Your own little Truman Show

“Reality … what a concept!” This title of a CD by the late Robin Williams suggests that what we think of as reality is our own conceptualization, and I believe that the brain assembles the only reality we are able to know. Every message we receive through our ears, eyes, nose, tongue, and skin is elaborately processed before we become aware of it. There is no way to experience life as raw data. Our brains feed us French toast rather than kernels of wheat topped with unshelled eggs. In that sense the direct realist’s claim that nothing stands between us and the objects we perceive is rather misleading.

Perceptions are processed in ways that help us cope. For example, visual information is cleaned up and enhanced after it arrives in the brain. Suppose we are looking at an object that is equally bright all over its surface, according to exact measurements of brightness levels. To us its brightness will not seem uniform; it will seem brighter at the edges and corners than in the middle. By artificially brightening edges and corners the brain exaggerates boundaries, so that it’s easier to tell one thing from another. How convenient to see a universe of specific objects instead of a swirl of bewildering stimuli.

Changes are also exaggerated, making it easier to notice the movements of an animal. And when we watch a moving object, we experience it as being slightly ahead of its actual location. This helps a baseball player hit a fastball that’s ripping along at nearly 100 mph – and helps pitchers fool batters by throwing them a curve. Cavanagh reports that “when targets are moving, they are seen ahead of their actual retinal location because they are seen at their predicted next location” (“Perceived Location: A New Measure of Attention,” Conference Handbook, Association for the Scientific Study of Consciousness, July, 2013, p. 15).

There are blood vessels in the eye, right in front of the retina, and it would be confusing to peek out at the world through a grillwork of capillaries. So how does the brain solve this problem? Very simply. Anything that stays perfectly still in relation to the eyeball is invisible. Whenever the eyeball moves, the blood vessels move with it, so the blood vessels aren’t seen except under unusual conditions.

As you look at an object, a river of information flows up the 1.2 million fibers of your optic nerve into your brain. Once it arrives there, an early stage of processing establishes edges. One neural system graphs the horizontal lines and another attends to straight-up-and-down vertical lines. Others monitor an object’s shape, color, location, or name.

Sometimes people who have had a small stroke will lose one of these subsystems, but the others will remain intact. For instance, they may be able to name an object they are looking at and accurately describe it – but they have no idea where the object is located in relation to other objects! Their visual experience has changed in a way that is virtually impossible for normal people to imagine. They’ve lost their inner map of object location.

In a film called The Truman Show, the main character starts to suspect that what he thinks is real is just a made-up story. Eventually he discovers that the world he had known since birth was actually an enormous stage set. And we are all the stars of our own Truman Show. The brain manufactures our world and fabricates the way we feel about it. Presumably a lot of this brain-made story is reasonably accurate, but some of it is pure fantasy.

I like to picture my brain as a huge Tinkertoy sculpture, with billions of interconnected spools and dowels. Activate the connections of these units in one way and you feel like dancing. Switch around their activation patterns and you sink into existential angst. It seems as if “reality” has changed, but it’s all just patterns in our heads. If you can change the pattern, you can change yourself.

Roger Christan Schriner

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Experiencing the “Layers” of Consciousness

I’ve been writing about the way conscious experiences inform us about several levels or layers of reality, all at the same time. Here’s a way to practice thinking of your mind as a multi-layer detection device. I’ve also found that this exercise helps me notice the complex texture of sensuous existence.

Turn on music (preferably instrumental music, or vocals in a language you do not understand) and close your eyes. Start by listening in your usual way. Then focus for a few minutes on each of the following interpretations:

(1) Think of the sounds you hear as states of the instruments themselves – the vibration of piano strings or drum-heads, or what a horn’s doing as the air flows through it.

(2) After a while, think of the music as sound-waves striking your ear.

(3) Then think of it as a series of sensory experiences, auditory perceptions inside of your head.

(4) Finally, think of the music as what you get, what you receive in being aware of your own perceptions. Now you are focusing on sound as a state of the experiencing self.

Which of these interpretations felt most fitting? Did it seem as if you were in touch with the outside world (interpretations 1 and 2) or your own mind (interpretations 3 and 4)? Or perhaps all of these interpretations seemed equally apropos.

You can do the same thing with other sensory modalities, such as taste. Are you directly experiencing a hot pepper or indirectly detecting it through taste-phenomena? With scent, are you directly or indirectly detecting the particles within an onion that make it smell so strong?

If you alternate between external and internal interpretations, this may help you empathize with both philosophical externalists and internalists.

Roger Christan Schriner

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Innies vs. Outies: A Philosophical Debate

Today I’ll say a little more about the battle between internalists and externalists. When we enjoy sensuous experiences such as sights, sounds, tastes, and tingles, internalism says we are accessing something inside of us. If the mind is in the brain, we’re detecting brain events. Nonsense! says the externalist. We are only conscious of objects out in the world and states of our own bodies. We do not detect our own brain-states.

I realize that there are serious problems with internalism, but it may contain a kernel of truth. Even though experiences seem to present us with external objects, this cannot always be so in any simple way. When we’re dreaming or hallucinating, for example, we are not typically perceiving events in the outside world.

Furthermore, sensory perceptions are actually much less world-like than we may imagine. Perceptions are processed in all sorts of convoluted ways, and the resulting experiences may be quite different from the things we’re perceiving. In fact, systematic visual illusions begin at the point where the surface of the eye meets the air. The air is full of atomic particles, but I visually experience air as if it were nothing. If I perceived air in the same way I perceive walls, I would be as blind as if my head were encased in concrete. It is an enormous distortion of reality to experience air as nothing, and a wall as something, and consciousness involves a great many such useful distortions.

The standard response to problem of illusions and hallucinations is that “we directly perceive external arrangements, but do not always perceive them as they actually are” (Harold I. Brown in Edmond Wright, ed. The Case for Qualia, p. 53). We can’t hear some sounds that dogs can hear, and they can’t see colors as we can. But we’re perceiving the world, and so is Bowser.

“That still smells fishy,” complains the internalist, who maintains, for example, that a pain in your toe is not literally “in” your toe, even though you automatically think of it that way. If sensory inputs stopped registering in your brain, someone could smack one of those little piggies with a hammer and you wouldn’t feel a thing. And if a surgeon stimulated the right spot in your brain, it might seem as if something ghastly was happening to your toe even though no one was touching it.

In one experiment during the 1950s, doctors installed electronic probes in the brain of someone with a severe mental illness. This ethically problematic procedure produced very vivid experiences: “The patient giggles again, transformed from a stone-faced zombie into a little girl with a secret joke. ‘What in the hell are you doing?’ she asks. ‘You must be hitting some goody place.’” In another experiment rats were allowed to press a lever that shot a jolt of electricity into their pleasure centers. They “self-stimulated until they passed out.”

(See http://www.hedweb.com/hedethic/orgasmic.htm.)

Philosophical “innies” also note that if something in the outside world changes, we will only perceive this change if it registers within our minds. But if our way of perceiving the world changes, it will seem as if the world has changed even if it has not. Want to make it seem as if the world in front of you has disappeared? Just close your eyes.

For their ultimate trump card, internalists can whip out the famous brain-in-a-vat scenario: A mad scientist of the future keeps a brain alive in a liquid solution, while stimulating it in a way that triggers seemingly normal sensory experiences. The brain therefore thinks it is inside of a body that’s walking around and living a normal life – the ultimate virtual reality simulation. But it is only in touch with its own internal states.

Some externalists deal with envatment by flatly denying that this brain would experience anything at all, even if its states happened to be identical to, say, the states of your brain right this second. But if a brain in a vat could, in principle, have conscious experiences, this seems to show that internalism is true. Experiential phenomena are, literally, in the head. Does that make sense to you, or do you tend to side with the externalists?

Roger Christan Schriner

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Your Sensory Experiences: Are They in Your Head or Out There in the World?

Suppose you’re at a jazz concert. You notice horn-like noises, along with what seems to be a visual image of someone working the slider of a bright, brassy trombone. Here are two ways of thinking about this episode, assuming that you are perceiving accurately rather than hallucinating.

❁ You are directly perceiving someone playing a trombone.
❁ You are inwardly experiencing sounds and sights, which leads you to infer that someone is playing a trombone. This inference happens with such lightening speed that you don’t even notice it. All you notice is that you’re seeing and hearing a trombone solo.

On the second interpretation, we do not directly perceive the world. Instead we are aware of an inner simulation of worldly objects, and we treat this simulation as if it were real.

Phenomena such as horn-sounds and the visual image of a musician have sometimes been called sense data. Some advocates of “indirect realism” claim that we know sense data directly, and this indirectly informs us about real events in the outside world.

In the early Twentieth Century many indirect realists thought sense data were non-physical, following in the footsteps of Seventeenth Century philosopher René Descartes. But this “Cartesian” view has been rejected by those who believe that everything is made of matter. To them, speaking of immaterial substances such as sense-data sounds like mumbo-jumbo. So indirect realism has acquired a rather bad odor these days, especially if it even hints at sense data. An influential paper by Gilbert Harman disparaged the “notorious sense datum theory.” (http://plato.stanford.edu/entries/sense-data/). Uriah Kriegel reports that indirect realism “is widely regarded as bankrupt …” (Subjective Consciousness, p. 225).

Many scholars have now abandoned the “internalist” idea that experiences are inside of us. Marching under the banner of externalism, they contend that conscious experiences only inform us about things in the outside world. Michael Tye, for example, has famously proclaimed that “[sensory] phenomenology ain’t in the head.” (Ten Problems of Consciousness, p. 151.) He concludes a recent book by calling scholars to the barricades:

“For the thoroughly modern materialist, the thesis of phenomenal internalism … should be ‘committed to the flames.’ Only then will all vestiges of Cartesianism be eliminated from the materialist worldview.”(Consciousness Revisited, p. 199)

In asking whether consciousness could be a brain event, we are actually dealing with two questions:

❁ Why don’t conscious experiences seem like brain events?
❁ Why does it seem as if they are definitely not brain events?

Obviously conscious experiences do not grant us admission to the nonstop party our neurons are having in our skulls. Nevertheless, experiences could consist of brain activity even though we cannot introspect them as brain activity. This may be no more mysterious than looking at a river or a geranium without detecting the atoms of which they are composed. In this blog I will mostly focus on the more difficult question – why sensory experiences seem to almost shout that they are not brain events.

When someone enjoys the sights and sounds of a concert, the smell and taste of pecan pie, or the tingle of a caress, are these experiences mental events? Are they the direct detection of objects in the world? Or both? Or neither? What do you think – and why?

Roger Christan Schriner

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