Object Permanence

This thesis uses concepts developed by Ruth Millikan as part of her “biosemantic” theory of intentional signs to explain her theory of about what it means to identify the “substance” that is the object of one’s thoughts. It then applies these concepts and the theory to elucidate her analysis of identity statements. Finally, it develops and explores Millikan’s notion of “sameness marker” functioning, the notion being that there exist sameness markers in the mind or brain that allow people to recognize that the same substance is being encountered at different points of time. It relates this notion to Millikan’s theory of identification, on the one hand, and to her analysis of identity statements, on the other. Throughout the thesis, Millikan’s notions are contrasted with those she attributes to Frege.

We are in strong agreement with many of the conclusions of Fields’s discussion [this issue], and would like to expand the theoretical context for his arguments in order to offer some further interpretations. Accordingly, in our commentary, we will introduce some historical and developmental considerations in an effort to situate Fields’s position within developmental theory more broadly. Such contextualization will help clarify how Fields’s arguments relate to extant frameworks for modeling development – including our own action-based framework.

Three experiments investigated the effect of an adult’s social cues on 2- and 3-year-old children’s ability to use a sign or symbol to locate a hidden object. Results showed that an adult’s positive, engaging facial expression facilitated children’s ability to identify the correct referent, particularly for 3-year-olds. A neutral facial expression and the presence of the adult’s hand also facilitated performance, but to a lesser degree than did an engaging facial expression. The effect of the adult’s social cues was greater for relatively unfamiliar signs and symbols (replica or arrow) than it was for a more familiar sign (pointing finger). These findings indicate that non-directional social cues such as facial expression help to convey communicative intent and facilitate children’s comprehension of signs and symbols.

One of the most interesting questions in cognitive development is how we acquire and mentally represent knowledge about objects. We investigated the development of object concepts in macaque monkeys. Monkeys viewed trajectory occlusion movies in which a ball followed a linear path that was occluded for some portion of the display while their point of gaze was recorded with a corneal-reflection eye tracker. We analyzed the pattern of eye movements as an indicator of object representation. A majority of eye movements of adult monkeys were anticipatory, implying a functional internal object representation that guided oculomotor behavior. The youngest monkeys lacked this strong internal representation of objects. Longitudinal testing showed that this ability develops over time providing compelling evidence that object concepts develop similarly in monkeys and humans. Therefore, the macaque monkey provides an animal model with which to examine neural mechanisms underlying the development of object representations. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 278–287, 2008.

This study tested participants' preparedness to acknowledge that an object could change as a result of magical intervention. Six-and 9-year-old children and adults treated perceived and imagined objects as being equally permanent. Adults treated a fantastic object as ...