European Journal of Neuroscience最新文献

Gait impairment and falls are common in multiple sclerosis (MS), yet the neural substrates contributing to mobility decline remain poorly understood. While prior studies have linked regional gray matter atrophy to motor outcomes, the role of diffuse cortical changes in complex gait tasks, such as backward walking, is less clear. This study examined whether diffuse cortical thinning is associated with forward and backward walking speed, and whether these relationships differ between fallers and nonfallers in MS. Forty-three individuals with MS (55 ± 10 years; 65% female) completed forward and backward Timed 25-Foot Walk assessments and high-resolution structural MRI. Cortical thickness and gray matter volume were estimated. Region-specific associations with gait speed were examined using regression with false discovery rate (FDR) correction. Principal component analysis revealed a global cortical thinning component that was associated with slower forward (β = −0.065, adjusted R² = 0.14) and backward (β = −0.061, adjusted R² = 0.19) walking speeds. In contrast, volumetric components did not significantly predict gait. Fallers and nonfallers did not differ in gait speed or cortical thinning, but exploratory moderation suggested stronger cortical thinning–gait associations in fallers, although effects did not remain significant after FDR correction. These preliminary findings suggest that diffuse cortical thinning is a consistent neural correlate of gait slowing in MS, with exploratory evidence suggesting that this relationship may be stronger among individuals with recent falls.

We live in an auditory world; we perceive and memorize sounds even before birth. Here, I have reviewed findings on the effects of implicit and explicit learning on auditory neurocognition. These findings, investigated in the mismatch negativity (MMN) paradigm, indicate that both implicit and explicit auditory expertise can modulate the neural encoding of sounds at the preattentive level of human cognition. This modulation is reflected in the MMN parameters latency and amplitude and its generators. Thus, studies on MMN can illustrate various forms of human auditory learning during development and learning across the entire lifespan.

Reduced vigilance can be captured as attentional lapses in sustained attention tasks, but just how these lapses relate to task-induced fatigue and motivation to maintain optimal performance across the age span is unclear. We induced fatigue in 18 young (mean age = 22.6 years) and 16 older participants (mean age = 66.5) using the Sustained Attention to Response Task while simultaneously recording electroencephalography (EEG). In the final block, we manipulated motivation levels in half of the participants by offering a financial incentive for best overall performance. We found that the young and older adults differed markedly in their response strategies from the outset (adopting distinct speed-accuracy trade-off strategies) with faster/more erroneous responses in the young adults and slower/more accurate responses in the older participants that remained stable over the experiment, while subjective fatigue increased irrespective of group. Poststimulus EEG activity showed two distinguishable beta signatures: a fronto-central topography as a marker of the age-specific response strategy and a fronto-parietal signal modulated by motivation per se. We speculate that these two signatures contribute to offsetting performance declines over time. Finally, although subjective fatigue or mind-wandering scores and prestimulus alpha power increased with time-on-task, we did not identify a correlation between these measures. Hence, strategy and motivation more than fatigue were associated with performance differences across age in a sustained attention task, reflected in decoupled beta signatures.

Gait impairments impact independence and quality of life of persons with Parkinson's disease (PD). The application of external and internal cueing strategies can improve gait, but not every person benefits equally from the same strategy. It remains unclear (i) which patient characteristics mediate cueing efficacy, (ii) how cueing efficacy changes over time, (iii) which patient characteristics are associated with long-term compliance, and (iv) what the neural correlates of cueing are. The UNITE-PD study is a collaboration between the Radboud University Medical Center (NLD), KU Leuven (BEL), Tel Aviv Sourasky Medical Center (ISR), and IRCCS Policlinico San Martino (ITA). The study consists of a joint prospective cohort project and four site-specific projects. We here describe the joint project, with the site-specific projects included as supplementary materials. All participants undergo a baseline assessment, consisting of extensive clinical testing and an objective gait assessment with and without external and internal cueing. Responders and non-responders to the strategy will be followed for 6 months. Responders will be instructed to apply the effective cueing strategies, as much as possible in daily life using a mobile cueing application which tracks compliance. At 6 months post-baseline, responders and non-responders return to the lab, during which the baseline protocol will be repeated to quantify the change in efficacy of the cueing strategies over time. The UNITE-PD study will identify the relationship between patient characteristics, cueing efficacy, compliance, and the underlying mechanisms of cueing. This knowledge will help refine personalized rehabilitation and identify new avenues for neuroscientific inquiry in this domain.

Alongside models and methods, concepts are crucial tools to study and understand the brain. They help us pursue various goals, such as describing phenomena based on patterns in the data or explaining why these phenomena occur. Yet while terms such as “action potential” or “network” guide our efforts to reach these goals, other concepts have failed to advance our understanding of the brain. In this paper, we draw on recent work from philosophy of science to show that the success or failure of concepts in neuroscience depends on the epistemic goals the field aims to achieve. Looking at cases such as “default mode network,” “cortical column,” and “hierarchy,” we formulate conditions under which introducing, refining, or replacing a concept succeeds or fails. These cases suggest that to better evaluate our concepts, we should make explicit which goals we aim to achieve when using them.

A recent study by Hausdorf et al. reported that combining closed-loop acoustic stimulation with transcranial direct current stimulation during sleep does not improve memory consolidation. This contrasts with past studies that reported a beneficial effect of each method individually. In this commentary, I discuss the relevance of the study in the current literature and offer potential explanations for this absence of effect.