Left Hemisphere: Objective, Analytical, Logical, Classical
According to J. W. Kalat (2003), our senses have evolved not to give us complete information about all the stimuli in the world but to give us the most useful information at the time. Through the act of focusing, we pay attention to what is interesting and disregard what is “useless.” For the majority of individuals, the left hemisphere is trained to be analytical—to look for components and strive for details. The data received from the different sense organs are gathered, then our brain analyzes the data to draw a comprehensible, detailed picture consisting of useful components. For example, the information received from a flower is divided and analyzed by the left hemisphere as petal, stem, stamen, and pollen. The left hemisphere is almost always dominant in both speech and handedness as well.
The so- called model dependant realism asserts that our brain interprets the input from our sensory organs by making a model of the world that is successful in explaining the events. (Hawking,Mlodinow 2010, 7). However this model does not necessarily reflect the reality out there in its totality.
In humans, the activation of the lateral cortical region in the left hemisphere is associated with language and conceptual representation (Bunge, Mackey, and Whitaker 2009, 73). The left brain is responsible for finding meaning in the data it receives. It extracts the details and draws a comprehensible picture out of a wide array of incoming information. It therefore must be judgmental to be able to draw a definite scheme. The analytic left hemisphere investigates the information critically and arranges it in a meaningful, logical, and rational fashion that we can live with, filtering out any unrelated data in the process. This is how our left brain hemisphere defines, categorizes, and draws a comprehensible, definite classical portrait out of the “big picture.” It pulls the tree out of the jungle and displays it in front of our eyes.
According to a study of individual differences in adult reasoning, during difficult tasks involving working memory, stronger prefrontal and parietal recruitment is associated with better fluid reasoning (the ability to find meaning in confusion and solve new problems). The level of activation between left lateral prefrontal cortex and bilateral parietal cortex accounted for more than 99.9 percent of the relationship between fluid intelligence and working memory performance in adults (Bunge, Mackey, and Whitaker 2009, 80). Fluid reasoning ability starts early in childhood and develops through adolescence and adulthood. Intelligence in adults is related to connectivity between the prefrontal and parietal cortices (81). Individual pieces of information are methodologically arranged and filed. The sensibly arranged data is the basis of our logic and the origin of our reasoning. Using logic, we can conclude that if A is bigger than B and B is bigger than C, then for sure A has to be bigger than C. Through logic, the left brain sketches a solid and dependable objective reality in front of our eyes. Logic is the domain of classical mechanics. Therefore, we can conclude that the left brain helps us to sketch the classical level of reality. Classical mechanics is all about definite situations and certainties, whereas quantum mechanics is sketched over uncertainty and the domain of superposition. Logical trace is pale in quantum mechanics.
Left hemisphere tries to make sense of events even with partial cues. Anosognosia is a rare syndrome associated with right brain damage. Patients who suffer from this disease have only one functioning hemisphere, the left. Neurologist Vilayanur Ramachandran reported on a patient of his who suffered with the above syndrome; the left side of her body was paralyzed, but she was ignorant of this fact. When she was asked to point to the examiner’s nose with her paralyzed left hand, she truly believed that her fingers were a couple of inches from the examiner’s nose, when in reality her hand lay paralyzed next to her. According to Ramachandran, this kind of self-deception arises from a defense mechanism in normal persons, wherein the left brain tries to maintain a consistent picture of the world despite the staggering amount of information flooding the brain at any minute. This mechanism keeps the brain from succumbing to directionless and uncertainties due to the explosion of possible scenarios produced from the material available to the senses (Springer and Deutsch, 1998). The elaborate rationalization effort of the left brain makes it prone to erroneous perceptions.
The left brain is also the origin of the sensing self. The left hemisphere creates the sensation that we are isolated as individuals. It defines the boundaries of our body—where we begin and where we are located in space. It perceives the self as an independent character. Doreen Kimura and her colleagues demonstrated that patient with left hemisphere damage and intact right hemisphere showed difficulty in hand and arm positioning and orientation with respect to the body (left brain/Right brain, Sally p. Springer Page 304). People with major left brain damage do not distinguish themselves from the rest of the world. In addition, the left hemisphere is responsible for learning motor skills and for controlling higher voluntary movements. During bodily movements, we have to identify an isolated body (our own) and its relationship to the environment. It is well known that damage to the left side results in disorders of learned voluntary movements. The asymmetry of motor control in the right and left hemispheres is well demonstrated by the fact that the majority of people are more skilled at using their right hand, which is fed by left brain, than their left.
Language ability mainly originates in the left hemisphere as well. Damage to the angular gyrus in the left hemisphere may selectively destroy a person's ability to read and speak. For such a patient, although he may see a printed page with the right hemisphere, the words will have lost their meaning. Damage to the Wernicke's area, near the base of the left temporal lobe, eliminates the capacity to understand spoken language. Speech continues to be heard, but the meaning is lost. Speaking involves isolating sounds and forming specific words. This is in line with the classical level of reality, where components are isolated and separated. At the quantum level, everything is entangled and can be treated as one.
In order to describe the verbal information it receives, the left hemisphere dissects the incoming data into words and probes their meanings individually and within the context of a sentence. This is part of analytic function of the left brain. In the depth of our awareness, we find a vast array of chaotic data playing in the background. The left hemisphere helps us to filter, reduce, and arrange only the related data so that our speech communicates a comprehensible, logical, and classical state of mind. In another words, it helps us to make meaningful statements that communicate a logical situation acceptable to our common sense. If one verbalized whatever passed through his or her background thoughts, we would likely call that person insane. Autistics and schizophrenics show such left hemisphere disorder and therefore lack the ability to filter their thoughts. Schizophrenia may be the impaired early development of the brain when specific synaptic pathways are formed to establish dominancy of the left hemisphere in certain tasks. Schizophrenics have a slightly larger right hemisphere and less gray matter than normal in the prefrontal cortex, temporal cortex, and hippocampus, particularly in the left hemisphere (Kalat 2003, 476–482).
“Making sense” means eliminating a huge amount of data during the process of speaking. Similarly, data is reduced as we come from the infinite information at the quantum level, with its quantum uncertainties and superposition of states (simultaneous existence of all possible states of objects—explained later in the article), to the focused and singular logical state observed in classical physics. In quantum mechanics, the Schrodinger’s equation describing the state of a particle is linear and homogenous. This means that a particle is in superposition of states rather than just one definite state. Different quantum mechanical experiments confirm the above description.
The classical perception pales when a person is under the influence of addictive drugs and hallucination prevails. Positron emission tomography shows that the brain has a lower rate of metabolism and lower overall activity under influence of cocaine (Kalat 2003, 455). Please note that assessing, evaluating, and logically interpreting data requires intense and structured cerebral activity, including inhibitory functions to remove unnecessary data from one’s awareness.
Time is one of the fundamental elements of objective reality. However Einstein’s special relativity describes it as a malleable element. Time is a tool of the left hemisphere. The left side of the brain gathers the information and arranges it in chronological sequence. That is how we sense the past, present, and future. Since the successive accumulation of memories creates the notion of time for us, time has a trajectory that extends from the past to the future, and not the other way around. As such, it mimics time as it is understood in classical physics. In contrast, time in quantum mechanics can be symmetric and flow in both directions. For marijuana users, the sensory receptions are intensified, and time seems to pass very slowly. The phenomenon of time delay during brain slowdown is an interesting one. In one experiment, rats were trained to press a lever for food on a fixed-interval schedule, such that only the first press during any thirty-second period produced food. With practice, each rat learned to wait a certain period of time after each press before it started pressing again. Under the influence of marijuana, rats pressed sooner after each instance of reinforcement. Instead of waiting twenty seconds, the rat might wait only ten to fifteen. Evidently, those ten to fifteen second felt like twenty seconds—for these rats, time was passing more slowly (Kalat 2003, 458). Therefore, when brain function is diminished, time passes slower. Does brain activity somehow contribute to the notion of time? Hallucination, by definition, happens when a waking person perceives something in the absence of obvious external stimuli. The seeming perception is vivid and located in external objective space. Hallucinations can occur in any sensory modality—visual, auditory, olfactory, gustatory, tactile, proprioceptive, equilibrioceptive, nociceptive, and temporal. Like a dream, the hallucination doesn’t follow the normal logic of classical space-time. Why do hallucinogenic drugs such as LSD release the imagination and transport the user out of the classical perception of the world? We know that LSD reduces the brain function by stimulating serotonin type-2 receptors. But why does brain slowdown lead to hallucination at all? Please note that LSD enhances the sensitivity to pure sensory input. One wonders how much of the concrete classical perception is the product of the brain function.
Brain chatter is another phenomenon attributed to the left brain. We are all familiar with it. It’s the voice in our mind that is always talking. It tells us what everything actually is. It tells us what is right and what is wrong, what are we allowed to do and what we should avoid. It tells us what is sensible and what is nonsense. What to focus at and what to ignore. It repeats over and over again the details of our life so we can remember them. Brain chatter is largely the result of parental guidance and social upraising. In addition, brain chatter is the creator of self. The left hemisphere strives for individuality and independence. Without it, we lose track of our life and our identity. In its absence, we are like electrons in a Bose-Einstein condensate, in which particle loses its identity (NOVA 2008). What is left is a feeling of oneness, an immersing into the whole of existence.
Intelligence is partly created by platform formation. By this process, the brain creates a library of past experiences, so that when we are faced with a similar situation we draw on scenes that we have filed away, evaluating and responding to the new situation with minimal attention and assessment. One might say that the left hemisphere has already “set the stage” for new events to arrive. It has pre-created a familiar scene based on our previous experiences and its understanding and interpretations of those experiences. Our brain is filled with these ingrained patterns, which we use to predict, plan, and carry out everyday activities. When we talk about a winter day, a cold and snowy condition automatically comes to mind. However, sometimes a day in winter can surprise us by being mild. This illustrates that although these patterns are usually very helpful, at times they distance us from reality. These pre-established patterns are the origin of our beliefs as well. We evaluate and judge every new encounter based on these established beliefs.
We may speculate that these thought pattern loops also create our classical level of reality. If the left hemisphere already has established logical loops and scenes that are consistent with rational classical level of reality, then any new incoming data must be perceived within the context of these scenes. Any unrelated and illogical data is ignored during the process. New experiences only further develop these modules and fortify the pre-established classical level patterns. The dorsal anterior cingulate cortex is likely to contribute to improvements in inhibitory cognitive control as we age (Bunge, Mackey, and Whitaker 2009, 73).
Arithmetic is also attributed to the left brain. In mathematics, we divide the whole into the integers, to facilitate analysis. However assessing the abstract relations between the integers is the function of the right hemisphere. Right parietal cortex shows abnormal responses in children with dyscalculia, a learning disability that affects math skills (Janelle Weaver 2011).
Considering all this, one may suppose that the left brain is the leading, more highly evolved and intellectual hemisphere. At the classical level, the left brain carries out all of our higher functions relating to the environment. Mind you, the classical perception is learned from the embryonic era onward. It seems that the left hemisphere starts as a “clean slate” at the beginning; learning and conditioning come after.
Dr. Jill Taylor is a Harvard-trained neurobiologist who had a stroke in 1996 while she was only thirty-seven years old. Following the hemorrhage in her left hemisphere, her left brain gradually lost its performance, while her right hemisphere remained intact and continued to function normally. Being a neurobiologist, she could sense and interpret the gradual changes that her mind went through at the time of stroke and during her recovery, which took about eight years. In her recently published book (Taylor 2008), she explains her experience with her massive stroke moment by moment. She had to retrain herself to obtain skills related to the so-called normal (classical) awareness during her recovery.
The formed platforms and neuronal circuitries are not rigid throughout one’s life and are subject to change according to later experiences. The change in neuronal circuitries and the strength of the synapses is called brain plasticity. However, there are plasticity limiting mechanisms in the brain that prohibit many unwanted circuitries from developing. The so-called perceptional abnormalities such as schizophrenia, depression, stress disorder, and ADH may all be disorders of brain plasticity (Pascual-Leone 2009, 147). Abnormal synaptic plasticity and disorders of limiting mechanisms can be the etiology behind the atypical sensory processing traits of Alzheimer’s, addiction, and autism as well.
In summary, it seems that the left brain receives incoming data from sense organs, then by conditioning and analyzing, the left hemisphere creates a simpler, more comprehensible, and dependable objective world. In most instances this fabricated world is sufficient for us to run our everyday life. The common belief is that mainly the left hemisphere has changed during evolution (left Brain/ Right Brain, page 307). Compared to lower species, the left hemisphere in the human brain is bigger than the right hemisphere, and its functioning distinguishes us as a more sophisticated animal. We owe most of our progress and scientific achievements to the left hemisphere’s function. However, it is notable that the perception it creates is manipulated to certain degree and can be different from actual reality. Michael Gazzaniga believes that the psychological unity we experience emerges out of a particular specialized system, called the interpreter. The interpreter appears to be uniquely human and localized in the left hemisphere. It is the trigger for the human beliefs that constrain our brain (Gazzaniga 2009).