Aphantasia and Conscious Thought

The sensory constraint on conscious thought says that if a thought is phenomenally conscious, its phenomenal properties must be reducible to some sensory phenomenal character. I argue that the burgeoning psychological literature on aphantasia, an impoverishment in the ability to generate mental imagery, provides a counterexample to the sensory constraint. The best explanation of aphantasics’ introspective reports, neuroimaging, and task performance is that some aphantasics have conscious thoughts without sensory mental imagery. This argument against the sensory constraint supports the existence of a non-sensory phenomenology of thought. Moreover, this argument can be extended to show that this non-sensory phenomenology determines a thought content. Finally, it can potentially diagnose the disagreement over cognitive phenomenology in the philosophy of mind, as such disagreement may turn on interpersonal variation in mental imagery