Brain Responses Research Articles

Maternal cortisol concentration is associated with reduced brain activation to infant cry and more intrusive parenting behavior

Previous research indicates that maternal cortisol function and maternal brain response to infant are each in turn related to variations in parenting behavior. However, little is known about how maternal cortisol and maternal brain function are associated, thus studying these two mechanisms together may improve our understanding of how maternal cortisol assessed during interactions with own infant is associated with brain response to infant cry. First-time mothers (N = 59) of infants aged 3–4 months old were recruited to participate. Mothers’ cortisol concentration was measured during a naturalistic interaction with their infant and their behavior was coded for two parenting behaviors-- maternal sensitivity and non-intrusiveness. In an fMRI session, mothers listened to their own infant and a control infant crying. Higher cortisol concentration was associated with more intrusive behavior. We found greater cortisol concentration was further associated with decreased activation in the brain to infant cry in the right precentral gyrus, the left culmen extending into the left inferior temporal gyrus and fusiform, two clusters in the superior temporal gyrus, and in the medial frontal gyrus. We also found that lower activation in these regions was associated with more intrusive maternal behavior. These data demonstrate the associations between maternal cortisol concentration and reduced brain activation to infant cry in both motor planning and auditory processing regions in predicting intrusive parenting behavior.

6953 Bridging the Gender Gap: Sexually Dimorphic Brain Responses in Distressing Low Sexual Desire

Abstract Disclosure: J. Tsoutsouki: None. N. Ertl: None. E.G. Mills: None. M.B. Wall: None. L. Thurston: None. L. Yang: None. S. Suladze: None. T. Hunjan: None. M. Phylactou: None. B. Patel: None. J. Howard: None. A. Abbara: None. D. Golmeier: None. A.N. Comninos: None. W.S. Dhillo: None. Background: Distressing low sexual desire, termed Hypoactive Sexual Desire Disorder (HSDD), affects 10% of women and 8% of men. The established ‘top-down’ neurofunctional model of HSDD in women suggests that in response to erotic cues, excessive activation of higher-level cognitive brain regions (involved in introspection/self-monitoring) suppresses lower-level sexual brain centres, thereby impeding normal sexual function. By contrast, the neurodysfunction in men with HSDD remains to be fully characterised and crucially unlike in women, there are currently no licensed therapies. Herein, we report the first direct comparison of the neural bases of HSDD in women and men. Methods: 32 premenopausal women with HSDD [mean age±SD (y) 29.2±6.7] and 32 men with HSDD [age 37.9±8.6] underwent a task-based functional MRI (fMRI) measuring sexual brain activity during erotic versus control (exercise) videos. Participants completed psychometric questionnaires before and after the fMRI scan, providing functional relevance for the brain activity changes. Results: Women displayed significantly greater activation in higher-level cortical regions (e.g. inferior frontal gyrus, superior frontal gyrus) and lower-level limbic brain regions (e.g. amygdala, striatum, thalamus) in response to erotic videos, compared to the men. Lower activation in lower-limbic sexual regions in women correlated with more severe HSDD, which along with a hyperactivation in the inferior-frontal gyrus relative to the men, supports the ‘top-down’ mechanism underlying HSDD in women. By contrast, men exhibited lower activation in both higher-cortical and lower-limbic regions, but greater activation than the women in the visual cortex in response to erotic videos. Hence, a heightened sensitivity to visual erotic cues in men might not be effectively relayed to the limbic system. In women only, hypothalamic hyperactivation in response to erotic videos correlated with ‘increased heartbeat’ (r=0.5, P=0.001), and ‘tingling all over’ (r=0.6, P<0.001), while higher striatal activation correlated with feeling more ‘stimulated’ (r=0.4, P=0.001) and ‘genital tingling’ (r=0.6, P<0.001) on the psychometric questionnaires. Crucially, these findings were specific to erotic stimuli as no differences were identified in the control comparison (exercise>baseline contrast). Discussion: This is the first study to directly compare the neural bases of distressing low sexual desire in women and men. While supporting the ‘top-down’ mechanism of HSDD in women, it suggests a different neurodysfunctional process in men with HSDD, highlighting a potential functional disconnection between sensory/attention and sexual centres. Our findings have key clinical implications as they identify a sexual dimorphism in the neural bases of low sexual desire relevant to the escalating development of therapeutics for patients with HSDD. Presentation: 6/3/2024

Assessing consciousness in acute coma using name-evoked responses

Detecting consciousness in clinically unresponsive patients remains a significant challenge. Existing studies demonstrate that electroencephalography (EEG) can detect brain responses in behaviorally unresponsive patients, indicating potential for consciousness detection. However, most of this evidence is based on chronic patients, and there is a lack of studies focusing on acute coma cases. This study aims to detect signs of residual consciousness in patients with acute coma by using bedside EEG and electromyography (EMG) during an auditory oddball paradigm. We recruited patients with acute brain injury (either traumatic brain injury or cardiac arrest) who were admitted to the intensive care unit within two weeks after injury, with a Glasgow Coma Scale (GCS) score of 8 or below. Auditory stimuli included the patients' own names and other common names (referred to as standard names), spoken by the patients’ relatives, delivered under two conditions: passive listening (where patients were instructed that sounds would be played) and active listening (where patients were asked to move hands when heard their own names). Brain and muscle activity were recorded using EEG and EMG during the auditory paradigm. Event-related potentials (ERP) and EMG spectra were analyzed and compared between responses to the subject’s own name and other standard names in both passive and active listening conditions. A total of 22 patients were included in the final analysis. Subjects exhibited enhanced ERP responses when exposed to their own names, particularly during the active listening task. Compared to standard names or passive listening, distinct differences in brain network connectivity and increased EMG responses were detected during active listening to their own names. These findings suggest the presence of residual consciousness, offering the potential for assessing consciousness in behaviorally unresponsive patients.

Comparative Electroencephalographic Profile of a New Anesthetic and Anticonvulsant That Is Selective for the GABAAR Slow Receptor Subtype

BACKGROUND: Anesthetics like propofol increase electroencephalography (EEG) power in delta frequencies (0.1–4 Hz), with a decrease of power in bandwidths >30 Hz. Propofol is nonselective for gamma amino butyric acid type A receptor subtypes (GABAAR) as it enhances all 3 GABAAR subtypes (slow, fast, and tonic). Our newly developed anesthetic class selectively targets GABAAR-slow synapses to depress brain responsiveness. We hypothesized that a selective GABAAR-slow agonist, KSEB 01-S2, would produce a different EEG signature compared to the broad-spectrum GABAAR agonist (propofol), and tested this using rat EEG recordings. METHODS: Male rats were studied after Institutional Animal Care and Use Committees (IACUC) approval from the US Army Medical Research Institute of Chemical Defense and the University of Michigan. Rats were anesthetized using isoflurane (3%–5% induction, 1%–3% maintenance) with oxygen at 0.5 to 1.0 L/min. Stainless steel screws were placed in the skull and used to record subcranial cortical EEG signals. After recovery, either propofol or KSEB 01-S2 was administered and effects on EEG signals were analyzed. RESULTS: As previously reported, propofol produced increased power in delta frequencies (0.1–4 Hz) compared to predrug recordings and produced a decrease in EEG power >30 Hz but no significant changes were seen within ±20 seconds of losing the righting reflex. By contrast, KSEB 01-S2 produced a significant increase in theta frequency percent power (median 14.7%, 16.2/13.8, 75/25 confidence interval; to 34.7%, 35/31.8; P < .015) and a significant decrease in low gamma frequency percent power (16.9%, 18.6/15.8; to 5.45%, 5.5/5.39; P < .015) for all rats at ± 20 seconds of loss of consciousness (LOC). Both anesthetics produced a flattening of chaotic attractor plots from nonlinear dynamic analyses, like that produced by volatile and dissociative anesthetics at LOC. CONCLUSIONS: KSEB 01-S2 produced a markedly different EEG pattern, with a selective increase observed in the theta frequency range. KSEB 01-S2 also differs markedly in its activity at the GABAAR-slow receptor subtype, suggesting a possible mechanistic link between receptor subtype specificity and EEG frequency band signatures. Increased theta together with depressed gamma frequencies is interesting because GABAAR slow synapses have previously been suggested to underlie theta frequency oscillations, while fast synapses control gamma activity. These reciprocal effects support a previous model for theta and nested gamma oscillations based on inhibitory connections between GABAAR fast and slow interneurons. Although each anesthetic produced a unique EEG response, propofol and KSEB 01-S2 both increased slow wave activity and flattened chaotic attractor plots at the point of LOC.

Evaluating attentional responses to electric vehicle driving noise through event-related potentials: a frequency bands analysis

The advent of electric vehicles (EVs), known for their quieter operation compared to Internal Combustion Engine (ICE) vehicles, has shifted auditory attention towards wind and road noise. This shift is further accentuated by the anticipated future dominance of autonomous vehicles, which is expected to reduce the cognitive demands of driving, potentially heightening sensitivity to external noise and leading to increased annoyance and discomfort. This research investigates the impact of driving noise on selective attention by identifying sounds that significantly disrupt adaptation to driving noise through the analysis of event-related potentials (ERPs). Unlike previous studies that concentrated on the peak high-frequency driving noise fluctuations around 1000 Hz, our study explores a broader spectrum of higher frequencies. By recording brain responses to driving-related auditory stimuli, we detected variations in ERPs across different frequency bands, thereby pinpointing the acoustic characteristics most disruptive to concentration. Our findings aim to contribute towards enhancing driver focus and improving the acoustic comfort inside vehicle cabins.

The divisive normalization model of visual number sense: model predictions and experimental confirmation.

Our intuitive sense of number allows rapid estimation for the number of objects (numerosity) in a scene. How does the continuous nature of neural information processing create a discrete representation of number? A neurocomputational model with divisive normalization explains this process and existing data; however, a successful model should not only explain existing data but also generate novel predictions. Here, we experimentally test novel predictions of this model to evaluate its merit for explaining mechanisms of numerosity perception. We did so by consideration of the coherence illusion: the underestimation of number for arrays containing heterogeneous compared to homogeneous items. First, we established the existence of the coherence illusion for homogeneity manipulations of both area and orientation of items in an array. Second, despite the behavioral similarity, the divisive normalization model predicted that these two illusions should reflect activity in different stages of visual processing. Finally, visual evoked potentials from an electroencephalography experiment confirmed these predictions, showing that area and orientation coherence modulate brain responses at distinct latencies and topographies. These results demonstrate the utility of the divisive normalization model for explaining numerosity perception, according to which numerosity perception is a byproduct of canonical neurocomputations that exist throughout the visual pathway.

Evoked Component Analysis (ECA): Decomposing the Functional Ultrasound Signal With GLM-Regularization.

Analysis of functional neuroimaging data aims to unveil spatial and temporal patterns of interest. Existing analysis methods fall into two categories: fully data-driven approaches and those reliant on prior information, e.g. the stimulus time course. While using the stimulus signal directly can help identify the activated brain areas, it is known that the relationship between stimuli and the brain's response exhibits nonlinear and time-varying characteristics. As such, relying completely on the stimulus signal to describe the brain's temporal response leads to a restricted interpretation of the brain function. In this paper, we present a new technique called Evoked Component Analysis (ECA), which leverages prior information up to a defined extent. This is achieved by including the general linear model (GLM) design matrix as a regulatory term and estimating the factor matrices in both space and time through an alternating minimization approach. We apply ECA to 2D and swept-3D functional ultrasound (fUS) experiments conducted with mice. When decomposing 2D fUS data, we employ GLM regularization at various intensities to emphasize the role of prior information. Furthermore, we show that incorporating multiple hemodynamic response functions within the design matrix can provide valuable insights into region-specific characteristics of evoked activity. Finally, we use ECA to analyze swept-3D fUS data recorded from five mice engaged in two distinct visual tasks. Swept-3D fUS images the 3D brain sequentially using a moving probe, resulting in different slice acquisition time instants. We show that ECA can estimate factor matrices with a fine resolution at each slice acquisition time instant and yield higher t-statistics compared to GLM and correlation analysis for all subjects.

Cross-Subject EEG Feedback for Implicit Image Generation.

Generative models are powerful tools for producing novel information by learning from example data. However, the current approaches require explicit manual input to steer generative models to match human goals. Furthermore, how these models would integrate implicit, diverse feedback and goals of multiple users remains largely unexplored. Here, we present a first-of-its-kind system that produces novel images of faces by inferring human goals directly from cross-subject brain signals while study subjects are looking at example images. We report on an experiment where brain responses to images of faces were recorded using electroencephalography in 30 subjects, focusing on specific salient visual features (VFs). Preferences toward VFs were decoded from subjects' brain responses and used as implicit feedback for a generative adversarial network (GAN), which generated new images of faces. The results from a follow-up user study evaluating the presence of the target salient VFs show that the images generated from brain feedback represent the goal of the study subjects and are comparable to images generated with manual feedback. The methodology provides a stepping stone toward humans-in-the-loop image generation.

EEG-based responses of patients with disorders of consciousness and healthy controls to familiar and non-familiar emotional videos

ObjectiveTo investigate the differences in the brain responses of healthy controls (HC) and patients with disorders of consciousness (DOC) to familiar and non-familiar audiovisual stimuli and their consistency with the clinical progress. MethodsEEG responses of 19 HC and 19 patients with DOC were recorded while watching emotionally-valenced familiar and non-familiar videos. Differential entropy of the EEG recordings was used to train machine learning models aimed to distinguish brain responses to stimuli type. The consistency of brain responses with the clinical progress of the patients was also evaluated. ResultsModels trained using data from HC outperformed those for patients. However, the performance of the models for patients was not influenced by their clinical condition. The models were successfully trained for over 75% of participants, regardless of their clinical condition. More than 75% of patients whose CRS-R scores increased post-study displayed distinguishable brain responses to both stimuli. ConclusionsResponses to emotionally-valenced stimuli enabled modelling classifiers that were sensitive to the familiarity of the stimuli, regardless of the clinical condition of the participants and were consistent with their clinical progress in most cases. SignificanceEEG responses are sensitive to familiarity of emotionally-valenced stimuli in HC and patients with DOC.

Unveiling the interplay of MAPK/NF-κB/MLKL axis in brain health: Omega-3 as a promising candidates against copper neurotoxicity

Excessive intake of copper (Cu) may lead to increased inflammatory responses in brain, which can cause damage to neurons and glial cells, thereby affecting normal brain function. Omega-3 (ω-3) is a common dietary supplement, particularly rich in DHA in the brain, known for its anti-inflammatory properties and its role in lipid balance regulation and structural maintenance. Here, ω-3 is supplemented to Cu-exposed chickens to assess its neuroprotection in vivo and in vitro. Pathologically, ω-3 significantly alleviated structural and functional abnormalities in brain under excess Cu, including barrier disruption, neuronal shrinkage necroptosis and increased release of inflammatory factors such as IL-1β. The molecular docking analyses unveiled high enrichment values of inflammation and MAPK pathway, with IL-1β gene enrichment the highest value. Mechanistically, DHA stabilized the active site of IL-1β, thereby reducing the activation of NF-κB signal and phosphorylation of MAPK/MLKL cascades, ultimately mitigating Cu-induced inflammatory effects. These mechanisms elucidate the action mode of Cu neurotoxicity from aspect of MAPK/NF-κB/MLKL axis and the promising neuroprotection of ω-3.

Trustworthiness evaluation of workers in critical facilities using electroencephalography-based acquaintance test

This study emphasized the critical importance of prioritizing workers' trustworthiness in safeguarding critical facilities from the potential harm caused by insiders' betrayal. By noting the limitations of existing physical protection systems in critical facilities, this study showed that effectively characterizing and detecting malicious insider activity can be possible by observing immediate brain physiological reactions to specific stimuli. Based on the finding, a novel approach using electroencephalography (EEG)-based acquaintance tests was introduced to objectively assess ’a level of suspicion between colleagues by measuring their brain responses when he/she is exposed to familiar and unfamiliar stimuli. If a person claims falsely about one's acquaintance, the model assumes he/she has malicious or suspicious intent by violating the reporting obligation. The experiment was designed with a relatively short time of monitoring of less than 2 min and with a simple EEG headband device called MUSE. The experiment is to analyze whether the model could provide reliable prediction of disguised acquaintance avoiding complex preparation process. Averaged N170 peak analysis indicated that MUSE provided adequate signal characteristics to classify acquaintance. Also, a machine learning-based subject-wise classification model showed adequate capability to differentiate the EEG signals of acquaintances from unknowns. The final prediction combined multiple single-trial classification results, correctly detected the participant's acquaintance about 94.1 % of the cases, with similar performance when strangers were presented. The results indicated the possibility of using biosignal to enhance security culture and mitigate insider threats in critical facilities, by providing an indication of behavior that disregards security policies and procedures.

Spine Pain.

Spine pain is one of the most common presenting concerns in health care settings. This article reviews clinical strategies for evaluating and managing patients with spine pain. Minimally invasive interventional procedures, virtual reality, predictive analytics, neuromodulation, and other evolving technologies are significantly impacting the management of spine pain. Advances in modern pain science have also led to effective skills and treatment strategies, including patient interviews and queries for insight regarding pain, education, and cognitive restructuring, and adjusting the timing of examination (after reeducation) and examination techniques to encourage the experience of movement in the absence of assumed tissue damage. An evolving understanding of the influence of patient-centric thoughts, framing, emotional status, and cognitive restructuring's influence on the brain's response to perceived threat are important aspects of spine pain management. The correlation of clinical presentations with structural abnormalities is necessary but insufficient to evaluate and manage spine pain. Modern pain science acknowledges pain as a subjective experience but recognizes a critical distinction between tissue damage, nociception, and the experience of pain. What and how we communicate with patients, as well as evolving neuromodulation technologies, augment conventional approaches.

Bisphenol F-induced precocious genesis of aggressive neurobehavioral response is associated with heightened monoamine oxidase activity and neurodegeneration in zebrafish brain

The production and use of plastics and plastics products has increased dramatically in recent decades. Moreover, their unprotected disposal into ambient life sustaining environment poses a significant health risk. Bisphenol F (BPF) an alternative to bisphenol A (BPA) has been extensively employed for making of plastics. Recent reports have documented the neurotoxic potential of BPF through induction of altered neurochemical profile, microglia-astrocyte-mediated neuroinflammation, oxidative stress, transformed neurobehavioral response, cognitive dysfunction, etc. In the present study, our approach was to understand the underlying mechanism of BPF-persuaded genesis of aggressive neurobehavioral response in zebrafish. The basic findings advocated a temporal transformation in native explorative behaviour and progressive induction of aggressive behavioural response in zebrafish following exposure to BPF. Our neurobehavioral findings supported the argument of oxidative stress-mediated neuromorphological transformation in the periventricular grey zone (PGZ) of the zebrafish brain. In line with earlier reports, our findings also showed that heightened monoamine oxidase (MAO) activity and downregulation in tyrosine hydroxylase expression in the zebrafish brain is associated with the precocious genesis of aggressive neurobehavioral response in zebrafish brain. Our findings also shed light on BPF-instigated apoptotic neuronal death as revealed by augmented chromatin condensation and cleaved caspase-3 expression. Further observation showed that the downregulation of NeuN (a marker of post-mitotic mature neuron) expression provided substantial neurotoxicity, leading to neurodegeneration in the PGZ region of the zebrafish brain. These basic findings grossly advocate that BPF acts as a potent neurotoxicant in transmuting native neurobehavioral response through the induction of oxidative stress, heightened MAO activity and neuromorphological transformation in the zebrafish brain.

Ndufs4 knockout mice with isolated complex I deficiency engage a futile adaptive brain response

Paediatric Leigh syndrome (LS) is an early-onset and fatal neurodegenerative disorder lacking treatment options. LS is frequently caused by mutations in the NDUFS4 gene, encoding an accessory subunit of mitochondrial complex I (CI), the first complex of the oxidative phosphorylation (OXPHOS) system. Whole-body Ndufs4 knockout (KO) mice (WB-KO mice) are widely used to study isolated CI deficiency, LS pathology and interventions. These animals develop a brain-specific phenotype via an incompletely understood pathomechanism. Here we performed a quantitative analysis of the sub-brain proteome in six-weeks old WB-KO mice vs. wildtype mice. Brain regions comprised of a brain slice (BrSl), cerebellum (CB), cerebral cortex (CC), hippocampus (HC), inferior colliculus (IC), and superior colliculus (SC). Proteome analysis demonstrated similarities between CC/HC, and between IC/SC, whereas BrSl and CB differed from these two groups and each other. All brain regions displayed greatly reduced levels of two CI structural subunits (NDUFS4, NDUFA12) and an increased level of the CI assembly factor NDUFAF2. The level of CI-Q module subunits was significantly more reduced in IC/SC than in BrSl/CB/CC/HC, whereas other OXPHOS complex levels were not reduced. Gene ontology and pathway analysis demonstrated specific and common proteome changes between brain regions.Across brain regions, upregulation of cold-shock-associated proteins, mitochondrial fatty acid (FA) oxidation and synthesis (mtFAS) were the most prominent. FA-related pathways were predominantly upregulated in CB and HC. Based upon these results, we argue that stimulation of these pathways is futile and pro-pathological and discuss alternative strategies for therapeutic intervention in LS. SignificanceThe Ndufs4 knockout mouse model is currently the most relevant and most widely used animal model to study the brain-linked pathophysiology of human Leigh Syndrome (LS) and intervention strategies. We demonstrate that the Ndufs4 knockout brain engages futile and pro-pathological responses. These responses explain both negative and positive outcomes of intervention studies in Leigh Syndrome mice and patients, thereby guiding novel intervention opportunities.

FMRI speech tracking in primary and non-primary auditory cortex while listening to noisy scenes

Invasive and non-invasive electrophysiological measurements during “cocktail-party”-like listening indicate that neural activity in the human auditory cortex (AC) “tracks” the envelope of relevant speech. However, due to limited coverage and/or spatial resolution, the distinct contribution of primary and non-primary areas remains unclear. Here, using 7-Tesla fMRI, we measured brain responses of participants attending to one speaker, in the presence and absence of another speaker. Through voxel-wise modeling, we observed envelope tracking in bilateral Heschl’s gyrus (HG), right middle superior temporal sulcus (mSTS) and left temporo-parietal junction (TPJ), despite the signal’s sluggish nature and slow temporal sampling. Neurovascular activity correlated positively (HG) or negatively (mSTS, TPJ) with the envelope. Further analyses comparing the similarity between spatial response patterns in the single speaker and concurrent speakers conditions and envelope decoding indicated that tracking in HG reflected both relevant and (to a lesser extent) non-relevant speech, while mSTS represented the relevant speech signal. Additionally, in mSTS, the similarity strength correlated with the comprehension of relevant speech. These results indicate that the fMRI signal tracks cortical responses and attention effects related to continuous speech and support the notion that primary and non-primary AC process ongoing speech in a push-pull of acoustic and linguistic information.

Functional Brain Adaptations During Speech Processing in 4-Month-Old Bilingual Infants.

Language learning is influenced by both neural development and environmental experiences. This work investigates the influence of early bilingual experience on the neural mechanisms underlying speech processing in 4-month-old infants. We study how an early environmental factor such as bilingualism interacts with neural development by comparing monolingual and bilingual infants' brain responses to speech. We used functional near-infrared spectroscopy (fNIRS) to measure 4-month-old Spanish-Basque bilingual and Spanish monolingual infants' brain responses while they listened to forward (FW) and backward (BW) speech stimuli in Spanish. We reveal distinct neural signatures associated with bilingual adaptations, including increased engagement of bilateral inferior frontal and temporal regions during speech processing in bilingual infants, as opposed to left hemispheric functional specialization observed in monolingual infants. This study provides compelling evidence of bilingualism-induced brain adaptations during speech processing in infants as young as 4 months. These findings emphasize the role of early language experience in shaping neural plasticity during infancy suggesting that bilingual exposure at this young age profoundly influences the neural mechanisms underlying speech processing.

Posttraumatic growth modulates the response to negative emotions related to COVID-19: An event-related potentials study.

There is increasing interest in identifying how posttraumatic growth (PTG) impacts emotional processing following traumatic events (e.g., the COVID-19 pandemic). Previous research suggests that high PTG levels may lead to enduring changes in positive emotional processing. Despite this fact, little is known regarding brain activation and responses to stressful emotional stimuli. The present study utilised event-related potentials (ERPs) to investigate whether individual differences in emotional responses toward neutral and negative emotional stimuli related to COVID-19 are related to self-reported PTG levels. A total of 77 participants were analysed: 21 in the high PTG group and 56 in the control group. The amplitude of the N2 was smaller in the high PTG group compared to the control group under both negative and neutral conditions. When viewing the negative emotion pictures (vs. neutral pictures), the N2 amplitude significantly decreased for the high PTG group in the right occipital and frontal-parietal areas, whereas no significant change was observed among the control group. In the time window Late Positive Potential (LPP) 600-1000ms, emotional stimuli and the group interaction were significant. Viewing negative pictures (vs. neutral pictures) decreased the LPP 600-1000ms amplitudes for the control group, mainly originating from the brain's frontal regions. However, there were no such significant differences for the PTG group. Due to the limited sample size and cultural differences, the applicability of these results to other regions or countries needs to be verified. The presented findings suggest that the impact of PTG during emotional response is reflected in both bottom-up (evidenced by the early ERP components) and top-down (evidenced by the later ERP components) processes. Individuals with high PTG may use a meditation-related emotional regulation strategy of acceptance at the basic stage and non-judgement at a later stage.

A novel, robust, and portable platform for magnetoencephalography using optically-pumped magnetometers

Abstract Magnetoencephalography (MEG) measures brain function via assessment of magnetic fields generated by neural currents. Conventional MEG uses superconducting sensors, which place significant limitations on performance, practicality, and deployment; however, the field has been revolutionised in recent years by the introduction of optically-pumped magnetometers (OPMs). OPMs enable measurement of the MEG signal without cryogenics, and consequently the conception of “OPM-MEG” systems which ostensibly allow increased sensitivity and resolution, lifespan compliance, free subject movement, and lower cost. However, OPM-MEG is in its infancy with existing limitations on both sensor and system design. Here, we report a new OPM-MEG design with miniaturised and integrated electronic control, a high level of portability, and improved sensor dynamic range. We show that this system produces equivalent measures compared with an established OPM-MEG instrument; specifically, when measuring task-induced beta-band, gamma-band, and evoked neuro-electrical responses, source localisations from the two systems were comparable and temporal correlation of measured brain responses was >0.7 at the individual level and >0.9 for groups. Using an electromagnetic phantom, we demonstrate improved dynamic range by running the system in background fields up to 8 nT. We show that the system is effective in gathering data during free movement (including a sitting-to-standing paradigm) and that it is compatible with simultaneous electroencephalography (EEG). Finally, we demonstrate portability by moving the system between two laboratories. Overall, our new system is shown to be a significant step forward for OPM-MEG and offers an attractive platform for next generation functional medical imaging.

The effect of multiband sequences on statistical outcome measures in functional magnetic resonance imaging using a gustatory stimulus

Recent technical developments have led to the invention of multiband functional magnetic resonance imaging (fMRI) sequences that allow for faster sampling rates. However, some studies have highlighted problems with these sequences, leading to a decreased temporal signal-to-noise ratio (tSNR). In addition, this temporal noise may interfere with detecting reward-related responses in mesolimbic regions. The blood-oxygen-level-dependent signal utilized in the majority of fMRI measurements is relatively slow. Furthermore, the cerebral response to gustatory stimuli would also be relatively slow. Therefore, given the temporal noise issues with multiband sequences, it is unclear whether multiband sequences are necessary for fMRI studies using gustatory stimuli. We thus conducted an fMRI experiment using a gustatory stimulus to investigate the effects of multiband sequences and increased sampling rates on statistical outcome measures. A single-band sequence with a repetition time (TR) of 2 s of phantom fMRI data and gustatory fMRI data from the gustatory regions exhibited the highest tSNR, although the tSNR of this sequence of gustatory fMRI was not statistically different from tSNR of multiband sequences with a TR of 2 s in any of the selected region of interests. Conventional general linear model analysis of fMRI showed that single-band sequences are more advantageous than multiband sequences for detecting brain responses to gustatory stimuli in the primary gustatory cortex. In addition, a Bayesian data comparison showed that data derived from a single-band sequence with a TR of 2 s was optimal for inferring neuronal connectivity in gustatory processing. Therefore, a conventional single-band sequence with a TR of 2 s is more appropriate for fMRI with gustatory stimuli. Image acquisition sequences should be selected aligned with the study objectives and target brain regions.

Response inhibition deficits in math-anxious individuals.

We examined whether math anxiety is related to a response inhibition deficit and, if so, whether it is a domain-specific inhibition deficit in numerical tasks or a general inhibition deficit. Behavioral performance and electroencephalogram activity were recorded while 28 highly math-anxious (HMA) and 28 low math-anxious (LMA) individuals performed both a numerical and a non-numerical Go/Nogo task. In the numerical task, single-digit numbers were presented, and participants were asked to press a button if the number was even. In the non-numerical task, letters were presented, and the button had to be pressed if the letter was a vowel. Nogo trials were answered less accurately and elicited larger Nogo-N2 and Nogo-P3 than Go trials in both tasks and both groups. Importantly, behavioral and brain response differences between tasks were only found in the HMA group. First, they were more error-prone in numerical Nogo than in non-numerical Nogo trials; and second, their Nogo-N2 and N2d (Nogo-Go difference) were smaller in the numerical task than in the non-numerical task. No differences were found in the LMA group. These results suggest that HMA individuals' response inhibition is impaired specifically when dealing with numbers, which could contribute to their low achievement in math tasks.