THE PERCEPTUAL COMPLETION PROCESS: EVIDENCE FROM 8-YEAR-OLDS, 11-YEAR-OLDS, AND ADULTS

Abstract

<p>Three main theories have been proposed to account for the completion of occluded objects, namely local theories (e.g., Kellman & Shipley, 1991), global theories (e.g., Boselie & Leeuwenberg, 1986), and integrative models of completion (e.g., Sekuler, 1994; van Lier et al., 1994). Here, we investigated age-related changes in the completion of a complex partially occluded object using a prime-matching task. Subjects were shown a prime (global, local, occluded, or no prime) that was followed immediately by two shapes that were judged as being the same or different. In Experiment 1, we tested adults (n = 36/group) at various prime durations (150 - 700 msec) to tap into earlier and later representations of the occluded object. Although the occluded object primed both the global and local shapes at 150 and 500 msec (<em>p</em>s<0.05), only the global shapes were primed at 300 and 700 msec (<em>p</em>s<0.05). Overall, our results are most consistent with integrative models of completion. In Experiment 2, we tested 8-year-olds (n = 20) at a prime duration of 700 msec and 11-year-olds (n = 30/group) at a prime duration of 300 or 700 msec. For 11-year-olds, unlike adults, the occluded object did not significantly prime either the global or local shapes at 300 msec (<em>p</em>>0.50). For both 8- and 11-year-olds, the global, local, and occluded primes did not significantly prime either shape at 700 msec (<em>p</em>s>0.50). Based on the current testing conditions, we found that the perceptual completion process may not be adult-like even at 11 years of age.</p>