Reaction Latency Research Articles

Measuring and Predicting Multisensory Reaction Latency: A Probabilistic Model for Visual-Auditory Integration.

Virtual/augmented reality (VR/AR) devices offer both immersive imagery and sound. With those wide-field cues, we can simultaneously acquire and process visual and auditory signals to quickly identify objects, make decisions, and take action. While vision often takes precedence in perception, our visual sensitivity degrades in the periphery. In contrast, auditory sensitivity can exhibit an opposite trend due to the elevated interaural time difference. What occurs when these senses are simultaneously integrated, as is common in VR applications such as 360° video watching and immersive gaming? We present a computational and probabilistic model to predict VR users' reaction latency to visual-auditory multisensory targets. To this aim, we first conducted a psychophysical experiment in VR to measure the reaction latency by tracking the onset of eye movements. Experiments with numerical metrics and user studies with naturalistic scenarios showcase the model's accuracy and generalizability. Lastly, we discuss the potential applications, such as measuring the sufficiency of target appearance duration in immersive video playback, and suggesting the optimal spatial layouts for AR interface design.

Comparison of Cognitive Functions Between Individuals With Chronic Low Back Pain With High and Low Pain Catastrophizing and Pain-free Controls: A Cross-sectional Study.

Researchers suggested that the interruptive effects of chronic pain on cognitive functions may be modulated by the level of pain catastrophizing (PC). However, in individuals with chronic low back pain (CLBP), domains of cognitive function that may be affected by the level of PC remain largely unclear. Therefore, this study aimed to compare cognitive functions between individuals with CLBP with high and low PC and pain-free controls. This cross-sectional study examined cognitive functions of 42 individuals with CLBP and 21 pain-free controls. The PC scale was used to stratify participants with CLBP into high and low PC. Participants performed 5 cognitive tests from the Cambridge Neuropsychological Test Automated Battery, namely 5-choice reaction time, rapid visual processing, spatial working memory, attention switching task, and stop signal task. The statistical analyses revealed that compared with individuals with CLBP with low PC and pain-free controls, individuals with high PC demonstrated greater values of the between errors ( P =0.01), reaction latency ( P <0.001), and stop signal reaction time variables ( P =0.004, 0.003, respectively) but lower values of probability of hit ( P =0.02, 0.01, respectively), A' ( P =0.01, <0.001, respectively), and percent correct trials variables ( P =0.002, <0.001, respectively). The results of the current study showed deficits in sustained attention, working memory, cognitive flexibility, and inhibitory control in individuals with CLBP with high PC. From a clinical perspective, therapeutic interventions targeting PC should be considered to decrease catastrophic thinking about pain in individuals with CLBP. Additional research is warranted to explore cognitive functioning as an outcome of these interventions in individuals with CLBP.

Assessing the influence of latency variability on EEG classifiers - a case study of face repetition priming

Data-driven strategies have been widely used to distinguish experimental effects on single-trial EEG signals. However, how latency variability, such as within-condition jitter or latency shifts between conditions, affects the performance of EEG classifiers has not been well investigated. Without explicitly considering and disentangling such attributes of single trials, neural network-based classifiers have limitations in measuring their contributions. Inspired by domain knowledge of subcomponent latency and amplitude from traditional cognitive neuroscience, this study applies a stepwise latency correction method on single trials to control for their contributions to classifier behavior. As a case study demonstrating the value of this method, we measure repetition priming effects of faces, which induce large reaction time differences, latency shifts, and amplitude effects in averaged event-related potentials. The results show that within-condition jitter negatively impacts classifier performance, but between-condition latency shifts improve accuracy, whereas genuine amplitude differences have no significant influence. While demonstrated in the case of priming effects, this methodology can be generalized to experiments involving many kinds of time-varying signals to account for the contributions of latency variability to classifier performance.

Dimensions of Alexithymia and Identification of Emotions in Masked and Unmasked Faces.

Alexithymia, a multifaceted personality construct, is known to be related to difficulties in the decoding of emotional facial expressions, especially in case of suboptimal stimuli. The present study investigated whether and which facets of alexithymia are related to impairments in the recognition of emotions in faces with face masks. Accuracy and speed of emotion recognition were examined in a block of faces with and a block of faces without face masks in a sample of 102 healthy individuals. The order of blocks varied between participants. Emotions were recognized better and faster in unmasked than in masked faces. Recognition performance was worst and slowest for participants starting the task with masked faces. In the whole sample, there were no correlations of alexithymia facets with accuracy and speed of emotion recognition for masked and unmasked faces. In participants starting the task with masked faces, the facet externally oriented thinking was positively correlated with reaction latencies of correct responses for masked faces. Our findings indicate that an externally oriented thinking style could be linked to a less efficient identification of emotions from faces wearing masks when task difficulty is high and support the utility of a facet approach in alexithymia research.

Long-term effects of an egg-protein hydrolysate on cognitive performance and brain vascular function: a double-blind randomized controlled trial in adults with elevated subjective cognitive failures

PurposeShort-term intake of the egg-protein hydrolysate Newtricious (NWT)-03 improved executive function, but underlying mechanisms and long-term effects, including other cognitive domains, are unknown.MethodsA 36-week randomized controlled trial involving 44 overweight/obese individuals experiencing elevated Subjective Cognitive Failures (SCF; aged 60–75 years) assessed the impact of daily consumption of 5.7 g of NWT-03 or placebo powders on cognitive performance (psychomotor speed, executive function, memory) and Cerebral Blood Flow (CBF), a marker of brain vascular function. Cognitive performance was evaluated using a neurophysiological test battery (CANTAB) and CBF was measured using magnetic resonance imaging perfusion method Arterial Spin Labeling (ASL). Serum samples were collected to determine brain-derived neurotrophic factor (BDNF) concentrations.ResultsAnthropometrics, and energy and nutrient intakes remained stable throughout the trial. NWT-03 was well tolerated, and compliance was excellent (median: 99%; range: 87–103%). No overall intervention effects were observed on cognitive performance or CBF, but post-hoc analyses revealed significant improvements on executive function in women, but not men. Specifically, a reduction of 74 ms in reaction latency on the multitasking task (95% CI: −134 to −15; p = 0.02), a reduction of 9 between errors (95%CI: −14 to −3; p < 0.001), and a reduction of 9 total errors (95%CI: −15 to −3; p < 0.001) on the spatial working memory task were found in women. No intervention effects were observed on serum BDNF concentrations (p = 0.31).ConclusionLong-term consumption of NWT-03 improved multitasking abilities and working memory in women with elevated SCF. Brain vascular function remained unaffected. Sex differences in executive function require additional clarification.

Gambaran Regulasi Emosi Pada Santri Baru Di Pondok Pesantren Mamba’ul Ushulil Hikmah Kembaran Banyumas

Background: Emotion regulation is an extrinsic and intrinsic process that is responsible for monitoring, evaluating, modifying emotional reactions, and intensively and specifically to achieve goals. Emotion regulation includes changes in the quality, intensity, duration and latency of emotional reactions and expressions in the process of adaptation. Objective: To understand the description of emotional regulation in new students at the Mamba'ul Uhulil Hikmah Islamic Boarding School. Research Method: The research carried out was quantitative research with a descriptive design. The approach used during the research was cross sectional. The population is new students at the Mamba'ul Ushulil Hikmah Islamic Boarding School. The number of new students at the Mamba'ul Ushulil Hikmah Islamic Boarding School in May 2023 is 54 students. The collection technique uses Total Sampling. The research instrument uses a questionnaire whose results are processed using univariate tests. Research Results: The characteristics of respondents based on gender are mostly female (55.6%). The education level of most is junior high school (66.7%). Emotional regulation in new students at the Mamba'ul Ushulil Hikmah Islamic Boarding School is mostly in the good emotional regulation category (64.8%)

An aqueous Commiphora myrrha extract ameliorates paclitaxel-induced peripheral neuropathic pain in mice.

Background: Chemotherapy-induced neuropathic pain (CINP) is a debilitating side effect in individuals undergoing cancer treatment. Treatment of CINP with the current available classes of drugs is limited and often yields unsatisfactory results. Finding therapeutic alternatives of plant origin could provide a new way for the management of CINP. Commiphora myrrha (CM) resin extract has been reported to have anti-inflammatory and analgesic activities, but the effect of CM on neuropathic pain is yet to be investigated in CINP. Objectives: The aim of this study was to investigate the antinociceptive effect of CM extract in a mouse model of paclitaxel-induced neuropathic pain (PINP). Methods: The effects of CM on thermal hyperalgesia and mechanical allodynia were assessed in female BALB/c mice with PINP using a hot plate and a plantar aesthesiometer, respectively. Motor coordination was evaluated using a rotarod apparatus. The involvement of transient receptor potential vanilloid channel 1 (TRPV1) in CM actions was investigated using a capsaicin (a TRPV1 agonist)-induced nociception test. The genetic expression of Trpv1, Nrf2, Sod2, and Hmox1 was assessed using real-time PCR, while protein expression of TRPV1, Iba-1, and CD11b was assessed using Wes™. Results: Administration of CM to mice with established PINP produced a dose-dependent reduction in thermal hyperalgesia. Prophylactic treatment of mice with CM prevented the development of paclitaxel-induced thermal hyperalgesia and mechanical allodynia. CM did not change the motor coordination of mice, as the reaction latency and the rotational velocity of animals pretreated with CM extract were similar to those of animals pretreated with vehicle. CM significantly decreased the number and duration of the flick responses following capsaicin injection into the dorsal surface of the hind paw of mice. The protein expression of TRPV1 was upregulated in the spinal cord of paclitaxel-treated animals compared to vehicle-only-treated control animals, while CM-treated animals had values similar to vehicle-only-treated control animals. The mRNA expression of Nrf2, a major antioxidant transcription factor, was upregulated in the paw skin of mice treated with CM compared to those treated with paclitaxel alone. Conclusion: These results indicate that CM may both treat established and prevent the development of paclitaxel-induced thermal hyperalgesia and mechanical allodynia without any impairment in the motor activity of mice. CM may mediate its action through the peripheral inhibition of TRPV1 channel activity, restoration of normal TRPV1 protein expression in the spinal cord, and elevation of cellular antioxidant defenses. CM has the potential to be used as a therapeutic alternative to treat CINP.

Acceptance and commitment training for reducing burnout in medical students during a clinical clerkship in psychiatry and palliative care: A pilot study

Physicians are likely to experience burnout early in their medical education, and it only accelerates as their clinical and academic responsibilities expand and they begin clinical practice. However, effective burnout interventions for clinical-year medical students are lacking. Avoidance of unpleasant internal experiences and decreased engagement in value-based behaviors are associated with burnout. This study, an open-label pilot research with a single-center, before-and-after comparative study design and without a control group, aimed to examine the feasibility and effectiveness of brief acceptance and commitment training (ACT) in reducing burnout during psychiatric clinical clerkships at a medical school. The feasibility proved to be good, with all the participants (n = 56) completing the training. There were no significant differences in the emotional exhaustion (EE) and depersonalization (DP) scores of burnout as measured by the Maslach Burnout Inventory (MBI) at the end of the ACT and two months following the intervention. A comparison was made with scores recorded before the intervention, and significant differences were observed. A subsample of medical students with moderate or greater burnout at T0 manifested significant burnout score reductions. The same subsample revealed a significant increase in psychological flexibility as indicated by the progress factor score on the Valuing Questionnaire (VQ) at T1 compared to T0 and a significant reduction in reaction latency to negative words as indicated by the DIRAP score of the Implicit Relational Assessment Procedure (IRAP) for anxiety. We argue that short-term ACT during clinical clerkships of medical students in psychiatry and palliative care is feasible and potentially effective, and a multi-site comparative study using more direct behavioral measures is warranted to further investigate its effectiveness.

Differences in Neurocognitive Functions Between Healthy Controls and Anterior Cruciate Ligament-Reconstructed Male Athletes Who Passed or Failed Return to Sport Criteria: A Preliminary Study.

Only 55% of anterior cruciate ligament-reconstructed (ACLR) athletes return to competitive sports. This brings into question the usefulness of current return to sport (RTS) criteria. High cognitive demand of sport environment clarifies the value of incorporating neurocognitive tests when making decisions regarding the time of RTS. This preliminary study aimed to compare the neurocognitive functions between healthy controls and ACLR male athletes who passed or failed RTS criteria. A total of 45 male football players, including 15 ACLR who passed RTS criteria, 15 ACLR who did not pass, and 15 healthy controls participated in this cross-sectional study. The Cambridge Neuropsychological Test Automated Battery was used to measure a battery of neurocognitive tasks, including speed of response, sustained attention, working memory, cognitive flexibility, and response inhibition. The results revealed that compared with both the ACLR-passed and healthy groups, the ACLR-failed group showed greater values of 5-choice movement time (P = .02, P = .01, respectively) but lower values of stop signal reaction time (P = .03, P = .001, respectively) and proportion of successful stops variables (P = .02). In addition, compared with the healthy group, both the ACLR-failed and ACLR-passed groups indicated greater values in between errors (P < .001, P = .008, respectively) and reaction latency variables (P = .002, P = .01, respectively) but lower values of A' (P < .001, P = .007, respectively), probability of hit (P < .001, P = .03, respectively), and percent correct trials variables (P = .006, P = .02, respectively). Our findings indicated deficits in neurocognitive functions in ACLR male athletes. In addition, poor performance in sustained attention, working memory, and cognitive flexibility measures observed in the ACLR-passed group highlighted the necessity for using a multimodal approach via implementation of neurocognitive measures in conjunction with the functional and muscular assessments when making RTS decisions.

The Influence of Sildenafil-Metformin Combination on Hyperalgesia and Biochemical Markers in Diabetic Neuropathy in Mice.

Background and objectives: Worldwide, approximately 500 million people suffer from diabetes and at least 50% of these people develop neuropathy. Currently, therapeutic strategies for reducing diabetic neuropathy (DN)-associated pain are limited and have several side effects. The purpose of the study was to evaluate the antihyperalgesic action of different sildenafil (phosphodiesterase-5 inhibitor) and metformin (antihyperglycemic agent) combinations in alloxan-induced DN. Methods: The study included 100 diabetic mice and 20 non-diabetic mice that were subjected to hot and cold stimulus tests. Furthermore, we determined the influence of this combination on TNF-α, IL-6 and nitrites levels in brain and liver tissues. Results: In both the hot-plate and tail withdrawal test, all sildenafil-metformin combinations administered in our study showed a significant increase in pain reaction latencies when compared to the diabetic control group. Furthermore, all combinations decreased blood glucose levels due to the hypoglycemic effect of metformin. Additionally, changes in nitrite levels and pro-inflammatory cytokines (TNF-α and IL-6) were observed after 14 days of treatment with different sildenafil-metformin combinations. Conclusions: The combination of these two substances increased the pain reaction latency of diabetic animals in a dose-dependent manner. Moreover, all sildenafil-metformin combinations significantly reduced the concentration of nitrites in the brain and liver, which are final products formed under the action of iNOS.

Artesunate Inhibits Apoptosis and Promotes Survival in Schwann Cells via the PI3K/AKT/mTOR Axis in Diabetic Peripheral Neuropathy.

Diabetic peripheral neuropathy (DPN) is an early developing complication of diabetes mellitus associated with nerve dysfunction. Artesunate (ART), a natural compound extracted from the herb Artemisia annua L., was reported to benefit neural injury. However, whether ART has a role in preventing DPN is still unknown. In this study, a rat model of DPN with a high fat diet feeding and streptozotocin (STZ) injection was established. The findings indicated that ART treatment significantly ameliorated hyperglycemia-induced hot plate reaction latency (HPRL) decline, cold sensitivity and mechanical allodynia, and nerve injury by inhibiting sciatic nerve apoptosis. Further, ART restored high glucose (HG)-induced elevated apoptosis and deficient survival in rat neuronal Schwann cells, RSC96 cells. We demonstrated that ART promoted protein kinase B (AKT) phosphorylation as well as its downstream factor mammalian target of rapamycin (mTOR) in vivo and in vitro. Of note, the protective effects of ART in RSC96 cells under HG condition could be counteracted by LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor. Taken together, ART mitigated hyperglycemia-induced nerve injury by suppressing apoptosis and promoting the viability of Schwann cells via the PI3K/AKT/mTOR signaling pathway.

Role of arousal, subjective significance and valence of affect in task-switching effectiveness

AbstractSwitching between two concurrent tasks is an important ability of the mind. In a series of two experiments, we explored the role of activation (arousal and subjective significance) and emotional valence in shaping the effectiveness of switching between two cognitive tasks: gender-marking and emotional categorisations of verbal stimuli. We expected arousal to disrupt and subjective significance to boost the effectiveness of cognitive switching. We employed a paradigm that allowed us to present emotional words and measure the reaction latencies when a task given to the participants was switched; thus, the response was more costly than when continuing to respond to the same task. The first experiment, conducted with neutral words, showed that high subjective significance reduced reaction latencies in comparison with medium subjective significance. The second experiment showed a similar pattern only for neutral stimuli in the emotional categorisation task, but not for negative and positive stimuli. We did not find a clear effect of arousal or valence. The results of our studies suggest that subjective significance is independent of arousal in enhancing the cognitive control resources.

VR-Based Immersive Service Management in B5G Mobile Systems: A UAV Command and Control Use Case

The management of remote services, such as remote surgery, remote sensing, or remote driving, has become increasingly important, especially with the emerging 5G and Beyond 5G technologies. However, the strict network requirements of these remote services represent one of the major challenges that hinder their fast and large-scale deployment in critical infrastructures. This article addresses certain issues inherent in remote and immersive control of virtual reality (VR)-based unmanned aerial vehicles (UAVs), whereby a user remotely controls UAVs, equipped with 360° cameras, using their head-mounted devices (HMD) and their respective controllers. Remote and immersive control services, using 360° video streams, require much lower latency and higher throughput for true immersion and high service reliability. To assess and analyze these requirements, this article introduces a real-life testbed system that leverages different technologies (e.g., VR, 360° video streaming over 4G/5G, and edge computing). In the performance evaluation, different latency types are considered. They are namely: 1) glass-to-glass latency between the 360° camera of a remote UAV and the HMD display; 2) user/pilot’s reaction latency; and 3) the command/execution latency. The obtained results indicate that the responsiveness (dubbed Glass-to-Reaction-to-Execution—GRE–latency) of a pilot, using our system, to a sudden event is within an acceptable range, i.e., around 900 ms.

Research of diver body functions’ state with different resistance to the toxic oxygen effect: prospective cohort study

INTRODUCTION: The relevance of this issue is due to the fact that nowadays there is no common understanding of the influence degree of high partial oxygen pressures on a body functions’ state, depending on individual resistance.OBJECTIVE: Research the state of the functions of the central nervous, cardiovascular and respiratory systems among people with different resistance to the toxic oxygen effect in the descending and the nearest post-descending period.MATERIALS AND METHODS: There was an examination of 11 divers aged 23 to 43 (the average age is 35.5±6.5 years) in conditions of a simulated descent in a pressure chamber to the depth of 15 m (0.25 MPa) while breathing oxygen, and also during 3 days after its termination. Statistic: Software SPSS, v. 20.0 (IBM) was applied for statistical processing of the results.RESULTS: Baseline heart rate (HR) in the low toxic oxygen resistant group (group I) is 10% (р&lt;0.05) higher than the subjects, recognized as resistant (group II). To 60 minutes oxygen breathing (pO2=0.25 MPa) there is a decrease in heart rate (HR) by 12.5% in group I and 11% in group II, comparing the baseline (р&gt;&lt;0.05). An increase of diastolic pressure level in group II is 10.5% to 15 min descent and 18% to 45 min, comparing the baseline (р&gt;&lt;0.05). In group I the pulse pressure level reduced by 18%, comparing the baseline (р&gt;&lt;0.05). Gencha test results after descent rose by 55% in group I and by 62.5% in group II, comparing the baseline (р�0.05), and indicators higher than initial remained for 3 days more. In group I there was reduction of information processing speed by a visual analyzer of 16% (from 0.788 to 0.661 b/sec) and increase in escape latency of a simple visual-motor reaction by 11.7%, comparing the baseline (р&gt;&lt;0.05). DISCUSSION: Divers with different resistance to the toxic oxygen effect experience multidirectional reaction of the central nervous, cardiovascular and respiratory systems. Individuals, resistant to the toxic oxygen effect, are characterized by more active inclusion of counteraction mechanisms to hyperoxia and significant reduction in the level of adaptation reserves and the efficiency of the cardiovascular system. People with low resistance experience a decrease in the functionality level of the central nervous system. CONCLUSION: The results obtained have a basis for admitting the application of the method of determining individual body resistance to the toxic oxygen effect and tests with increasing dosed physical activity in order to estimate adaptation reserves and efficiency. &gt;&lt; 0.05) higher than the subjects, recognized as resistant (group II). To 60 minutes oxygen breathing (pO2=0.25 MPa) there is a decrease in heart rate (HR) by 12.5% in group I and 11% in group II, comparing the baseline (р&lt; 0.05). An increase of diastolic pressure level in group II is 10.5% to 15 min descent and 18% to 45 min, comparing the baseline (р&lt; 0.05). In group I the pulse pressure level reduced by 18%, comparing the baseline (р&lt; 0.05). Gencha test results after descent rose by 55% in group I and by 62.5% in group II, comparing the baseline (р 0.05), and indicators higher than initial remained for 3 days more. In group I there was reduction of information processing speed by a visual analyzer of 16% (from 0.788 to 0.661 b/sec) and increase in escape latency of a simple visual-motor reaction by 11.7%, comparing the baseline (р&lt; 0.05).DISCUSSION: Divers with different resistance to the toxic oxygen effect experience multidirectional reaction of the central nervous, cardiovascular and respiratory systems. Individuals, resistant to the toxic oxygen effect, are characterized by more active inclusion of counteraction mechanisms to hyperoxia and significant reduction in the level of adaptation reserves and the efficiency of the cardiovascular system. People with low resistance experience a decrease in the functionality level of the central nervous system.CONCLUSION: The results obtained have a basis for admitting the application of the method of determining individual body resistance to the toxic oxygen effect and tests with increasing dosed physical activity in order to estimate adaptation reserves and efficiency.

Variation in Gut Microbiota Composition is Associated with Sleep Quality and Cognitive Performance in Older Adults with Insomnia.

PurposeInsomnia, a chronic condition affecting 50% of older adults, is often accompanied by cognitive decline. The mechanism underlying this comorbidity is not fully understood. A growing literature suggests the importance of gut microbiota for brain function. We tested associations between sleep quality and cognitive performance with gut microbiota in older adults with insomnia.Patients and MethodsSeventy-two older adults with insomnia (age 73.2 ± 5.73 years, 56 females) provided stool samples for gut microbial sequencing. Microbiota profile was determined using the DADA2 bioinformatics pipeline. Cognition was assessed with the Cambridge Neuropsychological Test Automated Battery. Objective sleep quality was monitored by a two-week actigraphic recording, and participants completed the Insomnia Severity Index (ISI). We used partial canonical correspondence analysis (pCCA) to examine the relative contribution of insomnia, based on actigraphic sleep efficiency (SE) and ISI, and of cognitive status, based on the Multitasking test of Median Reaction Latency (MTTLMD) and the Spatial Working Memory Between Errors (SWMBE), to variance in microbiota composition. We used Pearson correlations to correlate insomnia and cognitive status parameters with microbiota amplicon sequence variants, genera, and families.ResultsThe pCCA revealed that sleep quality and cognitive performance explained a variation of 7.5–7.9% in gut microbiota composition in older adults with insomnia. Correlation analysis demonstrated that Lachnoclostridium (genus) correlates positively with SE (r=0.42; P=0.05) and negatively with MTTLMD (r=−0.29; P=0.03), whereas Blautia (genus) correlates negatively with MTTLMD (r=−0.31; P=0.01).ConclusionFindings demonstrate the associations of sleep quality and cognitive performance with variance in gut microbiota composition and with specific genus abundance in older adults with insomnia. Further studies should validate the findings, determine causal relationships, and evaluate potential interventions for the comorbidity of insomnia and cognitive impairment in older adults with insomnia.

Low-intensity transcranial ultrasound stimulation facilitates hand motor function and cortical excitability: A crossover, randomized, double blind study.

ObjectiveTranscranial ultrasound stimulation (TUS) is a new form of non-invasive brain stimulation. Low-intensity TUS is considered highly safe. We aimed to investigate the effect of low-intensity TUS on hand reaction responses and cortical excitability in healthy adults.MethodsThis study used a crossover, randomized, and double-blind design. A total of 20 healthy participants were recruited for the study. All the participants received TUS and sham stimulation on separate days in random order. The finger tapping test (tapping score by using a tablet) and motor evoked potential (MEP) were assessed before and after stimulation, and discomfort levels were assessed using a visual analog scale (VAS) score.ResultsNo significant differences in tapping score or MEP amplitude between the two experimental conditions were registered before stimulation. After stimulation, tapping scores were increased regardless of the specific treatment, and the real stimulation condition receiving TUS (90.4 ± 11.0 points) outperformed the sham stimulation condition (86.1 ± 8.4 points) (p = 0.002). The MEP latency of real TUS (21.85 ± 1.33 ms) was shorter than that of sham TUS (22.42 ± 1.43 ms) (p < 0.001). MEP amplitude of real TUS (132.18 ± 23.28 μV) was higher than that of sham TUS (114.74 ± 25.5 μV, p = 0.005). There was no significant difference in the discomfort score between the two conditions (p = 0.163).ConclusionTranscranial ultrasound stimulation (TUS) can decrease the hand reaction response time and latency of the MEP, enhance the excitability of the motor cortex, and improve hand motor function in healthy individuals without obvious discomfort.

Image features influence reaction time

We aim to ask and answer an essential question " how quickly do we react after observing a displayed visual target?" To this end, we present psychophysical studies that characterize the remarkable disconnect between human saccadic behaviors and spatial visual acuity. Building on the results of our studies, we develop a perceptual model to predict temporal gaze behavior, particularly saccadic latency, as a function of the statistics of a displayed image. Specifically, we implement a neurologically-inspired probabilistic model that mimics the accumulation of confidence that leads to a perceptual decision. We validate our model with a series of objective measurements and user studies using an eye-tracked VR display. The results demonstrate that our model prediction is in statistical alignment with real-world human behavior. Further, we establish that many sub-threshold image modifications commonly introduced in graphics pipelines may significantly alter human reaction timing, even if the differences are visually undetectable. Finally, we show that our model can serve as a metric to predict and alter reaction latency of users in interactive computer graphics applications, thus may improve gaze-contingent rendering, design of virtual experiences, and player performance in e-sports. We illustrate this with two examples: estimating competition fairness in a video game with two different team colors, and tuning display viewing distance to minimize player reaction time.

Emotional Dysregulation and Altered Reward Processing in Self-Harm

AimsSelf-Harm (SH) is defined as “any act of self-injury or poisoning carried out by a person irrespective of their motivation”. SH increases the risk of adverse outcomes including suicide attempts, necessitating early intervention. The most widely reported reason for SH is to relieve negative affect (NA), with NA precipitating SH engagement. SH participants show altered reward processing, particularly reward hypersensitivity. NA could trigger reward hypersensitivity and therefore SH engagement. However, the interaction between NA and reward processing in SH remains unclear.Aim: To investigate whether those who SH show differences in processing SH stimuli compared to healthy controls (HCs) following NA induction.Hypothesis: NA induction will result in SH participants having significantly shorter reaction latency (RL) and significantly greater reaction accuracy (RA) in the SH condition of the Incentive Delay task (IDT) than HCs.Methods16–25-year-old SH (n = 35) and HC (n = 20) participants were recruited on social media. Participants completed the Trier Social Stress Test, to induce NA, followed by the IDT. In the latter, participants were cued to respond to a target as quickly as possible, and on responding were shown images of either a SH act (SH condition), people socializing (social condition) or money (monetary condition), where each condition had control trials where a neutral image was shown, which participants also had to respond to (SH neutral, social neutral and monetary neutral conditions respectively). RA was the percentage of IDT trials in which participants responded within the target's presentation time. RL in the IDT was the time (seconds) between the target appearance and the participant's response.ResultsA linear mixed effects model showed no significant main effect of group on RL (SH vs HC), condition (Social, SH or Monetary) or group x condition interaction (p &gt; 0.05). There was a significant main effect of condition on RA (p &lt; 0.05) but not group or group x condition interaction (p &gt; 0.05). Past-week SH frequency and RA were significantly and positively correlated in social, social neutral and monetary conditions (p &lt; 0.05).ConclusionOverall, there was a non-significant effect of NA on reward processing. However, as greater past-week SH frequency was significantly associated with greater RA, understanding how reward processing and NA interact in SH can provide greater insight into its triggers. Given this study's limited sample size and cross-sectional nature, future studies should investigate how NA and reward processing interact longitudinally and in larger samples to understand how SH can be reduced.

Emotional Dysregulation and Altered Reward Processing in Self-Harm

IntroductionSelf-Harm (SH) is any act of self-injury carried out by somebody irrespective of motivation. SH most commonly functions to relieve negative affect (NA). Tentative evidence suggests reward processing is altered in SH. NA may trigger reward hypersensitivity and therefore SH. Whether NA influences reward processing in SH remains unclear.ObjectivesTo investigate whether self-harmers differ in motivation to obtain SH stimuli than healthy controls (HCs) following NA induction.HypothesisAfter NA induction, SH participants will have a significantly shorter reaction latency (RL) and greater reaction accuracy (RA) than HCs in the SH condition of the Incentive Delay (ID) task.Methods16-25-year-old SH (n=35) and HC (n=20) participants were recruited online and underwent the Trier Social Stress Test, to induce NA, followed by the ID task, where participants were cued to respond to a target as quickly as possible. On responding, an image of either a SH act (SH Condition), people socializing (Social Condition) or money (Monetary Condition) appeared. Each condition included control trials showing a neutral image. RA was the percentage of trials responded to within the target’s presentation time. RL was the time (seconds) between target appearance and participants’ response.ResultsThere was no significant main effect of group, condition or group x condition interaction for RL. There was a significant main effect of condition (p &lt; 0.05) but not of group nor a group x condition interaction for RA.ConclusionsReward processing did not differ in the SH group compared to HCs post-NA induction. Future studies could investigate reward processing in longitudinal and larger SH samples.DisclosureNo significant relationships.

Agmatine prevents development of tolerance to anti-nociceptive effect of ethanol in mice.

Drug tolerance is directly correlated with drug abuse and physical dependence. The development of tolerance is manifested as the decline in pharmacological responses of drugs following repeated administration of the constant dose. The present study evaluated the effect of agmatine in ethanol-induced anti-nociception and tolerance in the tail-flick assay in mice. In an acute protocol, ethanol (1 and 2g/kg, i.p. [intraperitoneally]) and agmatine (20 and 40 μg/mouse, i.c.v. [intracerebroventricularly]) produced significant analgesic effects in mice, as was evident from the increased baseline tail-flick latency when tested 20 minutes after their administration. Agmatine in a per se non-effective dose (5 μg/mouse, i.c.v.), L-arginine (40 μg/mouse, i.c.v.), and arcaine (25 μg/mouse, i.c.v.) significantly potentiated the anti-nociceptive effect of ethanol. Blood ethanol analysis showed no significant differences in blood ethanol concentration between ethanol/saline- and ethanol/agmatine-treated mice, suggesting that the effects of agmatine were not due to any possible effects on the pharmacokinetics of ethanol. In a separate study, mice were injected with ethanol (2g/kg, i.p., 12%) or saline (1mL/kg, i.p.) once daily for 9 days. On days 1, 3, 5, 7, and 9 of the experiment, they were subjected to the tail-flick test. Agmatine (5-20 μg/mouse, i.c.v.), L-arginine (40 μg/mouse, i.c.v.), arcaine (25 μg/mouse, i.c.v.), aCSF (2 μL/mouse, i.c.v.), or saline (1mL/kg, i.p.) was administered daily prior to the first daily ethanol or saline injections, and reaction latencies were determined in the tail-flick assay. Injections of agmatine, L-arginine, and arcaine prevented the development of tolerance to ethanol-induced analgesia. Given that agmatine and its endogenous modulation can prevent tolerance to the anti-nociceptive effects of ethanol, these data suggest it as a possible new therapeutic strategy for the treatment of alcohol use disorder and associated complications.