The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning (46 page)

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Authors: Daniel Bor

BOOK: The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning
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Thus, a sustained period of stress or anxiety can largely turn off prefrontal function and consequently reduce conscious resources, with working memory half-disabled. In these situations, the brain learns by default to fear and to assume the most negative interpretation imaginable. The amygdala becomes trigger-happy, and its activity is sustained more aggressively, while the prefrontal parietal network is now easily and regularly inhibited. For schizophrenics, who may already have a far more fragile neurochemical system, stress may tip the scales toward catastrophic prefrontal dysfunction. But this mechanism may be an even more important clue to those mental illnesses more centrally defined by their emotional torments, such as post-traumatic stress disorder, anxiety disorder, and depression.
A WIDER, PURER OCEAN OF AWARENESS
 
If stress is such a profound game changer when it comes to mental illness, what can be done to reduce it and return the reins to the prefrontal parietal network? Aside from medication, which has only limited success, there is a practical list of lifestyle changes, which includes the usual suspects, such as avoiding or reevaluating those specific events that induce stress (not easy in most cases), getting decent quality sleep, exercising regularly, and so on. And these do all help reduce psychiatric symptoms, or have a protective effect against succumbing to a mental illness. But eclipsing this list in the fight against stress is one simple mental exercise: meditation. This is often written off as being too esoteric and not sufficiently scientific, but it’s been shown to profoundly help virtually any mental ailment, whether the person has a psychiatric condition or is merely suffering from the stresses and strains of everyday life.
There needn’t be anything mystical to meditation. Although there are hundreds of different varieties, in my view meditation is at its most powerful in its purest, most basic form: An ideal meditation is one where you try to be as aware as you can of as little as possible.
We can focus on the world with our attentional magnifying glass set in two broad modes: We can mainly attend to the thoughts, ideas, facts, and so on that relate to other mental events or what our senses are picking up;
or
we can simply attend to our senses directly, passively absorbing the experience without thoughts.
We may be on a mountaintop and feel a calm, profound awe as we attend entirely to the delicate beauty of the vast snowcapped peaks surrounding us.
Or
we could enter a very different experiential mode and try to calculate the volume of each mountain as a mathematical exercise, infer what the name of each mountain is from various clues, and recognize the different geological features of the rocks around us. In one state we have an open, quiet, passive perspective. In the other, we have a narrower, chattering mind, which isn’t nearly so aware of our sensory experiences. This quieter sense of beauty is closely related to the so-called meditative experience.
Spending 20 minutes or more with nothing to do may sound pointless and tedious, but for those who try it, boredom, strangely, never seems an issue. It’s as if, by intensely focusing attention continuously on the darkness of your closed eyes, a blank wall, or something equally minimal, you are telling your brain that this object is utterly fascinating. Early in meditation practice, there may be a struggle as the mind wanders, but after a while it becomes easier to sustain attention on virtually nothing for long periods of time.
And, far from being ineffectual, meditation causes substantial brain changes, both in the short term of a single session and in the long term, after months or years of practice. What’s more, these brain alterations seem the exact reverse of those caused by stress and many mental illnesses.
In striking contrast to the effects of anxiety and stress, the simple act of entering a meditative state increases activity in the prefrontal parietal network, especially in the lateral prefrontal cortex. So, intriguingly, this is indirect objective evidence that meditation really does raise awareness.
Over years of practice, regular meditation also seems to permanently change the prefrontal parietal network, such that it becomes more pliable and efficient in its activity. And, again in direct contrast to what happens in depression and anxiety disorders, long-term meditation shifts the see-saw battles between the amygdala and prefrontal cortex firmly in the prefrontal cortex’s favor: The amygdala becomes far less likely to activate, probably partly because the prefrontal parietal network is now so good at stepping in and taking control. There is even evidence that long-term meditation increases the thickness of the prefrontal cortex, helping to protect against the natural thinning of this part of the brain in old age. At the same time, two months of meditation is sufficient to shrink the size of the fear-creating amygdala in previously stressed individuals.
All these results fit perfectly with long-term meditators’ descriptions of how this practice modifies their experiences. They report becoming profoundly calm, largely free from fear, and better able to handle pains and bothersome emotions when they do arise. They describe a greater degree of awareness and mental control, as if they somehow have more space and flexibility by which to perceive and handle all the details of the world and their own inner life. It’s as if, by establishing new attentional habits that shift focus away from highly grooved mental chunks, any unhelpful old ideas can more easily be displaced. When it comes to our emotional habits particularly, meditation is undoubtedly an invaluable tool to dislodge those painful schemas that might have housed themselves firmly in our unconscious minds, and which can be the source of so much of our painful thoughts and feelings.
If meditation really can cause awareness to expand in a nourishing way, and consciousness is intimately linked with attention and working memory, then meditation should in turn generate improvements in tasks tapping these processes. This is exactly what researchers are discovering: Long-term meditation does improve a range of attentional tasks as well as working memory skills and spatial processing. Strikingly, regular meditation also seems to reduce a person’s need for sleep, possibly because it is a neurally nourishing activity.
However, one needn’t spend many years in intensive meditation practice before any benefits are seen. Fadel Zeidan and colleagues, for instance, found that just four meditation sessions were sufficient to reduce feelings of tiredness and increase working memory performance. Another study, by Yi-Yuan Tang and colleagues, found that only five days were needed for volunteers to improve on an attentional task that measured the subject’s ability to deal with conflicting stimuli. In addition to this improvement in a central component of cognition, the volunteers felt less anxiety, depression, anger, and tiredness.
Therefore, for normal, healthy participants, meditation reduces stress, improves alertness, and enhances performance on an impressive array of demanding tasks. It’s unsurprising, therefore, that meditation is increasingly being used as an effective weapon against depression, anxiety disorder, severe pain management, schizophrenia, and a host of other conditions.
HEALING CONSCIOUSNESS FROM MANY ANGLES
 
Along with our astounding conscious capacity to understand the universe and fashion increasingly sophisticated tools to control it, we have uniquely rich experiences punctuating our lives. The price for all this, though, is sharper suffering. Some traumas are to be expected, given that we lead such extensive, long lives, and thus have many decades by which to experience the sorrows as well as the joys. But we are also prone to, by far, the widest, most intense range of mental illnesses of any species, and these can cripple us as commonly as any disease of the heart or lungs. These heavy costs of a vast, immensely capable consciousness are themselves intimately related to awareness at every turn. While autism, the odd-one-out, partially relates to an overabundant awareness, other conditions reflect a permanent or episode-driven diminished consciousness, with working memory reduced and attention failing to filter out unhelpful thoughts and feelings. This combination creates an attachment to the aberrant and upsetting structures of thought that so heavily reinforce mental diseases.
Research is revealing many ways to soften symptoms and approach cures, with each method presenting a different angle to the challenge of returning consciousness to normal levels. Current and emerging drugs can rebalance a dysfunctional neurotransmitter system and in turn return prefrontal parietal processes to their optimal levels. Future tools of psychiatric diagnosis, however, need to give more emphasis to neuroscientific dysfunction, and appropriate drugs need to be provided that are tailored to meet this specific dysfunction. Cognitive training and meditation offer complementary routes to boosting working memory and refocusing attention. And all these methods can encourage a new sense of control over one’s inner mental world.
All the time, the details of mental-illness symptoms and the array of useful treatments reaffirms the view of consciousness as involving the prefrontal parietal network to support a combination of attentional and working memory systems, with pattern-searching a crucial function.
Although some of these nascent treatments haven’t as yet reached the clinic, hopefully this soon will change. And by holding in mind the putative perspective that each of these mental illnesses intimately relates to a skewed, misfiring consciousness, clinical researchers may make important new breakthroughs. It’s vital that this army of future strategies be given as much attention and as many resources as possible so that the pandemic of mental illness can be overcome.
Epilogue
 
A Delicious Life
 
The science of consciousness is coming of age. It can explain the origin and purpose of awareness, its mental features and neural mechanisms, as well as its intense fragility. From this picture, we can see the seeds of awareness in the history of life on earth. All ancient creatures blindly clung to survival by capturing and combining useful ideas about the environment—but this limited learning happened randomly, awkwardly, via DNA changes and the rhythmic fall of generations.
Consciousness first arose out of this evolutionary endeavor via a specialist information-processing organ, a neural computer capable of acquiring accurate concepts and deep strategies far more rapidly and flexibly than ever before. Some evolutionary branches created complex brains, which were optimized to build pyramids of knowledge out of simpler ideas cemented together. This critical skill in combining mental objects to generate increasingly meaningful, useful structures of thought is both the essence of consciousness and its overriding purpose.
Humans have a unique place in the world. We have an exceptionally complex brain, whose central wired core, in the form of the prefrontal parietal network, is greatly expanded even compared to our nearest primate relatives. We can process and combine information like no other species, and consequently we experience the world in exceptionally rich, varied ways.
Our consciousness allows us to unlock nature’s secrets, from the architecture of the smallest atom inside us to the swirling mist of galactic stars above us. Our consciousness enables us to ward off death by decades via medical technology, to travel to the moon in a couple of days, and to generate a plethora of immensely sophisticated gadgets by which to feed our prodigious appetite for stimulation. We should feel incredibly fortunate that evolution has endowed each of us with this immense biological computer, which can experience and control the world with such variety and depth.
But our pride in the mental richness of our lives and the power of our intellect should be tempered by a nagging sense that, in the case of human brains, evolution almost seems to have overreached. The signature skill of our conscious minds, our advanced powers to search for profound patterns that help us understand or conquer our environs, was only ever meant to serve our primitive evolutionary drives of survival and reproduction. This observation is most apparent in the vertiginous chasm that exists between the enormous wealth of conscious comprehension that any educated adult demonstrates daily and our embarrassing ignorance of the reasoning behind so many of our decisions. Some of us strive for a more enlightened life, somewhat divorced from these basic impulses, but such undercurrent motivations nevertheless rule and constrict us. Only in humans do these forceful evolutionary drives seem sometimes to clash so violently with higher conscious goals.
Moreover, we are so clever at spotting the patterns and tricks to meet our primitive desires that our lives can easily spiral out of control. Humanity’s prodigious conscious tools of innovation can be devoted to discovering broad truths about the world. But they are just as easily co-opted to generate inventive tactics to have affairs, to overeat, to steal, or to pursue all manner of other short-term goals that are likely to backfire when all the consequences are counted up.
And, all too easily, our aggressive ability to form such packets of ideas and behavior perpetuates unhappy traps of thought, or even, occasionally, outright delusions, as we unwittingly reveal the delicate fragility of the human mind. For some, this route leads to a debilitating mental illness, with consciousness mutating into an enemy—to such an extent that a few are so tormented that they wish to end their lives, to free themselves of this toxic inner foe. But all of us, to varying degrees, are both the beneficiaries and the victims of our own consciousness.

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