Cerebellar Transcranial Direct Current Stimulation Improves Procedural Learning in Nonclinical Psychosis: A Double-Blind Crossover Study

Abstract

The present double-blind crossover study examines the effects of cerebellar transcranial direct current stimulation (tDCS) in controls and in an analogue population to psychosis: individuals reporting elevated symptoms of nonclinical psychosis (NCP). A total of 18 controls and 24 NCP individuals were randomized into conditions consisting of 25 minutes of anodal (active) or sham cerebellar tDCS. Following this, both groups completed a pursuit rotor task designed to measure procedural learning performance. Participants then returned 1-week later and received the corresponding condition (either active or sham) and repeated the pursuit rotor task. Results indicate that in the sham condition, control participants showed significantly greater rates of motor learning when compared with the NCP group. In the active condition, the NCP group exhibited significant improvements in the rate of motor learning and performed at a level that was comparable to controls; these data support the link between cerebellar dysfunction and motor learning. Taken together, tDCS may be a promising treatment mechanism for patient populations and a useful experimental approach in elucidating our understanding of psychosis.

Cerebellar parcellation in schizophrenia and bipolar disorder

“…The cerebellum is connected to almost every region of the brain, with the exception of the visual cortex and might represent a potential therapeutic target. For example, transcranial direct current stimulation (tDCS) has been applied in patients with non‐clinical psychosis to improve their skills in procedural learning . Understanding the exact location of the cerebellar alterations in schizophrenia and bipolar disorder is important since the location of the cerebellar stimulation influence the effect of brain stimulation in the cerebellum and distant cortical regions .…”

Postural Control and Verbal and Visual Working Memory Correlates in Nonclinical Psychosis

“…If the CTTC circuit does show vulnerability across the psychosis continuum, it will also be important to build a better understanding of cognitive correlates. As noted, procedural learning has already been implicated [33], but it is important to also consider that the CTCC circuit is implicated in modulating a variety of higher-order cognitive functions including working memory [37,38]. Correlates with sway area and cognitive performance in NCP will help to provide early building blocks for understanding how a common circuit dysfunction may contribute to a wide array of symptoms and characteristics, something that has been well established in formal psychosis with theories such as cognitive dysmetria [24,25], but has not been investigated at the lower end of the psychosis continuum.…”

“…Specifically, in a double-blind, crossover paradigm, NCP and control participants completed a motor-learning pursuit rotor task after cerebellar transcranial direct current stimulation at one visit, and after a sham (placebo) stimulation at the other visit. The results indicated that, following the sham condition, NCP participants showed significantly lower rates of motor learning across trials; after the active condition, they performed at comparable rates to controls [33]. However, while this provides some support for a potential continuum of cerebellar vulnerability, currently we lack studies of motor behavior that would serve to enrich this perspective.…”

Cerebellar Transcranial Direct Current Stimulation (ctDCS) Effect in Perception and Modulation of Pain

“…Cerebellar direct current stimulation has been widely used for the treatment of several neuropsychiatric diseases, ranging from movement disorders [21][22][23][24][25] to autism and schizophrenia [26,27], but only few evidence has been reached so far regarding pain therapy.…”