State of the art and new directions of Quantitative Electroencephalography use in Differential Diagnosis of ADHD / Estado de la cuestión y uso de la electroencefalografía cuantitativa en el diagnóstico diferencial del TDAH

Advances in technology in recent years have made the use of quantitative electroencephalogram more accessible to clinicians. The incorporation ofnormative databases in QEEG studies and the possibility of detecting different electroencephalographic patterns in patients with a given pathology,despite showing an apparent symptomatology homogeneity, make it an interesting source of information. The relationship of these patterns with apossible response to treatment or with prognostic estimates would justify its inclusion as a routine test in the process of the differential diagnosisof ADHD. In this paper, we present the possible benefits of the use of QEEG in the differential diagnosis of ADHD, the different electroencephalographic patterns associated with ADHD most common in the literature, and a case showcasing the use of the technique in a patient with ADHD. (AU)

El avance de la tecnología en los últimos años ha hecho que el uso del electroencefalograma cuantitativo sea más accesible a los clínicos. La incorporación de bases de datos normativas enlos estudios de QEEG y la posibilidad de detectar diferentes patrones electroencefalográficos en pacientes con una patología determinada, a pesarde mostrar una aparente homogeneidad sintomatológica, hacen que sea una fuente de información interesante. La relación de estos patrones conuna posible respuesta a tratamientos o con estimaciones pronósticas justificarían su inclusión como prueba rutinaria en el proceso de diagnósticodiferencial del TDAH. En este trabajo se presentan los posibles beneficios del uso del QEEG en el diagnóstico diferencial del TDAH, los diferentespatrones electroencefalográficos asociados al TDAH más comunes en la literatura y un caso ilustrativo del uso de la técnica en un paciente con TDAH. (AU)

Resting-state EEG alpha/theta power ratio discriminates early-onset Alzheimer's disease from healthy controls.

OBJECTIVES: The present study aims to compare early-onset Alzheimer's disease (EOAD) patients with healthy controls (HC), and late-onset Alzheimer's disease (LOAD) patients using resting-state delta, theta, alpha, and beta oscillations and provide a cut-off score of alpha/theta ratio to discriminate individuals with EOAD and young HC. METHODS: Forty-seven individuals with EOAD, 51 individuals with LOAD, and demographically-matched 49 young and 51 older controls were included in the study. Spectral-power analysis using Fast-Fourier Transformation (FFT) is performed on resting-state electroencephalography (EEG) data. Delta, theta, alpha, and beta oscillations compared between groups and Receiver Operating Characteristic (ROC) curve analysis was conducted. RESULTS: Compared to healthy controls individuals with EOAD showed an increase in slow frequency bands and a decrease in fast frequency bands. Frontal alpha/theta power ratio is the best discriminating value between EOAD and young HC with the sensitivity and specificity greater than 80% with area under the curve (AUC) 0.881. CONCLUSIONS: EOAD display more widespread and severe electrophysiological abnormalities than LOAD and HC which may reflect more pronounced pathological burden and cholinergic deficits in EOAD. Additionally, the alpha/theta ratio can discriminate EOAD and young HC successfully. SIGNIFICANCE: This study is the first to report that resting-state EEG power can be a promising marker for diagnostic accuracy between EOAD and healthy controls.

Methylation of oxytocin related genes and early life trauma together shape the N170 response to human faces.

Childhood trauma fundamentally shapes social cognition and basic processing of social cues, which frequently cascade into adverse behavioral outcomes. Recent studies indicate that epigenetic changes in oxytocin functioning might contribute to these long-term effects, although a deeper understanding of the underlying mechanisms is still lacking. The electroencephalographic N170 response to faces might capture a neural response at the core of these interactive effects of oxytocin gene methylation and childhood adversity, given that this response is considered to reflect fundamental face processing, to be susceptible to oxytocin administration and also to be a biomarker of various psychiatric disorders. We assessed the N170 response to neutral faces in relation to participant's (81, women) recalled childhood trauma, methylation of their oxytocin structural (OXTg) and oxytocin receptor (OXTRg) genes, and endogenous levels of cortisol and testosterone. Additionally, we investigated the interactive effect of OXTg methylation and CTQ across three face sets of varying maturity. Methylation of OXTg relates to a weakened N170 response towards adults, children and infants. Moreover, methylation of both OXTRg and OXTg shaped the directionality of adversity effects, predicting a weakened N170 response in those with high methylation and hyper-vigilance with participants with low methylation. Our results are the first to relate OXT(R)g methylation to the N170 response. They shed light on biological processes linking childhood adversity and epigenetic marks to altered behavior and potentially psychopathologies.

Application of electroencephalographic (EEG) biofeedback therapy in the rehabilitation of patients with chronic diseases.

Schizophrenia is one of the chronic mental disorders characterized by disturbances in thought, emotion, language, perception, and behavior. There is no cure for this disease, and most of the current treatments are palliative. In this study, we aimed to analyze the application of electroencephalographic (EEG) biofeedback therapy, an adjunctive treatment used for many psychiatric disorders, in the rehabilitation of schizophrenic patients. Schizophrenic patients were selected as the experimental subjects, and the initial diagnosis criteria were set accordingly. A primary and a secondary efficacy index was then developed for the evaluation of EEG biofeedback therapy rather than traditional drug treatment. Lastly, the effects of the two methods were compared. The findings indicate that traditional drugs could be used in the treatment of mild schizophrenia, but showed poor results for severe and moderate schizophrenia. EEG biofeedback therapy was effective for the treatment of various degrees of schizophrenia and improved patients' sleep quality and anxiety. These findings have significant practical implications for the rehabilitation of schizophrenic patients and patients with chronic diseases in general.

Electroencephalographic characteristics of word finding during phonological and semantic verbal fluency tasks.

AIMS: Verbal Fluency is sensitive to brain damage and is employed to assess language abilities like the size of vocabulary and the semantic-lexical networks' integrity and executive functioning abilities particularly inhibition, working memory, and self-monitoring. Various studies revealed oscillatory changes related to word retrieval during different tasks. However, there are not enough studies on electroencephalographic characteristics of word retrieval routes (phonological or semantic pathway) during free recall. The purpose of our study was to investigate electroencephalography power relationship with semantic and phonological word finding routes during verbal fluency. METHODS: In this within-subject study, the electroencephalography of 20 healthy participants was recorded during written category and letter fluency tasks and compared with the rest state. Absolute power of the signals in delta (1-3.5 Hz), theta (4-7.5 Hz), alpha (8-12 Hz), and beta (12.5-30 Hz) was calculated in three lobes (frontal, parietal, and temporal). RESULTS: A repeated measures ANOVA showed significant interaction of condition × lobe × frequency × side (P < .001). Post hoc test for each lobe showed significant changes in the absolute power of delta, theta and beta for frontal, delta and theta for parietal, and theta and beta for temporal lobes (P-values < .05). CONCLUSION: Searching the words by phonological entries is associated with decreased beta and increased theta in left frontal lobe. These changes are not necessary for semantic word retrieval strategy.

Differentiating PNES from epileptic seizures using conversational analysis on French patients: A prospective blinded study.

Psychogenic nonepileptic seizures (PNES) resemble epileptic seizures (ES) but are not caused by the occurrence of excessive cortical neuronal discharge. Previous studies in German-, English-, and Italian-speaking patients showed that patients used a different communicative style to talk about their seizures. They demonstrated that the diagnosis between PNES and ES could be predicted using qualitative assessment and a diagnostic scoring aid (DSA). The objective of our study was to evaluate the contribution of linguistic analysis in the differential diagnosis between ES and PNES in a French patient population. During an extended video-electroencephalogram (video-EEG) monitoring, 13 patients presented PNES and 19 patients with ES. Two neurologists blindly and independently analyzed the interview of each patient. Rater 1 predicted the correct diagnosis in 27 of 32 patients (84%) and Rater 2 in 28 of 32 patients (88%). Interrater reliability of qualitative analysis was satisfactory (k = 0.68, interrater agreement = 84.4%). Using a simplified DSA, Rater 1 and Rater 2 would have correctly diagnosed 88% (28/32 patients) and 91 % (29/32) of the cases, respectively. Our blinded prospective study confirms the diagnostic value of conversational analysis, performed by neurologists, to differentiate PNES from ES in French-speaking patients.

Differentiating psychogenic nonepileptic from epileptic seizures: A mixed-methods, content analysis study.

BACKGROUND: Identification of clinical features that might distinguish psychogenic nonepileptic seizures (PNES) from epileptic seizures (ES) is of value for diagnosis, management, and understanding of both conditions. Previous studies have shown that patients' descriptions of their seizures reflect differences in content and delivery. We aimed to compare verbal descriptions of PNES and ES using a mixed-methods approach. METHODS: We analyzed data from semi-structured interviews in which patients with video-electroencephalography (EEG)-confirmed ES (n = 30) or PNES (n = 10) described their seizures. Two masked raters independently coded the transcripts for relevant psychological categories and discrepancies that were noted and resolved. Additional analyses were conducted using the Linguistic Inquiry and Word Count system. The identified phenomena were descriptively compared, and inferential analyses assessed group differences in frequencies. A logistic regression analysis examined the predictive power of the most distinctive phenomena for diagnosis. RESULTS: As compared with ES, PNES reported longer seizures, more preseizure negative emotions (e.g., fear), anxiety symptoms (e.g., arousal, hyperventilation), altered vision/olfaction, and automatic behaviors. During seizures, PNES reported more fear, altered breathing, and dissociative phenomena (depersonalization, impaired time perception). Epileptic seizures reported more self-injurious behavior. Postseizure, PNES reported more fear and weeping and ES more amnesia and aches. The predictive power when including these variables was 97.5%. None of the single predictor variables was significant. The few but consistent linguistic differences related to the use of some pronouns and references to family. CONCLUSIONS: Although no single clinical feature definitively distinguishes PNES from ES, several features may be suggestive of a PNES diagnosis, including longer duration, negative emotion (i.e., fear) throughout the events, preseizure anxiety, ictal dissociation, and postseizure weeping. Fewer reports of ictal self-injury and postseizure amnesia and aches may also indicate the possibility of PNES.

Cortical Microcircuit Mechanisms of Mismatch Negativity and Its Underlying Subcomponents.

In the neocortex, neuronal processing of sensory events is significantly influenced by context. For instance, responses in sensory cortices are suppressed to repetitive or redundant stimuli, a phenomenon termed "stimulus-specific adaptation" (SSA). However, in a context in which that same stimulus is novel, or deviates from expectations, neuronal responses are augmented. This augmentation is termed "deviance detection" (DD). This contextual modulation of neural responses is fundamental for how the brain efficiently processes the sensory world to guide immediate and future behaviors. Notably, context modulation is deficient in some neuropsychiatric disorders such as schizophrenia (SZ), as quantified by reduced "mismatch negativity" (MMN), an electroencephalography waveform reflecting a combination of SSA and DD in sensory cortex. Although the role of NMDA-receptor function and other neuromodulatory systems on MMN is established, the precise microcircuit mechanisms of MMN and its underlying components, SSA and DD, remain unknown. When coupled with animal models, the development of powerful precision neurotechnologies over the past decade carries significant promise for making new progress into understanding the neurobiology of MMN with previously unreachable spatial resolution. Currently, rodent models represent the best tool for mechanistic study due to the vast genetic tools available. While quantifying human-like MMN waveforms in rodents is not straightforward, the "oddball" paradigms used to study it in humans and its underlying subcomponents (SSA/DD) are highly translatable across species. Here we summarize efforts published so far, with a focus on cortically measured SSA and DD in animals to maintain relevance to the classically measured MMN, which has cortical origins. While mechanistic studies that measure and contrast both components are sparse, we synthesize a potential set of microcircuit mechanisms from the existing rodent, primate, and human literature. While MMN and its subcomponents likely reflect several mechanisms across multiple brain regions, understanding fundamental microcircuit mechanisms is an important step to understand MMN as a whole. We hypothesize that SSA reflects adaptations occurring at synapses along the sensory-thalamocortical pathways, while DD depends on both SSA inherited from afferent inputs and resulting disinhibition of non-adapted neurons arising from the distinct physiology and wiring properties of local interneuronal subpopulations and NMDA-receptor function.

Processing network emojis in Chinese sentence context: An ERP study.

As network emojis play an increasingly important role in modern communications, the question of how semantic processing of emojis is performed in the context arises. By comparing the N400 and P600 effects of emojis and words in contextually incongruent conditions, we investigated the neural basis of semantic processing of emojis. We found that incongruent words elicited robust N400 and P600 effects, while emojis only generated a more conspicuous and sustained N400 effect. This suggests that emojis may have more difficult semantic retrieval versus words in the context, with potentially inefficient semantic integration. These data suggest that the semantic processing of network emojis in context is not the same as words and the meaning of emojis is more difficult to process at sentence level.

Do all mammals dream?

The presence of dreams in human sleep, especially in REM sleep, and the detection of physiologically similar states in mammals has led many to ponder whether animals experience similar sleep mentation. Recent advances in our understanding of the anatomical and physiological correlates of sleep stages, and thus dreaming, allow a better understanding of the possibility of dream mentation in nonhuman mammals. Here, we explore the potential for dream mentation, in both non-REM and REM sleep across mammals. If we take a hard-stance, that dream mentation only occurs during REM sleep, we conclude that it is unlikely that monotremes, cetaceans, and otariid seals while at sea, have the potential to experience dream mentation. Atypical REM sleep in other species, such as African elephants and Arabian oryx, may alter their potential to experience REM dream mentation. Alternatively, evidence that dream mentation occurs during both non-REM and REM sleep, indicates that all mammals have the potential to experience dream mentation. This non-REM dream mentation may be different in the species where non-REM is atypical, such as during unihemispheric sleep in aquatic mammals (cetaceans, sirens, and Otariid seals). In both scenarios, the cetaceans are the least likely mammalian group to experience vivid dream mentation due to the morphophysiological independence of their cerebral hemispheres. The application of techniques revealing dream mentation in humans to other mammals, specifically those that exhibit unusual sleep states, may lead to advances in our understanding of the neural underpinnings of dreams and conscious experiences.

Characterization of the dynamic behavior of neural activity in Alzheimer's disease: exploring the non-stationarity and recurrence structure of EEG resting-state activity.

OBJECTIVE: Mild cognitive impairment (MCI) and dementia due to Alzheimer's disease (AD) have been shown to induce perturbations to normal neuronal behavior and disrupt neuronal networks. Recent work suggests that the dynamic properties of resting-state neuronal activity could be affected by MCI and AD-induced neurodegeneration. The aim of the study was to characterize these properties from different perspectives: (i) using the Kullback-Leibler divergence (KLD), a measure of non-stationarity derived from the continuous wavelet transform; and (ii) using the entropy of the recurrence point density ([Formula: see text]) and the median of the recurrence point density ([Formula: see text]), two novel metrics based on recurrence quantification analysis. APPROACH: KLD, [Formula: see text] and [Formula: see text] were computed for 49 patients with dementia due to AD, 66 patients with MCI due to AD and 43 cognitively healthy controls from 60 s electroencephalographic (EEG) recordings with a 10 s sliding window with no overlap. Afterwards, we tested whether the measures reflected alterations to normal neuronal activity induced by MCI and AD. MAIN RESULTS: Our results showed that frequency-dependent alterations to normal dynamic behavior can be found in patients with MCI and AD, both in non-stationarity and recurrence structure. Patients with MCI showed signs of patterns of abnormal state recurrence in the theta (4-8 Hz) and beta (13-30 Hz) frequency bands that became more marked in AD. Moreover, abnormal non-stationarity patterns were found in MCI patients, but not in patients with AD in delta (1-4 Hz), alpha (8-13 Hz), and gamma (30-70 Hz). SIGNIFICANCE: The alterations in normal levels of non-stationarity in patients with MCI suggest an initial increase in cortical activity during the development of AD. This increase could possibly be due to an impairment in neuronal inhibition that is not present during later stages. MCI and AD induce alterations to the recurrence structure of cortical activity, suggesting that normal state switching during rest may be affected by these pathologies.

Hyperparameter-tuned prediction of somatic symptom disorder using functional near-infrared spectroscopy-based dynamic functional connectivity.

OBJECTIVE: Somatic symptom disorder (SSD) is a reflection of medically unexplained physical symptoms that lead to distress and impairment in social and occupational functioning. SSD is phenomenologically diagnosed and its neurobiology remains unsolved. APPROACH: In this study, we performed hyper-parameter optimized classification to distinguish 19 persistent SSD patients and 21 healthy controls by utilizing functional near-infrared spectroscopy via performing two painful stimulation experiments, individual pain threshold (IND) and constant sub-threshold (SUB) that include conditions with different levels of pain (INDc and SUBc) and brush stimulation. We estimated a dynamic functional connectivity time series by using sliding window correlation method and extracted features from these time series for these conditions and different cortical regions. MAIN RESULTS: Our results showed that we found highest specificity (85%) with highest accuracy (82%) and 81% sensitivity using an SVM classifier by utilizing connections between right superior temporal-left angular gyri, right middle frontal (MFG)-left supramarginal gyri and right middle temporal-left middle frontal gyri from the INDc condition. SIGNIFICANCE: Our results suggest that fNIRS may distinguish subjects with SSD from healthy controls by applying pain in levels of individual pain-threshold and bilateral MFG, left inferior parietal and right temporal gyrus might be robust biomarkers to be considered for SSD neurobiology.

Empathy for pain in fibromyalgia patients: An EEG study.

BACKGROUND: Recent research in cognitive neurosciences highlights how the neural circuitries are activated during pain responses in empathic context. AIMS: The present study was designed to test if healthy subjects and Fibromyalgia (FM) patients, both evaluated by Laser Evoked Potentials (LEPs) and Event-Related Spectral Perturbation (ERSP), might reveal the empathic response to the partner's nociceptive stimulation. METHODS: The emphatic nociceptive paradigm was recorded through 64 channels EEG and laser stimulation of the right hand in a shared visual open setting (Open Condition) or in a blind setting (Blind condition) where the subjects didn't receive visual information about partner nociceptive condition. Twenty one healthy subjects and 19 FM patients were evaluated in pairs. All subjects were tested by the Empathy for Pain Scale (EPS). RESULTS: The averaged LEPs were similar between patients and controls in the different conditions. In attendance of the partner's stimulation, FM patients desynchronized the same fronto-central regions as before own stimulation, while healthy subjects shared the other's pain by activating scalp areas compatible with visual attention. These EEG features were more represented in subjects with higher EPS scores. CONCLUSIONS: While empathic features of healthy subjects seemed influenced by the specific visual attentional task, patients expressed an EEG pattern compatible with somatosensory circuits activation in the expectation of own and other's pain. The visual empathic involvement in other's noxious stimulation could evoke a different EEG response depending upon the experience of chronic pain.

Fast Periodic Visual Stimulation EEG Reveals Reduced Neural Sensitivity to Fearful Faces in Children with Autism.

We objectively quantified the neural sensitivity of school-aged boys with and without autism spectrum disorder (ASD) to detect briefly presented fearful expressions by combining fast periodic visual stimulation with frequency-tagging electroencephalography. Images of neutral faces were presented at 6 Hz, periodically interleaved with fearful expressions at 1.2 Hz oddball rate. While both groups equally display the face inversion effect and mainly rely on information from the mouth to detect fearful expressions, boys with ASD generally show reduced neural responses to rapid changes in expression. At an individual level, fear discrimination responses predict clinical status with an 83% accuracy. This implicit and straightforward approach identifies subtle deficits that remain concealed in behavioral tasks, thereby opening new perspectives for clinical diagnosis.

Others' Pain Appraisals Modulate the Anticipation and Experience of Subsequent Pain.

The present study investigated how pain appraisals from other individuals modulated self-pain anticipation and perception. Appraisals of pain intensity from 10 other individuals were presented before the participants received identical electrical pain stimulation themselves. In reality, the presented other's pain appraisals, with either low or high in mean and variance, were generated by the experimenter, and were randomly paired with the subsequent electrical stimulation at either low or high intensity. Specifically, the mean and variance of others' pain appraisals were manipulated to induce participants' expectation and certainty to the upcoming pain. Subjective ratings of pain intensity and electroencephalographic (EEG) responses to the electrical stimulation, as well as anticipatory EEG activities measured prior to the onset of electrical stimulation, were compared. Results showed that the mean and variance of others' pain appraisal modulated the subjective pain ratings and the affective-motivational P2 responses elicited by the electrical stimulation, as well as anticipatory sensorimotor α-oscillation measured before the onset of pain stimulation. When the mean of others' pain appraisal was low, higher variance suppressed the sensorimotor α-oscillations and enhanced subsequent pain perception. In contrast, when the mean was high, the higher variance enhanced sensorimotor α-oscillations and suppressed subsequent pain perception. These results demonstrated that others' pain appraisals can modulate both of the anticipation and perception of first-hand pain. It also suggested that the top-down modulation of others' pain appraisals on pain perception could be partially driven by the different brain states during the anticipation stage, as captured by the prestimulus sensorimotor α-oscillations.

Waking qEEG to assess psychophysiological stress and alertness during simulated on-call conditions.

INTRODUCTION: On-call schedules are associated with stress and disrupted sleep. In a recent study, under non-sleep deprived conditions, low and high-stress on-call conditions did not significantly impact sleep quality but did impact next day performance. Our aim was to determine whether quantitative electroencephalography (qEEG) would reflect changes in cortical activity in on-call conditions, predicting that the high-stress condition would display faster qEEG frequencies compared with the control and low-stress condition. METHODS: Twenty-four healthy male participants (age: 26.5 ±â€¯4.0 yrs) spent four nights in a time-isolated sleep laboratory. The within-subjects, repeated measures experimental design assessed waking EEG, via the Karolinska Drowsiness Test (KDT) during four time-points across a control day and two experimental (on-call) days. Experimental days comprised a low-stress (LS - reading task) and high-stress (HS - speech task) condition and were counterbalanced. Mixed-models analysis was used to assess condition and time by EEG biomarkers: Alpha Attenuation Coefficient (AAC), Slowing Ratio (SR) and Scaling Exponent (SE). RESULTS: Main effects were found for all three biomarkers by condition, with pairwise analysis reported. There was a significant difference in AAC between the LS condition (M = 1.26 ±â€¯=1.24) and HS condition (M = 1.01 ±â€¯0.76 p = .02) indicating decreased alertness between LS and HS. A significant increase in SR between control (M = 7.1 ±â€¯4.3) and LS (M = 10.1 ±â€¯8.5 p = .0001), and a significant increase between the LS and HS (M = 7.8 ±â€¯6.8 p = .018) showing greatest EEG slowing in the LS condition, reflecting of a passive, sleepier brain state. The SE was significantly higher in the LS (M = 1.09, ±0.17) condition compared with control (M = 1.0, ±0.11 p = .001) indicating decreased alertness in the LS task. DISCUSSION: Using qEEG biomarkers, in contrast with our initial hypothesis, the current study found that compared with control, the LS condition resulted in greater EEG slowing. These findings have implications for on-call workers who engage in periods of passive attention and highlight a protective role task stress may play in maintaining alertness levels during on-call conditions.

A comparison study of anxiety in children undergoing brain MRI vs adults undergoing brain MRI vs children undergoing an electroencephalogram.

BACKGROUND: Magnetic resonance imaging (MRI) of the brain in children and adolescents is a well-established method in both clinical practice and in neuroscientific research. This practice is sometimes viewed critically, as MRI scans might expose minors (e.g. through scan-associated fears) to more than the legally permissible "minimal burden". While there is evidence that a significant portion of adults undergoing brain MRI scans experience anxiety, data on anxiety in children and adolescents undergoing brain MRI scans is rare. This study therefore aimed to examine the prevalence and level of anxiety in children and adolescents who had MRI scans of the brain, and to compare the results to adults undergoing brain MRI scans, and to children and adolescents undergoing electroencephalography (EEG; which is usually regarded a "minimal burden"). METHOD: Participants were 57 children and adolescents who had a brain MRI scan (MRI-C; mean age 12.9 years), 28 adults who had a brain MRI scan (MRI-A; mean age 43.7 years), and 66 children and adolescents undergoing EEG (EEG-C; mean age 12.9 years). Anxiety was assessed on the subjective (situational anxiety) and on the physiological level (arousal), before and after the respective examination. RESULTS: More than 98% of children and adolescents reported no or only minimal fear during the MRI scan. Both pre- and post-examination, the MRI-C and the MRI-A groups did not differ significantly with respect to situational anxiety (p = 0.262 and p = 0.374, respectively), and to physiological arousal (p = 0.050, p = 0.472). Between the MRI-C and the EEG-C group, there were also no significant differences in terms of situational anxiety (p = 0.525, p = 0.875), or physiological arousal (p = 0.535, p = 0.189). Prior MRI experience did not significantly influence subjective or physiological anxiety parameters. CONCLUSIONS: In this study, children and adolescents undergoing a brain MRI scan did not experience significantly more anxiety than those undergoing an EEG, or adults undergoing MRI scanning. Therefore, a general exclusion of minors from MRI research studies does not appear reasonable.

Altered auditory feedback perception following an 8-week mindfulness meditation practice.

Our own ongoing motor actions are perceived through sensory feedback pathways, and are integrated with neural processes to modulate further actions. This sensory feedback mechanism is known to contribute to the rehabilitation of impaired motor functions. Recent evidence also suggests that mindfulness meditation improves our awareness to sensation; therefore, enhancement of awareness to sensory feedback through mindfulness meditation training may have potential clinical applications. This study investigated an effect of eight-week practice of mindfulness meditation on speech perception/production processes. Among the thirty healthy participants, half of them engaged in regular meditation practice of 10 min per day for eight weeks, and the other half were not given any instructions for their daily life. The change of speech performance in sentence reading under 200 ms delayed auditory feedback (DAF) condition were assessed compared to without delay condition. Also, event-related potential response to the short sound of /a/, were measured. The result showed that, after the eight-week practice, the meditation group showed significantly improved speech fluency in the DAF condition, when 16-min meditation was introduced before the experiments. Furthermore, significantly increased auditory evoked potentials were observed in the central-parietal region when the participants listened to the delayed auditory feedback sound of their own voice. These findings provide the first glimpses into the possible relationship between mindfulness meditation and auditory feedback. Different instructions for daily activity between the meditation and control groups should be considered in further studies.

Event-related potentials in the odd-ball paradigm and behavioral scales for the assessment of children and adolescents with disorders of consciousness: A proof of concept study.

OBJECTIVE: Quantification of signatures of conscious processing in children with disorders of consciousness (DoC) using odd-ball paradigms in multiple modalities. METHOD: We review the diagnostic approaches available in the field, from clinical scales to neuroimaging methods, and concentrate upon measures derived from electroencephalographic event related potentials. RESULTS: Evoked potentials were recorded in five procedures, encompassing visual, auditory and tactile modalities, from ten pediatric DoC patients-six in a minimally conscious state (MCS), three in unresponsive wakefulness syndrome (UWS) and one who emerged from MCS (eMCS)-and the control group of 10 healthy children. In almost all the eMCS and MCS patients, higher amplitude of P300 was observed and the effect was statistically significant in at least one out of the five performed procedures. Additionally, signs of conscious information processing were detected in one UWS patient. CONCLUSION: The presented results provide a proof of concept for the possibility of applying ERP-derived electrophysiological measures as an aid in the assessment of children and adolescents in DoC.

Neuropsychological and resting-state electroencephalographic markers of older adult neurocognitive adaptability.

OBJECTIVE: This study was undertaken to explore multimethod neurocognitive screening tools to aid in detection of older adults who may be at heightened risk of pathological cognitive decline (preclinical dementia). In so doing, this study advances the theoretical conceptualization of neurocognitive adaptability in the context of aging and dementia. METHOD: This article reports original data from the baseline measurement occasion of a longitudinal study of healthy, community-dwelling older adults from the Victoria, British Columbia region. Participants were diagnosed as normal, subtle decline, or mild cognitive impairment according to actuarial neuropsychological criteria (adjusted for age only or adjusted for age and premorbid IQ). Diagnostic classification was employed to illustrate group differences in a novel metric of multi-timescale neural adaptability derived from 4-min of resting-state electroencephalographic data collected from each participant (immediately following their neuropsychological evaluation). RESULTS: Prior findings were replicated; adjusting raw neuropsychological test scores for individual differences in estimated premorbid IQ appeared to increase the sensitivity of standardized clinical tasks to subtle cognitive impairment. Moreover, and consistent with prior neuroscientific research, timescale-specific (i.e. at ∼12-20 ms timescales) differences in resting-state neural adaptability appeared to characterize groups who differed in terms of neuropsycholgoical diagnostic classification. CONCLUSIONS: Recently proposed actuarial neuropsychological criteria for subtle cognitive decline identify older adults who show timescale-specific changes in resting brain function that may signal the onset of preclinical dementia. The subtle decline stage may represent a critical inflection point-partial loss of neurocognitive adaptability-on a pathological aging trajectory. These findings illustrate areas of potential future development in neurocognitive health care.