O papel da cor no reconhecimento visual de objectos: um contributo de estudos comportamentais, electrofisiológicos e de neuroimagem

Tese de dout., Psicologia, Faculdade de Ciências Humanas e Sociais, Univ. do Algarve, 2011In this thesis, we present six studies that investigated the role of color information during visual object recognition. The interactions between surface color and color knowledge information were investigated in two studies (chapters 2 and 3). In chapters 4 and 5, we present data that identify the visual processing stage at which color information improves color and non-color diagnostic object recognition. In chapter 6, the neural pathways supporting color object recognition were investigated. Additionally, in an attempt to bring some consistency to the literature, we performed a systematic meta-analysis on the effects of color on object recognition in chapter 7. Chapter 2 and 3 provided data suggesting that surface color information is more influential than color knowledge information during object recognition. Chapter 4 and 5 showed that color information improves the recognition of color and non-color diagnostic objects at different stages of visual processing. Although color information is an important cue for both of these types of objects in the early visual processes, it is also important in later stages of visual processing for color diagnostic object recognition. In chapter 6, we observed that colored objects, when compared with black and white objects, activated a more extensive brain network related to visuo-semantic activation and retrieval. Finally, the meta-analysis in chapter 7 conclusively showed a significant effect of color information during object recognition. In summary, the general picture that emerges from this body of work is that color information takes part in object recognition processes at multiple levels of representation.Fundação para a Ciência e a Tecnologia (FCT