Elsevier BVActa Medica Okayama0010-94521942026Increasing visual uncertainty modulates multisensory decision-making5062ENXiangfuYangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityWeipingYangDepartment of Psychology, Faculty of Education, Hubei UniversityYinghuaYuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYoshimichiEjimaGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJiajiaYangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityThe brain integrates and transforms information from multiple senses to make optimal decisions, a process that is critical for navigating complex environments with perceptual uncertainty. Despite a growing consensus that individuals adapt flexibly to uncertain sensory input, whether increasing visual uncertainty influences the decision process itself or other, non-decision sensory processes during multisensory decision-making are unclear. Here, an audiovisual categorization task was used to examine the responses of human participants (N = 30) to visual and audiovisual stimuli under low-, medium-, and high-uncertainty conditions. Modeling the behavioral data using a drift‒diffusion model indicated that increased visual uncertainty in the audiovisual context decreased the evidence accumulation rate but had no effect on non-decision processes. Electrophysiological recordings confirmed and expanded upon these results: increased visual uncertainty in the audiovisual context reduced the amplitude during the late decision-making stage (300–380 msec) but had no effect on the amplitude during the early sensory encoding stage (140–220 msec). More importantly, electroencephalography analyses revealed that audiovisual integration in the early sensory encoding stage occurred robustly across all visual uncertainty conditions, whereas audiovisual integration in the late stage occurred only under medium and high visual uncertainty conditions. This study demonstrated that increased visual uncertainty modulates the decision process itself rather than early sensory encoding during multisensory decision-making. Moreover, multisensory integration strategies dynamically adapt to increasing visual uncertainty by engaging different mechanisms to maintain effective decision-making.No potential conflict of interest relevant to this article was reported.MDPIActa Medica Okayama2076-34251452024Go/No-Go Ratios Modulate Inhibition-Related Brain Activity: An Event-Related Potential Study414ENNanZhangGraduate of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityWeichaoAnGraduate of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYinghuaYuGraduate of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJinglongWuGraduate of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJiajiaYangGraduate of Interdisciplinary Science and Engineering in Health Systems, Okayama University(1) Background: Response inhibition refers to the conscious ability to suppress behavioral responses, which is crucial for effective cognitive control. Currently, research on response inhibition remains controversial, and the neurobiological mechanisms associated with response inhibition are still being explored. The Go/No-Go task is a widely used paradigm that can be used to effectively assess response inhibition capability. While many studies have utilized equal numbers of Go and No-Go trials, how different ratios affect response inhibition remains unknown; (2) Methods: This study investigated the impact of different ratios of Go and No-Go conditions on response inhibition using the Go/No-Go task combined with event-related potential (ERP) techniques; (3) Results: The results showed that as the proportion of Go trials decreased, behavioral performance in Go trials significantly improved in terms of response time, while error rates in No-Go trials gradually decreased. Additionally, the NoGo-P3 component at the central average electrodes (Cz, C1, C2, FCz, FC1, FC2, PCz, PC1, and PC2) exhibited reduced amplitude and latency; (4) Conclusions: These findings indicate that different ratios in Go/No-Go tasks influence response inhibition, with the brain adjusting processing capabilities and rates for response inhibition. This effect may be related to the brain's predictive mechanism model.No potential conflict of interest relevant to this article was reported.Academic Press Inc. Elsevier ScienceActa Medica Okayama1053-81192482022Layer-specific activation in human primary somatosensory cortex during tactile temporal prediction error processing118867ENYinghuaYuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityLaurentiusHuberMR-Methods Group, MBIC, Cognitive Neuroscience Department, Faculty of Psychology and Neuroscience, University of Maastricht, Cognitive NeuroscienceJiajiaYangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityMasakiFukunagaDivision of Cerebral Research, National Institute for Physiological SciencesYuhuiChaiSection on Functional Imaging Methods, National Institute of Mental HealthDavid C.JangrawSection on Functional Imaging Methods, National Institute of Mental HealthGangChenScientific and Statistical Computational Core, National Institute of Mental HealthDaniel A.HandwerkerSection on Functional Imaging Methods, National Institute of Mental HealthPeter J.MolfeseSection on Functional Imaging Methods, National Institute of Mental HealthYoshimichiEjimaGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityNorihiroSadatoDivision of Cerebral Research, National Institute for Physiological SciencesJinglongWuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityPeter A.BandettiniSection on Functional Imaging Methods, National Institute of Mental HealthThe human brain continuously generates predictions of incoming sensory input and calculates corresponding prediction errors from the perceived inputs to update internal predictions. In human primary somatosensory cortex (area 3b), different cortical layers are involved in receiving the sensory input and generation of error signals. It remains unknown, however, how the layers in the human area 3b contribute to the temporal prediction error processing. To investigate prediction error representation in the area 3b across layers, we acquired layer specific functional magnetic resonance imaging (fMRI) data at 7T from human area 3b during a task of index finger poking with no-delay, short-delay and long-delay touching sequences. We demonstrate that all three tasks increased activity in both superficial and deep layers of area 3b compared to the random sensory input. The fMRI signal was differentially modulated solely in the deep layers rather than the superficial layers of area 3b by the delay time. Compared with the no-delay stimuli, activity was greater in the deep layers of area 3b during the short delay stimuli but lower during the long-delay stimuli. This difference activity features in the superficial and deep layers suggest distinct functional contributions of area 3b layers to tactile temporal prediction error processing. The functional segregation in area 3b across layers may reflect that the excitatory and inhibitory interplay in the sensory cortex contributions to flexible communication between cortical layers or between cortical areas.No potential conflict of interest relevant to this article was reported.MDPIActa Medica Okayama2076-341711152021A New Method for Haptic Shape Discriminability Detection7049ENYulongLiuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJiajiaYangCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYinghuaYuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYiyangYuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityWuWangThe School of Psychological and Cognitive Sciences, Peking UniversityHuazhiLiCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversitySatoshiTakahashiCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYoshimichiEjimaCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityQiongWuDepartment of Psychology, Suzhou University of Science and Technology,JinglongWuResearch Center for Medical Artificial Intelligence, Shenzhen Institute of Advanced Technology, Chinese Academy of SciencesTouch shape discrimination is not only closely related to tactile mechanoreceptors but also higher cognitive function. However, previous shape discrimination methods are difficult to complete in a short time, and the devices are complicated to operate and not user-friendly for nonprofessionals. Here, we propose a new method, the evaluation quantity of which is the angle discrimination threshold. In addition, to make this method easy to use for nonprofessionals, we designed a haptic angle sorting system, including the device and software. To evaluate this method, the angle sorting and two-angle discrimination experiments were compared, and it was found that participants spent significantly less time in the former experiment than in the latter. At the same time, there is a strong correlation between the performance of angle sorting and two-angle discrimination, which shows that the angle threshold obtained by the new method can also be used to evaluate the ability of touch discrimination. Moreover, the angle sorting results of different age groups also further demonstrate the feasibility of the method. The efficiency of this new method and the effectiveness of the system also provide a convenient means for evaluating haptic shape discrimination, which may have potential clinical application value in the early diagnosis of peripheral neuropathy and even in the evaluation of cognitive function.No potential conflict of interest relevant to this article was reported.WileyActa Medica Okayama2162-32791132021Functional heterogeneity in the left lateral posterior parietal cortex during visual and haptic crossmodal dot-surface matchinge02033ENJiajiaYangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYinghuaYuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityHiroakiShigemasuKochi University of TechnologyHiroshiKadotaKochi University of TechnologyKiyoshiNakaharaKochi University of TechnologyTakanoriKochiyamaATR Brain Activity Imaging CenterYoshimichiEjimaGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJinglongWuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityBackground</br>
Vision and touch are thought to contribute information to object perception in an independent but complementary manner. The left lateral posterior parietal cortex (LPPC) has long been associated with multisensory information processing, and it plays an important role in visual and haptic crossmodal information retrieval. However, it remains unclear how LPPC subregions are involved in visuo]haptic crossmodal retrieval processing.</br>
Methods</br>
In the present study, we used an fMRI experiment with a crossmodal delayed match]to]sample paradigm to reveal the functional role of LPPC subregions related to unimodal and crossmodal dot]surface retrieval.</br>
Results</br>
The visual]to]haptic condition enhanced the activity of the left inferior parietal lobule relative to the haptic unimodal condition, whereas the inverse condition enhanced the activity of the left superior parietal lobule. By contrast, activation of the left intraparietal sulcus did not differ significantly between the crossmodal and unimodal conditions. Seed]based resting connectivity analysis revealed that these three left LPPC subregions engaged distinct networks, confirming their different functions in crossmodal retrieval processing.</br>
Conclusion</br>
Taken together, the findings suggest that functional heterogeneity of the left LPPC during visuo]haptic crossmodal dot]surface retrieval processing reflects that the left LPPC does not simply contribute to retrieval of past information; rather, each subregion has a specific functional role in resolving different task requirements.No potential conflict of interest relevant to this article was reported.American Association for the Advancement of ScienceActa Medica Okayama2375-2548552019Layer-specific activation of sensory input and predictive feedback in the human primary somatosensory cortexeaav9053ENYinghuaYuGraduate School of Interdisciplinary Science and Engineering in Health Systems,Okayama UniversityLaurentiusHuberSection on Functional Imaging Methods, National Institute of Mental HealthJiajiaYangGraduate School of Interdisciplinary Science and Engineering in Health Systems,Okayama UniversityDavid C.JangrawSection on Functional Imaging Methods, National Institute of Mental HealthDaniel A.HandwerkerSection on Functional Imaging Methods, National Institute of Mental HealthPeter J.MolfeseSection on Functional Imaging Methods, National Institute of Mental HealthGangChenScientific and Statistical Computing Core, National Institute of Mental HealthYoshimichiEjimaGraduate School of Interdisciplinary Science and Engineering in Health Systems,Okayama UniversityJinglongWuGraduate School of Interdisciplinary Science and Engineering in Health Systems,Okayama UniversityPeter A.BandettiniSection on Functional Imaging Methods, National Institute of Mental HealthWhen humans perceive a sensation, their brains integrate inputs from sensory receptors and process them based on their expectations. The mechanisms of this predictive coding in the human somatosensory system are not fully understood. We fill a basic gap in our understanding of the predictive processing of somatosensation by examining the layer-specific activity in sensory input and predictive feedback in the human primary somatosensory cortex (S1). We acquired submillimeter functional magnetic resonance imaging data at 7T (n = 10) during a task of perceived, predictable, and unpredictable touching sequences. We demonstrate that the sensory input from thalamic projects preferentially activates the middle layer, while the superficial and deep layers in S1 are more engaged for cortico-cortical predictive feedback input. These findings are pivotal to understanding the mechanisms of tactile prediction processing in the human somatosensory cortex.No potential conflict of interest relevant to this article was reported.ElsevierActa Medica Okayama2405-8440582019Stroking hardness changes the perception of affective touch pleasantness across different skin sitese02141ENJiabinYuCognitive Neuroscience Laboratory, Graduate School of Natural Science and Technology, Okayama UniversityJiajiaYangCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityYinghuaYuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityQiongWuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversitySatoshiTakahashiCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityYoshimichiEjimaCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityJinglongWuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityHuman unmyelinated tactile afferents (CT afferents) in hairy skin are thought to be involved in the transmission of affective aspects of touch. How the perception of affective touch differs across human skin has made substantial progress; however, the majority of previous studies have mainly focused on the relationship between stroking velocities and pleasantness ratings. Here, we investigate how stroking hardness affects the perception of affective touch. Affective tactile stimulation was given with four different hardness of brushes a three different forces, which were presented to either palm or forearm. To quantify the physical factors of the stimuli (brush hardness), ten naive, healthy participants assessed brush hardness using a seven-point scale. Based on these ten participants, five more participants were added to rate the hedonic value of brush stroking using a visual analogue scale (VAS). We found that pleasantness ratings over the skin resulted in a preference for light, soft stroking, which was rated as more pleasant when compared to heavy, hard stroking. Our results show that the hairy skin of the forearm is more susceptible to stroking hardness than the glabrous of the palm in terms of the perception of pleasantness. These findings of the current study extend the growing literature related to the effect of stroking characteristics on pleasantness ratings.No potential conflict of interest relevant to this article was reported.ElsevierActa Medica Okayama24058440582019Stroking hardness changes the perception of affective touch pleasantness across different skin sitese02141ENJiabinYuCognitive Neuroscience Laboratory, Graduate School of Natural Science and Technology, Okayama UniversityJiajiaYangCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityYinghuaYuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityQiongWuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversitySatoshiTakahashiCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityYoshimichiEjimaCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityJinglongWuCognitive Neuroscience Laboratory, Graduate School of Interdisciplinary, Science and Engineering in Health Systems, Okayama UniversityHuman unmyelinated tactile afferents (CT afferents) in hairy skin are thought to be involved in the transmission of affective aspects of touch. How the perception of affective touch differs across human skin has made substantial progress; however, the majority of previous studies have mainly focused on the relationship between stroking velocities and pleasantness ratings. Here, we investigate how stroking hardness affects the perception of affective touch. Affective tactile stimulation was given with four different hardness of brushes at three different forces, which were presented to either palm or forearm. To quantify the physical factors of the stimuli (brush hardness), ten naïve, healthy participants assessed brush hardness using a seven-point scale. Based on these ten participants, five more participants were added to rate the hedonic value of brush stroking using a visual analogue scale (VAS). We found that pleasantness ratings over the skin resulted in a preference for light, soft stroking, which was rated as more pleasant when compared to heavy, hard stroking. Our results show that the hairy skin of the forearm is more susceptible to stroking hardness than the glabrous of the palm in terms of the perception of pleasantness. These findings of the current study extend the growing literature related to the effect of stroking characteristics on pleasantness ratings.No potential conflict of interest relevant to this article was reported.