The level of object conceptualization in human infants as manifested by linear tracking responses to a moving object

Prior studies by Bower (1971) and Gardner (1971) have claimed that 5 month olds, in visual tracking situations, reveal that they have a concept of object permanence in Piaget's Stage VI sense. This study was designed to evaluate their claim. Toward this end, the investigation had three distinct purposes: 1) to establish the characteristics of infants' tracking behavior in a linear tracking task when no screens are involved; 2) to observe and characterize the infants' tracking behavior and coping strategies when a screen is placed at the center of the track, and 3) to diagnose levels of object concept via the introduction of trick situations designed to violate possible expectations of infants. Forty infants were used in this study; 20 5-month old infants corresponding to Piaget's Stage III and 20 9-month old infants corresponding to Piaget's Stage IV. All infants viewed three sequences of trials; the warm-up trials, the screened pre-trick trials, and the trick trials. During the first sequence (or warm-up trials) the infants watched an object move back and forth along a linear track. This was followed by a sequence where an object was obscured briefly by a screen placed at the center of the track. The final sequence was either a transformation or a stop sequence. In the transformation sequence the Initial object was replaced behind the screen by a different object which completed the expected course. In the stop sequence, the object remained behind the screen 5 times longer than it would have on a non-trick trial. On each trial, the infants' tracking was assessed in terms of how attentive the infant was to the object in view, how the Infant followed it while in view and as it disappeared, where the infant looked while it was behind the screen, and how the infant reacted to the object's reappearance. The latter reaction was coded in two ways: how the infant reacted affectively to the initial sight of the object and how the Infant reacted to it subsequently (instrumental reaction). It was hypothesized that if the 5 month old Infants had acquired a concept of object in Piaget's Stage VI sense, then they would tend to be surprised by the transformation as it represents a violation of such a concept of object. They were also expected to look back to the screen for the missing object. On the stop trials, if the 5 month old infants had a concept of object, then they were expected to look for the hidden toy around the screen. The results indicated that all of the older infants and slightly more than half of the younger infants were able to visually track the object consistently and accurately when no screens were involved. On the screened trials, both age groups were similar in their ability to track the toy as it approached the screen and watch as it disappeared. However, the 5 month old infants were unable to anticipate the reappearance of the toy. Instead, they tended to look away from the display when the toy disappeared behind the screen. The 9 month old infants tended to anticipate the toy at the exit end of the screen indicating that they had an idea of where the toy should reappear. They did not seem to have this idea clearly as they frequently tended to look back to the entrance or at the screen before the object reappeared. On the pre-trick trials, neither age group showed signs of elevated affect or unusual instrumental looking reactions when the same toy reappeared. Both age groups tended to look at the toy and to continue to track 1t for the remainder of the trial. However, on the transformation trial, both age groups showed significantly increased affective scores. The older Infants tended to show more puzzlement and bafflement than the younger infants. But neither age group looked back to the screen for the missing toy. Instead they both continued to track the toy. On the stop trial, both age groups showed significantly higher affective scores than on non-trick trials. The older Infants tended to react to the stop with more puzzlement and bafflement than the younger ones, but the difference was not statistically significant. However, the older infants' instrumental reactions differed from the younger infants'. The older group was significantly more likely to stare vigilantly at the screen or monitor both ends of the screen as if looking for the missing toy. The younger infants tended to look away from the screen. The study did not tend to support the claim of Bower and Gardner that 5 month old infants had a Stage VI concept of object. This conclusion must be qualified in the light of procedural differences between this study and their studies. However on the whole it was concluded that this study of infants' performance in a visual tracking task indicated that their levels of object conception were consistent with those attributed by Piaget to infants of these ages.Psychology, Department o