How experimental neuroscientists can fix the hard problem of consciousness

Abstract

For the materialist, the hard problem is fundamentally an explanatory problem. Solving it requires explaining why the relationship between brain and experience is the way it is and not some other way. We use the tools of the interventionist theory of explanation to show how a systematic experimental project could help move beyond the hard problem. Key to this project is the development of second-order interventions and invariant generalizations. Such interventions played a crucial scientific role in untangling other scientific mysteries, and we suggest that the same will be true of consciousness. We further suggest that the capacity for safe and reliable self-intervention will play a key role in overcoming both the hard and meta-problems of consciousness. Finally, we evaluate current strategies for intervention, with an eye to how they might be improved.

Predictive processing as a systematic basis for identifying the neural correlates of consciousness

“…After paradigm-defining research in the early 1990s, the NCC methodology became a focus of the science of consciousness (Metzinger, 2000), and has received several reviews and commentaries since, reporting on significant progress (Aru et al, 2012;Fink, 2016;Hohwy, 2009;Klein & Barron, 2020;Koch et al, 2016;Miller, 2007;Seth, 2009;Tononi & Koch, 2008). An influential early discussion was given in Chalmers (Chalmers, 2000), which pointed to a crucial and so far underappreciated distinction between arbitrary and systematic NCCs.…”

“…If there are three causally chained neural states NS1, NS2, NS3 that tightly and reliably correlate with the conscious experience of seeing a face, it may be that NS1 is a mere causal precursor, and NS3 a causal consequent of the true (and presumably most explanatory) constituent NS2, even though the empirical correlation between all three and the conscious experience is much the same (Graaf et al, 2012;Miller, 2015). One response to the screening off challenge is to make use of techniques for causal inference (Aru et al, 2012;Hohwy, 2009;Klein & Barron, 2020;Neisser, 2012;Pearl, 2000;Woodward, 2003). In particular, better methods for causal intervention should be able to advance the issues.…”

Distinguishing absence of awareness from awareness of absence

“…For the aware absence -unaware absence contrast, a content-invariant NCC is predicted to show a similar activation profile to the more typical aware presenceunaware presence contrast, whereas a content-specific NCC is predicted to show divergent results (because a content-specific NCC should track the contentspecific awareness of stimulus presence). Importantly, this differential prediction for content-specific and content-invariant NCC is achieved without pharmacological or invasive interventions (in contrast with Aru et al, 2012;Klein & Barron, 2020), circumventing ethical concerns and practical challenges. Furthermore, using an inverted design allows detecting content-invariance in a different, potentially stronger sense than what is afforded by using a broad set of stimuli that spans multiple semantic categories (Rutiku et al, 2016).…”

Predictive processing as a systematic basis for identifying the neural correlates of consciousness

“…After paradigm-defining research work in the early 1990s, the NCC methodology became a focus of the science of consciousness (Metzinger 2000), and has received several reviews and commentaries since, reporting on significant progress (Miller 2007, Tononi and Koch 2008, Seth 2009, Aru, Bachmann et al 2012, Hohwy and Bayne 2015, Klein and Barron 2020. An influential early discussion was given in Chalmers (Chalmers 2000), which pointed to a crucial and so far underappreciated distinction between arbitrary and systematic NCCs.…”

“…One response to the screening off challenge is to make use of techniques for causal inference (Pearl 2000, Woodward 2003, Aru, Bachmann et al 2012, Neisser 2012, Hohwy and Bayne 2015, Klein and Barron 2020. In particular, better methods for causal intervention should be able to advance the issues.…”