Evidence against functionalism from neuroimaging of the alien colour effect in synaesthesia.
Cortex; a journal devoted to the study of the nervous system and behavior February 1, 2006 Jeffrey A Gray, David M Parslow, Michael J Brammer et al.
Coloured hearing synaesthetes experience colors when hearing words, and some also experience the 'alien colour effect' (ACE), where color names trigger a different color than the one named. The ACE slows color naming in a Stroop task, reflecting cognitive interference from consciously experienced synaesthetic colors. Functional magnetic resonance imaging shows that hippocampal activation distinguishes synaesthetes with the ACE from those without it and from non-synaesthetes. These findings challenge reductive functionalism, which identifies mental states with causal roles. In synaesthesia, color qualia arise from both hearing words and seeing surfaces, and in the ACE these functions oppose each other, providing empirical grounds to argue that reductive functionalism cannot account for conscious experiences.