To better understand what is going on in the brain during conversation, the researchers enlisted the assistance of 26 volunteers who were asked to participate in a common word-association game in which a person was shown a word (a noun) and was then asked to offer an immediate response (a verb), e.g. when given the word “ball,” a reply might be the word “throw.” In the lab, the volunteers interacted with a face on a computer (that sometimes looked away) as they played the game with different types of words that the researchers had preselected—some were easy while others were more difficult—coming up with a verb for “sky,” for example, can be difficult for some because of the lack of choices, while coming up with a response to a word like “leaf” may be difficult because it has so many options to choose from.
The researchers then compared responses to the words with how long it took a volunteer to respond and their tendency to break eye contact. They found that the volunteers were likely to take more time when responding to harder words, but not as much time if they broke eye contact. This, the research pair suggest, indicates that the dual task of maintaining eye contact (and the inherent intimate connection it involves) while also racking the brain for a word to meet the request is just too demanding—to save itself, the brain pushes for breaking eye contactso it can focus exclusively on finding a word that will fulfill the obligation.
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.