114. THE MYSTERY OF CONSCIOUSNESS
What we know about consciousness and how we deal with it are very important. Some years ago in a TIME magazine article, Harvard professor Steven Pinker wrote that consciousness was a mystery. In this post, we will read what Pinker had to say, and I will add more recent views about consciousness in future posts. Pinker began his article noting that 100 billion jabbering neurons create the knowledge — or illusion — that we exist. The excerpts from the article that follow introduce this topic for us.
“It shouldn’t be surprising that research on consciousness is alternately exhilarating and disturbing. No other topic is like it. As René Descartes noted, our own consciousness is the most indubitable thing there is.” Pinker adds that consciousness cannot be equated with self-awareness.
“Some kinds of information in the brain — such as the surfaces in front of you, your daydreams, your plans for the day, your pleasures and peeves — are conscious. You can ponder them, discuss them and let them guide your behavior. Other kinds, like the control of your heart rate, the rules that order the words as you speak and the sequence of muscle contractions that allow you to hold a pencil, are unconscious.”
“Not only does a green thing look different from a red thing, remind us of other green things and inspire us to say, ‘That’s green’…, but it also actually looks green: it produces an experience of sheer greenness that isn’t reducible to anything else.”
“Using functional MRI, cognitive neuroscientists can almost read people’s thoughts from the blood flow in their brains. They can tell, for instance, whether a person is thinking about a face or a place or whether a picture the person is looking at is of a bottle or a shoe.
“And consciousness can be pushed around by physical manipulations. Electrical stimulation of the brain during surgery can cause a person to have hallucinations that are indistinguishable from reality, such as a song playing in the room or a childhood birthday party. Chemicals that affect the brain, from caffeine and alcohol to Prozac and LSD, can profoundly alter how people think, feel and see. Surgery that severs the corpus callosum, separating the two hemispheres (a treatment for epilepsy), spawns two consciousnesses within the same skull ….”
“Consciousness turns out to consist of a maelstrom of events distributed across the brain. These events compete for attention, and as one process outshouts the others, the brain rationalizes the outcome after the fact and concocts the impression that a single self was in charge all along.”
“What about the brain itself? You might wonder how scientists could even begin to find the seat of awareness in the cacophony of a hundred billion jabbering neurons.” According to [Francis] Crick and Christof Koch, “consciousness resides only in the ‘higher’ parts of the brain that are connected to circuits for emotion and decision making ….”
“Neuroscientists have long known that consciousness depends on certain frequencies of oscillation in the electroencephalograph (EEG). These brain waves consist of loops of activation between the cortex (the wrinkled surface of the brain) and the thalamus (the cluster of hubs at the center that serve as input-output relay stations). Large, slow, regular waves signal a coma, anesthesia or a dreamless sleep; smaller, faster, spikier ones correspond to being awake and alert.
“These waves are not like the useless hum from a noisy appliance but may allow consciousness to do its job in the brain. They may bind the activity in far-flung regions (one for color, another for shape, a third for motion) into a coherent conscious experience, a bit like radio transmitters and receivers tuned to the same frequency. Sure enough, when two patterns compete for awareness in a binocular-rivalry display, the neurons representing the eye that is ‘winning’ the competition oscillate in synchrony, while the ones representing the eye that is suppressed fall out of synch.”
Why does consciousness exist? “One reason is information overload. Just as a person can be overwhelmed today by the gusher of data coming in from electronic media, decision circuits inside the brain would be swamped if every curlicue and muscle twitch was registered somewhere in the brain and constantly being delivered to them. Instead, our working memory and spotlight of attention receive executive summaries of the events and states that psychologist Bernard Baars likens … to a global blackboard on which brain processes post their results and monitor the results of the others.”
Pinker acknowledges that some scientists think that consciousness is beyond the activity of the brain, but he disagrees with that. He concludes: “I would argue that nothing gives life more purpose than the realization that every moment of consciousness is a precious and fragile gift.”
Stay tuned.
Q: How important to you is understanding your own consciousness?
