Frontiers in Human Neuroscience最新文献

Tourette syndrome (TS) is a neuropsychiatric disorder characterized by chronic motor and phonic tics, with a higher prevalence among boys. This condition can significantly impact patients' learning and daily life. Due to the limited efficacy and potential side effects of pharmacological treatments for TS, there is a critical need to develop novel, tailored therapeutic strategies. Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have been proposed as potential treatments for TS, and have shown promising results. Here, we report a case of refractory TS, in which low-frequency rTMS was delivered to the left supplementary motor area (SMA), combined with tDCS targeting the primary motor cortex (M1) and the cerebellum, with the cathode positioned over the right M1 and the anode over the left cerebellum. This is the first reported case using a multi-target combination therapy for TS. This treatment yielded favorable outcomes and maintained good efficacy during a three-month follow-up period. Although larger-scale trials are needed, our findings pave the way for the application of non-invasive brain stimulation techniques in TS, offering a transformative path to improve treatment outcomes and quality of life for those with TS.

Introduction: While considerable research in language production has focused on incremental processing during conceptual and grammatical encoding, prosodic encoding remains less investigated. This study examines whether focus and accentuation processing in speech production follows linear or hierarchical incrementality.

Methods: We employed visual world eye-tracking to investigate how focus and accentuation are processed during sentence production. Participants were asked to complete a scenario description task where they were prompted to use a predetermined sentence structure to accurately convey the scenario, thereby spontaneously accentuate the corresponding entity. We manipulated the positions of focus with accentuation (initial vs. medial) by changing the scenarios. The initial and medial positions correspond to the first and second nouns in sentences like "N1 is above N2, not N3."

Results: Our findings revealed that speech latencies were significantly shorter in the sentences with initial focus accentuation than those with medial focus accentuation. Furthermore, eye-tracking data demonstrated that speakers quickly displayed a preference for fixating on initial information after scenarios onset. Crucially, the time-course analysis revealed that the onset of the initial focus accentuation effect (around 460 ms) preceded that of the medial focus accentuation effect (around 920 ms).

Discussion: These results support that focus and accentuation processing during speech production prior to articulation follows linear incrementality rather than hierarchical incrementality.

Introduction: Fibromyalgia (FM) is a widespread chronic pain condition with prevalence increasing in older adults. Older adults living with FM experience longer pain symptom durations that can negatively impact their quality of life. Affect and neuroinflammation are potential factors that can exacerbate pain symptoms. Exercise is a recommended intervention to manage pain symptoms; however, adherence limitations persist. Drawing on the Biopsychosocial Framework of Chronic Pain, this scoping review explores how exercise impacts factors related to neuroinflammation and affect, and how these factors contribute to exercise adherence in older adults living with FM.

Methods: We conducted a scoping search of articles related to exercise and older adults living with FM published before 2024. The extracted study characteristics include publication type, study design, affect outcomes, neuroinflammation outcomes, exercise type, exercise adherence, and sample demographic information.

Results: We have provided an overview of the relationship between affect and neuroinflammation in studies including older adults living with FM and highlight the impact of exercise on affect and neuroinflammation in older adults living with FM. A conceptual framework is provided illustrating the reciprocal relationship between exercise, affective changes, neuroinflammation, and exercise adherence.

Discussion: Our results suggest that exercise may improve affect, while limited evidence suggests that aerobic and resistance exercise improve neuroinflammation. Finally, implications for importance and future directions in the context of potential biological factors impacted are provided.

These case studies explore the subjective visual experiences of individuals with cerebral visual impairment (CVI), specifically dorsal stream dysfunction (DSD) characterized by simultanagnosia. Through three in-depth case studies, this work documents the challenges these individuals face when navigating cluttered environments. The individuals were asked to describe their visual experiences while watching videos of varying complexity, with the future aim of creating a simulation of simultanagnosia. This process revealed a dynamic constriction of their attentional visual fields as scene complexity increased, and vice versa. Notably, the volunteers experienced a phenomenon where their vision could "get stuck" on specific items, with an apparent concurrent reduction in their ability to perceive and describe visual information as visual clutter increased. These consistent observations indicate that the symptoms of simultanagnosia are not simply limited to perceiving one or two objects at a time but can vary dynamically in response to environmental complexity. They enhance our understanding of how DSD impacts visual search and perceptual experiences, prompting us to propose the term "simultanagnostic vision" to describe this more nuanced and dynamic manifestation of CVI. The results are critical for developing effective interventions and optimizing support strategies for individuals affected by DSD, particularly children at sensitive developmental stages. Furthermore, we recommend deeper investigation into how different visual processing streams in the brain interconnect and influence each other, which may open new avenues for targeted therapeutic interventions.

Interest has been growing in the use of mindfulness meditation (MM) as a therapeutic practice, as accumulating evidence highlights its potential to effectively address a range of mental conditions. While many fMRI studies focused on neural activation and functional connectivity during meditation, the impact of long-term MM practice on spontaneous brain activity, and on the expression of resting state networks over time, remains unclear. Here, intrinsic functional network dynamics were compared between experienced meditators and meditation-naïve participants during rest. Our analysis revealed that meditators tend to spend more time in two brain states that involve synchrony among cortical regions associated with sensory perception. Conversely, a brain state involving frontal areas associated with higher cognitive functions was detected less frequently in experienced meditators. These findings suggest that, by shifting attention toward enhanced sensory and embodied processing, MM effectively modulates the expression of functional network states at rest. These results support the suggested lasting effect of long-term MM on the modulation of resting-state networks, reinforcing its therapeutic potential for disorders characterized by imbalanced network dynamics. Moreover, this study reinforces the utility of analytic approaches from dynamical systems theory to extend current knowledge regarding brain activity and evaluate its response to interventions.

Introduction: The detection of, and adaptation to delayed visual movement feedback has been extensively studied. One important open question is whether the Weber-Fechner Laws hold in the domain of visuomotor delay; i.e., whether the perception of changes in visuomotor delay depends on the amount of delay already present during movement.

Methods: To address this, we developed a virtual reality based, continuous hand movement task, during which participants had to detect changes in visuomotor mapping (delay): Participants (N = 40) performed continuous, auditory-paced grasping movements, which were measured with a data glove and transmitted to a virtual hand model. The movements of the virtual hand were delayed between 0 and 700 ms with the delay changing repeatedly in a roving oddball design. Participants had to indicate any perceived delay changes by key press. This design allowed us to investigate detection accuracy and speed related to the magnitude of the delay change, and to the "baseline" delay present during movement, respectively.

Results: As expected, larger delay changes were detected more accurately than smaller ones. Surprisingly, delay changes were detected more accurately and faster when participants moved under large > small delays.

Discussion: These results suggest that visual movement feedback delay indeed affects the detection of changes in visuomotor delay, but not as predicted by the Weber-Fechner Laws. Instead, bodily action under small delays may have entailed a larger tolerance for delay changes due to embodiment-related intersensory conflict attenuation; whereas better change detection at large delays may have resulted from their (visual) saliency due to a strong violation of visuomotor predictions.

The recent progress in auditory attention decoding (AAD) methods is based on algorithms that find a relation between the audio envelope and the neurophysiological response. The most popular approach is based on the reconstruction of the audio envelope from electroencephalogram (EEG) signals. These methods are primarily based on the exogenous response driven by the physical characteristics of the stimuli. In this study, we specifically investigate higher-level cognitive responses influenced by auditory attention to natural speech events. We designed a series of four experimental paradigms with increasing levels of realism: a word category oddball paradigm, a word category oddball paradigm with competing speakers, and competing speech streams with and without specific targets. We recorded EEG data using 32 scalp electrodes, as well as 12 in-ear electrodes (ear-EEG) from 24 participants. By using natural speech events and cognitive tasks, a cognitive event-related potential (ERP) component, which we believe is related to the well-known P3b component, was observed at parietal electrode sites with a latency of ~625 ms. Importantly, the component decreases in strength but is still significantly observable in increasingly realistic paradigms of multi-talker environments. We also show that the component can be observed in the in-ear EEG signals by using spatial filtering. We believe that the P3b-like cognitive component modulated by auditory attention can contribute to improving auditory attention decoding from electrophysiological recordings.

Introduction: As brain-computer interfacing (BCI) systems transition fromassistive technology to more diverse applications, their speed, reliability, and user experience become increasingly important. Dynamic stopping methods enhance BCI system speed by deciding at any moment whether to output a result or wait for more information. Such approach leverages trial variance, allowing good trials to be detected earlier, thereby speeding up the process without significantly compromising accuracy. Existing dynamic stopping algorithms typically optimize measures such as symbols per minute (SPM) and information transfer rate (ITR). However, these metrics may not accurately reflect system performance for specific applications or user types. Moreover, many methods depend on arbitrary thresholds or parameters that require extensive training data.

Methods: We propose a model-based approach that takes advantage of the analytical knowledge that we have about the underlying classification model. By using a risk minimization approach, our model allows precise control over the types of errors and the balance between precision and speed. This adaptability makes it ideal for customizing BCI systems to meet the diverse needs of various applications.

Results and discussion: We validate our proposed method on a publicly available dataset, comparing it with established static and dynamic stopping methods. Our results demonstrate that our approach offers a broad range of accuracy-speed trade-offs and achieves higher precision than baseline stopping methods.

Backgrounds: Functional near-infrared spectroscopy (fNIRS) is widely used for the evaluation of mental workload (MWL), but it is not yet clear whether it is affected by physical factors during cognitive tasks. Therefore, the combined effects of physical and cognitive loads on hemodynamic features in the prefrontal cortex were evaluated.

Methods: Thirty-three eligible healthy male subjects were asked to perform three types of cognitive tasks (1-back, 2-back and 3-back). Concurrently, isotonic contraction aerobic exercise of the left upper limb was added. During this compound task, fNIRS signals, workload perception and task performance were recorded. Based on the oxyhemoglobin concentration, Pearson's correlation coefficient (CORR), coherence value (COH) and the phase-locking value (PLV) were calculated to reflect FC among eight channels.

Results: On the basis of effects of cognitive tasks, the concurrent physical activities would further increase National Aeronautics and Space Administration Task Load Index score (p < 0.05) and decrease task performance (p < 0.05). The fNIRS-based results showed that cognitive and physical loads had significant interaction effects on CORR (p < 0.05), COH (p < 0.05), and PLV (p = 0.010), while their main effects were not significant. The results of different channel pairs suggested that the functional connectivity between the right dorsolateral prefrontal cortex and the bilateral orbital frontal cortex was significantly enhanced under the combined effects of high physical and high cognitive load.

Discussion: From the perspective of prefrontal functional connectivity, this study supports measurable effects of physical factor on operators' mental load. The results provide a reference for the real-time (or online) assessment of the MWL level in the natural environment.