The measurement of consciousness: assuming completeness of first-person report significantly restricts scope and reliability of theory-discrimination

INTRODUCTION The target of this comment is a recent and welcome paper (Gamez, 2014) that addresses foundational issues for neuralcorrelates-of-consciousness empiricism. This comment discusses whether Gamez’ assumptions actually allow the suggested framework to support the kind of theorydiscrimination necessary for advancing the field. Specifically, present discussions solely concern the theory-discrimination consequences of assumption A4, which states that all detailed features of conscious experience are first-person-reportable (at least, in principle). The present claim is that A4 limits subsequent theory-discrimination such that Gamez’ approach is incapable of addressing certain centrally-significant controversies in the field. This claim is not meant to demean the value of Gamez’ contribution, but rather to draw attention to still-unresolved issues. The primary challenges to A4 justified and discussed here are explicit cases in which certain details of conscious experience are not fully reportable (although these details are of course experienced by the subject). ORIENTING EXAMPLE OF A THEORY-DISCRIMINATION PROBLEM IN CONSCIOUSNESS RESEARCH Consider two alternative theories for spatiotemporal structures (Gamez, p. 2) directly associated (Gamez, p. 4) with conscious experience (Figures 1A,B). According to theory-I, activity in a relatively early area, S2 say, is directly associated, whereas according to theoryII, the direct associate is activity in a later area C1 that e-causally (Gamez, p. 6) receives information (Shannon, 1948) from S2. By construction of theory-I and theory-II, area S2 dynamically encodes some information concerning the external environment that cannot be decoded from C1-dynamics. Put differently, the e-causal transfer of dynamically-encoded information from S2 to C1 e.g., via S3, loses some details in granularity of representation. (In Figure 1, granularity is illustratively depictedas degree-ofspatial-resolution, although in principle it could relate to any aspect of conscious experience potentially associated with multiple hierarchical representations in brain-dynamical encoding). Crucially, both theory-I and theory-II suppose (by construction) that first-person report is limited to information encoded in C1activity (because report-governing area R3 is presumed e-causally connected to S2-encoded information only via C1), so that first-person report definitively cannot reflect the granularity available e.g., from detailed third-person decoding of S2activity using complete knowledge of both S2-dynamics and neural codes. Under Gamez’ causality assumptions, neuralcorrelates-of-consciousness approaches cannot discriminate between theory-I and theory-II in order to establish whether it is S2 or C1 that is directly associated with consciousness, because first-person report and neural dynamics are identical under the two theories (Figures 1A,B).