Behavioural Processes 106 (2014) 172–179 Contents lists available at ScienceDirect Behavioural Processes jo ur nal home p ag e: www.elsevier.com/locate/behavproc Evidence of a relational spatial strategy in learning the centre of enclosures in human children (Homo sapiens) Luca Tommasi ∗ , Alda Giuliano University of Chieti, Italy a r t i c l e i n f o Article history: Received 8 April 2014 Received in revised form 9 June 2014 Accepted 12 June 2014 Available online 19 June 2014 Keywords: Place learning Centre Children Geometry Spatial strategies Spatial cognition a b s t r a c t Three- to five-year-old children were trained to localize a sensor hidden underneath the floor, in the centre of a square-shaped enclosure (1.5 m × 1.5 m). Walking over the sensor caused a pleasant music to be played in the environment, thus engaging children in a playful spatial search. Children easily learned to find the centre of the training environment starting from random positions. After training, children were tested in enclosures of different size and/or shape: a larger square-shaped enclosure (3 m × 3 m), a rectangle-shaped enclosure (1.5 m × 3 m), an equilateral triangle-shaped enclosure (side 3 m) and an isosceles triangle-shaped enclosure (base 1.5 m; sides 3 m). Children searched in the central region of the enclosures, their precision varying as a function of the similarity of the testing enclosure’s shape to the shape of the training enclosure. This suggests that a relational spatial strategy was used, and that it depended on the encoding of geometrical shape. This result highlights a distinctive role of the geometric centre of enclosed spaces in place learning in children, as already observed in nonhuman species. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Remembering the location of objects and places in the envi- ronment is an ability that allows animals to move around in meaningful ways, sometimes heading to relevant places that are directly perceived as beacons (as are figures in a figure–ground relationship), other times locating places that do not stand out against their surroundings but that have to be reached by refer- ence to one or more distant landmarks, to the surrounding spatial frame of reference, or to a combination of these two aspects. Many species have been tested in a variety of place learning tasks involving reference to (i) individual or multiple landmarks, (ii) extended surfaces surrounding the goal region, or (iii) a combina- tion of landmarks and surfaces (see Tommasi et al., 2012; Tommasi and Laeng, 2012, for recent reviews). In many cases, empirically evaluating the presence and the precision of such abilities has been accompanied by assessing changes in spatial behaviour following transformations of an environment. There are many examples in which the global arrangement of an array of landmarks was shown to be exploited as a spatial reference to localize a goal (see Collett et al., 1986, for seminal studies carried out in the gerbil). In this ∗ Corresponding author at: Department of Psychological Science, Humanities and Territory, University of Chieti, BLOCCO A, Via dei Vestini, 29, I-66013 Chieti, Italy. Tel.: +39 0871 3554210; fax: +39 0871 3554163. E-mail address: luca.tommasi@unich.it (L. Tommasi). respect, experiments that played on transformations of the land- mark arrays (contractions, expansions, etc.) have proven crucial in revealing which type of information is used by animals orient- ing to a goal (the ‘transformational approach’; Cheng and Spetch, 2001). If an animal has been trained to find the central position between two landmarks, tests carried out following increases (or decreases) of the inter-landmark distance can tell us whether the animal relies upon vector-like information from either landmark or upon a rela- tional strategy, such as the acquisition of a ‘middle’ rule (gerbil: Collett et al., 1986; Clark’s nutcracker: Kamil and Jones, 1997). An array of landmarks arranged in a given geometric shape (e.g. the four vertices of a square) offers exactly the same opportunity: if an animal is trained to find the centre of the array, tests in expanded or contracted arrays (leaving the square shape unchanged) can provide researchers with very useful information on what infor- mation is stored and retrieved to accomplish the task (e.g. the exact distance and direction from one isolated landmark or equidis- tance from all of the landmarks). Removing one or more landmarks while leaving the others in place would be another interesting test of those alternative mechanisms (gerbil: Collett et al., 1986; pigeon: Spetch et al., 1997). Finally, if the position to be localized is at the centre of a square-shaped enclosure made of continuous walls, a test in a larger (or in a smaller) replica of the enclosure can provide interesting results about the use of the global spatial framework represented by the walls of the enclosure in determin- ing the position of the goal. Again, a transformation of the shape of http://dx.doi.org/10.1016/j.beproc.2014.06.004 0376-6357/© 2014 Elsevier B.V. All rights reserved.