Stimulus Intensity Research Articles

A subset of human dermal fibroblasts overexpressing Cockayne syndrome group B protein resist UVB radiation-mediated premature senescence.

Ultraviolet B (UVB) radiation is a major contributor to skin photoaging. Although mainly absorbed by the epidermis, UVB photons managing to penetrate the upper dermis affect human dermal fibroblasts (HDFs), leading, among others, to the accumulation of senescent cells. Invitro studies have shown that repeated exposures to subcytotoxic UVB radiation doses provoke HDFs' premature senescence shortly after the end of the treatment period. Here, we found that repetitive exposures to non-cytotoxic UVB radiation doses after several days lead to mixed cultures, containing both senescent cells and fibroblasts resisting senescence. "Resistant" fibroblasts were more resilient to a novel intense UVB radiation stimulus. RNA-seq analysis revealed that ERCC6, encoding Cockayne syndrome group B (CSB) protein, is up-regulated in resistant HDFs compared to young and senescent cells. CSB was found to be a key molecule conferring protection toward UVB-induced cytotoxicity and senescence, as siRNA-mediated CSB loss-of-expression rendered HDFs significantly more susceptible to a high UVB radiation dose, while cells from a CSB-deficient patient were found to be more sensitive to UVB-mediated toxicity, as well as senescence. UVB-resistant HDFs remained normal (able to undergo replicative senescence) and non-tumorigenic. Even though they formed a distinct population in-between young and senescent cells, resistant HDFs retained numerous tissue-impairing characteristics of the senescence-associated secretory phenotype, including increased matrix metalloprotease activity and promotion of epidermoid tumor xenografts in immunodeficient mice. Collectively, here we describe a novel subpopulation of HDFs showing increased resistance to UVB-mediated premature senescence while retaining undesirable traits that may negatively affect skin homeostasis.

Artificial Photothermal Nociceptor Using Mott Oscillators.

Bioinspired sensory systems based on spike neural networks have received considerable attention in resolving high energy consumption and limited bandwidth in current sensory systems. To efficiently produce spike signals upon exposure to external stimuli, compact neuron devices are required for signal detection and their encoding into spikes in a single device. Herein, it is demonstrated that Mott oscillative spike neurons can integrate sensing and ceaseless spike generation in a compact form, which emulates the process of evoking photothermal sensing in the features of biological photothermal nociceptors. Interestingly, frequency-tunable and repetitive spikes are generated above the threshold value (Pth =84mWcm-2) as a characteristic of "threshold" in leaky-integrate-and-fire (LIF) neurons; the neuron devices successfully mimic a crucial feature of biological thermal nociceptors, including modulation of frequency coding and startup latency depending on the intensity of photothermal stimuli. Furthermore, Mott spike neurons are self-adapted after sensitization upon exposure to high-intensity electromagnetic radiation, which can replicate allodynia and hyperalgesia in a biological sensory system. Thus, this study presents a unique approach to capturing and encoding environmental source data into spikes, enabling efficient sensing of environmental sources for the application of adaptive sensory systems.

Correlated photoluminescence blinking phenomenon on InGaN/GaN nanopillar structures

Light-emitting devices that take advantage of the wide bandgap characteristics of InGaN/GaN are widely used in the industry. However, inhomogeneities have been reported in their photoluminescence (PL) mapping at the nanometer and submicrometer scale, even in samples of high crystal quality. In addition, a blinking phenomenon (time variation of PL intensity) under photoexcitation has been reported in relation to these inhomogeneities. The reason why this blinking phenomenon occurs is still unclear; it has been observed in quantum dots and other single and multilayer quantum well structures. Nevertheless, there are very few publications on nanopillar InGaN quantum well samples, which are the focus of this research. Here, we report and analyze the behavior of the blinking phenomena on a nanopillar sample. We noticed that the blinking of the pillars is somehow synchronized on a long timescale among several spatially separated nanopillars. We demonstrated that the synchronization is not due to random intensity fluctuations. We suggest instead that the synchronization is caused by a nonlinear response of the quantum wells to the UV source. In other words, when the stimulation intensity surpasses a certain value, it triggers an ON/OFF state switch in the PL of some of the pillars. Even if preliminary, our study helps to provide clues to understanding the mechanism of the occurrence of the blink phenomenon.

Does persistent crossover (ipsilateral) motor evoked potential (MEP) responses represent a technical failure for intracranial motor tract monitoring? A case example and practical solution.

Attention to motor evoked potential (MEP) stimulation intensity is necessary to avoid false negative MEP results during intracranial procedures. Observing ipsilateral (crossover) MEP responses has been hypothesized to indicate inappropriately strong stimulation intensity. We describe a case where persistent crossover MEP responses falsely suggested that stimulus intensity was too high and describe an alternative method to guide the selection of MEP stimulation intensity. A patient undergoing a suboccipital craniotomy for tumor resection had bilateral transcranial electrical MEP monitoring under total intravenous anesthesia. MEP results were obtained from left and right hand using C4-Cz and C3-Cz stimulation montages respectively. Selection of an appropriately superficial stimulus intensity was guided using MEP onset latencies. MEP acquisition proceeded normally for contralateral left hand (C4-Cz montage). However, using the C3-Cz montage, persistent crossover responses were noted at stimulation intensities as low as threshold for contralateral right hand MEP (94V/166mA). Appropriate MEP stimulus intensity for subsequent monitoring (approximately 96V/172mA) was determined utilizing onset latency measurements from contralateral hand MEP responses. The stimulus intensity chosen was predicated on onset latency being ≥ 2 ms longer than latency at maximal stimulus level (shortest latency). A stimulus intensity-latency plot was generated offline to illustrate this important relationship for intracranial MEP use. MEP acquisition proceeded without incident and gross total resection was achieved without postoperative motor deficits. Despite crossover appearance contralateral hand MEP were quantitatively validated for intraoperative application using onset latency guidance.

Impact of different muscle lengthening amplitudes combined with electrical nerve stimulation on torque production.

This study investigated torque production resulting from the combined application wide-pulse neuromuscular electrical stimulation (NMES), delivered over the posterior tibial nerve, and muscle lengthening at two distinct amplitudes. Wide-pulse NMES (pulse duration: 1ms; stimulation intensity: 5 - 10% of maximal voluntary contraction) was delivered at both low (20 Hz) and high (100 Hz) stimulation frequencies, either alone (NMES condition) or combined with a muscle lengthening at two amplitudes (10 or 20° ankle joint rotation; NMES+LEN10 and NMES+LEN20 conditions, respectively). For each frequency, the torque-time integral (TTI) and the muscle activity following the cessation of stimulation trains (sustained EMG activity) were calculated. At 20 Hz, TTI was higher (P=0.007) during NMES+LEN10 (233.2 ± 101.5 Nm.s) and NMES+LEN20 (229.2 ± 92.1 Nm.s) than during the NMES condition (187.5 ± 74.5 Nm.s), without any change in sustained EMG activity (P=0.54). At 100 Hz, TTI was higher (P=0.038) during NMES+LEN10 (226.6 ± 115.3 Nm.s) than during NMES+LEN20 (180.6 ± 84.0 Nm.s) and NMES (173.9 ± 94.9 Nm.s). This torque enhancement was accompanied by a higher sustained EMG activity (P=0.045) in the NMES+LEN10 condition. These findings show that, for low-frequency NMES, significant torque increases were observed with both a 10- or a 20-degree lengthening amplitude, probably linked to increased afferents' activation. In contrast, with high-frequency NMES, a significant TTI enhancement was observed only with the 10-degree amplitude, accompanied by increased sustained EMG activity, suggesting neural mechanisms' involvement. When a greater lengthening amplitude was superimposed during high-frequency NMES, these mechanisms were probably inhibited, precluding torque enhancement.

Multisensory integration enhances audiovisual responses in the Mauthner cell.

Multisensory integration (MSI) combines information from multiple sensory modalities to create a coherent perception of the world. In contexts where sensory information is limited or equivocal, it also allows animals to integrate individually ambiguous stimuli into a clearer or more accurate percept and, thus, react with a more adaptive behavioral response. Although responses to multisensory stimuli have been described at the neuronal and behavioral levels, a causal or direct link between these two is still missing. In this study, we studied the integration of audiovisual inputs in the Mauthner cell, a command neuron necessary and sufficient to trigger a stereotypical escape response in fish. We performed intracellular recordings in adult goldfish while presenting a diverse range of stimuli to determine which stimulus properties affect their integration. Our results show that stimulus modality, intensity, temporal structure, and interstimulus delay affect input summation. Mechanistically, we found that the distinct decay dynamics of FFI triggered by auditory and visual stimuli can account for certain aspects of input integration. Altogether, this is a rare example of the characterization of MSI in a cell with clear behavioral relevance, providing both phenomenological and mechanistic insights into how MSI depends on stimulus properties.

NMR-Based Investigation of Pore–Fracture Structure Heterogeneity in Deep Coals of Different Macrolithotypes in the Daning-Jixian Block, Ordos Basin

Deep coalbed methane (CBM) demonstrates significant production potential, and a fervent exploration and development boom is currently underway in China. The permeability of coal reservoirs is heavily influenced by pore–fracture structure heterogeneity. Some researches have been conducted on deep coals’ pore–fracture structure; however, these studies mostly consider coal as a homogeneous material, neglecting the heterogeneity of the macrolithotypes within the coal. In this study, 33 deep coals with burial depths of more than 2000 m were obtained from the Daning-Jixian block of the Ordos Basin, covering all macrolithotypes: bright coal (BC), semi-bright coal (SBC), semi-dull coal (SDC), and dull coal (DC). These samples were subjected to three sets of NMR tests in dry, fully saturated, and irreducible water conditions, with the pore–fracture structure characteristics being analyzed. The results demonstrate that the sampled deep coals’ pore–fracture structure is highly heterogeneous, with transitional pores being dominant, followed by mesopores, “macropores and fractures”, and micropores. The NMR T2C ranges from 0.61 to 2.44 ms, with an average of 1.19 ms; a higher T2C value indicates more developed micropores. The ranges for producible water porosity (φpr) and producible water saturation (Spr) are 0.31–7.24% (avg. 2.42%) and 6.97–71.47% (avg. 31.06%), respectively. Both of them exhibit a high positive correlation with the total volumes of “macropores and fractures” and mesopores. Compared to SDC and DC, the BC and SBC, especially the former, overall contain more “macropores and fractures” and mesopores, fewer transitional pores and micropores, and higher φpr and Spr. These findings suggest that regions with abundant BC and SBC should be prioritized during deep CBM exploration and production due to the inherently superior permeability and gas extraction potential of BC and SBC, and these coals are likely to require less intensive stimulation to achieve higher recovery rates and could provide more sustainable gas production over time.

Radiation of pain: psychophysical evidence for a population coding mechanism in humans.

The spread of pain across body locations remains poorly understood but may provide important insights into the encoding of sensory features of noxious stimuli by populations of neurons. In this psychophysical experiment, we hypothesized that more intense noxious stimuli would lead to spread of pain, but more intense light stimuli would not produce perceptual radiation. Fifty healthy volunteers (27 females, 23 males, ages 14-44 years) participated in this study wherein noxious stimuli (43, 45, 47, and 49°C) were applied to glabrous (hand) and hairy skin (forearm) skin with 5-second and 10-second durations. Also, visual stimuli displayed on the target bodily area were used as a control. Participants provided pain (and light) spatial extent ratings as well as pain (and light) intensity ratings. In the extent rating procedure, participants adjusted the extent of the square displayed on the screen with the extent of pain (or light) that they experienced. Pain extent ratings showed statistically significant radiation of pain indicated by 12.42× greater spatial spread of pain (pain extent) than the area of the stimulation with 49°C (P < 0.001), in contrast to visual ratings, which closely approximated the size of the stimulus (1.22×). Pain radiation was more pronounced in hairy than glabrous skin (P < 0.05) and was more pronounced with longer stimulus duration (P < 0.001). Pain intensity explained only 14% of the pain radiation variability. The relative independence of the pain radiation from pain intensity indicates that distinct components of population coding mechanisms may be involved in the spatial representation of pain vs intensity coding.

Immediate Effects of Distinct Intensities of Transcutaneous Spinal Direct Current Stimulation on Chronic Pain: A Randomized Controlled Trial

This study aimed to assess the immediate effects of transcutaneous spinal direct current stimulation (tsDCS) on pain outcomes, measured using the visual analog scale (VAS) and pressure pain thresholds in a cohort of 55 participants experiencing chronic pain using a controlled, randomized trial with 55 participants allocated into 2 groups: 2 mA and 0.5 mA of tsDCS for 20 min. Anodal stimulation was applied on the 12th thoracic vertebra, with the cathode positioned on the 7th cervical vertebra. Pain outcomes were assessed before and post intervention using the VAS and pressure algometry. Between- and within-group differences, along with chi-square tests, were used to determine the differences and responsiveness. Significance was established at p &lt; 0.05. Findings showed significant temporal effects for both VAS (p &lt; 0.001) and pressure algometry (p = 0.04). However, no between-group differences were noted for the time × group factor for VAS (p = 0.46) and pressure algometry (p = 0.78). No significant between-group differences were observed for the responsiveness analysis. The results indicate that a single 20-min session of 2 and 0.5 mA tsDCS improves pain scores for both intensities equally. However, there were no statistically significant between-group differences in pain perception or pressure pain threshold.

Calibrating position and orientation of multiple ultrasound phased array units using Bayesian optimization.

Airborne ultrasound phased arrays (AUPAs) generate non-contact tactile sensations and enable acoustic levitation with specific focus fields. Using multiple units together offers numerous advantages, such as increased stimulus intensity and the ability to overcome occlusion. The AUPA units are typically mounted on a fixed frame, with their poses manually measured using tools such as a ruler for calibration. However, to increase the degrees of freedom for these units, a more flexible calibration method is required. With a wavelength of 8.5 mm, a 4 mm deviation in propagation distance from the two phased arrays can weaken the pressure at the focus position. Hence, in this study, calibration based on pose and focus information obtained through image processing was performed. First, augmented reality markers are attached to each AUPA unit for rough estimation of pose parameters. Second, using these approximate poses, the pressure distribution generated on a specific plane is estimated through thermal imaging. Finally, Bayesian optimization is employed to efficiently explore the pose parameters to minimize the error between the desired position and generated focal point. This approach enables the efficient calibration of the relative poses of AUPA units, even when they are placed in challenging-to-measure locations.

Responses to the activation of different intranasal trigeminal receptors: Evidence from behavioral, peripheral and central levels

AimThere are various receptors that mediate intranasal trigeminal sensations. However, few studies compare the response patterns across different receptor activations. MethodsWe recorded negative mucosal potentials (NMPs) in 24 healthy participants and event-related potentials (ERPs) in 17 participants during exposure to five odors that trigger trigeminal sensations and one olfactory stimulus. Additionally, 10 participants completed a continuous odor intensity rating task. ResultsWe observed a significant effect of odor type on NMP amplitudes (F=13.51 to 21.88, p’s<0.01), with cyclohexanone (TRPV1) and CO2 (TRPV1+A1) inducing greater N1 and/or P1N1 amplitudes than other stimuli (t=3.28 to 7.54, p’s<0.05). Similar differences were seen in ERP amplitudes (F=3.69 to 12.25, p’s<0.05), with cyclohexanone showing greater P2 and/or N1P2 amplitudes than PEA (odorant), carvacrol (TRPV3+A1), and perillaldehyde (TRPA1) (t=3.13 to 4.10, p’s<0.05). CO2 also produced greater amplitudes than carvacrol (t=3.53 to 4.42, p’s<0.05). In the odor intensity rating task, cyclohexanone, CO2, and isopulegol (TRPM8+TRPA1) had higher peak ratings, steeper slopes, and/or shorter latencies (F=6.15 to 13.86, p’s<0.01; t=3.14 to 7.76, p’s<0.05). ConclusionsActivation of different intranasal trigeminal receptors yields varied responses. Notably, stimuli involving TRPV1 activation, linked to irritation or pain, elicited stronger behavioral and neural activity compared to stimuli involving other receptors, even when controlling for rated stimulus intensity. This emphasizes TRPV1’s significance in survival adaptation. Future studies should test different sets of stimulants to verify the robustness of these findings.

Genetic machinery which accompanies metaplasticity operates differentially in experimental model of autism

AbstractThe present study investigated metaplasticity‐related mRNA expressions in valproic acid (VPA)‐rats, focusing on the PI3K/AKT pathway. Wistar dams were treated with a single intraperitoneal injection of 600 mg/kg VPA or saline on embryonic day E12.5 or an equal volume of saline solution. Three behavioral tests were conducted on these males' offspring: grid‐walking test, negative geotaxis test, and three‐chamber social interaction test. Metaplasticity was induced in 60‐day‐old male progeny by giving high‐frequency stimulation for 5 minutes following low‐frequency stimulation to the perforant pathway. For the baseline stimulation protocol (n = 6), stimulation was delivered to the dentate gyrus at the previously determined stimulation intensity (0.33 Hz 0.175 msec 30 s) for 75 min. The percent change of slope of field excitatory postsynaptic potential (fEPSP) and amplitude of population spike were calculated 55–60 min after induction protocol. The mRNA levels of PI3K, PTEN, AKT, GSK‐3β, and MAPT were measured in the hippocampus by using quantitative rt‐PCR. We found that offspring of VPA‐treated rats showed significantly impaired sensorimotor coordination, decreased sociability, impaired preference for social novelty, and reduced input–output curve of fEPSP slope, compared to control animals. Despite a similar metaplastic response, mRNA levels of genes of interest were similar but considerably down‐regulated after induction in offspring of VPA‐treated dams. Our study provides evidence that the induced expression of autism‐related genes has evolved to enable an adaptation mechanism during metaplastic control of long‐term potentiation.

A PHENOMENOLOGICAL INVESTIGATION OF EARTHQUAKE EXPERIENCES: THE CASE OF THE FEBRUARY 6, 2023 MARAŞ EARTHQUAKE

This study investigates the experiences of individuals who survived the Maraş earthquake on February 6, 2023, employing a phenomenological approach to examine the multifaceted effects of the disaster. Structured interviews were conducted with 16 participants (eight women and eight men) who relocated to Bolu temporarily or permanently following the earthquake. As one of Turkey's most catastrophic seismic events, it has resulted in significant physical destruction and profound psychological and social ramifications. The majority of survivors perceived the earthquake as a form of "punishment" or "warning," interpreting it through scientific, religious, and conspiratorial frameworks. They experienced intense fear, helplessness, guilt, and a sense of victimization, recounting the event as a combination of intense auditory stimuli, darkness, cold, and mortality. The earthquake significantly altered their perspective on life, leading to increased maturity, religiosity, and heightened awareness regarding the transience of existence. Social relationships were also affected by the earthquake, with some survivors withdrawing from relatives and close acquaintances, while others formed stronger interpersonal bonds. This study underscores the complex nature of the earthquake experience, emphasizing that survivors' needs extend beyond physical reconstruction to encompass psychological, social, and economic support. Limitations include the small sample size and the geographic focus on the province of Bolu. Future research should expand to larger, more diverse populations, and consider the long-term effects of such traumatic events. These findings are critical for developing effective post-earthquake interventions and support strategies that address the comprehensive needs of survivors.

No enhancement of vestibular stimulation on visual working memory for actions

Holding and processing actions in visual working memory (VWM) is crucial for daily functioning, but it is capacity-limited. The vestibular system, which is activated by both vestibular signals and visual gravitational motion, may be involved in this cognitive process. Past research indicates that galvanic vestibular stimulation (GVS) is a non-invasive technique that can enhance motor functions and various cognitive functions. However, the impact of GVS on VWM for actions has not been explored. This study addresses this gap by investigating whether GVS can improve VWM capacity for both upright and inverted actions. Using a virtual reality platform, we assessed VWM capacity in a change detection task, applying either STIM-current (0.8 mA) or SHAM-current (0 mA) GVS. The results showed no significant effect of GVS on VWM for either upright or inverted actions, at least for non-noisy GVS with stimulation intensity below cutaneous threshold. Despite the absence of significant effects, this study provides valuable insights into the interactions between the vestibular system and cognitive processes, laying the groundwork for future research on GVS applications in cognitive enhancement.

Posterior Tibial Nerve Stimulation Effect on Treatment of Overactive Bladder: A Systematic Review and Meta-analysis

Context: Overactive bladder (OAB) is a symptomatic syndrome indicative of lower urinary tract dysfunction. Current treatments for OAB syndrome include behavioral therapy, pharmacotherapy, minimally invasive procedures like sacral nerve stimulation and tibial nerve stimulation, as well as surgical options. Objectives: This systematic review aimed to evaluate the effectiveness of posterior tibial nerve stimulation (PTNS) as a treatment for OAB syndrome and to identify potentially effective stimulation methods. Evidence Acquisition: A systematic search was conducted using PubMed, Scopus, ProQuest, Web of Science, Google Scholar, and The Cochrane Library databases for predefined keywords. Two independent reviewers screened the studies’ titles, abstracts, and full texts. The quality of the studies was assessed using the JBI risk of bias (RoB) checklists. Studies meeting the inclusion criteria were summarized in an extraction table. Meta-analysis was performed using Review Manager Software. Results: Out of 2,282 studies identified, 63 were included in the data extraction table, and 19 of these were included in the meta-analysis to compare the effect of PTNS based on the number of treatment sessions (less than 12 sessions vs. 12 - 24 sessions). Despite heterogeneity among the studies, results showed a significant reduction in voiding frequency post-intervention (95% confidence interval, -4.25 to -1.48, P &lt; 0.0001, Z = 4.06), with a greater reduction in the 12 - 24 sessions group (chi2 = 8.40, df = 1 (P &lt; 0.004); I2 = 88.1%). Additionally, specific electrode placement methods further reduced voiding frequency after PTNS. Conclusions: Posterior tibial nerve stimulation can reduce voiding frequency in patients with OAB and painful bladder syndrome. However, establishing a standard PTNS method remains challenging due to variations among studies and the absence of control groups in many cases. Based on the results, PTNS with a frequency of 20 Hz, pulse duration of 200 µs, and stimulation intensity at the pain threshold appears effective for both transcutaneous and percutaneous techniques over 12 - 24 sessions. The percutaneous method may be more effective than the transcutaneous method.

Corticospinal excitability and voluntary activation of the quadriceps muscle is not affected by a single session of anodal transcutaneous spinal direct current stimulation in healthy, young adults.

The aim of the present study was to determine if anodal transcutaneous spinal direct current stimulation (tsDCS) affects corticospinal excitability (CSE) and voluntary activation (VA) of the quadriceps femoris muscle (QM). This was a double-blind, randomized study in which spine-shoulder anodal tsDCS (active electrode centered over T11-12, 2.5mA, 20 min) was applied in a seated position. Transcranial magnetic stimulation (TMS) was used to measure motor evoked potentials (MEP) and construct stimulus-response curves in healthy participants (eight females and five males, Experiment 1). VA was measured via the interpolated twitch technique, whereby muscle twitches were evoked using electrical femoral nerve stimulation and TMS (seven females and six males, Experiment 2). Measurements were carried out before, directly, and 30 min after sham and anodal tsDCS (with ≥4days between sessions). There was no interaction between stimulation × time on stimulus-response curve expressed by slope, stimulus intensity corresponding to 50% of the maximal MEP, and peak-to-peak amplitude of the maximal MEP. Maximal voluntary isometric contraction (MVIC) torque did not change and VA was not affected regardless of the QM torque level (25, 50, or 100% of MVIC). A single, twenty-minute session of spine-shoulder anodal tsDCS did not increase CSE and VA of QM during submaximal and maximal contraction. This suggests that neither excitability to a known input nor responsiveness of motoneurons to submaximal and maximal cortical drive were affected by anodal tsDCS.

Interaction of Sensitivity, Emotions, and Motivations During Visual Perception.

When an organism is exposed to environmental stimuli of varying intensity, the adaptive changes in the CNS can be explained by several conceptual provisions: the law of motivation-activation by Yerkes and Dodson, the laws of force and pessimal protective inhibition, and the theory of emotion activation. Later, reinforcement sensitivity theory was developed in the fields of psychology and psychophysics. At the same time, cortical prepulse inhibition (PPI), the prepulse inhibition of perceived stimulus intensity (PPIPSI), and the augmentation/reduction phenomenon were proposed in sensory neurophysiology, which expanded our understanding of consciousness. The aim of this study was to identify markers of levels of activity of cognitive processes under normal and in psychopathological conditions while amplifying the information stimulus. For this purpose, we changed the contrast level of reversible checkerboard patterns and mapped the visual evoked potentials (VEPs) in 19 monopolar channels among 52 healthy subjects and 39 patients with a mental illness without an active productive pathology. Their cognitive functions were assessed by presenting visual tests to assess invariant pattern recognition, short-term visual memory, and Gestalt perception. The personalities of the healthy subjects were assessed according to Cattell's 16-factor questionnaire, linking the data from neurophysiological and cognitive studies to factors Q4 (relaxation/tension) and C (emotional stability). According to the N70 and N150 VEP waves, the healthy subjects and the patients were divided into two groups. In some, there was a direct relationship between VEP amplitude and contrast intensity (21 patients and 29 healthy persons), while in the others, there was an inverse relationship, with a reduction in VEP amplitude (18 patients and 23 healthy persons). The relationship and mechanisms of subjects' cognitive abilities and personality traits are discussed based on the data acquired from the responses to information stimuli of varied intensity.

Spatiotemporal integration of contextual and sensory information within the cortical hierarchy in human pain experience.

Pain is not a mere reflection of noxious input. Rather, it is constructed through the dynamic integration of current predictions with incoming sensory input. However, the temporal dynamics of the behavioral and neural processes underpinning this integration remain elusive. In the current study involving 59 human participants, we identified a series of brain mediators that integrated cue-induced expectations with noxious inputs into ongoing pain predictions using a semicircular scale designed to capture rating trajectories. Temporal mediation analysis revealed that during the early-to-mid stages of integration, the frontoparietal and dorsal attention network regions, such as the lateral prefrontal, premotor, and parietal cortex, mediated the cue effects. Conversely, during the mid-to-late stages of integration, the somatomotor network regions mediated the effects of stimulus intensity, suggesting that the integration occurs along the cortical hierarchy from the association to sensorimotor brain systems. Our findings advance the understanding of how the brain integrates contextual and sensory information into pain experience over time.

Visual Piezoresistive Dual‐Response Sensor Based on CaZnOS: Mn Mechanoluminescence Materials

AbstractThe ability to achieve real‐time movement visualization in piezoresistive sensors remains a challenge. A visual piezoresistive sensor to perceive the intensity of mechanical stimuli and visible spatial location information is designed based on the mechanoluminescence material CaZnOS: Mn. The linearity, detection range, sensitivity, and stability of the sensor are tested, and the sensing mechanism of the sensor is discussed, and the relationship between force, resistance, and light intensity is established. A 5 × 5 sensor array is prepared to realize the visual detection of dynamic force trajectory, and combined with a convolutional neural network and random forest algorithm, the human writing number and pressure characteristics are recognized, and the writing path and handwriting of the robot arm are controlled by multi‐feature input. The experimental results show that the machine learning algorithm is very reliable with an accuracy of 98.33% for digit recognition and 97.21% for identity recognition. The visual piezoresistive pressure sensor provides a new idea for the visualization of flexible pressure and promotes the development of flexible sensors towards integration and intelligence.

Temporal summation of pain in sickle cell disease: comparison of adolescents and young adults with chronic vs. infrequent pain.

This study examined the role of central sensitization in the experience of pain among adolescents and young adults with the most severe genotypes of sickle cell disease (SCD). We hypothesized that adolescents and young adults with chronic SCD pain would demonstrate a higher perceptual response to repeated stimulation of identical intensity (i.e., temporal summation of pain, TSP) compared to counterparts with infrequent pain. We also examined psychological risk factors that can impact pain sensitivity. Patients ages 12-21 years, diagnosed with SCD type Hb SS or Hb S Beta0Thalasemia, who reported infrequent pain (≤2 pain days/month; n = 25) or met AAPT criteria for chronic SCD pain (n = 25) were enrolled. Patients were age- and sex-matched, with similar proportions receiving chronic blood transfusion and hydroxyurea. Patients completed static quantitative sensory testing (QST) and dynamic TSP testing to assess pain sensitivity. Patients and a caregiver completed demographic and psychological measures (depression, anxiety, pain interference, pain catastrophizing). Simple slope analysis revealed differentially elevated heat TSP among adolescents and young adults with chronic SCD pain (b = 3.14, p = .002) but not those with infrequent pain (b = 0.45, p = .61). Faster habituation was further observed for those with chronic compared to infrequent pain. Adolescents and young adults with chronic pain reported more frequent depression, anxiety, and pain interference symptoms; however, psychological symptoms and pain catastrophizing were not associated with QST or TSP (ps >.17). Current results demonstrate that a well-established, prognostic, QST risk marker (i.e., TSP) may distinguish chronic from infrequent pain subgroups of adolescents and young adults with SCD.