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We investigate when infants exhibit knowledge of the familiar size of well‐known objects and whether this knowledge is affected by stimulus format, that is, whether the stimuli are presented as real objects or matched pictures. Infants (130 7‐ and 12‐month‐olds) saw everyday objects such as sippy cups and pacifiers in their familiar size and novel sizes (larger or smaller than the familiar size) placed pairwise within infants' reach. We used a preferential‐looking paradigm to investigate whether infants are able to discriminate familiar from novel sizes. Although, infants of both age groups looked longer toward real objects that were smaller or larger than the familiar size, there were no looking preferences for the pictures. These results suggest that although 7‐ and 12‐month‐olds demonstrate familiar size knowledge for real objects, this understanding does not generalize to pictorial representations of those objects. [ABSTRACT FROM AUTHOR]

The role of binocular vision in grasping has frequently been assessed by measuring the effects on grasp kinematics of covering one eye. These studies have typically used three or fewer objects presented at three or fewer distances, raising the possibility that participants learn the properties of the stimulus set. If so, even relatively poor visual information may be sufficient to identify which object/distance configuration is presented on a given trial, in effect providing an additional source of depth information. Here we show that the availability of this uncontrolled cue leads to an underestimate of the effects of removing binocular information, and therefore to an overestimate of the effectiveness of the remaining cues. We measured the effects of removing binocular cues on visually open-loop grasps using (1) a conventional small stimulus-set, and (2) a large, pseudo-randomised stimulus set, which could not be learned. Removing binocular cues resulted in a significant change in grip aperture scaling in both conditions: peak grip apertures were larger (when reaching to small objects), and scaled less with increases in object size. However, this effect was significantly larger with the randomised stimulus set. These results confirm that binocular information makes a significant contribution to grasp planning. Moreover, they suggest that learned stimulus information can contribute to grasping in typical experiments, and so the contribution of information from binocular vision (and from other depth cues) may not have been measured accurately. [ABSTRACT FROM AUTHOR]