we previously demonstrated that an endogenous neuroactive steroid epipregnanolone [(3β,5β)-3-hydroxypregnan-20-one] (EpiP) exerts potent peripheral analgesia and blocks T-type calcium currents while sparing GABAA currents in rat sensory neurons. This study seeks to investigate the behavioral effects elicited by systemic administration of EpiP and to characterize its use as an adjuvant agent to commonly used general anesthetics (GAs). MethodsHere, we utilized electroencephalographic (EEG) recordings to characterize thalamocortical oscillations, as well as behavioral assessment and mouse genetics with wild-type (WT) and different knockout (KO) models of T-channel isoforms to investigate potential sedative/hypnotic and immobilizing properties of EpiP. ResultsConsistent with increased oscillations in slower EEG frequencies, EpiP induced an hypnotic state in WT mice when injected alone intra-peritoneally (i.p.) and effectively facilitated anesthetic effects of isoflurane (ISO) and sevoflurane (SEVO). The CaV3.1 (Cacna1g) KO mice demonstrated decreased sensitivity to EpiP-induced hypnosis when compared to WT mice, whereas no significant difference was noted between CaV3.2 (Cacna1h), CaV3.3 (Cacna1i) and WT mice. Finally, when compared to WT mice, onset of EpiP-induced hypnosis was delayed in CaV3.2 KO mice but not in CaV3.1 and CaV3.3 KO mice. ConclusionWe posit that EpiP may have an important role as novel hypnotic and/or adjuvant to volatile anesthetic agents. We speculate that distinct hypnotic effects of EpiP across all three T-channel isoforms is due to their differential expression in thalamocortical circuitry.

Midlatency auditory evoked potentials during anesthesia in children: A narrative review.

The brain is considered as the major target organ of anesthetic agents. Despite that, a reliable means to monitor its function during anesthesia is lacking. Mid latency auditory evoked potentials are known to be sensitive to anesthetic agents and might therefore be a measure of hypnotic state in pediatric patients. This review investigates the available literature describing various aspects of mid latency auditory evoked potential monitoring in pediatric anesthesia.

WS5.8. Anaesthesia and Intraoperative Neurophysiological Monitoring

There has been a growth of monitoring in the operating room today. From a “finger on the pulse” as a standard to ECGs and pulse oximeters. Now neurological monitoring in also used extensively in the OR. There are three types of neuro monitoring in the OT which will be discussed today. Firstly, single nerve monitoring, eg the facial nerve during parotid surgery. Next, we have the monitoring of the depth of anaesthesia via the bispectral index and density spectral array. This helps us understand the depth of anaesthesia especially in total intravenous anaesthesia. BIS monitoring is good at indicating an “alert” state, which is why it can reduce the incidence of intraoperative awareness. However, its algorithm does not always accurately predict an “asleep” state. This means an unknown percentage of patients who are already asleep will not be identified because of falsely elevated BIS values. These patients will receive unnecessary dosage of anesthetics resulting in a deep hypnotic state. Given that there may be falsely elevated values, we have to consider when it is best to use the monitors and if it is cost effective. Lastly, we monitor the spinal cord using SSEPs and MEPs during spine surgery especially scoliosis surgery. Today it is standard practice to conduct some form of monitoring when performing any spinal operation that is associated with a high risk of spinal injury. Generally, operations are considered to carry such a risk when corrective forces are applied to the spine, the patient has preexisting neurological damage, the cord is being invaded, or an osteotomy or other procedure is being carried out in immediate juxtaposition to the cord. In this presentation we will look at the latter two monitoring modalities and whether they are needed and are cost effective in the OR.

Sexual Aversion and Lack of Sexual Desire in Woman: a Case from Clinical Practice

The article presents a clinical case with a 25-year-old female patient A., who has been married for 1 year, but before she was in a commonlaw marriage during 5 years with her present spouse, who is 30. They have not got any children. When she sought medical advice the patient informed that during 1.5 years she had been feeling sexual aversion to her husband (when he tried to take her in his arms, she had creeping sensations on her arms and back, a feeling of lump in her throat, and a desire to cry). She attributed it to the fact that her husband “does not pay enough attention to me”, he did not defend her against accusations from the side of his relatives and stood with his mother, faulting the patient for causing conflictual relations between the women. She did not feel any sexual desire toward her husband. Their sexual life was once a week. She let her husband loose with her only after she drank alcohol. A month before it was the end of their 8-month period, when she did not let her husband loose with her at all. Her husband put up with restrictions in their sexual life; he did not have any lover. Four months before she parted with her lover, with whom she was going 3-4 months. She did not feel any aversion to him. With time, by means of long conversations she succeeded in making her husband completely take her part in the conflict with his parents, and the spouses even severed any contacts with them.
 Our additional examination succeeded in revealing a number of the patient’s characterological peculiarities, particularly histrionic personality disorder, this fact confirming our clinical observations. The following diagnosis was made: sexual aversion, absence of sexual desire (selective variants) with development by the conversion (hysterical) mechanism. Treatment was provided with help of cognitive effects and hypnosuggestive therapy (its seven sessions were given). The cognitive effects were targeted at the patient’s complete acceptance of the belief that her husband fully supported her at that time and was entirely reliable. It was explained that in some cases disorders might base on the mechanism of conditioned pleasantness/desirability (conversion mechanism). But it was done in a very nuanced and kind way, since a straight-line explanation of this mechanism (“it is in your interests”) may cause a negative response and the treatment may be discontinued by patients.
 It was pointed out that sexual dysfunctions could result from influence of psychological factors: her bad relationships with her husband’s parents and with him. Suggestion in the hypnotic state was particularly targeted at elimination of sexual aversion, appearance of sexual desire toward her husband, generation of pleasant sensations during his caresses and kisses, presence of voluptuous (lascivious) sensations in frictions during coitus. Sexual intercourses were modeled too. It was also suggested that her husband was her defender, he stood with her and was entirely reliable. As the result of the given treatment, sexual aversion to the patient’s husband was nullified and her sexual desire toward him was completely restored.

Hypnotic interventions in the management of chronic pain

This article describes the pain neuro-matrix and shows how hypnotic suggestions can be used directed at each part of this in order to be maximally effective. Although inducing the hypnotic state may be relatively simple, it is important to know how to utilise it effectively using suggestion and imagery. An understanding of the patient’s clinical condition and some counselling or psychological training are essential.

Effects of isoflurane and sevoflurane alone and in combination with butorphanol or medetomidine on the bispectral index in chickens

BackgroundThe bispectral index (BIS) is an anaesthesia monitoring technique able to assess the level of central nervous system depression in humans and various animal species. In birds, it has been validated in chickens undergoing isoflurane anaesthesia. The aim of this study was to evaluate in an avian species the influence of isoflurane and sevoflurane on BIS, each at different minimum anaesthetic concentrations (MAC) multiples, alone or combined with butorphanol or medetomidine. Ten chickens (5 males and 5 females) underwent general anaesthesia with isoflurane or sevoflurane alone, and combined with either intramuscular administration of butorphanol (1 mg/kg) or medetomidine (0.1 mg/kg), in a prospective and cross-over study (i.e., 6 treatments per animal). BIS measurements were compared to heart rate (HR), non-invasive blood pressure (NIBP) and to a visual analogue scale (VAS) of anaesthesia depth.ResultsHR was significantly increased, and both NIBP and VAS were significantly reduced, with higher gas concentrations. NIBP (but not HR or VAS) was additionally affected by the type of gas, being lower at higher concentrations of sevoflurane. Butorphanol had no additional effect, but medetomidine led to differences in HR, NIBP, and in particular a reduction in VAS. With respect to deeper level of hypnosis at higher concentrations and the absence of difference between gases, BIS measurements correlated with all other measures (except with HR, where no significant relationship was found) The difference in BIS before (BISpre) and after stimulation (BISpost) did not remain constant, but increased with increasing MAC multiples, indicating that the BISpost is not suppressed proportionately to the suppression of the BISpre values due to gas concentration. Furthermore, neither butorphanol nor medetomidine affected the BIS.ConclusionsThe difference of degree of central nervous system depression monitored by BIS compared with neuromuscular reflexes monitored by VAS, indicate that BIS records a level of anaesthetic depth different from the one deducted from VAS monitoring alone. BIS provided complementary information such as that medetomidine suppressed spinal reflexes without deepening the hypnotic state. As a consequence, it is concluded that BIS improves the assessment of the level of hypnosis in chickens, improving anaesthesia monitoring and anaesthesia quality in this species.

An EEG-Based Hypnotic State Monitor for Patients During General Anesthesia

Most surgical procedures are not possible without general anesthesia which necessitates continuous and accurate monitoring of the patients' level of hypnosis (LoH). Currently, the LoH is monitored using the conventional methods of either observing the patient's physiological parameters or using electroencephalogram (EEG)-based monitors. To overcome the limitations of the conventional methods, this work implements an accurate EEG-based LoH monitoring processor using a bagged tree machine-learning (BTML) classifier. It is based on 12 temporal and spectral features to incorporate robustness against age variation and achieve high classification accuracy. Spectral features are computed using discrete wavelet transform (DWT) that uses time-multiplexed filter (TMF) architecture. The TMF DWT consumes 110.6-nJ/feature vector for a 100-tap filter while reducing the area by 11% compared with the conventional method. Moreover, the BTML is implemented using a pipelined approach which enables an efficient on-chip implementation to reduce the hardware cost by 15× compared with the parallel approach. The proposed processor is implemented using a 180-nm CMOS process with an active area of 0.9 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> while consuming 1.6 mW. The accuracy of the proposed hypnotic state monitor is verified using two EEG databases with a total of 95 patients and achieves a sensitivity and specificity of 95.4% and 97.7%, respectively.

No evidence for theta power as a marker of hypnotic state in highly hypnotizable subjects

EEG spectral-power density was analyzed in a group of nine highly hypnotizable subjects via ten frontal, central, parietal, and occipital electrodes under four conditions: 1) wake state, 2) neutral hypnosis, 3) hypnotic suggestion for altering perception of tones, and 4) post-hypnosis. Results indicate no theta-power changes between conditions, challenging previous findings that increased theta power is a marker of hypnosis. A decrease in gamma power under hypnotic suggestion and an almost significant decrease under neutral hypnosis were observed, compared to post-hypnosis. Anteroposterior power distribution remained stable over all conditions. The results are discussed and compared to earlier studies, which report heterogenous findings.

The Hypnotic Induction Profile (HIP) in Clinical Practice and Research

ABSTRACT The Hypnotic Induction Profile (HIP) was developed as a brief, yet thorough, assessment of a person’s level of trait hypnotizability and their potential to experience a hypnotic state. The HIP quantitatively and qualitatively measures hynotizability by evaluating biological and sensorimotor experiences designed to assess 3 fundamental observable and measurable components of hypnosis: absorption, dissociation, and suggestibility through a guided assessment that takes 5 to 10 minutes. From conception, the HIP has been utilized in clinical settings to assess appropriateness for the use of hypnosis in treatment planning and research protocols to stratify research participants. The brevity, accessibility, and reliability of the HIP have allowed it to adapt, not only across settings but through media platforms as technology and remote delivery become increasingly incorporated in the field of hypnosis.

The Effectiveness of Hypnotherapy in Reducing Pain in Patients with Cervical Cancer

Background: Complaints of pain in cervical cancer patients make the patient suffer more. Pain is a subjective matter so that hypnothe­rapy can reduce the pain suffered by patients. The use of hypnotherapy in cancer patients focuses on the emotional aspects and dynamics that occur in the client's subconscious mind. Hypnotherapy can change sensations, percep­tions, thoughts, feelings or behavior after being suggested. Positive suggestions given are able to influence the perception of someone who is in a hypnotic state so that they behave or per­ceive according to the suggestions given. The purpose of this study was to analyze the effect of hypnotherapy as a complementary therapy in reducing pain in cervical cancer patients. Subjects and Method: The experimental study used a random control trial which was conducted at the Dr. Moewardi Hospital from January to September 2019. A sample of 90 patients was selected by purposive sampling. 45 subjects from the treatment group received the hypnotherapy intervention and 45 subjects from the control group received standard care. The dependent variable is the level of pain. The independent variable is hypnotherapy. The level of pain is measured by a numerical pain scale of 0 to 10. Hypnotherapy is performed using hypnosis recording/ audio. Data analysis was performed using an independent t test . Results: The mean pain level after hypno­therapy (Mean= 0.8; SD= 1.96) was lower than the control group (Mean= 3.2; SD= 1.7), effect size= -1.31, and it was statistically significant (p <0.001). Conclusion: Hypnotherapy complementary therapy can help reduce pain levels in cervical cancer patients. Keyword s : hypnotherapy, pain, cervical cancer Correspondence: Hanung Prasetya. Study Program in Acu­puncture, Health Polytechnics, Ministry of Health. Jl. Letjend Sutoyo, Mojosongo, Sura­karta 57127, Central Java. Email: Hanung­prasetya71@yahoo.com. Mobile: +62812263­8908. Indonesian Journal of Medicine (2021), 06(02): 152-158 https://doi.org/10.26911/theijmed.2021.06.02.04

Time-Frequency Analysis of EEG Signals and GLCM Features for Depth of Anesthesia Monitoring.

One of the important tasks in the operating room is monitoring the depth of anesthesia (DoA) during surgery, and noninvasive techniques are very popular. Hence, we propose a new scheme for DoA monitoring considering the time-frequency analysis of electroencephalography (EEG) signals and GLCM features extracted from them. To this end, at first, the time-frequency map (TFM) of each channel of each EEG is computed by smoothed pseudo-Wigner–Ville distribution (SPWVD), where the EEG signal used in this paper is recorded in 15 channels. After that, we consider the gray-level co-occurrence matrix (GLCM) to obtain the content of TFM, and after that, four features such as homogeneity, correlation, energy, and contrast are obtained for each GLCM. Finally, after the selection of efficient features using the minimum redundancy maximum relevance (MRMR) method, the K-nearest neighbor (KNN) classifier is utilized to determine the DoA. Here, we consider the three states, namely, deep hypnotic, surgical anesthesia, and sedation and awake states according to bispectral index (BIS), and each EEG epoch is classified to these states. We also employ data augmentation to enhance the training phase and increase accuracy. We obtain the accuracy and confusion matrix of the proposed method. We also analyze the effects of a number of gray levels of GLCM, distance measure in KNN classifier, and parameters of data augmentation on the performance of the proposed method. Results indicate the efficiency of the proposed method to determine the DoA during surgery.

Continuing professional development module : An updated introduction to electroencephalogram-based brain monitoring during intended general anesthesia.

The electroencephalogram (EEG) provides a reliable reflection of the brain’s electrical state, so it can reassure us that the anesthetic agents are actually reaching the patient’s brain, and are having the desired effect. In most patients, the EEG changes somewhat predictably in response to propofol and volatile agents, so a frontal EEG channel can guide avoidance of insufficient and excessive administration of general anesthesia. Persistent alpha-spindles (around 10 Hz) phase-amplitude coupled with slow delta waves (around 1 Hz) are commonly seen during an “appropriate hypnotic state of general anesthesia”. Such patterns can be appreciated from the EEG waveform or from the spectrogram (a colour-coded display of how the power in the various EEG frequencies changes with time). Nevertheless, there are exceptions to this. For example, administration of ketamine and nitrous oxide is generally not associated with the aforementioned alpha-spindle coupled with delta wave pattern. Also, some patients, including older adults and those with neurodegenerative disorders, are less predisposed to generate a strong electroencephalographic “alpha-spindle” pattern during general anesthesia. There might also be some rare instances when the frontal EEG shows a pattern suggestive of general anesthesia, while the patient has some awareness and is able to follow simple commands, albeit this is typically without obvious distress or memory formation. Thus, the frontal EEG alone, as currently analyzed, is an imperfect but clinically useful mirror, and more scientific insights will be needed before we can claim to have a reliable readout of brain “function” during general anesthesia.

One-Class-Based Intelligent Classifier for Detecting Anomalous Situations During the Anesthetic Process

Abstract Closed-loop administration of propofol for the control of hypnosis in anesthesia has evidenced an outperformance when comparing it with manual administration in terms of drug consumption and post-operative recovery of patients. Unlike other systems, the success of this strategy lies on the availability of a feedback variable capable of quantifying the current hypnotic state of the patient. However, the appearance of anomalies during the anesthetic process may result in inaccurate actions of the automatic controller. These anomalies may come from the monitors, the syringe pumps, the actions of the surgeon or even from alterations in patients. This could produce adverse side effects that can affect the patient postoperative and reduce the safety of the patient in the operating room. Then, the use of anomaly detection techniques plays a significant role to avoid this undesirable situations. This work assesses different one-class intelligent techniques to detect anomalies in patients undergoing general anesthesia. Due to the difficulty of obtaining real data from anomaly situations, artificial outliers are generated to check the performance of each classifier. The final model presents successful performance.

Suggested deafness during hypnosis and simulation of hypnosis compared to a distraction and control condition: A study on subjective experience and cortical brain responses.

Hypnosis is a powerful tool to affect the processing and perception of stimuli. Here, we investigated the effects of hypnosis on the processing of auditory stimuli, the time course of event-related-potentials (ERP; N1 and P3b amplitudes) and the activity of cortical sources of the P3b component. Forty-eight participants completed an auditory oddball paradigm composed of standard, distractor, and target stimuli during a hypnosis (HYP), a simulation of hypnosis (SIM), a distraction (DIS), and a control (CON) condition. During HYP, participants were suggested that an earplug would obstruct the perception of tones and during SIM they should pretend being hypnotized and obstructed to hear the tones. During DIS, participants’ attention was withdrawn from the tones by focusing participants’ attention onto a film. In each condition, subjects were asked to press a key whenever a target stimulus was presented. Behavioral data show that target hit rates and response time became significantly reduced during HYP and SIM and loudness ratings of tones were only reduced during HYP. Distraction from stimuli by the film was less effective in reducing target hit rate and tone loudness. Although, the N1 amplitude was not affected by the experimental conditions, the P3b amplitude was significantly reduced in HYP and SIM compared to CON and DIS. In addition, source localization results indicate that only a small number of neural sources organize the differences of tone processing between the control condition and the distraction, hypnosis, and simulation of hypnosis conditions. These sources belong to brain areas that control the focus of attention, the discrimination of auditory stimuli, and the organization of behavioral responses to targets. Our data confirm that deafness suggestions significantly change auditory processing and perception but complete deafness is hard to achieve during HYP. Therefore, the term ‘deafness’ may be misleading and should better be replaced by ‘hypoacusis’.