On the Trail of Human Consciousness

By Keith Tidman 

Daniel Dennett once called consciousness the “last surviving mystery” humankind faces. That may be premature and even a bit hyperbolic, but not by much. At the very least, consciousness ranks among the biggest of the remaining mysteries. Two questions central to this are: Does the source of conscious experience rest solely in the neurophysiology of the brain, reducible to myriad sets of mechanical functions that necessarily conform to physical laws? Or, as some have contended, is consciousness somehow airily, dualistically separate from the brain, existing in some sort of undefinably ethereal dimension? 

Consciousness is an empirical, bridge-like connection to things, events, and conditions, boiling down to external stimuli that require vetting within the brain. Conscious states entail a wide range of human experiences, such as awareness, identity, cognition, wakefulness, sentience, imagination, presence in time and space, perception, enthrallment, emotion, visions of alternative futures, anchors to history, ideation, attention, volition, sense of agency, thought experimentation, self-optimisation, memories, opinions — and much more. Not to forget higher-order states of reality, able to include the social, political, legal, familial, educational, environmental, scientific, and ethical norms of the community. The process includes the brain's ability to orchestrate how the states of consciousness play their roles in harmony. As philosopher Thomas Nagel therefore concluded, “there is something it is like to be [us]” — that something being our sense of identity, acquired through individual awareness, perception, and experience.

The conscious mind empirically, subjectively edits objective reality. In the phrase of David Chalmers, philosopher of mind and cognitive scientist, “there is a whir of information processing” as all that complexly happens. The presence of such states makes it hard, if not impossible, to disbelieve our own existence as just an illusion, even if we have hesitancy about the accuracy of our perception of the presumed objective reality encircling us. Thought, introspection, sensing, knowing, belief, the arrow of perpetual change — as well as the spatial and temporal discernments of the world — contribute to confirming what we are about. It’s us, in an inexorable abundance of curiosity, wondering as we gaze upon the micro to the macro dimensions of the universe.

 

None of these states, however, requires the presence of mysterious goings-on — an “ethereal mind,” operating on a level separate from the neuronal, synaptic activity of the brain. Accordingly, “consciousness is real and irreducible,” as Dennett’s fellow philosopher, John Searle, observed while pointing out that the seat of consciousness is the brain; “you can’t get rid of it.” True enough. The centuries-old Cartesian mind-body distinction, with its suspicious otherworldly spiritual, even religious, underpinnings and motive, has long been displaced by today’s neuroscience, physics, and biology. Today, philosophers of mind cheerfully weigh in on the what-if modeling aspects of human consciousness. But it must be said that the baton for elucidating consciousness, two and a half millennia after the ancient world’s musings on the subject, has been handed off to the natural sciences. And there is every reason to trust the latter will eventually triumph, filling the current explanatory gap — whether the path to ultimate understanding follows a straight line or, perhaps more likely, zigs and zags. A mix of dusky and well-lit alleys.

 

Sensations, like the taste of silky chocolate, the sight of northern lights, the sound of a violin concerto, the smell of a petunia, hunger before an aromatic meal, pleasure from being touched, pain from an accident, fear of dark spaces, roughness of volcanic rock, or happiness while watching children play on the beach, are sometimes called qualia. These are the subjective, qualitative properties of experience, which purportedly differ from one person to another. Each person interpreting, or editing, reality differently, whether only marginally so or perhaps to significant extents — all the while getting close enough to external reality for us to get on with everyday life in workably practical ways. 

So, for example, my experience of an icy breeze might be different from yours because of differences — even microscopically — between our respective neurobiological reactions. This being the subjective nature of experience of the same thing, at the same time and in the same place. And yet, qualia might well be, in the words of Chalmers, the “hard problem” in understanding consciousness; but they aren’t an insoluble problem. The individualisation of these experiences, or something that seems like them, will likely prove traceable to brain circuitry and activity, requiring us to penetrate the finer-coarse granularity of the bustling mind. Consciousness can thus be defined as a blend of what our senses absorb and process, as well as how we resultantly act. Put another way, decisions and behaviours matter.

 

The point is, all this neurophysiological activity doesn’t merely represent the surfacing or emergence or groundswell of consciousness, it is consciousness — both necessary and sufficient. That is, mind and consciousness don’t hover separate from the brain, in oddly spectral form. It steadfastly remains a fundamentally materialist framework, containing the very nucleus of human nature. The promise is that in the process of developing an increasingly better understanding of the complexity — of the nuance and richness — of consciousness, humanity will be provided with a vital key for unlocking what makes us, us. 

 

‘Mary’s Room’: A Thought Experiment

Posted by Keith Tidman

Can we fully understand the world through thought and language—or do we only really understand it through experience? And if only through experience, can we truly communicate with one another on every level? These were some of the questions which lay behind a famous thought experiment of 1982:

A brilliant neurophysiologist, Mary, knows all there is to know about her academic specialty, the science of vision: the physics, biology, chemistry, physiology, and neuroscience. Also how we see colour.

There’s a catch, however: Mary has lived her entire life in a totally black-and-white room, watching a black-and-white screen, and reading black-and-white books. An entirely monochromatic existence. Then, unexpectedly, her screen reveals a bright-red tomato.

What was it like for Mary to experience colour for the first time? Or as the Australian philosopher Frank Jackson asked, who originated this thought experiment, ‘Will [Mary] learn anything or not?’ *

Jackson’s original takeaway from his scenario was that Mary’s first-time experience of red amounted to new knowledge—despite her comprehensive scientific knowledge in the field of colour vision. Jackson believed at the time that colour perception cannot entirely be understood without a person visually experiencing colour.

However, not everyone agreed. Some proposed that Mary’s knowledge, in the absence of first-hand experience, was at best only ever going to be partial, never complete. Indeed, renowned philosopher Thomas Nagel, of ‘what is it like to be a bat’ fame, was in the camp of those who argue that some information can only be understood subjectively.

Yet, Mary's complete acquaintance with the science of vision might well be all there is to understanding the formation of knowledge about colour perception. Philosopher and neurobiologist Owen Flanagan was on-board, concluding that seeing red is a physical occurrence. As he put it, 'Mary knows everything about colour vision that can be expressed in the vocabularies of a complete physics, chemistry, and neuroscience.

Mary would not have learned anything new, then, when the bright-red tomato popped up on her screen. Through the completeness of her knowledge of the science of colour vision, she already fully knew what her exposure to the red tomato would entail by way of sensations. No qualities of the experience were unknowable. The key is in how the brain gives rise to subjective knowledge and experience.

The matter boils down to whether there are nonphysical, qualitative sensations—like colour, taste, smell, feeling, and emotion—that require experience in order for us to become fully familiar with them. Are there limits to our comprehension of something we don’t actually experience? If so, Mary did learn something new by seeing red for the first time.

A few years after Frank Jackson first presented the ‘Mary’s room’ thought experiment, he changed his mind. After considering opposing viewpoints, he came to believe that there was nothing apart from redness’s physical description, of which Mary was fully aware. This time, he concluded that first-hand experiences, too, are scientifically objective, fully measurable events in the brain and thus knowable by someone with Mary’s comprehension and expertise.

This switching of his original position was prompted, in part, by American philosopher and cognitive scientist Daniel Dennett. Dennett asserted that if Mary indeed knew ‘absolutely everything about colour’, as Jackson’s thought experiment presumes, by definition her all-encompassing knowledge would include the science behind people’s ability to comprehend the actual sensation of colour.

To these points, Mary’s factual expertise in the science of colour experience—and the experience’s equivalence and measurability in the brain—appears sufficient to conclude she already knew what red would look like. The experience of red was part of her comprehension of human cognitive functions. Not just with regard to colour, but also to the full array of human mental states: for instance, pain, sweetness, coldness, exhilaration, tedium—ad infinitum.

As Jackson ultimately concluded, the gist is that, given the special particulars of the thought experiment—Mary acquired ‘all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like red and blue’—Mary did not acquire new information upon first seeing the red tomato. She didn’t learn anything. Her awareness of redness was already complete.

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* Frank Jackson, 'Epiphenomenal Qualia', Philosophical Quarterly, 32, April 1982.