The impact of cerebellar transcranial direct current stimulation (tDCS) on sensorimotor and inter-sensory temporal recalibration

Abstract

The characteristic temporal relationship between actions and their sensory outcomes allows us to distinguish self- from externally generated sensory events. However, the complex sensory environment can cause transient delays between action and outcome calling for flexible recalibration of predicted sensorimotor timing. Since the neural underpinnings of this process are largely unknown this study investigated the involvement of the cerebellum by means of cerebellar transcranial direct current stimulation (ctDCS). While receiving anodal, cathodal, dual-hemisphere or sham ctDCS, in an adaptation phase, participants were exposed to constant delays of 150 ms between actively or passively generated button presses and visual sensory outcomes. Recalibration in the same (visual outcome) and in another sensory modality (auditory outcome) was assessed in a subsequent test phase during which variable delays between button press and visual or auditory outcome had to be detected. Results indicated that temporal recalibration occurred in audition after anodal ctDCS while it was absent in vision. As the adaptation modality was visual, effects in audition suggest that recalibration occurred on a supra-modal level. In active conditions, anodal ctDCS improved sensorimotor recalibration at the delay level closest to the adaptation delay, suggesting a precise cerebellar-dependent temporal recalibration mechanism. In passive conditions, the facilitation of inter-sensory recalibration by anodal ctDCS was overall stronger and tuned to larger delays. These findings point to a role of the cerebellum in supra-modal temporal recalibration across sensorimotor and perceptual domains, but the differential manifestation of the effect across delay levels in active and passive conditions points to differences in the underlying mechanisms depending on the availability of action-based predictions. Furthermore, these results suggest that anodal ctDCS can be a promising tool for facilitating effects of temporal recalibration in sensorimotor and inter-sensory contexts.

Facilitation of sensorimotor temporal recalibration mechanisms by cerebellar tDCS in patients with schizophrenia spectrum disorder and healthy subjects

“…2,4,18–21 The adaptation of these predictions when required due to changing environmental conditions could also be associated with processes in the cerebellum. 19,28,29,48,49 Thus, the faciliatory impact of cerebellar tDCS on the TRE suggests that the recalibration of these predictive processes in the cerebellum was amplified by the stimulation, which is in line with previous studies demonstrating a faciliatory influence of cerebellar stimulation on sensorimotor temporal recalibration mechanisms in healthy subjects. 28,29 This is further supported by the fact that the TRE was generally larger in active than in passive conditions for both groups in our study.…”

“…19,28,29,48,49 Thus, the faciliatory impact of cerebellar tDCS on the TRE suggests that the recalibration of these predictive processes in the cerebellum was amplified by the stimulation, which is in line with previous studies demonstrating a faciliatory influence of cerebellar stimulation on sensorimotor temporal recalibration mechanisms in healthy subjects. 28,29 This is further supported by the fact that the TRE was generally larger in active than in passive conditions for both groups in our study. In both active and passive conditions, the TRE can be associated with the recalibration of the expected inter-sensory timing between the tactile sensation of the button movement and the visual or auditory outcome.…”

“…Interestingly, non-invasive brain stimulation techniques have demonstrated the potential to modulate these processes. For instance, transcranial magnetic stimulation (TMS) 28 or transcranial direct current stimulation (tDCS) 29 of the cerebellum influenced the effect of sensorimotor temporal recalibration on perception in healthy subjects. Furthermore, tDCS on the angular gyrus, 30 the pre-supplementary motor area, 31,32 and frontal regions 33,34 modulated measures for agency and action-outcome-related processing, even in SSD.…”

Neural correlates of temporal recalibration to delayed auditory feedback of active and passive movements

“…A recent tDCS study further showed that anodal stimulation of the bilateral cerebellum influenced temporal recalibration. By comparing the TRE resulting from the exposure to delayed outcomes of actively performed versus passively elicited movements, it appeared that this effect was not exclusive to the sensorimotor context (active movements) but extended to the intersensory context (passive movements) where no action and thus no sensorimotor prediction was involved (Schmitter & Straube, 2022).…”

Pre‐movement event‐related potentials and multivariate pattern of EEG encode action outcome prediction

“…We employed a device which uses an electromagnet to produce the involuntary movements (passive movement device). This and similar devices have been used in several previous studies (Arikan et al, 2017(Arikan et al, , 2019Ody et al, 2023;Pazen et al, 2020;Schmitter et al, 2021;Schmitter & Straube, 2022;Straube et al, 2020;Uhlmann et al, 2020Uhlmann et al, , 2021van Kemenade et al, 2016). Participants made active (self-initiated) or passive (finger moved by device) movements.…”