Introduction:

In this paper I will define bimodal consciousness and discuss its characteristics.  I will assess the evidence that bimodal consciousness acquires knowledge through the two hemispheres of the human brain and will speculate upon the significance that split-brain surgical procedures has had and can have on human consciousness research.

Bimodal consciousness is the term that applies to two hypothetically separate modes of acquiring human knowledge through awareness, thinking, or response, utilizing the right and left cerebral hemispheres of the human brain.  Conscious/unconscious, abstract/concrete, and logical/emotional models are examples of bimodal consciousness.

The human brain is divided into three major parts, the cerebrum, the cerebellum, and the medulla oblongata.  The largest part of the brain, the cerebrum, is believed to be the part of the brain where consciousness takes place.  The cerebrum is separated into two separate hemispheres, the left and right cerebral hemispheres.  Dependent upon which hemisphere is being attentive, will determine the type and level of awareness, thinking and response the human will have to acquiring information.  This information will then be assessed and assimilated with previously acquired data to form a personal experiential knowledge base.  The result of the assimilation of the bimodal consciousness experiences will help to incorporate the human concepts of intentionality, human purpose, potentiality, and overall optimal functioning (Krippner, 1990).

Characteristics Of Bimodal Concsiousness:

Both hemispheres of the human brain function and are conscious at all times but the dominate brain hemisphere will be dependent upon the type of data and the required response activity.  Different levels of consciousness effect the different hemispheres of the human brain.  The left hemisphere is usually the dominate hemisphere for conscious activity and thought.  The right hemisphere is considered the dominant hemisphere for unconscious processing.  To define consciousness is difficult.  The definition of consciousness is different for different researchers.

Consciousness is an especially confusing topic because the word means different things to different investigators.  One calls consciousness a style of thinking or a way of viewing the world.  Another may use the term to mean "self-awareness".  Yet another may mean all the information of which one is aware at a given moment. (Springer & Deutsch, p.304)

For the purpose of this paper, consciousness is defined as the attention, awareness, and memory of the individual self, the given moment, and the acquired knowledge of the individual.

Psychologist Julian Jaynes states, consciousness is learned on the basis of language and taught to others.  It is a cultural invention rather than a biological necessity, (Springer & Deutsch, 1989 p.326).

According to Springer and Deutsch (1989) the bimodal consciousness characteristics can be formed into five main groups of processes which form a bimodal consciousness hierarchy.  These five groups represent conscious and unconscious activities and awareness that effect human thinking and responses.  These consciousness activities are associated with and take place in the right and left hemispheres of the brain.
 
Right Hemisphere:
Nonverbal, visuo-spatial
Simultaneous, spatial, analogical
Gestalt, synthetic
Intuitive
Eastern thought
 
Left Hemisphere:
Verbal
Sequential, temporal, digital
Logical, analytical
Rational
Western thought
 

The basic difference between these characteristical processes of bimodal consciousness is in how data is processed and interpreted as information by the mind.  Each hemisphere is capable of handling many kinds of tasks but often the efficiency and approach of and to the task differs from the other hemisphere dependent upon its characteristics.

[David] Galin believes that although each hemisphere is exposed to the same sensory input, it effectively receive a different input because each emphasizes only one of the messages.  The left will attend to the verbal cues, and the right will attend to the nonverbal cues. (Springer & Deutsch, 1989, p.329).

As an example, if a mother looks at a child and verbally says, "I love you," and her facial expression says, "I hate you," the child will be confused.  The child's left brain hears and understands "I love you," as a positive stimuli but the left brain reads the nonverbal stimuli of, "I hate you."  The child becomes uncomfortable because it rationally hears one thing, however, intuitively it knows another, based upon previous learning.  As the child matures, it is expected that if he/she is knowledgeable of the intuitive processes of the right side of the brain and nurtures its development, the child will tend to develop enhanced intuitive powers not by believing everything he/she hears, but will form an opinion or reaction based upon all available data.

Acquistion Of Knowledge:

Knowledge is a learned experience as the different brain hemispheres record and process the data/stimuli that are reaching its awareness.  The characteristics of the bimodal mind reflect the different types of stimuli, reasoning, and responses the human will have as a result of having two hemispheres of consciousness.

Split brain surgery research has had a marked influence on the research of the bimodal mind.  The corpus callosum normally connects the two sides of the cerebrum and keeps them up to date with each other (Gazzaniga, 1988).  By surgically separating the corpus callosum, a large nerve fiber system that connects the right and left hemisphere of the brain, researchers have been able to study the consciousness associated with the right and left brain hemispheres.

Consciousness research has significantly been advanced as a result of split-brain research.  It has provided data to effectively study both sides of the brain.  Without separating the corpus callosum, the two hemispheres would continually update each other and therefore would eliminate the isolation of the response of the researched hemisphere.  By separating the corpus callosum, the two hemispheres operate independently and can be studied separately.  Roger Sperry has argued that the results of split-brain research point to a doubling of consciousness in these individuals.

Everything we have seen so far indicates that the surgery has left these people with two separate minds, that is, two separate spheres of consciousness.  What is experienced in the right hemisphere seems to lie entirely outside the realm of experience of the left hemisphere.  This mental dimension has been demonstrated in regard to perception, cognition, volition, learning, and memory.  (Springer & Deutsch, 1989, p. 322).

The two hemispheres of the human cerebrum record and react to stimuli that is presented to it by the opposite side of the body.  The right side of the body is reactive to the left side of the brain and the left side of the body is reactive to the right side of the brain.  A normal, intact brain will record and respond to information, such as a picture or a written word, which is presented to the left eye and projected to the right side of the brain.  The data is quickly named and if a response is necessary, will respond accordingly.  However, if a picture is presented to the right eye of a split-brain individual, the individual will be able to name the item quickly.  The picture has been presented to the dominant left side of the brain, the location of language and speech, and therefore the individual can verbally identify the picture.  A picture that is presented to the left eye is "read" by the right side of the brain but is unable to be identified, although the individual intuitively knows what the picture means.  The right side of the brain cannot talk, therefore the left side of the brain, that has not seen the picture cannot report the projection.  However, if the individual is asked to point the same picture that is being presented to the right brain, the picture will be identified.

The command "walk" was flashed to the right hemisphere, the patient stood up from his chair and began to leave the testing van.  When asked were he was going, his left brain said, 'I'm going into the house to get a coke, (Gazzaniga, 1988, p.13).

The human brain must have order to maintain a balance of understanding.  Therefore, in the above example, when the patient responded to the right brain cue, the left had to make sense of the action so it rationalized that it was going somewhere to get something.

Galin believes that during such moments of disconnection, the left hemisphere alone governs consciousness.  Mental events in the right hemisphere, however, continue a life of their own and act as a 'Freudian' unconsciousness, as an independent reservoir of inaccessible cognition, which may create uneasy emotional states in a person,   (Springer & Deutsch, 1988, p.325).

The left hemisphere is the dominate side of the brain.  It attempts to dominate learning and responses to stimuli/data.  The left side dominates verbal responses and logical, analytical, and rational thought.  The right brain can express itself through creativity, such as art and music, and by nonverbal, unconscious activity, such as improvisational dance, emotions, and dreaming.

Several investigators have suggested that dreaming is a part of the realm of the right hemisphere.  Some believe that the right hemisphere does all the dreaming; others feel that the dream state allows the right hemisphere to express itself more freely than usual because the left hemisphere does not dominate or interfere, (Springer & Deutsch, 1988, p.328)

A number of altered states of consciousness (e.g. trance states, hypnosis, meditation, and dreaming) have been associated with right brain functions such as visual imagery and recognition of emotional overtones of external stimuli, (Tolaas, 1986, p.60).

The right brain is often said to be "unconscious" because split-brain patients cannot verbally explain right brain activities, so that in recalling and recording dreams and other image-based experiences, we are speaking about our unconscious, (Tolaas, 1986, p.61).

Split-brain research has demonstrated that each hemisphere of the brain has a separate plane of consciousness, dependent upon its characteristics.  In normal individuals, whose corpus callosum has not been severed, the two hemispheres communicate with each other and update the learning of each other.  Effective learning is directly related to the level of development and utilization of the characteristics of both hemispheres of the brain.  By utilizing both hemispheres of the brain, the individual will achieve a higher level of total consciousness and acquisition of knowledge.

Conclusion:

Split-brain research has had a significant impact on the research of the bimodal consciousness of the human brain.  As a result of this research work, researchers have been able to effectively isolate and evaluate the characteristics and functions of the right and left hemisphere of the human brain.

Consciousness functions in both hemispheres of the cerebrum of the brain and interprets, responds, and records data in its characteristic modality.  The left side of the cerebrum is considered to be the dominant side due to its effective skills in language and mathematical abilities and its deductive aspects of language and analytical thinking.  The right hemisphere specializes in parallel, pictorial-spatial thinking.  According to Tolaas (1986) & Springer & Deutsch (1989) it is believed that the unconscious mind operates in this hemisphere since, according to researchers, it is the side of the brain that meditation, dreaming and intuition take place .

Knowledge is acquired through the conscious and unconscious awareness and all of the senses of the human body which are sent for interpretation, action, and recording to the appropriate cerebral hemisphere.  Whether the individual is right or left handed, in a normal human brain, this information is shared with the other hemisphere and each hemisphere "learns" about the knowledge creating stimuli by its characteristic.  If the child, in the previously discussed "I love you" example, has always been exposed to the words "I love you" and the facial expressions "I hate you", then the child will learn that this is a normal verbal and nonverbal response.  Effective teaching should involve both hemispheres of the brain in order to effectively learn.  By using both hemispheres in learning the individual will more richly understand, respond and record the learning experience.
 

References:
 
Tolaas, J.  (1986).  Transformatory framework: Pictorial to verbal.  In B. Wolman & M. Ullman (Eds.),  Handbook of states of consciousness.  (pp. 31-67).  New York: Van Nostrand Reinhold.

Gazzaniga, M.S. (1988).  Mind matters. Boston: Houghton Mifflin.

Kolb, B. (1989).  Brain development, plasticity and behavior.  American Psychologist, 44, 1203-1212.

Krippner, S. (1990).  Introduction to Psychology of Consciousness  Study Guide.  San Francisco, CA: Saybrook Institute.

Natsoulas, T.  (1978).  Consciousness. American Psychologist, 33, 906-914.

Natsoulas, T.  (1983).  Addendum to "Consciousness."  American Psychologist, 38, 121-122.

Springer, S., & Deutsch, G.  (1989).  Left brain, right brain. (3rd Edition)  New York: W.H. Freeman.