New article shows causal role of right auditory cortex in pitch learning.

This new article published in NeuroImage is the fruit of another successful collaboration with Robert Zatorre’s lab, also at the Montreal Neurological Institute.

The study was driven by Robert’s grad student Reiko Matsushita, in collaboration with Dr. Sebastian Puschmann.

The goal was to show that pitch learning was inhibited by applying transcranial electrical stimulation (tDCS) over right vs. left auditory cortex.

The neurophysiological effects caused by tDCS were characterized via simultaneous MEG imaging.

Reiko used a simple but clever micro-melody pitch discrimination task designed to probe pitch learning over 3 consecutive days.

Participants in 3 groups received right vs left vs sham auditory cortex tDCS while in the MEG (Day 1) & performing the micro-melody task.

They were tested again on two other days, to evaluate the sustainability of tDCS effects (no MEG).

Of course, tDCS creates large artifacts in MEG, but they are stereotypical and can be attenuated using ICA or similar techniques.

Reiko extracted the early auditory responses bilaterally from auditory cortical regions: at baseline, during tDCS/sham and after tDCS.

There was a striking reduction of the N1m response (~100ms), ipsilateral to the side of tDCS stimulation.

What are the behavioral implications?

Well, it looks like the folks who received right auditory cortex inhibition were not able to improve on the task over the next 2 days.

The other folks (sham and left tDCS) improved just fine.

Finally and closing the loop, Reiko showed the amount of neurophysiological signal reduction in auditory cortex from tDCS was related to (reduced) task performance.

Access to the study is open and free.