Guess who? Investigating the proper name processing network by means of tDCS

Learning people's names is a challenging task for most individuals and becomes increasingly difficult with age. In the current study, we investigated the role of the fronto-temporal network in this task by applying tDCS over the left anterior temporal lobe (ATL) and the left inferior frontal gyrus (IFG) during unfamiliar face-name association learning. Proper name retrieval was tested with a face naming and a face-name association task. In Experiment 1, we found that real anodal tDCS over the left ATL decreased naming accuracy compared to sham stimulation because participants produced significantly more intrusions. The stimulation may have increased interference among arising competitors when retrieving the correct name associated to the presented face, as indicated by the longer response latencies in the association task after real tDCS. In Experiment 2, cathodal tDCS applied over the left ATL did not affect the participants' performance in the same tasks, ruling out a possible effect of discomfort or stimulation side effects. In Experiment 3, anodal tDCS over the left IFG led to a significant decrease in intrusions compared to sham stimulation, possibly improving a selection mechanism. Our results confirm the role of the left ATL and the IFG in the retrieval of proper names, and demonstrate the importance of their functional interaction in processing proper names.