MDPIActa Medica Okayama2076-342514122024The Impact of Selective Spatial Attention on Auditory-Tactile Integration: An Event-Related Potential Study1258ENWeichaoAnGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityNanZhangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityShengnanLiGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYinghuaYuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJinglongWuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJiajiaYangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityBackground: Auditory-tactile integration is an important research area in multisensory integration. Especially in special environments (e.g., traffic noise and complex work environments), auditory-tactile integration is crucial for human response and decision making. We investigated the influence of attention on the temporal course and spatial distribution of auditory-tactile integration. Methods: Participants received auditory stimuli alone, tactile stimuli alone, and simultaneous auditory and tactile stimuli, which were randomly presented on the left or right side. For each block, participants attended to all stimuli on the designated side and detected uncommon target stimuli while ignoring all stimuli on the other side. Event-related potentials (ERPs) were recorded via 64 scalp electrodes. Integration was quantified by comparing the response to the combined stimulus to the sum of the responses to the auditory and tactile stimuli presented separately. Results: The results demonstrated that compared to the unattended condition, integration occurred earlier and involved more brain regions in the attended condition when the stimulus was presented in the left hemispace. The unattended condition involved a more extensive range of brain regions and occurred earlier than the attended condition when the stimulus was presented in the right hemispace. Conclusions: Attention can modulate auditory-tactile integration and show systematic differences between the left and right hemispaces. These findings contribute to the understanding of the mechanisms of auditory-tactile information processing in the human brain.No potential conflict of interest relevant to this article was reported.MDPIActa Medica Okayama2076-342514122024Contributions of the Primary Sensorimotor Cortex and Posterior Parietal Cortex to Motor Learning and Transfer1184ENChenyuWangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityYinghuaYuGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityJiajiaYangGraduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama UniversityBackground: Transferring learned manipulations to new manipulation tasks has enabled humans to realize thousands of dexterous object manipulations in daily life. Two-digit grasp and three-digit grasp manipulations require different fingertip forces, and our brain can switch grasp types to ensure good performance according to motor memory. We hypothesized that several brain areas contribute to the execution of the new type of motor according to the motor memory. However, the motor memory mechanisms during this transfer period are still unclear. In the present functional magnetic resonance imaging (fMRI) study, we aimed to investigate the cortical mechanisms involved in motor memory during the transfer phase of learned manipulation tasks. Methods: Using a custom-built T-shaped object with an adjustable weight distribution, the participants performed grasp and lift manipulation tasks under different conditions to simulate the learning and transfer phases. The learning phase consisted of four grasp-and-lift repetitions with one motor type, followed by a transfer phase with four repetitions involving different motors (adding or removing a digit). Results: By comparing brain activity in the learning and transfer phases, we identified three regions (the superior frontal gyrus, supramarginal gyrus, and postcentral gyrus) associated with motor memory during the transfer of learned manipulations. Conclusions: Our findings improve the understanding of the role of the posterior parietal cortex in motor memory, highlighting how sensory information from memory and real-time input is integrated to generate novel motor control signals that guide the precise reapplication of control strategies. Furthermore, we believe that these areas contribute to motor learning from motor memory and may serve as key regions of interest for investigating neurodegenerative diseases.No potential conflict of interest relevant to this article was reported.