Excerpt from an interview with clinical neuroscientist, Kate Hoy. The paper referenced is Testing the limits: Investigating the effect of tDCS dose on working memory enhancement in healthy controls

What is the most surprising or interesting research case you have worked on?

The findings where the data doesn’t show what you expected are always the ones that mean the most. In one study we were looking at the effect of gentle electrical stimulation (tDCS) on memory in healthy people; we compared sham (‘fake’) stimulation with a low and a high dose of tDCS. My hypothesis was that the higher the dose the better would be the performance and I couldn’t have been more wrong. The findings showed that the sham stimulation did nothing (as predicted), the low dose improved performance significantly, and the high dose behaved most similar to the sham stimulation.

This puzzled us so we brainstormed the findings and came back to the idea of homeostasis, where you can push the healthy brain a little but if you push it too much it will ‘push back’. Essentially, there are only limited gains in brain function that can be achieved in the healthy brain. That finding, which was from an Honours project, that I had initially worried was uninterpretable, resulted in a publication, two current PhD projects, and set me off on a different path with this aspect of my research.