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1.
Hum Brain Mapp ; 42(10): 3228-3252, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33783922

RESUMO

Meditation practice is believed to foster states of mindful awareness and mental quiescence in everyday life. If so, then the cultivation of these qualities with training ought to leave its imprint on the activity of intrinsic functional brain networks. In an intensive longitudinal study, we investigated associations between meditation practitioners' experiences of felt mindful awareness and changes in the spontaneous electrophysiological dynamics of functional brain networks. Experienced meditators were randomly assigned to complete 3 months of full-time training in focused-attention meditation (during an initial intervention) or to serve as waiting-list controls and receive training second (during a later intervention). We collected broadband electroencephalogram (EEG) during rest at the beginning, middle, and end of the two training periods. Using a data-driven approach, we segmented the EEG into a time series of transient microstate intervals based on clustering of topographic voltage patterns. Participants also provided daily reports of felt mindful awareness and mental quiescence, and reported daily on four experiential qualities of their meditation practice during training. We found that meditation training led to increases in mindful qualities of awareness, which corroborate contemplative accounts of deepening mental calm and attentional focus. We also observed reductions in the strength and duration of EEG microstates across both interventions. Importantly, changes in the dynamic sequencing of microstates were associated with daily increases in felt attentiveness and serenity during training. Our results connect shifts in subjective qualities of meditative experience with the large-scale dynamics of whole brain functional EEG networks at rest.


Assuntos
Conscientização/fisiologia , Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Meditação , Rede Nervosa/fisiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
Brain Topogr ; 34(5): 681-697, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34292447

RESUMO

Although prior studies have compared sensory event-related potential (ERP) responses between groups of autistic and typically-developing participants, it is unclear how heterogeneity contributes to the results of these studies. The present study used examined individual differences in these responses. 130 autistic children and 81 typically-developing children, aged between 2 and 5 years, listened to tones at four identity levels while 61-channel electroencephalography was recorded. Hierarchical clustering was used to group participants based on rescaled ERP topographies between 51 and 350 ms. The hierarchical clustering analysis revealed substantial heterogeneity. Some of the seven clusters defined in this analysis were characterized by prolonged fronto-central positivities and/or weak or absent N2 negativities. However, many other participants fell into clusters in which N2 responses were present at varying latencies. Atypical response morphologies such as absent N2 responses and/or prolonged positive-going responses found in some autistic participants may account for prior research findings of attenuated N2 amplitudes in autism. However, there was also considerable overlap between groups, with participants of both groups appearing in all clusters. These results emphasize the utility of using clustering to explore individual differences in brain responses, which can expand on and clarify the results of analyses of group mean differences.


Assuntos
Transtorno Autístico , Estimulação Acústica , Criança , Pré-Escolar , Análise por Conglomerados , Eletroencefalografia , Potenciais Evocados , Potenciais Evocados Auditivos , Humanos
3.
Neuroimage ; 211: 116631, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32062082

RESUMO

Microstates reflect transient brain states resulting from the synchronous activity of brain networks that predominate in the broadband EEG. There has been increasing interest in how the functional organization of the brain varies across individuals, or the extent to which its spatiotemporal dynamics are state dependent. However, little research has examined within and between-person correlates of microstate temporal parameters in healthy populations. In the present study, neuroelectric activity recorded during eyes-closed rest and during simple visual fixation was segmented into a time series of transient microstate intervals. It was found that five data-driven microstate configurations explained the preponderance of topographic variance in the EEG time series of the 374 recordings (from 187 participants) included in the study. We observed that the temporal dynamics of microstates varied within individuals to a greater degree than they differed between persons, with within-person factors explaining a large portion of the variance in mean microstate duration and occurrence rate. Nevertheless, several individual differences were found to predict the temporal dynamics of microstates. Of these, age and gender were the most reliable. These findings not only suggest that the rich temporal dynamics of whole-brain neuronal networks vary considerably within individuals, but that microstates appear to differentiate persons based on trait individual differences. Rather than focusing exclusively on between-person differences in microstates as measures of brain function, researchers should turn their attention towards understanding the factors contributing to within-person variation.


Assuntos
Afeto/fisiologia , Envelhecimento/fisiologia , Atenção/fisiologia , Córtex Cerebral/fisiologia , Eletroencefalografia , Neuroimagem Funcional , Personalidade/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Idoso , Feminino , Humanos , Individualidade , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Adulto Jovem
4.
Brain Behav Immun ; 89: 256-267, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32640286

RESUMO

Prior work has linked meditation practice to improvements in interference control. However, the mechanisms underlying these improvements are relatively unknown. In the context of meditation training, improvements in interference control could result eitherfrom increases in controlled attention to goal-relevant stimuli, or from reductions in automatic capture by goal-irrelevant stimuli. Moreover, few studies have linked training-related changes in attention to physiological processes, such as inflammatory activity, that are thought to influence cognitive function. This study addresses these gaps by examining associations between cognitive performance and cytokines in the context of an intensive meditation retreat. Participants were randomly assigned to complete 3 months of meditation training first, or to serve as waitlist controls. The waitlist-control participants then later completed a separate 3-month training intervention. We assessed participants' interference control with a flanker task and used computational modeling to derive component processes of controlled and automatic attention. We also collected blood samples at the beginning, middle, and end of training to quantify changes in cytokine activity. Participants who completed training evidenced better controlled attention than waitlist controls during the first retreat intervention, and controls showed significant improvements in controlled attention when they completed their own, second retreat. Importantly, inflammatory activity was inversely associated with controlled attention during both interventions. Our results suggest that practice of concentration meditation influences interference control by enhancing controlled attention to goal-relevant task elements, and that inflammatory activity relates to individual differences in controlled attention.


Assuntos
Meditação , Humanos
5.
J Cogn Neurosci ; 31(8): 1184-1204, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31059348

RESUMO

The ability to discriminate among goal-relevant stimuli tends to diminish when detections must be made continuously over time. Previously, we reported that intensive training in shamatha (focused-attention) meditation can improve perceptual discrimination of difficult-to-detect visual stimuli [MacLean, K. A., Ferrer, E., Aichele, S. R., Bridwell, D. A., Zanesco, A. P., Jacobs, T. L., et al. Intensive meditation training improves perceptual discrimination and sustained attention. Psychological Science, 21, 829-839, 2010]. Here we extend these findings to examine how discrimination difficulty and meditation training interact to modulate event-related potentials of attention and perceptual processing during vigilance. Training and wait-list participants completed a continuous performance task at the beginning, middle, and end of two 3-month meditation interventions. In the first intervention (Retreat 1), the continuous performance task target was adjusted across assessments to match training-related changes in participants' perceptual capacity. In the second intervention (Retreat 2), the target was held constant across training, irrespective of changes in discrimination capacity. No training effects were observed in Retreat 1, whereas Retreat 2 was associated with changes in the onset of early sensory signals and an attenuation of within-task decrements at early latencies. In addition, changes at later stimulus processing stages were directly correlated with improvements in perceptual threshold across the second intervention. Overall, these findings demonstrate that improvements in perceptual discrimination can modulate electrophysiological markers of perceptual processing and attentional control during sustained attention, but likely only under conditions where an individual's discrimination capacity is allowed to exceed the demand imposed by the difficulty of a visual target. These results contribute to basic understanding of the dependence of perceptual processing and attentional control to contextual demands and their susceptibility to directed mental training.


Assuntos
Atenção/fisiologia , Discriminação Psicológica/fisiologia , Potenciais Evocados/fisiologia , Meditação , Prática Psicológica , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Idoso , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Brain Behav Immun ; 70: 233-245, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29518528

RESUMO

A growing body of evidence suggests that meditation training may have a range of salubrious effects, including improved telomere regulation. Telomeres and the enzyme telomerase interact with a variety of molecular components to regulate cell-cycle signaling cascades, and are implicated in pathways linking psychological stress to disease. We investigated the effects of intensive meditation practice on these biomarkers by measuring changes in telomere length (TL), telomerase activity (TA), and telomere-related gene (TRG) expression during a 1-month residential Insight meditation retreat. Multilevel analyses revealed an apparent TL increase in the retreat group, compared to a group of experienced meditators, similarly comprised in age and gender, who were not on retreat. Moreover, personality traits predicted changes in TL, such that retreat participants highest in neuroticism and lowest in agreeableness demonstrated the greatest increases in TL. Changes observed in TRGs further suggest retreat-related improvements in telomere maintenance, including increases in Gar1 and HnRNPA1, which encode proteins that bind telomerase RNA and telomeric DNA. Although no group-level changes were observed in TA, retreat participants' TA levels at post-assessment were inversely related to several indices of retreat engagement and prior meditation experience. Neuroticism also predicted variation in TA across retreat. These findings suggest that meditation training in a retreat setting may have positive effects on telomere regulation, which are moderated by individual differences in personality and meditation experience. (ClinicalTrials.gov #NCT03056105).


Assuntos
Meditação/psicologia , Homeostase do Telômero/fisiologia , Telômero/fisiologia , Adulto , Feminino , Humanos , Masculino , Meditação/métodos , Neuroticismo/fisiologia , Personalidade/genética , Personalidade/fisiologia , Estresse Psicológico/metabolismo , Telomerase/análise
7.
Conscious Cogn ; 65: 109-125, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30099318

RESUMO

Yoga-based practices (YBP) typically involve a combination of movement sequences, conscious regulation of the breath, and techniques to engage attention. However, little is known about whether effects of YBP result from the synergistic combination of these components, or whether a subset may yield similar effects. In this study we compared the effect of a movement-focused practice and a breath-focused practice on stress parameters (perceived stress and salivary cortisol) and sustained attention (response inhibition) in yoga naïve university students. While participants of both programs showed a reduction in perceived stress and salivary cortisol, only the breath-focused group showed improvements in sustained attention. In addition, improvement in sustained attention was correlated with reduction in perceived stress but not with reduction in salivary cortisol. We discuss these findings in the context of a theoretical framework outlining bottom-up neurophysiological and top-down neurocognitive mechanisms hypothesized to be engaged by YBP.


Assuntos
Atenção/fisiologia , Movimento/fisiologia , Respiração , Estresse Psicológico/fisiopatologia , Yoga , Adolescente , Adulto , Feminino , Humanos , Hidrocortisona/metabolismo , Masculino , Avaliação de Resultados em Cuidados de Saúde , Projetos Piloto , Saliva , Estresse Psicológico/metabolismo , Estresse Psicológico/terapia , Adulto Jovem
8.
Neuroimage ; 114: 88-104, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25862265

RESUMO

Meditation training has been shown to enhance attention and improve emotion regulation. However, the brain processes associated with such training are poorly understood and a computational modeling framework is lacking. Modeling approaches that can realistically simulate neurophysiological data while conforming to basic anatomical and physiological constraints can provide a unique opportunity to generate concrete and testable hypotheses about the mechanisms supporting complex cognitive tasks such as meditation. Here we applied the mean-field computational modeling approach using the scalp-recorded electroencephalogram (EEG) collected at three assessment points from meditating participants during two separate 3-month-long shamatha meditation retreats. We modeled cortical, corticothalamic, and intrathalamic interactions to generate a simulation of EEG signals recorded across the scalp. We also present two novel extensions to the mean-field approach that allow for: (a) non-parametric analysis of changes in model parameter values across all channels and assessments; and (b) examination of variation in modeled thalamic reticular nucleus (TRN) connectivity over the retreat period. After successfully fitting whole-brain EEG data across three assessment points within each retreat, two model parameters were found to replicably change across both meditation retreats. First, after training, we observed an increased temporal delay between modeled cortical and thalamic cells. This increase provides a putative neural mechanism for a previously observed reduction in individual alpha frequency in these same participants. Second, we found decreased inhibitory connection strength between the TRN and secondary relay nuclei (SRN) of the modeled thalamus after training. This reduction in inhibitory strength was found to be associated with increased dynamical stability of the model. Altogether, this paper presents the first computational approach, taking core aspects of physiology and anatomy into account, to formally model brain processes associated with intensive meditation training. The observed changes in model parameters inform theoretical accounts of attention training through meditation, and may motivate future study on the use of meditation in a variety of clinical populations.


Assuntos
Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Meditação , Modelos Neurológicos , Tálamo/fisiologia , Adulto , Ritmo alfa , Ritmo beta , Simulação por Computador , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiologia
9.
Front Endocrinol (Lausanne) ; 15: 1345527, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38863930

RESUMO

Background: Given its putative roles in mediating prosocial behavior, attachment bonds, and stress physiology, oxytocin modulation has been hypothesized to be a biological correlate of the salubrious effects of meditation practice. Here we investigated the effects of a month-long silent meditation retreat on changes in oxytocin, and the related hormone and vasopressin, in relation to psychosocial changes in attachment style, anxiety, personality measures, and feelings of social connectedness with fellow meditators. Methods: Plasma oxytocin and vasopressin and self-report questionnaires were measured in retreat participants (n = 28) at the beginning of, and 3 weeks into, a residential meditation retreat. Control participants (n = 34), who were similar in age, gender, and meditation experience, were also assessed across a 3-week interval. Linear mixed effects models were used to assess outcomes. Results: The retreat group showed a small but significant decrease in oxytocin compared to controls who showed no change. In the retreat group, higher openness to experience at Time 1 predicted greater reductions in oxytocin during the retreat, and lower oxytocin at Time 2 was related to stronger feelings of personal connection with fellow meditators. The changes in oxytocin were not related to attachment style or anxiety. Vasopressin decreased over time across both groups, suggesting no specific effect of retreat. Conclusion: These preliminary findings suggest that meditation training in the context of a silent residential retreat may reduce circulating levels of oxytocin. We interpret this finding from multiple theoretical perspectives, discussing key measurement limitations and proposing future study designs that may help to differentiate the effects of different meditation practices and contexts on oxytocin signaling.


Assuntos
Meditação , Ocitocina , Vasopressinas , Humanos , Ocitocina/sangue , Meditação/psicologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Vasopressinas/sangue , Ansiedade/sangue , Ansiedade/psicologia
10.
Neuroimage ; 81: 110-118, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23684866

RESUMO

Recent advances in brain imaging have improved the measure of neural processes related to perceptual, cognitive and affective functions, yet the relation between brain activity and subjective experience remains poorly characterized. In part, it is a challenge to obtain reliable accounts of participant's experience in such studies. Here we addressed this limitation by utilizing experienced meditators who are expert in introspection. We tested a novel method to link objective and subjective data, using real-time fMRI (rt-fMRI) to provide participants with feedback of their own brain activity during an ongoing task. We provided real-time feedback during a focused attention task from the posterior cingulate cortex, a hub of the default mode network shown to be activated during mind-wandering and deactivated during meditation. In a first experiment, both meditators and non-meditators reported significant correspondence between the feedback graph and their subjective experience of focused attention and mind-wandering. When instructed to volitionally decrease the feedback graph, meditators, but not non-meditators, showed significant deactivation of the posterior cingulate cortex. We were able to replicate these results in a separate group of meditators using a novel step-wise rt-fMRI discovery protocol in which participants were not provided with prior knowledge of the expected relationship between their experience and the feedback graph (i.e., focused attention versus mind-wandering). These findings support the feasibility of using rt-fMRI to link objective measures of brain activity with reports of ongoing subjective experience in cognitive neuroscience research, and demonstrate the generalization of expertise in introspective awareness to novel contexts.


Assuntos
Atenção/fisiologia , Mapeamento Encefálico/métodos , Giro do Cíngulo/fisiologia , Imageamento por Ressonância Magnética/métodos , Neurorretroalimentação/métodos , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Meditação/psicologia , Pessoa de Meia-Idade , Neurorretroalimentação/fisiologia
12.
J Exp Psychol Gen ; 152(10): 2897-2924, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37166841

RESUMO

Contemplative traditions have long affirmed that compassion and kindness are trainable skills. While research on meditation practice has recently flourished, the mechanisms that might engender such changes are still poorly understood. Here, we present a motivational framework to explain why meditation training should increase concern for others and modulate empathic engagement with human suffering over time. Meditation practices are conceived as tools for enacting cognitive and emotion regulatory goals that are conditioned by the underlying ethical motivation of the training-to reduce and alleviate suffering. In support of this account, we present data from a randomized, wait-list-controlled study of intensive meditation. In Study 1, we use a novel cardiovascular index to show that 3 months of meditation training can increase the motivational salience of others' suffering, as compared to the salience of threats to oneself. In Study 2, we demonstrate that training-related changes in the ability to orient attention to suffering are mediated by the dynamic regulation of distress-related physiological arousal. Finally, in Study 3, we provide exploratory evidence suggesting that meditation training may influence how human suffering is encoded in memory, leaving lasting imprints on the recollection of emotional experience. Together, our findings suggest that meditation training can strengthen the motivational relevance of others' suffering, prompting a shift from self-focused to other-focused evaluative processing. Considering meditation training from a motivational standpoint offers an important perspective for understanding how compassion can be cultivated through intentional practice. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Meditação , Humanos , Meditação/psicologia , Emoções/fisiologia , Empatia
13.
Autism Res ; 16(10): 1903-1923, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37688470

RESUMO

Prior studies suggest that habituation of sensory responses is reduced in autism and that diminished habituation could be related to atypical autistic sensory experiences, for example, by causing brain responses to aversive stimuli to remain strong over time instead of being suppressed. While many prior studies exploring habituation in autism have repeatedly presented identical stimuli, other studies suggest group differences can still be observed in habituation to intermittent stimuli. The present study explored habituation of electrophysiological responses to auditory complex tones of varying intensities (50-80 dB SPL), presented passively in an interleaved manner, in a well-characterized sample of 127 autistic (MDQ = 65.41, SD = 20.54) and 79 typically developing (MDQ = 106.02, SD = 11.50) children between 2 and 5 years old. Habituation was quantified as changes in the amplitudes of single-trial responses to tones of each intensity over the course of the experiment. Habituation of the auditory N2 response was substantially reduced in autistic participants as compared to typically developing controls, although diagnostic groups did not clearly differ in habituation of the P1 response. Interestingly, the P1 habituated less to loud 80 dB sounds than softer sounds, whereas the N2 habituated less to soft 50 dB sounds than louder sounds. No associations were found between electrophysiological habituation and cognitive ability or participants' caregiver-reported sound tolerance (Sensory Profile Hyperacusis Index). The results present study results extend prior research suggesting habituation of certain sensory responses is reduced in autism; however, they also suggest that habituation differences observed using this study's paradigm might not be a primary driver of autistic participants' real-world sound intolerance.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Humanos , Criança , Pré-Escolar , Estimulação Acústica/métodos , Habituação Psicofisiológica/fisiologia , Encéfalo
14.
J Autism Dev Disord ; 52(9): 3840-3860, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34499275

RESUMO

This study uses factor mixture modelling of the Short Sensory Profile (SSP) at two time points to describe subgroups of young autistic and typically-developing children. This approach allows separate SSP subscales to influence overall SSP performance differentially across subgroups. Three subgroups were described, one including almost all typically-developing participants plus many autistic participants. SSP performance of a second, largely-autistic subgroup was predominantly shaped by a subscale indexing behaviours of low energy/weakness. Finally, the third subgroup, again largely autistic, contained participants with low (or more "atypical") SSP scores across most subscales. In this subgroup, autistic participants exhibited large P1 amplitudes to loud sounds. Autistic participants in subgroups with more atypical SSP scores had higher anxiety and more sleep disturbances.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Transtornos Globais do Desenvolvimento Infantil , Criança , Humanos
15.
Front Hum Neurosci ; 16: 811547, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35620155

RESUMO

Background: Reconciling results obtained using different types of sensory measures is a challenge for autism sensory research. The present study used questionnaire, psychophysical, and neurophysiological measures to characterize autistic sensory processing in different measurement modalities. Methods: Participants were 46 autistic and 21 typically developing 11- to 14-year-olds. Participants and their caregivers completed questionnaires regarding sensory experiences and behaviors. Auditory and somatosensory event-related potentials (ERPs) were recorded as part of a multisensory ERP task. Auditory detection, tactile static detection, and tactile spatial resolution psychophysical thresholds were measured. Results: Sensory questionnaires strongly differentiated between autistic and typically developing individuals, while little evidence of group differences was observed in psychophysical thresholds. Crucially, the different types of measures (neurophysiological, psychophysical, questionnaire) appeared to be largely independent of one another. However, we unexpectedly found autistic participants with larger auditory Tb ERP amplitudes had reduced hearing acuity, even though all participants had hearing acuity in the non-clinical range. Limitations: The autistic and typically developing groups were not matched on cognitive ability, although this limitation does not affect our main analyses regarding convergence of measures within autism. Conclusion: Overall, based on these results, measures in different sensory modalities appear to capture distinct aspects of sensory processing in autism, with relatively limited convergence between questionnaires and laboratory-based tasks. Generally, this might reflect the reality that laboratory tasks are often carried out in controlled environments without background stimuli to compete for attention, a context which may not closely resemble the busier and more complex environments in which autistic people's atypical sensory experiences commonly occur. Sensory questionnaires and more naturalistic laboratory tasks may be better suited to explore autistic people's real-world sensory challenges. Further research is needed to replicate and investigate the drivers of the unexpected association we observed between auditory Tb ERP amplitudes and hearing acuity, which could represent an important confound for ERP researchers to consider in their studies.

16.
Mindfulness (N Y) ; 13(10): 2488-2506, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36258902

RESUMO

Objectives: A core assumption of meditation training is that cognitive capacities developed during formal practice will transfer to other contexts or activities as expertise develops over time. This implies that meditation training might influence domain-general neurocognitive systems, the spontaneous activity of which should be reflected in the dynamics of the resting brain. Previous research has demonstrated that 3 months of meditation training led to reductions in EEG beta band power during mindfulness of breathing practice. The current study extends these findings to ask whether concomitant shifts in power are observed during 2 min of eyes closed rest, when participants are not explicitly engaged in formal meditation. Methods: Experienced meditation practitioners were randomly assigned to practice 3 months of focused attention meditation in a residential retreat, or to serve as waitlist controls. The waitlist controls later completed their own 3-month retreat. Permutation-based cluster analysis of 88-channel resting EEG data was used to test for spectral changes in spontaneous brain activity over the course of the retreats. Results: Longitudinal reductions in EEG power in the beta frequency range were identified and replicated across the two independent training periods. Less robust reductions were also observed in the high alpha frequency range, and in individual peak alpha frequency. These changes closely mirror those previously observed during formal mindfulness of breathing meditation practice. Conclusions: These findings suggest that the neurocognitive effects of meditation training can extend beyond the bounds of formal practice, influencing the spontaneous activity of the resting brain. Rather than serving as an invariant baseline, resting states might carry meaningful training-related effects, blurring the line between state and trait change. Supplementary Information: The online version contains supplementary material available at 10.1007/s12671-022-01974-9.

17.
J Autism Dev Disord ; 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36434480

RESUMO

Elevated "neural noise" has been advanced as an explanation of autism and autistic sensory experiences. However, functional neuroimaging measures of neural noise may be vulnerable to contamination by recording noise. This study explored variability of electrophysiological responses to tones of different intensities in 127 autistic and 79 typically-developing children aged 2-5 years old. A rigorous data processing pipeline, including advanced visualizations of different signal sources that were maximally independent across different time lags, was used to identify and eliminate putative recording noise. Inter-trial variability was measured using median absolute deviations (MADs) of EEG amplitudes across trials and inter-trial phase coherence (ITPC). ITPC was elevated in autism in the 50 and 60 dB intensity conditions, suggesting diminished (rather than elevated) neural noise in autism, although reduced ITPC to soft 50 dB sounds was associated with increased loudness discomfort. Autistic and non-autistic participants did not differ in MADs, and indeed, the vast majority of the statistical tests examined in this study yielded no significant effects. These results appear inconsistent with the neural noise account.

18.
Neuropsychologia ; 175: 108340, 2022 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-36028085

RESUMO

Most prior studies of multisensory integration (MSI) in autism have measured MSI in only a single combination of modalities - typically audiovisual integration. The present study used onset reaction times (RTs) and 125-channel electroencephalography (EEG) to examine different forms of bimodal and trimodal MSI based on combinations of auditory (noise burst), somatosensory (finger tap), and visual (flash) stimuli presented in a spatially-aligned manner using a custom desktop apparatus. A total of 36 autistic and 19 non-autistic adolescents between the ages of 11-14 participated. Significant RT multisensory facilitation relative to summed unisensory RT was observed in both groups, as were significant differences between summed unisensory and multisensory ERPs. Although the present study's statistical approach was not intended to test effect latencies, these interactions may have begun as early as ∼45 ms, constituting "early" (<100 ms) MSI. RT and ERP measurements of MSI appeared independent of one another. Groups did not significantly differ in multisensory RT facilitation, but we found exploratory evidence of group differences in the magnitude of audiovisual interactions in ERPs. Future research should make greater efforts to explore MSI in under-represented populations, especially autistic people with intellectual disabilities and nonspeaking/minimally-verbal autistic people.


Assuntos
Transtorno Autístico , Percepção Visual , Estimulação Acústica , Adolescente , Percepção Auditiva , Criança , Audição , Humanos , Estimulação Luminosa , Tempo de Reação
19.
Compr Psychoneuroendocrinol ; 11: 100152, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35818436

RESUMO

Background: Meditation retreats are characterized by intensive or concentrated periods of meditation practice, commonly undertaken in a residential setting. Although research indicates that meditation training can positively influence physical and mental health outcomes, the biological consequences of meditation retreat interventions are relatively understudied. In this study, we examined the influence of a month-long, silent meditation retreat on the expression of genes involved in epigenetic modulation and immune processes. Method: We assessed gene expression changes in experienced meditators attending a month-long Insight meditation retreat (n = 28), as compared to a community control group (n = 34) of experienced practitioners living their everyday lives. Blood samples were collected on day two of the retreat (Time 1) and again 3 weeks later (Time 2). Control participants were also assessed across a 3-week interval, during which they maintained their regular daily routines. Results: As compared to controls, retreat participants showed differential changes in the expression of several genes involved in chromatin modulation and inflammation. The most substantive finding was downregulation of the TNF pathway in retreat participants, which was not observed in controls. Conclusions: These findings indicate that meditation retreat participation may influence some of the inflammatory mechanisms involved in the development of chronic diseases, and that this style of psychosocial intervention may have therapeutic potential, particularly in experienced practitioners.

20.
Neuropsychologia ; 156: 107837, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-33781752

RESUMO

Limited research has investigated the development of auditory ERPs in young children, and particularly how stimulus intensity may affect these auditory ERPs. Previous research has also yielded inconsistent findings regarding differences in the development of auditory ERPs in autism and typical development. Furthermore, stimulus intensity may be of particular interest in autism insofar as autistic people may have atypical experiences of sound intensity (e.g., hyperacusis). Therefore, the present study examined associations between age and ERPs evoked by tones of differing intensities (50, 60, 70, and 80 dB SPL) in a large sample of young children (2-5 years) with and without an autism diagnosis. Correlations between age and P1 latencies were examined, while cluster-based permutation testing was used to examine associations between age and neural response amplitudes, as well as group differences in amplitude, over all electrode sites in the longer time window of 1-350 ms. Older autistic participants had faster P1 latencies, but these effects only attained significance over the right hemisphere in response to soft 50 dB sounds. Autistic participants had slower P1 responses to 80 dB sounds over the right hemisphere. Over the scalp regions associated with the later N2 response, more negative response amplitudes (that is, larger N2 responses) were observed in typically-developing than autistic participants. Furthermore, continuous associations between response amplitudes and age suggested that older typically-developing participants exhibited stronger N2 responses to all intensities, though this effect may have at least in part reflected the absence of small positive voltage deflections in the N2 latency window. Age was associated with amplitudes of responses to 50 dB through 70 dB sounds in autism, but in contrast to Typical Development (TD), little evidence of relationships between age and amplitudes in the N2 latency window was found in autism in the 80 dB condition. Although caution should be exercised in interpretation due to the cross-sectional nature of this study, these findings suggest that developmental changes in auditory responses may differ across diagnostic groups in a manner that depends on perceived loudness and/or stimulus intensity.


Assuntos
Transtorno Autístico , Estimulação Acústica , Criança , Pré-Escolar , Estudos Transversais , Eletroencefalografia , Potenciais Evocados Auditivos , Humanos , Tempo de Reação
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