When we cannot speak: Eye contact disrupts resources available to cognitive control processes during verb generation.

Although eye contact and verbal processing appear independent, people frequently avert their eyes from interlocutors during conversation. This suggests that there is interference between these processes. We hypothesized that such interference occurs because both processes share cognitive resources of a domain-general system and explored the influence of eye contact on simultaneous verb generation processes (i.e., retrieval and selection). In the present experiment, viewing a movie of faces with eyes directed toward the viewer delayed verbal generation more than a movie of faces with averted eyes; however, this effect was only present when both retrieval and selection demands were high. The results support the hypothesis that eye contact shares domain-general cognitive resource with verb generation. This further indicates that a full understanding of functional and dysfunctional communication must consider the interaction and interference of verbal and non-verbal channels.