The effects of transcranial direct current stimulation on pragmatic processing

- We tested the role of the STG in processing sentences with a pragmatic violation.
- Bilateral tDCS applied over the STG improved pragmatic processing.
- tDCS did not affect the processing of sentences with a semantic violation.
- Pragmatic but not semantic information is derived from the STG.

The current study used the violation paradigm to assess responses to pragmatically and semantically violated sentences. Thirteen participants received bilateral tDCS stimulation (anodal -- left Superior Temporal Gyrus (STG) and cathodal -- right STG). The participants listened to sentences with no violations as well as sentences with pragmatic or semantic violations and had to indicate whether each sentence “makes sense”. This task was conducted in three conditions - without stimulation, after active stimulation, and after a sham procedure. The results showed faster response times for the pragmatic violations than for the semantic violations. The response times for the pragmatic violations after active stimulation were faster than after a sham stimulation. No similar difference in response times was observed for the semantic violations. These findings suggest that brain stimulation of the STG area modulates the processing of pragmatic but not semantic information.