Sensory processing sensitivity is mainly captured based on questionnaires and it’s neurophysiological basis is largely unknown. As hitherto no electroencephalography (EEG) study has been carried out, the aim of this work was to determine whether the self-reported level of SPS correlates with the EEG activity in different frequency bands. For the first time, neurophysiological signatures associated with SPS during a task free resting state were demonstrated. Evidence is provided that neural processes differ between HSP and non-HSP. During resting with eyes open HSP exhibit higher EEG activity suggesting increased information processing. The findings could be of importance for the development of biomarkers for clinical diagnostics and intervention efficacy evaluation. Volume 17 - 2023 | https://doi.org/10.3389/fnins.2023.1200962 Background: Sensory processing sensitivity is mainly captured based on questionnaires and it’s neurophysiological basis is largely unknown As hitherto no electroencephalography (EEG) study has been carried out the aim of this work was to determine whether the self-reported level of SPS correlates with the EEG activity in different frequency bands Methods: One hundred fifteen participants were measured with 64-channel EEG during a task-free resting state a power spectrum time series was calculated using the Fast Fourier Transform (FFT) for the following frequency bands: Delta: 1–3.5 Hz Correlations with the ‘Highly Sensitive Person Scale’ (HSPS-G) scores were determined the lowest and the highest 30% of the cohort were contrasted as polar opposites EEG features were compared between the two groups applying a paired two-tailed t-test Results: The HSPS-G scores correlated statistically significantly positive with beta 1 and 2 and global EEG power during resting with eyes open The highly sensitive group revealed higher beta power (4.38 ± 0.32 vs higher gamma power (4.21 ± 0.37 vs and increased global EEG power (4.38 ± 0.29 vs The higher EEG activity in the HSP group was most pronounced in the central whereas lower EEG activity was most present in occipital areas neurophysiological signatures associated with SPS during a task free resting state were demonstrated Evidence is provided that neural processes differ between HSP and non-HSP During resting with eyes open HSP exhibit higher EEG activity suggesting increased information processing The findings could be of importance for the development of biomarkers for clinical diagnostics and intervention efficacy evaluation Although questionnaires and behavioral observational assessments have primarily captured SPS, only a limited number of fMRI studies (Jagiellowicz et al., 2011; Acevedo et al., 2014, 2018, 2021; Schaefer et al., 2022) have explored its neurobiological basis no electroencephalography (EEG) study has investigated the neurophysiological correlates of SPS there is a lack of empirical neurophysiological markers to identify the level of SPS Such markers could have significant implications for clinical diagnostics enabling differentiation between psychopathologies and monitoring the effectiveness of therapeutic interventions the notion of enhanced information processing in SPS remains theoretical and has not been experimentally confirmed It is hypothesized that this trait is reflected in increased electrophysiological activity which are associated with cognitive processing and the temporal binding of perceptual stimuli To address this hypothesis and shed light on the neurophysiological mechanisms of SPS the present study aimed to (1) examine the correlation between self-reported SPS levels and EEG activity and (2) identify differences in power spectral density between participants with low and high levels of SPS The participants were recruited throughout Germany via various social networks the Research Association for sensory-processing sensitivity and internal university invitation notifications An amount of 30 euros was offered as an incentive to participate in the study Psychology students received subject hours Participation was accepted from the age of 18 years acute suicidality and substance dependence All 115 participants signed an informed consent before participating in the laboratory study The laboratory surveys took place in a sound- and magnetic field-isolated cabin from 03.05 to 02.07.2021 on the campus of the University of the Bundeswehr in Munich Measurement times were between 8.00 a.m Electrophysiological data was recorded using a 72 channels QuickAmp amplifier system (BrainProducts GmbH EEG was measured with a 64-channel ANT Waveguard electrode cap (ANT B.V. The Netherlands) with active shielding and Ag/AgCl electrodes which were arranged according to the international 10/10 system Vertical electrooculograms (EOGs) were recorded above and below one eye Electrode impedances were kept below 10 kΩ Data was sampled at 250 Samples/s in a range from DC to 70 Hz with a notch filter at 50 Hz Data was acquired during a task-free resting state with eyes closed and eyes open for a duration of 3 min each Germany) and SPSS Version 28 (IBM SPSS Statistical Package 28.0 the Independent Component Analysis (ICA) as implemented in the Brain Vision Analyser was applied using the standard protocol to identify and reject data containing muscular activity EEG artifact rejection was carried out with the EEGLAB plugin clean_rawdata Bad channels were removed if (i) it was flat for more than 5 s (ii) had a low signal to noise ratio with standard deviation above 4 or (iii) was poorly correlated with nearby channels (threshold: 0.8) The time-series of the raw data was then visually inspected for continuous artifacts Power spectral density was calculated using the Fast Fourier Transform (FFT) algorithm (Nussbaumer, 1981) FFT was calculated on 2 s time windows for the following frequency bands: Delta: 1–3.5 Hz To obtain a measure of the power spectral density (PSD) FFT values were squared and all FFT bins within a frequency band range were averaged EEG PSD was calculated for each participant The resulting PSD data set consisted of the dimensionality of 2 conditions we averaged the values across all electrodes resulting in the global band power (1–45 Hz) FDR adjustment was applied on all three dimensions Significance was set at p < 0.05 nor job status was found to be statistically significantly correlated with any of the frequency bands Topographical maps of differences in the effect size calculated for each frequency band comparing the groups of highly sensitive persons and low sensitive persons which supports the results presented in this study This study represents an initial step towards achieving similar diagnostic markers for SPS provided that validation and consistency can be confirmed in other samples and email distribution lists of HSP coaches it cannot be ruled out that study participants were already aware of the SPS trait and the associated questionnaire which might have influenced their responses based on knowledge rather than personal experience the group division limits the generalizability of the results and the comparison with existing studies the study not only reported extreme group comparisons but also provided correlative results Finally, it is worth noting that the different investigators involved potentially could have influenced the highly sensitive subjects, as HSPs can be strongly influenced by people’s moods or emotions (Jagiellowicz et al., 2011) the investigators underwent extensive training and received detailed instructions on how to interact with HSP individuals Further neurophysiological studies are required for validation and testing of consistency there are many implications for future research gustatory) should be stimulated in a controlled setting during neurophysiological assessment This could test whether HSP also respond more strongly to other sensory input or whether perhaps different HSP types exist with respect to sensory stimulus processing it would be interesting to see whether neurophysiological studies show specific patterns of stimulus overload in the brain of HSP compared to LSP above a certain stimulus threshold The question arises whether HSP switch into an automatic protection or coping mechanism after a certain stimulus threshold psychopathologies should be measured with clinical interviews and standardized questionnaires in future studies in order to control for them and to better compare different psychopathologies in electrophysiological studies with HSP future studies should control the influence of factors such as age The findings of the current study have practical implications in psychotherapeutic practice Developing psychoeducational interventions for individuals with high levels of SPS can assist patients in gaining a better understanding and acceptance of their innate distinct neural stimulus processing patients may become more adept at distinguishing between symptoms of their mental illness and those stemming from stimulus overload stress reduction techniques that foster resilience it is crucial to prioritize enhancing the self-efficacy of individuals with mental health conditions and high sensitivity levels by acknowledging sensitivity-related needs This can involve addressing specific workplace conditions or accommodating unique requirements during medical examinations The study’s findings suggest that Highly Sensitive Persons (HSPs) exhibit heightened sensitivity to environmental stimuli it is essential to investigate how to optimize the handling and environmental conditions for this patient group particularly in clinical settings such as doctors’ offices or clinics HSPs may experience reduced stress levels and potentially even less pain during medical examinations neurophysiological signatures associated with Sensory Processing Sensitivity (SPS) These findings have potential implications for developing biomarkers for clinical diagnostics to differentiate between psychopathologies and for monitoring the effectiveness of therapeutic interventions The study provides evidence that neural processes differ between Highly Sensitive Persons (HSPs) and Low Sensitive Persons (LSPs) high levels of SPS were found to be significantly associated with increases in high beta and gamma frequency power as well as increased global EEG power during a task-free resting state with eyes open These findings support the central theoretical assumption of enhanced information processing in HSPs The raw data supporting the conclusions of this article will be made available by the authors The studies involving human participants were reviewed and approved by Institutional Review Board of the University of the Bundeswehr Munich The patients/participants provided their written informed consent to participate in this study NM-S and NW: conceptualization and writing—original draft preparation All authors contributed to the article and approved the submitted version We acknowledge financial support by the University of the Bundeswehr Munich The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher The highly sensitive brain: an fMRI study of sensory processing sensitivity and response to others' emotions The functional highly sensitive brain: a review of the brain circuits underlying sensory processing sensitivity and seemingly related disorders Sensory processing sensitivity predicts individual differences in resting-state functional connectivity associated with depth of processing Relationship between sensory processing sensitivity CrossRef Full Text | Google Scholar Sensory-processing sensitivity and its relation to introversion and emotionality Adult shyness: the interaction of temperamental sensitivity and an adverse childhood environment Sensory processing sensitivity: a review in the light of the evolution of biological responsivity Genetic architecture of environmental sensitivity reflects multiple heritable components: a twin study with adolescents dispositional mindfulness and negative psychological symptoms CrossRef Full Text | Google Scholar The highly sensitive person: stress and physical symptom reports CrossRef Full Text | Google Scholar Controlling the false discovery rate: a practical and powerful approach to multiple testing CrossRef Full Text | Google Scholar Statistical power analysis for the behavioral sciences Google Scholar Temperamental sensitivity: two constructs or one CrossRef Full Text | Google Scholar Gerstenberg Sensory-processing sensitivity predicts performance on a visual search task followed by an increase in perceived stress CrossRef Full Text | Google Scholar “A critique of Eysenck’s theory of personality” in A model for personality Google Scholar Sensory processing sensitivity in the context of environmental sensitivity: a critical review and development of research agenda Induced gamma band responses: an early marker of memory encoding and retrieval Hinterberger A brain–computer interface (BCI) for the locked-in: comparison of different EEG classifications for the thought translation device Sensory processing sensitivity and serotonin gene variance: insights into mechanisms shaping environmental sensitivity Jagiellowicz The trait of sensory processing sensitivity and neural responses to changes in visual scenes Human gamma-frequency oscillations associated with attention and memory Do highly sensitive persons experience more nonordinary states of consciousness during sensory isolation CrossRef Full Text | Google Scholar Psychometric properties and validation of a German high sensitive person scale (HSPS-G) CrossRef Full Text | Google Scholar tulips and orchids: evidence for the existence of low-sensitive medium-sensitive and high-sensitive individuals Sensory processing sensitivity and its association with personality traits and affect: a meta-analysis The relationships between sensory processing sensitivity CrossRef Full Text | Google Scholar Sensory processing sensitivity and its relation to parental bonding CrossRef Full Text | Google Scholar EEG frequency bands in psychiatric disorders: a review of resting state studies “The fast Fourier transform” in Fast Fourier transform and convolution algorithms Google Scholar Individual differences in environmental sensitivity CrossRef Full Text | Google Scholar Environmental sensitivity in children: development of the highly sensitive child scale and identification of sensitivity groups Sensory processing sensitivity and somatosensory brain activation when feeling touch A psychometric evaluation of the highly sensitive person scale: the components of sensory-processing sensitivity and their relation to the BIS/BAS and “big five” Trait sensory-processing sensitivity and subjective well-being: distinctive associations for different aspects of sensitivity CrossRef Full Text | Google Scholar Turjeman-Levi Sensory-processing sensitivity versus the sensory-processing theory: convergence and divergence Resting state EEG abnormalities in autism spectrum disorders Hinterberger T and Kruse J (2023) Neurophysiological signatures of sensory-processing sensitivity Received: 05 April 2023; Accepted: 07 July 2023; Published: 20 July 2023 Copyright © 2023 Meinersen-Schmidt, Walter, Kulla, Loew, Hinterberger and Kruse. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) distribution or reproduction in other forums is permitted provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited in accordance with accepted academic practice distribution or reproduction is permitted which does not comply with these terms *Correspondence: Nicole Meinersen-Schmidt, bmljb2xlLm1laW5lcnNlbi1zY2htaWR0QHVuaWJ3LmRl; Nike Walter, bmlrZS53YWx0ZXJAdWtyLmRl †These authors have contributed equally to this work ‡These authors share senior authorship Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher 94% of researchers rate our articles as excellent or goodLearn more about the work of our research integrity team to safeguard the quality of each article we publish image: The robotic metamaterial with a soliton and anti-soliton lying at the boundaries between left- and right-leaning sections of the chain Each blue rod is connected to its neighbours with pink elastic bands and a little motor under each rod makes the interactions between neighbouring rods non-reciprocal and talks like a particle… it may still not be a particle A topological soliton is a special type of wave or dislocation which behaves like a particle: it can move around but cannot spread out and disappear like you would expect from researchers from the University of Amsterdam demonstrate the atypical behaviour of topological solitons in a robotic metamaterial something which in the future may be used to control how robots move The unique features of topological solitons – that they can move around but always retain their shape and cannot suddenly disappear – are particularly interesting when combined with so-called non-reciprocal interactions an agent A reacts to an agent B differently to the way agent B reacts to agent A,” explains Jonas Veenstra a PhD student at the University of Amsterdam and first author of the new publication Veenstra continues: “Non-reciprocal interactions are commonplace in society and complex living systems but have long been overlooked by most physicists because they can only exist in a system out of equilibrium By introducing non-reciprocal interactions in materials we hope to blur the boundary between materials and machines and to create animate or lifelike materials.” The Machine Materials Laboratory where Veenstra does his research specialises in designing metamaterials: artificial materials and robotic systems that interact with their environment in a programmable fashion The research team decided to study the interplay between non-reciprocal interactions and topological solitons almost two years ago when then-students Anahita Sarvi and Chris Ventura Meinersen decided to follow up on their research project for the MSc course ‘Academic Skills for Research’ The soliton-hosting metamaterial developed by the researchers consists of a chain of rotating rods that are linked to each other by elastic bands - see the figure below Each rod is mounted on a little motor wich applies a small force to the rod depending on how it is oriented with respect to its neighbours the force applied depends on which side the neighbour is on making the interactions between neighbouring rods non-reciprocal magnets on the rods are attracted by magnets placed next to the chain in such a way that each rod has two preferred positions Solitons in this metamaterial are the locations where left- and right-rotated sections of the chain meet The complementary boundaries between right- and left-rotated chain sections are then so-called ‘anti-solitons’ This is analogous to kinks in an old-fashioned coiled telephone cord where clockwise and anticlockwise-rotating sections of the cord meet When the motors in the chain are turned off the solitons and anti-solitons can be manually pushed around in either direction once the motors – and thereby the reciprocal interactions – are turned on the solitons and anti-solitons automatically slide along the chain with a speed set by the anti-reciprocity imposed by the motors Veenstra: “A lot of research has focussed on moving topological solitons by applying external forces solitons and anti-solitons were found to naturally travel in opposite directions if you want to control the behaviour of (anti-)solitons you might want to drive them in the same direction We discovered that non-reciprocal interactions achieve exactly this The non-reciprocal forces are proportional to the rotation caused by the soliton such that each soliton generates its own driving force.” The movement of the solitons is similar to a chain of dominoes falling the non-reciprocal interactions ensure that the ‘toppling’ can only happen in one direction And while dominoes can only fall down once a soliton moving along the metamaterial simply sets up the chain for an anti-soliton to move through it in the same direction any number of alternating solitons and anti-solitons can move through the chain without the need to ‘reset’ Understanding the role of non-reciprocal driving will not only help us to better understand the behaviour of topological solitons in living systems but can also lead to technological advances The mechanism that generates the self-driving one-directional solitons uncovered in this study can be used to control the motion of different types of waves (known as waveguiding) or to endow a metamaterial with a basic information processing capability such as filtering Future robots can also use topological solitons for basic robotic functionalities such as movement sending out signals and sensing their surroundings These functionalities would then not be controlled from a central point but rather emerge from the sum of the robot’s active parts the domino effect of solitons in metamaterials may soon start to play a role in different branches of engineering and design Video: An endless domino effect (youtube.com) Non-reciprocal topological solitons in active metamaterials 10.1038/s41586-024-07097-6 Non-reciprocal topological solitons in active metamaterials are not responsible for the accuracy of news releases posted to EurekAlert by contributing institutions or for the use of any information through the EurekAlert system Copyright © 2025 by the American Association for the Advancement of Science (AAAS)