The current findings see more are relevant for our understanding of the mechanisms underlying social attention cueing and gaze following in early development. To account for the apparently contradictory findings of very early gaze cueing effects
(even in newborns, see Farroni et al., 2004), but relatively late overt following of eye gaze without head orientation cues, Moore and Corkum (1998) have argued that early attention cueing through eye gaze may not depend on awareness of the other person’s attention focus and should be distinguished from more deliberate gaze following and joint attention in older infants. In accordance with this notion, it is conceivable that the effects of eye gaze and head orientation on object processing rely on relatively automatic attention cueing in young infants. The direction-of-attention detector (DAD), proposed by Perrett and colleagues (Perrett & Emery, 1994; Perrett et al., 1992), is an influential model to account Forskolin supplier for attention cueing effects from different kinds of information that can indicate another person’s visual attention. They found that single cells in the macaque superior temporal sulcus respond to information from eye
gaze, head orientation, and body orientation and some are sensitive to conjunctions of these cues, for example eyes and head looking downwards. The DAD is supposed to combine information from all of these cues through a network of inhibitory connections in which information from the eyes overrides information from the other cues. For instance, Ergoloid responses
to a head looking downward are suppressed when the eyes look upward. When the eyes are invisible, the system relies on head and body orientation alone. Later research with human adults has shown that head information is not completely inhibited by incongruent eye information, but rather attenuated (Langton, Watt, & Bruce, 2000). Our results add an intriguing developmental perspective to this model. We show that 4-month-old infants follow head turns as well as eye gaze shifts to the side which consequently affects their processing of peripheral objects. This suggests that two subcomponents of the DAD, the eye gaze detector and the head orientation detector, are already functional at this age. However, the inhibitory connections between these components may not be mature yet. Thus, head orientation can cue infants’ attention to the side despite incongruent information from the eyes. We conclude that head orientation and eye gaze effectively direct infants’ attention toward peripheral objects, thus facilitating processing of cued objects. Uncued objects, in contrast, seem to require relatively more processing and examination when being presented again.