Sections include: psychological dimensions of consciousness (behavioral intelligence, intellectual intelligence, emotional effects on mental activity), neurological underpinnings of consciousness, why consciousness?
The meaning of consciousness can be quite varied, depending on who is using the word and in what context. At a basic level, to “lose consciousness” can mean to go to sleep, to faint, or to go into a stupor—which are all different states. We also use the word conscious to mean being aware of something in the present, as in, “I was suddenly very conscious of a large dog in my lap.” And some people speak of a “level of consciousness” or “higher consciousness,” meaning both a state of awareness and a state of being. Not all these uses of the word are scientific, but they are all related, and their range of meanings shows how fundamental and wide-ranging consciousness is.
In 1890 the psychologist William James defined consciousness as a person’s “awareness of self and the environment.” But that definition omits two critical words: consciousness is the accurate and chronologic awareness of self and the environment. Each of us, when mentally healthy, has a sense of who we are and what we are not— what parts of what we experience come from outside ourselves. Each of us also has a sense of time, especially the distinction between what we have experienced in the past and what we are experiencing now. The healthy, awake human brain never lets go of that consciousness. Consciousness reflects a person’s inner and outer cognitive world. Like a brain-generated Mount Everest, it towers over all the other remarkable functions of a person’s body. Consciousness is thus the mental quality that identifies, measures, and expresses the quantity of the self.
Almost everyone with a healthy brain can describe consciousness if asked. Our descriptions may vary in detail or wording: “I’m awake and I’m here”; “I think; therefore, I am”; “I’m Jane Smith, and I know it!” Most educated people recognize conscious awareness as a continuously unfolding, automatic sense of being alive and filled with flowing thoughts, normal language, recent memories, and specifically expressed learned motor behavior.
Even the most educated people, however, rarely consider how their brains express their normal emotions, generate logical thinking, and produce a smooth flow of thoughts and deeds. “Now, how did I come to think of that?” is a question we might occasionally ask ourselves, but we rarely carry it into everyday conversation with others. Nor do people wonder what happens in their brains to make them daydream or take a daily walk. We are happy that these functions are largely automatic.
Ironically, even though our consciousness is founded on a sense of time, it is usually catching up to the activity in our minds. Many of our behaviors go through a “preconscious” stage—our brains actually start the process of acting or feeling a very brief time before the results are registered in our consciousness. When people instinctively jump out of the way of an oncoming vehicle, they don’t stop to think. Only after they reflect on the danger they just encountered do they become consciously aware of their preconscious behavior and express an emotional response. When you converse, your mind preconsciously, explicitly formulated what you say a half second or more before you actually say it. Gerald Edelman recognized this necessary preformulation of thoughts and words when he ingeniously titled his book on consciousness The Remembered Present.
The Psychological Dimensions of Consciousness
Consciousness interweaves our outer perceptions, our inner memories, and our immediately occurring thoughts. Emotional feelings imbue our conscious awareness and sharpen our intentional actions. Memory, however, provides the foundation of consciousness. Memory’s qualities and quantities depend on the combination of a person’s innate cognitive talents, subsequent schooling, and ongoing activities. All evidence indicates that the earlier people pursue learning, the greater their conscious mental and behavioral capacities will be. Indeed, many reliable studies indicate that the longer a person undergoes education and engages in occupationsthat require thought, the longer his or her mental
and physical health will endure.
Several other distinct neuropsychological qualities accompany organized human consciousness. These include sensory perception, attention and intention, and instinctive awareness of spatial relationships. Additional general traits include the chronological ordering of events, mood, and emotion. Contributing to the special qualities of normal human consciousness are the symbolic abstractions of verbal, musical, numerical, and geometric languages.
Normal consciousness reflects the product of at least three closely interdependent and often integrated aspects of awareness: behavioral intelligence, intellectual intelligence, and the emotional modulation of both.
We can loosely define behavioral intelligence as “knowing how to move to accomplish certain things.” This quality is expressed in several forms by the brain’s two frontal lobes. Each lobe contains neural circuits that stimulate the conscious mind’s intentions and attention, as discussed below. That preconscious quality of intention and attention rules almost all our daily behavior. We normally walk, run, and undertake other coordinated activities without specifically directing preconscious attention to those performances. Mundane, nonconscious undertakings can include walking at a routine pace, riding a bicycle, and even skiing a downhill slope. Practiced musicians, automobile drivers, and airplane pilots seldom apply continuous intentional consciousness to how they act unless they anticipate some difficulty.
Automatic motor performances are likely generated first in the frontal lobes, and are only partially recognized by the perception-generating neuronal circuits of the posterior lobes. Psychologists in the past have termed these primary frontal lobe–generated actions as reflecting “implicit” memory—in other words, directing actions before the mind presents conscious orders.
What we classically consider intelligence depends almost entirely on short- and long-term stored memories of facts, ideas, time, events, language, and most other nonbehavioral knowledge. All of these specific functions are generated primarily from the posterior areas of the brain, including the parietal, occipital, and temporal lobes. Activity in these regions boils down all the stimuli our brains receive into what becomes our knowledge.
The normal, awake, conscious mind never ceases to scan its environment. Nor does it lose its memory of past events, thoughts, the expressed content of behavioral activities, the self, and its ever-growing knowledge. Only a few people report that they suffer from episodes in which their minds express no thought of self, memory, or intention. Serious psychiatric disease, certain illegal drugs, and brief epileptic seizures may cause such episodes.
Even people with the best of minds, of course, sometimes become bored and lapse into daydreaming. Their minds wander listlessly. But this nonintellectual holiday can end in an instant because of an unexpected stimulus or an intruding thought. The healthy mind quickly returns to attention, once again aware of the world around it.
Emotional Effects on Mental Activity
Emotional states are noncognitive and nonsymbolic contributions to our overall experience of consciousness. They may affect both our behavioral and intellectual intelligence. They can either sharpen a person’s performance by providing increased motivation or degrade it with excessive distractions, anxiety, fear, and other emotional states. If we are worrying about a family member’s health, for example, we may experience the disruption as difficulty in concentrating on a book or sinking a free throw. Yet research has also shown that loss of these primitive states of emotional awareness leads to overwhelming failures of behavioral and intellectual intelligence.
The Neurological Underpinnings of Consciousness
A relatively simple brain map helps identify the cerebral areas that generate the behavioral intentions and psychological perceptions that express normal consciousness. The critical areas include the two cerebral hemispheres, each of which possesses approximately half of the cerebral cortex, the thalamus, and the basal ganglia. In the base of the skull, these structures connect with the large cerebellum and the arousal systems inside the brain stem. Discovering just how this network generates consciousness has become a major scientific effort.
The anatomical interconnections among the above areas are extremely complicated. During the last 20 years, about 30,000 published scientific reports have delved into just how this wiring in the brain generates human consciousness. We have learned a great deal but produced no fully satisfying answers. Nevertheless, these efforts are helping us to understand the general anatomy and workings of the conscious brain.
We have learned that nonspecific arousal, which is simply one’s state of wakefulness or alertness, is generated largely in the brain stem and is indispensable to arousing consciousness. By itself, however, nonspecific arousal cannot formulate or express neuropsychological qualities. The brain mechanisms that govern sleep states and dreams overlap only partially with the circuitry of normal wakeful consciousness.
Our frontal lobes largely govern and express our behavior, both immediate and well learned. Their functions dictate consciousness and its generation of mood, behavior, and mind. The lobes’ basal forebrain area has evolved from ancient mammalian brains and occupies most of the undersurface of the two frontal lobes. It participates in generating emotional feelings and social behavior, as well as stimulating a person’s intentional purposes. The lateral and medial prefrontal areas largely influence physical coordination and participate in volitional and cognitive aspects of attention and working memory. The rearmost regions of the lateral and medial frontal lobe generate and regulate coordinated expressions of logical, cognitive language, intentional eye movements, and ultimately, all coordinated, intentional behavior. When we perform complex, rapid activity, like skilled athletics or a well-practiced musical piece, we rely on those parts of the brain.
Examples of preconscious frontal lobe activity abound. Consider the experiences of a man who had recently had a close call on the road: “A car about 20 feet ahead of mine was going 30 miles an hour, and suddenly it braked. I swerved to the left and just slipped between that car and an oncoming driver. As I passed the rear door of the braked car, I suddenly felt perspiration. And for the first time, I felt scared.” In this case, the driver’s quick reaction to the danger posed by the stopped car in front of him was preconscious. His conscious and emotional reaction to the situation came about a half second after turning the steering wheel.
This driver’s response to danger was more complex than the automatic reflex of jerking one’s hand away from a flame. It required his knowledge of how to steer a car through a narrow gap. But his mind did not have to become fully conscious of the danger to react. Because this man had lots of practice driving, his brain was able to respond as quickly as needed. Most of our bodies’ welltrained and frequently practiced behaviors perform their implicit, intended reactions without entering normal awareness. Such automatic expressions seldom reach consciousness unless we stumble. In that case, the conscious mind springs to the rescue and directs the brain’s escape.
The posterior parts of the cerebrum, including the parietal, occipital, and temporal lobes, plus the thalamus, generate the contents of our thoughtful consciousness. They receive their initial commands of attention and intention from the frontal lobes and express their immediate demands. The occipital lobes receive the crude symbols sent by the eyes’ retinas, and, in conjunction with the inferior temporal lobe, mature their associations. The temporal lobe also processes auditory stimuli. Our intellectually conscious knowledge relies on verbal, musical, mathematical, geometric, and pictorial languages; the left cerebral hemisphere dominates in expressing most of these cognitive contents.
Awareness of where we are in space arises from the lateral-ventral surface of each parietal lobe. As with language, the functional machinery behind that quality also has a dominant side, this time the right. Each parietal lobe normally provides us with automatic knowledge of the functional state of the other side of the body and the space immediately around us. Serious damage to the vulnerable dominant right parietal lobe can erase all of a person’s knowledge of the left side of the body and the left side of the surrounding world. This is an example of what is called focal unconsciousness—lack of consciousness about a particular aspect of life—which is a feature of several disorders.
As stated above, normal integration of all these aspects of action and mind requires memory. Using the resources of many distributed cerebral regions, memory creates our reflective intelligence. In this way, memory is indispensable to consciousness.
Why does defining consciousness matter? The answer is that our consciousness equals our personhood. It confirms our existence and our individuality. “No man is an island,” John Donne wrote, but in fact each of us lives on our own island of consciousness. Every spontaneous sentence, every unstated thought, every action is at least partially unique. Every human brain in one way or another expresses its conscious or behavioral actions differently from the brains of all other human beings on the planet. Even the shape of your brain is a little different from all others.
Our words and actions can be telephone lines from one island of consciousness to another, but they can convey only a portion of what’s happening on the end of the line. Much of our human consciousness remains a mystery, and neuroscience is only beginning to understand how our brains generate this state. Even with advances that show us when and where the brain becomes active, and what neurochemicals and genes are at work, we suspect that science will never tell us exactly what is on someone else’s mind.
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