Temporal Lobe
Parietal Lobe
Posterior (Back) Anterior
(Front)
Frontal Lobe
B roca's
A rea W ernicke's
A rea
Orbitofrontal Cortex
A Some of the fibers connecting inferior (lower) frontal with temporal lobes also pass through the arcuate fasciculus.
In the area of speech, the aspect of brain functioning most thoroughly studied, research solidly backs up the idea of a back quadrant of the cortex forming a system with its corresponding frontal quadrant. Speech deficits are divided into three major categories, depending upon the precise location of the damage.
If Broca‟s area (in the inferior left frontal cortex) is damaged, comprehension is preserved and individual words can be remembered, but the patient loses his ability to form sentences. In other words, as far as speech is concerned, automatic thought remains intact, but the internal world is crippled.
On the other hand, if the damage occurs in Wernicke‟s area (in the left temporal lobe), patients can produce structured sentences, but they are unable to fill these sentences with meaningful words. Thus both speech and comprehension become empty, devoid of content. This means that the internal world is functioning, but the storage shed of specific items has been smashed.
Finally, if the fibers which interconnect these two regions are destroyed, the result is conduction aphasia.A Here both speech and comprehension are fairly normal, but the patient finds it difficult to repeat words or name objects. It is as if the storage shed and the internal world are still present, but the mechanism for retrieving information from the storage shed has become faulty.
Given this basic neurological information, the question of relating cognitive style to brain region takes on a completely different light. It is not a question of somehow pasting personality patterns haphazardly onto brain areas. Rather, our study of personality suggests that there are four distinctive personality types—the simple styles—which deal with mental content. Likewise, our research indicates that each of these four styles combines automatic thought with an internal world. Turning to neurology, we find that the cortex—the region of the brain which deals with content—
is also divided into eight well-defined regions. Therefore, in order to connect personality with neurology, we only need to answer a single question. Is there a correspondence between the eight aspects of personality demonstrated by the simple styles and the functions of the eight major regions of the human cortex? I suggest that this answer is yes.
We will finish this first look at neurology by analyzing the connection between Mercy strategy and brain location. First, it is known that the mind stores memories of experiences in the right temporal lobe. Neurology has discovered that if this part is damaged, then long-term non-verbalB memory is impaired.2 Thus, we conclude that Mercy automatic thought is located within the right temporal lobe.
A Aphasia is a medical term for speech deficit.
B Note the use of the term „non-verbal.‟
I have mentioned that the left temporal lobe and left inferior (lower) frontal cortex act together to handle speech. Neurology has discovered a similar system linking the right temporal lobe with the right inferior frontal cortex. As expected, the described linkage is speech-centered, but one can see that researchers are definitely referring to Mercy type processing. Our research has found that the Mercy person is especially adept at picking up non-verbal (that word again) speech. He concentrates so much on the way something is said, that he often misses what is being spoken.
If the area of the right temporal lobe which corresponds to Wernicke‟s area in the left area is damaged, then a condition called sensory aprosodia emerges, in which the patient is severely impaired at comprehending gestures and interpreting the emotional aspect of speech. In other words, the area of the Mercy storage shed which deals with communication is destroyed.4
On the other hand, damage to the right inferior frontal cortex produces what is called motor aprosodia. These individuals can still comprehend emotional communication, but they talk in a monotone and their speech is unaccompanied by any gestures. This suggests that their Mercy internal world is unable to form any mental structures related to speech.
The connection between multiple personalities and suppressed Mercy memories has also been noted by neurology. I have suggested that Mercy memories are stored in the right temporal lobe. Based upon our understanding of multiple personalities, we would suspect that this region of the brain would be underactive when the core personality was in control, and that brain activity would increase when the secondary personalities emerged. Precisely this was observed when an individual with multiple personalities was placed under a brain scanner. When the mental activity of a secondary personality—to whom painful memories have been assigned—
was measured, the only difference noted on the scanner was an increase in blood flow in the right temporal lobe.3A
A Why would activitation go up? Because the secondary personality can access many of the Mercy experiences which the core personality has suppressed. Accessing Mercy memories would activate the region of the brain which contains the Mercy „storage shed.‟
Turning our attention now to the front of the cortex, some evidence specifically linking the right orbitofrontal cortex to the Mercy internal world does exist. For instance, one researcher mentions that “...patients who are restless, impulsive, explosive, self indulgent, inappropriate, sexually disinhibited, little concerned for others…are more likely to have right orbitofrontal lesions.”4 These undesirable traits can be summarized as emotional reactions to experiences without the help of a set of emotional guidelines.
Most of the evidence, though, looks at the right and left orbitofrontal cortices as a complete system. For example, “Few patients who sustain major frontal lobe lesions ever engage in creative endeavors or in the pursuit of meaningful interpersonal relationships.
Taste, in the aesthetic and social sense, is a trait that the frontal-lobe- damaged patient will find difficult or impossible to cultivate…We believe this set of behavioral abnormalities is strongly associated with lesions of the orbitofrontal region and not at all with the more superior dorsolateral or mesial lesions.”5
We have looked at the content of Mercy thought. Evidence suggests that there is also a specific brain center which does the actual Mercy processing. Neurology has found that buried within the temporal lobe is a nucleus, called the amygdala, which processes feelings. As one researcher states, “the amygdala mediates the encoding into memory of both positive and negative emotional attributes associated with reinforcement contingencies during a specific learning experience. A learning may be encoded into memory by different neural systems, the amygdala encoding the emotional attributes of the experience.” 6
This same volume mentions that when the amygdala is removed in humans, “hyperactivity is said to decrease, fear and aggression harder to provoke; emotional control enhanced, resulting in better concentration, a steadier mood, and more rewarding social interactions…There can also be problems: decreased spontaneity, productivity, and elaboration of emotion.
Amygdalectomy does not significantly impair general intellectual or memory function.”
In other words, science, in its infinite wisdom, has determined that humans can survive reasonably well without emotional processing. Scary, isn‟t it? As we go through this book, we will see that this statement is not an academic aberration. Rather, it defines the fundamental premise of modern science: Humans do better without feelings.