Abstract
There is indirect evidence that categorical colour perception (better discrimination of colours from different categories than those from the same category — CP) can be learned. For instance, CP can be induced across a newly learned category boundary (Özgen & Davies, 2002). Here we replicate and extend Özgen and Davies’s category learning study, to try and pinpoint the nature of the changes underlying category learning. Participants learned to divide green into two new egories ‘yellow-green’ /‘blue-green’ across four days. The trained group showed CP across the new boundary on a target detection task and this was restricted to the left hemisphere (LH; cf. Drivonikou et al. 2007), whereas the controls did not. The results could suggest that category training produces changes at early stages in visual processing mainly in the LH.