Although the human cerebellum has a surface that is about 80% of that of the cerebral cortex and has about four times as many neurons, its functional organization is still very much uncharted. Despite recent attempts to provide resting-state and task-based parcellations of the cerebellum, these two approaches lead to large discrepancies. This article describes a comprehensive task-based functional parcellation of the human cerebellum based on a large-scale functional database, NeuroSynth, involving an unprecedented diversity of tasks, which were reliably associated with ontological key terms referring to psychological functions. Involving over 44,500 participants from this database, we present a parcellation that exhibits replicability with earlier resting-state parcellations across cerebellar and neocortical structures. The functional parcellation of the cerebellum confirms the major networks revealed in prior work, including sensorimotor, directed (dorsal) attention, divided (ventral) attention, executive control, mentalizing (default mode) networks, tiny patches of a limbic network, and also a unilateral language network (but not the visual network), and the association of these networks with underlying ontological key terms confirms their major functionality. The networks are revealed at locations that are roughly similar to prior resting-state cerebellar parcellations, although they are less symmetric and more fragmented across the two hemispheres. This functional parcellation of the human cerebellum and associated key terms can provide a useful guide in designing studies to test specific functional hypotheses and provide a reference for interpreting the results.

The global aging population faces significant health challenges, including an increasing vulnerability to disability due to natural aging processes. Wearable lower limb exoskeletons (LLEs) have emerged as a promising solution to enhance physical function in older individuals. This systematic review synthesizes the use of LLEs in alignment with the WHO’s healthy aging vision, examining their impact on intrinsic capacities and functional abilities. We conducted a comprehensive literature search in six databases, yielding 36 relevant articles covering older adults (65+) with various health conditions, including sarcopenia, stroke, Parkinson’s Disease, osteoarthritis, and more. The interventions, spanning one to forty sessions, utilized a range of LLE technologies such as Ekso^®, HAL^®, Stride Management Assist^®, Honda Walking Assist^®, Lokomat^®, Walkbot^®, Healbot^®, Keeogo Rehab^®, EX1^®, overground wearable exoskeletons, Eksoband^®, powered ankle–foot orthoses, HAL^® lumbar type, Human Body Posturizer^®, Gait Enhancing and Motivation System^®, soft robotic suits, and active pelvis orthoses. The findings revealed substantial positive outcomes across diverse health conditions. LLE training led to improvements in key performance indicators, such as the 10 Meter Walk Test, Five Times Sit-to-Stand test, Timed Up and Go test, and more. Additionally, enhancements were observed in gait quality, joint mobility, muscle strength, and balance. These improvements were accompanied by reductions in sedentary behavior, pain perception, muscle exertion, and metabolic cost while walking. While longer intervention durations can aid in the rehabilitation of intrinsic capacities, even the instantaneous augmentation of functional abilities can be observed in a single session. In summary, this review demonstrates consistent and significant enhancements in critical parameters across a broad spectrum of health conditions following LLE interventions in older adults. These findings underscore the potential of LLE in promoting healthy aging and enhancing the well-being of older adults.

Implicit motor sequence learning (IMSL) is affected in Parkinson's disease (PD). Research in healthy young participants shows the potential for transcranial direct‐current stimulation (tDCS) over the primary motor cortex (M1) to enhance IMSL. In PD, only null effects have been reported to date. We determined concurrent, short‐term, and long‐term effects of anodal tDCS over M1 on IMSL, as measured by the serial reaction time (SRT) task, in persons with PD with mild cognitive impairment (MCI). Concurrent (anodal/sham tDCS intervention during the SRT task), short‐term (5 min post‐intervention), and long‐term (1 week post‐intervention) effects on IMSL were evaluated in persons with idiopathic PD (Hoehn and Yahr stage II‐III) with MCI. Results of 11 persons with PD (8 men and 3 women; mean age = 77.1 years; mean disease duration = 7.7 years) showed significant IMSL in the anodal ( p = .016), but not in the sham tDCS condition ( p = .937). Post‐hoc analyses showed that IMSL reached statistical significance at 1 week post‐intervention ( p < .001). Anodal tDCS over M1 exerted beneficial effects on IMSL in persons with PD with MCI, in particular one week post‐intervention. Our study is the first to report a positive effect of tDCS on IMSL in PD. Further research should include a larger, more cognitively diverse sample and additional follow‐up periods.

Background: Implicit motor sequence learning (IMSL) is a cognitive function that allows us to execute multiple movements in a specific sequential order and plays a crucial role in our daily functional activities. Although the role of the basal ganglia network in IMSL is well-established, the exact involvement of the cerebellar network is less clear.Aim: Here, we aimed to address this issue by investigating the effects of cerebellar transcranial direct-current stimulation (tDCS) on IMSL.Methods: In this sham-controlled, crossover study in 45 healthy young adults, we used mixed-effects models to analyze sequence-specific (primary outcome) and general learning effects (secondary outcome) in the acquisition (during tDCS), short- (five minutes post-tDCS) and long-term consolidation (one week post-tDCS) phases of IMSL, as measured by the serial reaction time (SRT) task.Results: Analyses based on response times (RTs) revealed that anodal tDCS over the cerebellum significantly increased sequence-specific learning during acquisition, compared to sham (anodal: M = 38.24 ms, sham: M = 26.78 ms, p = 0.032); did not affect general learning; and significantly slowed overall RTs (anodal: M = 362.03 ms, sham: M = 356.37 ms, p = 0.049). Accuracy-based analyses revealed that anodal tDCS reduced the probability of correct responses occurring in random trials versus sequential trials by 1.17%, p = 0.009, whereas sham tDCS had no effect, p = 0.999.Conclusion: Our finding of enhanced sequence-specific learning, but not general learning, suggests that the cerebellar network not only plays a role in error correction processes, but also serves a sequence-specific function within the integrated motor learning network that connects the basal ganglia and cerebellum.

Various studies investigated implicit sequence learning in Parkinson's disease (PD) by means of the traditional motor Serial Reaction Time (SRT) task and found a general pattern of impaired sequence learning. However, as perceptual and motor sequences of the SRT-task were correlated in previous studies, implicit sequential knowledge acquisition that is tested independently from motor sequences remains to be determined in PD. In this study, we investigated implicit sequence learning independently from motor sequence learning in individuals with PD. To this end, we used a perceptual SRT-task that did not rely upon sequential motor knowledge. We measured response times (RTs) of 19 participants with PD (Hoehn & Yahr II or III; mean age 65) and 18 age-matched healthy controls (HC; mean age 61.5) in a perceptual SRT-task. General learning effects and sequence-specific learning effects were analyzed using repeated measures ANOVAs. A significant decreasing linear trend (p < .001) in RTs was revealed in both the PD and HC groups as the SRT-task progressed, indicating general learning effects. Notably, a significant, strong main effect of sequence-specific learning occurred (p < .001), irrespective of group (p = .436). Sequence-specific learning did not differ significantly between the PD (M = 156.5 ms; SD = 50.7) and HC group (M = 173.0 ms; SD = 104.2). Bayesian analyses confirmed this as evidence of absence of an effect (B₁₀ = 3.543). Our results suggest that, at least in Hoehn & Yahr stages II and III, implicit sequential knowledge acquisition may be preserved in individuals with PD, when tested independently from motor sequence learning. (PsycInfo Database Record (c) 2021 APA, all rights reserved).