Brain Sciences

Background: Cognitive aging is highly heterogeneous, not only in performance but also in how individuals perceive their own aging. Such self-perceptions may shape emotional reactions and adaptation to memory difficulties, yet little is known about their organization in patients referred to a memory clinic for a first diagnostic consultation. The primary aim of this study was to identify the internal configuration of self-perceptions of aging in such patients. A secondary aim was to compare these patterns with those observed in older adults recruited in a research unit of experimental psychology, who reported subjective complaints but had no medical referral. Methods: In total, 130 memory clinic patients and 84 laboratory participants completed, prior to the same neuropsychological testing, a psychosocial questionnaire assessing four domains: self-perceptions of memory deficits, attitudes toward aging, aging stereotypes, and multiple facets of subjective age. Network analysis was applied to examine how these variables were interrelated and to determine their relative importance in each group. Results: Across both samples, network analyses revealed distinct organizational patterns. Patients showed a unified representational system characterized by more positive associations and centered on subjective age variables. By contrast, the laboratory group showed a two-cluster network with more negative connections, organized around negative aging stereotypes. Conclusions: These findings provide novel insights into the psychosocial profile of memory clinic patients, highlighting the added value of network approaches for capturing the interrelations among key self-representations of aging and memory, and for informing and contextualizing clinical evaluation.

Background/Objectives: It is widely recognized that malfunctions in the GABAergic system can be one of the underlying mechanisms in chronic pain. However, the use of GABAergic drugs to improve pain perception has strong and unwanted side effects, particularly in terms of sedation. Therefore, the present exploratory single-case study tested an alternative treatment using balance training to upregulate the GABAergic system in a 62-year-old patient with widespread chronic pain. Previously, balance training was shown to increase short-interval intracortical inhibition (SICI), a neurophysiological marker commonly associated with GABA-mediated intracortical inhibition, as assessed using paired-pulse transcranial magnetic stimulation (TMS), in healthy young and older adults. Therefore, we hypothesized that the balance-training-induced increase in GABA_A-related intracortical inhibition would alleviate pain and increase quality of life. Methods: After two baseline measures, the patient participated in two balance training periods of 4 weeks each, followed by two detraining phases of 2 months each. At baseline and after each intervention and each detraining, intracortical inhibition (i.e., SICI) as well as pain and ‘well-being’ (questionnaires) was assessed. Results: Our results demonstrated enhanced and better modulated intracortical inhibition after 4 weeks of balance training, which was in line with analgesia and improved sleep and mood scores. However, after the first detraining, all parameters went back to baseline. In a subsequent second period of 4 weeks of balance training, intracortical inhibition was again increased, even above the values of the first training period. Pain, sleep, and mood scores were also further improved. After the second detraining period, all values dropped back close to their baseline values. Conclusions: The findings support the assumption that the GABAergic system is highly relevant in the processing and perception of pain. More importantly, our results suggest the possibility that balance training may be an effective way not only to upregulate intracortical inhibition but also to alleviate pain and improve well-being in patients with unspecific chronic pain.

Background: Motor imagery-based brain-computer interfaces (MI-BCIs) enable individuals who are unable to perform physical movements to interact with the external world by imagining movements. Users are typically classified as good performers or BCI-illiterate based on the classification accuracy of distinct EEG patterns (e.g., 60% or 70%). Yet, studies show that approximately 70% of users fall within intermediate accuracies between 60% and 80%, and although exceed the chance level, they often fail to achieve reliable MI-BCI control. Intermediate users often exhibit asymmetric motor imagery abilities between left and right hands, highlighting the need for refined early assessment and stratified training approaches. Methods: We employed ICA to decompose each participant’s EEG data and extract independent ERD/ERS components as indicators using a rule-based automated framework. This framework integrated dipole localization, ERD/ERS characteristics, and frequency-band power features of ICs. Importantly, we applied a power spectral parameterization approach to remove the 1/f-like background activity in power estimation and used statistical methods to precisely estimate the latency and duration of ERD. The extracted indicators were subsequently subjected to clustering analysis to categorize participants into four groups. Results: In addition to good performers (24.8%) and poor performers (35.8%), two groups were identified: LgoodRpoor (27.5%), who performed well in left-hand MI but poorly in right-hand MI, and LpoorRgood (11.9%), who showed the opposite pattern. Notably, these unilateral performers did not show significant differences in contralateral ERD but exhibited substantial differences in ipsilateral ERS. Conclusions: The proposed independent event-related brain dynamics model enables more refined stratification of MI-BCI users. Findings from this characterization study may inform the design of graded training protocols, especially for users demonstrating unilateral motor imagery proficiency.