Mechanisms for the integration of information from eye gaze, head, and possibly body orientation, for example inhibitory connections as proposed in the DAD, seem to mature only later in development. This work was supported by the Deutsche Forschungsgemeinschaft (DFG) [Grant Number HO 4342/2-1]. We are grateful to the infants and parents who participated. “
“Previous work has shown that 4-month-olds can discriminate between two-dimensional (2D) RGFP966 in vitro depictions of structurally possible and impossible objects [S. M. Shuwairi (2009), Journal of Experimental Child Psychology, 104, 115; S. M. Shuwairi, M. K. Albert, & S. P. Johnson (2007), Psychological

Science, 18, 303]. Here, we asked whether evidence of discrimination of possible and impossible pictures would also be revealed in infants’ patterns of reaching and manual exploration. Nine-month-old infants were presented with realistic photograph displays of structurally possible and

impossible cubes along with a series of perceptual controls, and engaged in more frequent manual exploration of pictures of impossible objects. In addition, the impossible cube FK506 order display elicited significantly more social referencing and vocalizations than the possible cube and perceptual control displays. The increased manual gestures associated with the incoherent figure suggest that perceptual and manual action mechanisms are interrelated in early development. The infant’s visual system extracts structural information contained in 2D images in analyzing the projected 3D configuration, and this information serves to control both the oculomotor and

manual action systems. The question of how we are able to perceive objects in the real world as coherent in three dimensions, and how we are able to use visual information to act appropriately on a variety of objects, has been a topic of interest in the fields of development and perception for decades. Impossible figures, such as the cube shown in Figure 1, have long intrigued next a wide range of individuals, including artists and psychologists, and recent research has established that young infants share this interest (Shuwairi, Albert, and Johnson, 2007). Specifically, when shown cubes with possible intersections of elements versus cubes with an impossible one as in Figure 1, 4-month-old infants looked longer at the impossible object (Shuwairi, 2009; Shuwairi et al., 2007). Additional eye-tracking data revealed that 4-month-old infants showed longer dwell times and increased oculomotor activity for impossible relative to possible object displays (Shuwairi, 2008; Shuwairi & Johnson, 2006). Of most importance, they also engaged in active visual comparison of the critical regions in the impossible displays: those parts of the display containing overlapping edges that “defined” the images as impossible configurations in three-dimensional (3D) space.