Academic literature on the topic 'Oxytocin magnetoencephalography'

Watching another person’s hand movement modulates somatosensory evoked magnetic fields (SEFs). Assuming that the mirror neuron system may have a role in this phenomenon, oxytocin should enhance these effects. This single-blinded, placebo-controlled, crossover study therefore used magnetoencephalography (MEG) to investigate SEFs following electrical stimulation of the right median nerve in 20 healthy male participants during hand movement observation, which were initially presented as static images followed by moving images. The participants were randomly assigned to receive either oxytocin or saline during the first trial, with the treatment being reversed during a second trial. Log-transformed ratios of the N20 and N30 amplitudes were calculated and compared between moving and static images observations. Phase locking (calculated using intertrial phase coherence) of brain oscillations was also analyzed to evaluate alpha, beta and gamma rhythm changes after oxytocin administration. Log N30 ratios showed no significant changes after placebo administration but showed a decreasing tendency (albeit not significant) after placebo administration, which may suggest mirror neuron system involvement. In contrast, log N20 ratios were increased after placebo administration, but showed no significant change after oxytocin administration. Interestingly, the gamma band activity around N20 increased after placebo administration, suggesting that oxytocin exerted an analgesic effect on median nerve stimulation, and inhibited the gamma band increase. Oxytocin might therefore modulate not only the mirror neuron system, but also the sensory processing associated with median nerve stimulation.

Listeners interpret utterances by integrating information from multiple sources including word level semantics and world knowledge. When the semantics of an expression is inconsistent with their knowledge about the world, the listener may have to search through the conceptual space for alternative possible world scenarios that can make the expression more acceptable. Such cognitive exploration requires considerable computational resources and might depend on motivational factors. This study explores whether and how oxytocin, a neuropeptide known to influence social motivation by reducing social anxiety and enhancing affiliative tendencies, can modulate the integration of world knowledge and sentence meanings. The study used a between-participant double-blind randomized placebo-controlled design. Semantic integration, indexed with magnetoencephalography through the N400m marker, was quantified while 45 healthy male participants listened to sentences that were either congruent or incongruent with facts of the world, after receiving intranasally delivered oxytocin or placebo. Compared with congruent sentences, world knowledge incongruent sentences elicited a stronger N400m signal from the left inferior frontal and anterior temporal regions and medial pFC (the N400m effect) in the placebo group. Oxytocin administration significantly attenuated the N400m effect at both sensor and cortical source levels throughout the experiment, in a state-like manner. Additional electrophysiological markers suggest that the absence of the N400m effect in the oxytocin group is unlikely due to the lack of early sensory or semantic processing or a general downregulation of attention. These findings suggest that oxytocin drives listeners to resolve challenges of semantic integration, possibly by promoting the cognitive exploration of alternative possible world scenarios.

Adolescents’ participation in intergroup conflicts comprises an imminent global risk, and understanding its neural underpinnings may open new perspectives. We assessed Jewish-Israeli and Arab-Palestinian adolescents for brain response to the pain of ingroup/outgroup protagonists using magnetoencephalography (MEG), one-on-one positive and conflictual interactions with an outgroup member, attitudes toward the regional conflict, and oxytocin levels. A neural marker of ingroup bias emerged, expressed via alpha modulations in the somatosensory cortex (S1) that characterized an automatic response to the pain of all protagonists followed by rebound/enhancement to ingroup pain only. Adolescents’ hostile social interactions with outgroup members and uncompromising attitudes toward the conflict influenced this neural marker. Furthermore, higher oxytocin levels in the Jewish-Israeli majority and tighter brain-to-brain synchrony among group members in the Arab-Palestinian minority enhanced the neural ingroup bias. Findings suggest that in cases of intractable intergroup conflict, top-down control mechanisms may block the brain’s evolutionary-ancient resonance to outgroup pain, pinpointing adolescents’ interpersonal and sociocognitive processes as potential targets for intervention.

AbstractRecent discoveries have highlighted the effects of oxytocin (OT) on social behavior and perception among autistic individuals. However, a gap persists in the literature regarding the potential effects of OT and the neural temporal dynamics due to OT administration. We explored the effect of OT on autistic individuals using magnetoencephalography (MEG), focusing on M100, M170, and M250, social perception-related components that tend to show atypical patterns in autistic individuals. Twenty-five autistic adolescents participated in this randomized, double-blind MEG study. Autistic individuals arrived at the lab twice and received an acute dose of intranasal OT or placebo in each session. During the scans, participants were asked to identify pictures of social and non-social stimuli. Additionally, 23 typically developing (TD) adolescents performed the same task in the MEG as a benchmark that allowed us to better characterize neural regions of interest and behavioral results for this age group in this task. A source-model beamformer analysis revealed that OT enhanced neural activity for social stimuli in frontal regions during M170. Additionally, in each of the preselected time windows, OT increased activation in the left hemisphere, regardless of the content of the presented stimuli. We suggest that OT increased the processing of social stimuli through two separate mechanisms. First, OT increased neural activity in a nonspecific manner, allowing increased allocation of attention toward the stimuli. Second, OT enhanced M170 activity in frontal regions only in response to social stimuli. These results reveal the temporal dynamics of the effects of OT on the early stages of social and non-social perception in autistic adolescents.Trial registration: This study was a part of a project registered as clinical trial October 27th, 2021. ClinicalTrials.gov Identifier: NCT05096676.

INTRODUCTION Schizophrenia-spectrum disorders (SZ) are characterized by disturbances of early information processing across various sensory modalities that originate from disrupted spatial and temporal linkage in critical neural networks that include the limbic system and sensory cortices. These disturbances are known to underlie impairments in social cognition, i.e. the ability to understand the thoughts and behaviors of others, which is a critical skill for effectively navigating the social world. Patients with SZ have widespread social cognitive deficits that interfere with social relationships and impair occupational functioning. Current pharmacological treatments are ineffective in remediating social cognitive deficits and in regulating their neurophysiological underpinnings. The oxytocin (OT) system, which is critically involved in social behavior and cognition in mammals and is dysregulated in SZ, is a promising target. Intranasal administration of exogenous OT is well tolerated and improves social cognition in patients with SZ. Additionally, neuroimaging studies in healthy individuals suggest that OT improves information processing and social cognition by modulating regional activity within those neural networks that are impaired in SZ. While work on healthy individuals is promising, no studies investigated the effects induced by OT on spatiotemporal neural oscillatory patterns in patients with SZ. MATERIAL & METHODS. In this study, I used Magnetoencepholagraphy Imaging (MEG-I) to examine the effects of OT. I administered a single intranasal dose of OT (40 IU) or placebo (PL) in a randomized, doubleblind, counterbalanced order with a cross-over, within-subject design to 25 males with SZ and 25 matched healthy controls (HC). Participants’ brain activity was recorded using MEG-I while they completed an auditory deviance task and a facial emotion processing task that robustly activate neural networks underlying information processing and social cognition. Change in auditory mismatch negativity induced by OT/PL in SZ and HC was assessed repeated measures ANOVA. Induced oscillatory activity in regions displaying early activation patterns was examined using adaptive spatial filtering techniques. Broadband activity estimated at each time point in a trial was averaged across trials, root-mean-square transformed, and z-normalized. Average amplitude from early time windows post-stimulus onset was calculated to assess early responses in the bilateral occipital face area (OFA) and the right amygdala. The Neurodynamic Utility Toolbox for MEG-I was used to conduct an exploratory time-frequency analysis of the neural sources during the processing of facial emotions. Task-induced neural oscillatory power changes were localized and examined after OT and PL administration. RESULTS. Compared to HC, SZ showed reduced amplitude of the mismatch negativity under PL. This impairment was normalized after OT administration. Under the effects of PL, the exploratory time-frequency analysis found differential early activations in SZ subjects relative to HC in several regions of interest, including the bilateral OFA and the right amygdala. In the OFA, SZ subjects showed impaired M100 responses that were normalized by OT, while HC showed no effects of OT on M100 response. In the right amygdala, SZ showed aberrant theta activity and impaired M100 under PL. These responses were normalized by OT. CONCLUSION. MEG-I analysis provided detailed measures of the location and time course of neural activations induced by OT. In SZ, OT remediated impaired facial emotion processing and auditory deviance processing, by normalizing the aberrant underlying early activation patterns. Future analyses will examine the neurophysiological effects of OT on late activation patterns in associative and cognitive control areas. This knowledge is critical to optimizing the use of OT as a treatment for social cognitive impairments in SZ and other neuropsychiatric illnesses.