The influence of anodal transcranial direct current stimulation over the right auditory cortex on interference effects in memory for melodies

Abstract

The study investigates how transcranial direct current stimulation (tDCS) over the auditory cortex (AC) modulates memory for melodies under different noise conditions, whilst also considering cumulative disruptive interference effects. Forty-one participants completed a continuous recognition melody task, as well as a visual control task, which included four noise conditions for which noise was either present only during encoding (N-C), only during retrieval (C-N), during both (N-N) or not at all (C-C) and completed the tasks after receiving anodal or sham tDCS over the right AC. The results of the sham session replicate previous findings by revealing that memory for melodies is worse when noise in added to the encoding phase (N-C) whereas the N-N condition shows good performance, highlighting a context effect, and that cumulative disruptive interference is not present in memory for melodies except in the N-C condition. After anodal stimulation the memory pattern differs such as that memory performance is best in the C-C condition and furthermore the cumulative disruptive interference effect in the N-C condition is diminished. In sum, the study highlights the involvement of the right AC for memory for melodies and the results indicate an association of the AC for creating context effects.