Consciousness and Criterion: On Blocks Case for Unconscious Seeing

Block (2012) highlights two experimental studies of neglect patients which, he contends, provide ‘dramatic evidence’ for unconscious seeing. In Block’s hands this is the highly non-trivial thesis that seeing of the same fundamental kind as ordinary conscious seeing can occur outside of phenomenal consciousness. Block’s case for it provides an excellent opportunity to consider a large body of research on clinical syndromes widely held to evidence unconscious perception. I begin by considering in detail the two studies of neglect to which Block appeals. I show why their interpretation as evidence of unconscious seeing faces a series of local difficulties. I then explain how, even bracketing these issues, a long-standing but overlooked problem concerning our criterion for consciousness problematizes the appeal to both studies. I explain why this problem is especially pressing for Block given his view that phenomenal consciousness overflows access consciousness. I further show that it is epidemic—not only affecting all report-based studies of unconscious seeing in neglect, but also analogous studies of the condition most often alleged to show unconscious seeing, namely blindsight.