Eye Movements during Cognition and Conversation

Femme fatales, interrogators, and cult leaders know the importance of eye movements. Gaze can act as a signal of attraction, a window into someone's thoughts, and a means of persuasion. The close link between eye movements and psychological processes results from the anatomy of the eyeball. Detailed information can only be discerned from a small region in the center of the field of view, the fovea. So, unlike a wide-angled closed-circuit television camera that can slowly and passively sweep a large area, the small fovea must be rapidly and constantly moved around the world. For these motions to be efficient, they have to be intelligent. Therefore, eye movements are closely linked to the beliefs, expectations, and intentions of the observer. This link between eye and mind has recently been exploited by cognitive psychologists, but, perhaps implicitly, we are all attuned to the gaze patterns of those around us and what they indicate about the observer's mental state. This entry examines the connection [Page 437]between gaze and cognition, and the role this plays in social interaction and conversation.

The mental processes of a simple decision can be seen in how the eye moves between choices. For example, the distribution of eye movements among a set of faces will reveal relatively how much each is preferred. If someone is asked to make a simple judgment, such as placing a sound or an object into one of two categories presented on screen, that person's eye movements between the options will reflect how certain he or she is of each item's membership. Moreover, influencing how the eyes move can influence mental processes. Researchers recorded the eye movements of participants interpreting an ambiguous picture or solving a difficult deductive problem from a diagram. Using low-level visual cues, such as brightening some areas of the image, a second set of participants were then influenced to attend to the same regions of the picture. The second set of participants was more likely to form the same interpretation of the ambiguous picture, and remarkably, was more likely to solve the deductive problem.

We do not have to be looking at objects or pictures for gaze to reveal cognitive processes. When looking at a blank screen and recalling an image or a painting, the eyes tend to move as they did during the initial viewing. When recalling nonvisual, spoken facts, the eyes will return to areas of a blank screen that were associated with the information. Not just memory, but imagery too can drive eye movements. Gaze becomes more active during spatial mental imagery and vivid dreams, and the eyes will move either horizontally or vertically when listening to a story about a train leaving the station or a man rappelling down a canyon.

How we move our eyes when listening to people speak reveals the time course of language comprehension and the way in which we ground spoken information in the visual world. For example, when people were asked to “pick up the candle” from the table, half way through the last word, they would often look at a candy lying nearby. This demonstrates that language comprehension is incremental: Listeners continually search for potential referents of spoken words in the visual world. Similarly, eye movements are yoked to language production. Speakers reliably look at objects just under a second before naming them. When two people talk to each while looking at the same visual scene, while watching a movie for example, their eye movements are closely coupled. The degree to which their eye movements are coordinated relates to how well they understand each other.

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