Toddlers' use of metric information and landmarks to reorient

Mobile organisms can keep track of spatial location (both their own locatio n and that of objects in the environment) using either an external referent system or one centered on the self and updated by information about moveme nt through space. When the latter system is disabled (e.g., by rapid turnin g), aspects of the external world must be used to reestablish orientations Recently, it has been claimed that, both for rats and for human toddlers, r eorientation is achieved using a geometric module that accepts only informa tion about the metric properties of the environment (C. R. Gallistel, 1990, L. Hermer & E. S. Spelke, 1994, 1996). In a series of experiments, this pa per confirms that geometric information is used for reorientation by young children, but gives reason to doubt that the use of this information is ach ieved using a module impenetrable to nongeometric information. (C) 2001 Aca demic Press.