The left angular gyrus is causally involved in information buffering and context formation: evidence from a narrative reading task

The role of the left angular gyrus (Ag) in semantic processing remains unclear. In this study, we used transcranial magnetic stimulation (TMS) to test the hypothesis that the left Ag supports the information buffering processes necessary for context-dependent semantic integration (narrative reading task). We applied online TMS to the left Ag to disrupt the buffering processes while female and male human participants integrated information between two paragraphs of text presented sequentially (i.e., context and target conditions). We assessed the effect of TMS on the left Ag by recording reading times for target conditions during the reading task and by asking participants to retrieve contextual information given the target condition as cue in a successive memory task. TMS applied over the left Ag during the reading task impaired the retrieval of contextual information in the memory task without affecting reading times. These results suggest that the Ag supports information buffering and context formation. This study provides the first evidence of a causal role of the left Ag in language tasks that require context-dependent semantic integration. Significance statementThe present study offers novel insights into the processes that are associated with the left angular gyrus (Ag) activation during context-dependent naturalistic language processing. We used TMS while human participants read written narratives to interfere with online language integration. We measured how TMS over the left Ag was affecting reading times and retrieval of integrated narrative representations. We were able to show that the left Ag is causally involved in information buffering and context formation.