Here’s a new paper ( https://bit.ly/3hLxgbM ) by the awesome @Delia_Gheorghe, the wonderful Muriel Panouillères and myself. A reviewer called it ‘rigorous but speculative’ that I thought was fair/amusing. To spread the word I thought I would create a Twitter thread. 1/

It won’t be of interest to that many people, given that no other researchers are investigating how stress affects the cerebellum with transcranial stimulation (that I’m aware of). Also it’s a controversial area whether and if so, how the cerebellum is affected by stress. 2/

However previous work by myself and colleagues have shown the cerebellum is affected by SSRI’s (Walsh et al. 2007) and is smaller in individuals exposed to early-life stress (Walsh et al. 2014). 3/

However, the specific neurocognitive mechanisms explaining these affects are currently incompletely understood. We’re learning more and more about the anatomical connections between the cerebellum and other stress-related regions e.g. between the cerebellum and hypothalamus. 4/

In an earlier study https://bit.ly/3hJKLZC  we showed that exposure to an experimental stressor can affect performance on a cerebellar-dependent task (saccadic adaptation). 5/

In this new study we wanted to see if by experimentally modulating cerebellar activity, through tDCS, we could not only modulate behavioural performance, but we could also modulate stress-related measures such as subjective experience and the cortisol response. 6/

Previous studies have shown TMS and tDCS over the prefrontal cortex can modulate cortisol output and autonomic measures, but only in the context of an experimental stressor. There doesn’t seem to be an effect on cortisol or mood when people are at rest. 7/

However, given the strong connections with the hypothalamus we wanted to investigate is this is similarly the case with cerebellar tDCS. So this was the experiment, to see how cerebellar tDCS affected saccadic adaptation performance, subjective stress experience and cortisol. 8/

In replication of prior work by others, we found cerebellar tDCS affected behaviour (saccadic adaptation), with anodal stimulation increasing learning compared to sham and cathodal stimulation. However, we found no effect on mood or cortisol. 9/

The obvious next experiment was to run this experiment again but in the context of an experimental stressor but sadly we ran out of road (PhD time/funding) to do this. 10/

So it is still an open question whether cerebellar tDCS affects stress regulation following an experimental stressor. Such is science! But it was fun running this experiment and please check out the paper for more details! 11/