Assessing the Impact of Language on Visual Threat Detection: cTBS over the anterior temporal lobe impairs semantic processing but not visual threat detection

Constructionist models of emotion propose that conceptual knowledge is integral to emotion perception, but whether the rapid detection of threat depends on conceptual knowledge remains causally untested. The ventrolateral anterior temporal lobe (vATL), a core hub of the semantic system, offers a site for testing this dependence with neuromodulation. In a within-subject, sham-controlled design, 20 healthy adults received continuous theta-burst stimulation (cTBS) over the left vATL and a sham stimulation in separate sessions. Before and after stimulation, participants completed three reaction-time tasks: a category membership task indexing semantic processing, a pattern matching task serving as a non-semantic control, and a visual search task measuring the threat superiority effect (faster detection of threatening than neutral targets). Relative to sham, cTBS slowed semantic categorization but not pattern matching, indicating that the stimulation disrupted semantic processing. In contrast, the threat superiority effect was present before and after both stimulations, and its magnitude did not differ significantly between conditions. Rapid visual threat detection therefore showed no detectable reliance on the conceptual knowledge supported by the left vATL. Constructionist accounts may need to distinguish the rapid prioritization of danger from the categorization and experience of threat, where conceptual knowledge may still play a role.