Elsevier, Neurobiology of Learning and Memory, 3(95), p. 231-238
DOI: 10.1016/j.nlm.2010.11.012
Full text: Unavailable
Young chicks (Gallus gallus) are able to use ordinal information to identify the 3rd, the 4th or the 6th target element in a series of 10 identical, fixed and equally spaced elements, sagittaly oriented with respect to the chicks’ body. Interestingly, whenever, during a subsequent generalisation test, the target had to be identified on a series identical to the training one but oriented from left to right, chicks would refer the correct position starting from the left end of the series (Rugani et al., 2007; 2010). This asymmetry could be due to a right hemispheric dominance for the spatial processing required by the test. Though in those experiments numerical and spatial information were intertwined. We therefore devised a series of experiments to disentangle the information coded by the two hemispheres. In Experiment 1, birds were trained to identify a target element solely on the basis of ordinal information. To avoid any possible use of spatial information, the inter-elements distances were changed from trial to trial, throughout training and testing. When solely the ordinal information was available, chicks identified as correct both the target positions from the left (t(11)=4.532; p