IEEE Trans Neural Syst Rehabil Eng
April 2024
Visual selective attention studies generally tend to apply cuing paradigms to instructively direct observers' attention to certain locations, features or objects. However, in real situations, attention in humans often flows spontaneously without any specific instructions. Recently, a concept named "willed attention" was raised in visuospatial attention, in which participants are free to make volitional attention decisions.
View Article and Find Full Text PDFMirror therapy (MT) has been proposed to promote motor recovery post-stroke through activation of mirror neuron system, recruitment of ipsilateral motor pathways, or/and increasing attention toward the affected limb. However, neuroimaging evidence for these mechanisms is still lacking. To uncover the underlying mechanisms, we designed a randomized controlled study and used a voxel-based whole-brain analysis of resting-state fMRI to explore the brain reorganizations induced by MT.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2023
Mirror visual feedback (MVF) intervention is an adjunctive approach for motor recovery after stroke. It has been hypothesized that MVF can increase visual perception, motor imagery, and attention of/to the hands. However, neuroimaging evidence for this hypothesis is still lacking.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2023
Low-intensity ultrasound stimulation (LIUS) is an emerging neuro- and vascular-modulation technique. Studies on humans and animals have shown that LIUS could induce changes in neuronal oscillations or blood flow. However, it is still inconclusive whether the hemodynamic response to LIUS is due to neurovascular coupling (NVC), direct ultrasound-vessel interactions, or both.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2023
Event-related potential (ERP) is one of the commonly used electrophysiologic measures for brain activity with millisecond time resolution, which has been widely applied to psychology and neuroscience research. Conventionally, ERP is obtained by grand-averaging EEG recordings across multiple trials to improve the signal-to-noise ratio (SNR). Reliable quantitative analysis of the amplitude or latency of ERP requires sufficient SNR.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2024
Purpose: We studied changes in the choroid, particularly variation in blood flow, during the development of myopia. The hemodynamic mechanism in play remains unclear. We evaluated blood flow by quantitating indocyanine green (ICG) fluorescence in a guinea pig model of form-deprivation myopia.
View Article and Find Full Text PDFElectroencephalography alpha-band (8-13 Hz) activity during visual spatial attention declines in normal aging. We recently reported the impacts of pre-cue baseline alpha and cueing strategy on post-cue anticipatory alpha activity and target processing in visual spatial attention (Wang et al., Cerebral Cortex, 2023).
View Article and Find Full Text PDFThe ability of attentional orienting has been suggested to keep developing throughout childhood. Electroencephalography (EEG) studies have shown that 6-10 year old children exhibit lateralized alpha-band (8-13 Hz) activity and event-related potentials (ERPs) that are classic markers of spatial attentional orienting in adults. However, the lack of a direct comparison of these EEG correlates between children and adults in the same experiment made it difficult to evaluate developmental effects on neural activity throughout attentional stages.
View Article and Find Full Text PDFThe efficacy of motor imagery training for motor recovery is well acknowledged, but with substantial inter-individual variability in stroke patients. To help optimize motor imagery training therapy plans and screen suitable patients, this study aimed to explore neuroimaging biomarkers explaining variability in treatment response. Thirty-nine stroke patients were randomized to a motor imagery training group (n = 22, received a combination of conventional rehabilitation therapy and motor imagery training) and a control group (n = 17, received conventional rehabilitation therapy and health education) for 4 weeks of interventions.
View Article and Find Full Text PDFTransmissive laser speckle imaging (LSI) is useful for monitoring large field-of-view (FOV) blood flow in thick tissues. However, after longer transmissions, the contrast of the transmitted speckle images is more likely to be blurred by multiple scattering, resulting in decreased accuracy and spatial resolution of deep vessels. This study proposes a deep-learning-based strategy for high spatiotemporal resolution three-dimensional (3D) reconstruction from a single transilluminated laser speckle contrast image, providing more structural and functional details without multifocus two-dimensional (2D) imaging or 3D optical imaging with point/line scanning.
View Article and Find Full Text PDFLaser speckle contrast imaging (LSCI) provides full-field and label-free imaging of blood flow and tissue perfusion. It has emerged in the clinical environment, including the surgical microscope and endoscope. Although traditional LSCI has been improved in resolution and SNR, there are still challenges in clinical translations.
View Article and Find Full Text PDFObjective: Various EEG source localization methods have been proposed for functional brain research. The evaluation and comparison of these methods are usually based on simulated data but not real EEG data, as the ground truth of source localization is unknown. In this study, we aim to evaluate source localization methods quantitatively under the real situation.
View Article and Find Full Text PDFObjective: Here we investigate the ability of low-intensity ultrasound (LIUS) applied to the spinal cord to modulate the transmission of motor signals.
Methods: Male adult Sprague-Dawley rats (n = 10, 250-300 g, 15 weeks old) were used in this study. Anesthesia was initially induced with 2% isoflurane carried by oxygen at 4 L/min via a nose cone.
. Low-intensity transcranial ultrasound stimulation (TUS) could induce both immediate and long-lasting neuromodulatory effects in human brains. Interhemispheric imbalance at prefrontal or motor cortices generally associates with various cognitive decline in aging and mental disorders.
View Article and Find Full Text PDFBackground: Motor imagery training (MIT) has been widely used to improve hemiplegic upper limb function in stroke rehabilitation. The effectiveness of MIT is associated with the functional neuroplasticity of the motor network. Currently, brain activation and connectivity changes related to the motor recovery process after MIT are not well understood.
View Article and Find Full Text PDFRecent neuroimaging studies on upper-limb amputation have revealed the reorganization of bilateral sensorimotor cortex after sensory deprivation, underpinning the assumption of changes in the interhemispheric connections. In the present study, using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), we aim to explore the alterations in the interhemispheric functional and structural connectivity after upper-limb amputation. Twenty-two upper-limb amputees and 15 age- and sex-matched healthy controls were recruited for MRI scanning.
View Article and Find Full Text PDFThe electroencephalography alpha-band (8-13 Hz) activity may represent a crucial neural substrate of visual spatial attention. However, factors likely contributing to alpha activity have not been adequately addressed, which impedes understanding its functional roles. We investigated whether pre-cue alpha power was associated with post-cue alpha activity in 2 independent experiments (n = 30 each) with different cueing strategies (instructional vs.
View Article and Find Full Text PDFRandom matrix theory provides new insights into multiple scattering in random media. In a recent study, we demonstrated the statistical separation of single- and multiple-scattering components based on a Wishart random matrix. The first- and second-order moments were estimated with a Wishart random matrix constructed using dynamically backscattered speckle images.
View Article and Find Full Text PDFBackground: There have been mixed reports on the beneficial effects of meditation in cardiovascular disease (CVD), which is widely considered the leading cause of death worldwide.
Methods: To clarify the role of meditation in modulating the heart-brain axis, we implemented an extreme phenotype strategy, i.e.
Pain is a multidimensional process, which can be modulated by emotions; however, the mechanisms underlying this modulation are unknown. We used pictures with different emotional valence (negative, positive, and neutral) as primes and applied electrical painful stimuli as targets to healthy participants. We assessed pain intensity and unpleasantness ratings and recorded electroencephalograms (EEGs).
View Article and Find Full Text PDFPatients with schizophrenia show widespread impairments in clinical, cognitive and psychosocial functioning. Mismatch negativity (MMN) and gamma-band auditory steady-state response (ASSR) are two neurophysiological biomarkers widely used to inform diagnosis, guide treatments and track response to interventions in schizophrenia. However, evidence for the test-retest reliability of these indices across multiple sessions in schizophrenia patients remains scarce.
View Article and Find Full Text PDF