Should We Solve Access Consciousness Before the Hard Problem?

Should we first explain how information becomes available for reasoning, memory and report before attempting to explain subjective experience itself?
Or is that strategy destined to leave the most important question unanswered?

I stepped away from research on machine consciousness about fifteen years ago. At the time, my work focused primarily on functional models of access consciousness, particularly Bernard Baars’ Global Workspace Theory (GWT). That focus made perfect sense from an engineering perspective. My goal was to understand whether these models could improve AI systems and, ultimately, to demonstrate their practical value in building more capable intelligent agents.

Yet access consciousness was never my ultimate destination. What has always intrigued me is phenomenal consciousness—the subjective experience of what it feels like to perceive, think or simply exist. I suspect this is true for many people drawn to the study of consciousness. While functional theories are popular and help explain how information becomes available for reasoning, memory and decision-making, the question that continues to captivate us is the one David Chalmers famously called the hard problem: why should any physical process give rise to subjective experience at all?

The Many Meanings of Consciousness

If you’re interested in the scientific study of consciousness, you’ve probably noticed that the word consciousness is both deeply familiar and remarkably difficult to define. Researchers use it in different ways, often referring to related but distinct phenomena, and there is still no universally accepted definition.

One way to make progress is to adopt a kind of divide-and-conquer strategy: instead of trying to explain consciousness as a single, monolithic concept, we can separate it into different dimensions and investigate each one individually. Several taxonomies have been proposed over the years, but one of the most influential comes from the philosopher Ned Block, who distinguished between access consciousness and phenomenal consciousness.

Access consciousness refers to information that is available to the cognitive system for reasoning, decision-making, verbal report, planning and the control of behavior. In other words, it is information that the brain can use. Modern cognitive neuroscience has developed increasingly detailed models of how this might be implemented, including Bernard Baars’ Global Workspace Theory (GWT) and Stanislas Dehaene’s Global Neuronal Workspace (GNW), in which information becomes globally available through large-scale recurrent interactions across the cortex.

Phenomenal consciousness, by contrast, refers to subjective experience itself—the what it is like to see the color red, hear a violin, or feel pain. This is the realm of qualia and the focus of what David Chalmers called the hard problem of consciousness.

Within philosophy of mind and consciousness research, these two concepts have become fundamental because they separate two very different explanatory challenges. One concerns the functional role of information in cognition; the other concerns the existence of subjective experience.

This raises an intriguing methodological question: Do we need to understand access consciousness before we can hope to explain phenomenal consciousness?

The Case for Explaining Access First

Many cognitive neuroscientists argue that beginning with access consciousness is not only practical but scientifically unavoidable.

First, access consciousness is experimentally tractable. Researchers can manipulate visual awareness using masking, binocular rivalry, or attentional paradigms while recording brain activity with EEG, MEG, fMRI, or intracranial electrodes. These methods have revealed reproducible neural signatures associated with conscious access, such as widespread cortical activation, recurrent processing and late electrophysiological components.

Second, explaining access establishes a bridge between observable behavior and neural mechanisms. Rather than asking why experience exists, researchers can ask questions that admit experimental answers:

Why can a subject report one stimulus but not another?
What neural events distinguish conscious from unconscious processing?
How does information become available to memory, reasoning and decision-making?

These questions generate testable hypotheses and measurable predictions.

There is also a historical argument. Science often progresses by explaining functional mechanisms before tackling deeper conceptual questions. Biology explained heredity before DNA was discovered. Thermodynamics preceded statistical mechanics. Flight was achieved long before aerodynamic theory became complete. Perhaps consciousness research will follow a similar path: understanding the mechanisms of conscious access may eventually reveal principles that illuminate subjective experience.

Finally, proponents argue that some philosophical puzzles may dissolve rather than require separate explanations. If the brain mechanisms underlying conscious access become sufficiently well understood, our intuitions about the “hard problem” may eventually change.

The Case Against This Strategy

Critics argue that explaining access consciousness, no matter how completely, cannot by itself explain phenomenal consciousness.

One reason is conceptual. Access consciousness concerns what information can do within a cognitive system. Phenomenal consciousness concerns what experience is like from the first-person perspective. These appear to be different explanatory targets.

Imagine a future neuroscientist who can predict every behavioral report, every decision, every memory and every neural state associated with seeing red. According to critics, one question would still remain:

Why is there something it is like to see red instead of there being no experience at all?

No amount of functional description seems to answer that question directly.

This criticism underlies David Chalmers’ distinction between the “easy problems” of consciousness—which concern behavioral and cognitive functions—and the “hard problem,” which concerns subjective experience itself.

Some researchers therefore argue that beginning with access may unintentionally restrict the scope of investigation. By focusing on reportability, working memory or decision-making, scientists may end up explaining the cognitive consequences of consciousness rather than consciousness itself.

Alternative theories illustrate this concern. Integrated Information Theory, for example, attempts to characterize consciousness in terms of intrinsic causal structure rather than global cognitive access. Other proposals focus on recurrent sensory processing, predictive processing or embodied interaction with the environment, each suggesting that conscious experience might not depend on the same mechanisms that enable report and reasoning.

Is Access Necessary, Sufficient or Neither?

The debate ultimately turns on three possibilities.

The first is that explaining access consciousness is necessary but not sufficient. Under this view, understanding global availability, attention, memory and decision-making provides an essential foundation, even if an additional principle is ultimately required to explain phenomenal experience.
The second possibility is that access consciousness is both necessary and sufficient. Once the mechanisms of conscious access are fully understood, subjective experience may turn out not to require any further explanation. Some proponents of functionalist approaches lean toward this position, although opinions vary considerably.
The third possibility is that access consciousness is neither necessary nor sufficient. If phenomenal consciousness depends on principles fundamentally different from information access, then focusing on access could even become a scientific detour.

At present, there is no consensus on which of these possibilities is correct.

A More General Question About Scientific Progress

Perhaps the debate reflects a broader issue about how science advances.

History shows that scientists rarely solve the deepest questions directly. Instead, they build explanations layer by layer, developing theories that explain increasingly rich sets of observations. The mechanisms uncovered at one level often become the foundation for deeper theoretical advances.

Whether consciousness will follow this pattern remains unknown.

Understanding conscious access may eventually reveal the principles from which phenomenal consciousness naturally emerges. Or it may reveal the limits of current computational and neuroscientific frameworks, forcing us to develop entirely new concepts.

Either outcome would represent scientific progress.