Background
Even when we are awake and attentive, the contents of awareness may vary in ways that are independent of other aspects of mental function. For example, when your mind wanders while driving - but you continue to steer, change gear, and respond to changes in traffic. In recent decades, new tools and techniques have been developed to better understand these dissociations between task performance and conscious awareness. However, the psychological, computational and neural mechanisms supporting consciousness remain poorly understood.
Higher-order theories of consciousness
Higher-order (HO) theories propose that consciousness depends on a first-order (FO) brain state being in some way monitored or meta-represented by a HO representation. This distinction between HO and FO states is computational/theoretical, rather than anatomical.
See Brown et al. (2019) Understanding the higher-order approach to consciousness for an overview
Comparing different theory variants
ETHOS aims to harness the power of adversarial collaboration to test between distinct predictions of Higher-Order Theories of consciousness. We focus on two “axes” of disagreement between HOT variants:
Axis 1 - Rich vs Sparse
Axis 1 examines to what degree HO representations are rich or sparse (note here rich vs. sparse refers to the neurocomputational architecture supporting phenomenal experience, not whether or not perceptual experience is itself rich or sparse).
Sparse HOTs (eg PRM, HOSS) propose that phenomenal experience is jointly determined by FO and HO states, with HO states playing a lean role in tracking the precision, intensity or reliability of first-order states.
Rich HO theories (eg HOROR, SOMA) propose that phenomenal experience is fully determined by higher-order states, such that higher-order representations are just as rich and detailed as perceptual experience itself.
Axis 2 - Misrepresentation
Axis 2 examines whether HO representations can “misrepresent” their FO targets, and in what way. For instance, a subject may be conscious of the colour green even if their first-order perceptual system is signalling strong evidence for red. The possibility of misrepresentation is central to non-relational HOTs: if there are mismatches between FO and HO states, conscious experience changes in tandem with the HO state. Strong misrepresentation is precluded under relational theories under which the FO state supplies the mental content which is monitored by a HO index.
Different Higher Order Theories of Consciousness and where they fall on the 2 axes of disagreement
How will we test these hypotheses
The two axes of disagreement will be tested in 3 experiments with a number of convergent methodologies, including psychophysics, neuroimaging, and hypnotic suggestion. We follow the high standards set by previous adversarial collaborations in collecting large samples to allow novel findings to be replicated on a hold-out dataset using identical procedures, reducing the risk of obtaining false positives in high-dimensional brain and behavioural data. All of our experimental procedures, datasets and analysis tools developed as part of this project will be made freely available to other researchers and adhere to the principles of Open Science. This feature of our project will facilitate future discovery science aimed at further evaluating higher-order (and other) theories of consciousness.