The Psychopath Whisperer: The Science of Those Without Conscience (25 page)

Figure 5
. Lateral (top) and medial (bottom) illustrations of the human brain. The medial view is as if you sliced the brain down the middle and pulled the two halves apart to look inside. The numbers represent areas defined by a labeling system developed by Dr. Brodmann in 1909. Scientists use the Brodmann numbering system to help them compare results across studies and across laboratories. The results from the abstract word processing studies implicate the anterior temporal pole in psychopathy (Brodmann area 38).

Figure 6
. Summary of the brain regions believed to be implicated in psychopaths by the year 2000. Regions include the amygdala, hippocampal complex, anterior and posterior cingulate, anterior temporal pole, and the orbital frontal cortex. The numbers represent different areas of the brain as defined by the work of Dr. Brodmann. See prior figures for complete details on the illustrations.

One of the great benefits of being at Yale was that there were top experts in the world in nearly every topic imaginable. I immersed myself in the Yale community and continued my education as a scientist, attending all the speaker lectures in psychology, psychiatry, neurology, neuroscience, and economics.

I also started a new quest: to figure out how all the pieces of the psychopath’s brain puzzle fit together. I began reviewing different theories of brain development. The burning question was, Why do psychopaths have abnormalities in so many different regions of the brain? Was there any logic to it? Was there any way to create a unified theory around the results that I, and others, had published to date?

The answer to this puzzle started to form when Dr. Hilary Blumberg of the Yale Psychiatry Department gave a seminar on brain correlates of depression. Hilary started her lecture using a map of Brodmann areas. Korbinian Brodmann (1869–1918) was the physician who painstakingly developed an anatomical classification system for different brain regions, classifying brain systems by the type and density of different neurons that occupied these regions.

I was familiar with Brodmann areas as an anatomical labeling system, but Hilary put up a figure that I had never seen before. It showed the Brodmann maps of various brain systems in different colors.

In blue were the basic sensory systems—vision, hearing, and motor. These areas had similar types and densities of neurons that generally performed the same functions—processing basic sensory inputs. The color yellow indicated higher-order sensory cortices. Pink signified the prefrontal and parietal cortex. The larger prefrontal cortex in humans is what differentiates us from other primates. And then finally in green were regions of the brain Brodmann had classified as paralimbic. The paralimbic regions included the classic limbic structures: the amygdala, hippocampus, and anterior and posterior cingulate. But it also included the orbital frontal cortex, insula, and temporal pole (see
Figure 7
).

Figure 7
. Brodmann’s maps of the different systems in the brain based upon how neurons are organized. Notice the similarities between Brodmann’s paralimbic circuitry (the shaded areas) and the areas neuroscience had shown are abnormal in psychopaths in Figure 6. The two figures are dramatically similar, a fact that led to the development of my paralimbic dysfunction model of psychopathy.

It was at that point that a lightbulb went off in my head.
That’s it
, I thought! The brain regions I had found to be abnormal in psychopaths mapped directly onto the regions Brodmann labeled paralimbic. It was uncanny how much the two maps overlapped. I begged Hilary for a copy of her slide, and then I went straight to the library to read everything I could about this paralimbic circuitry Brodmann had described.

A year of research—and reading thousands of articles—followed. It was a monumental effort, as I labored weekends and evenings to pull together a comprehensive picture of psychopaths’ brains. As a result, I developed what I called the
paralimbic dysfunction model of psychopathy
, which I published in a peer-reviewed neuroscience journal.
⁵
My original draft of the paralimbic dysfunction model of psychopathy was longer than my doctoral dissertation.

But the complete picture came together like a meal with the perfect bottle of wine. My model included converging evidence from the emerging field of brain imaging in psychopaths, reanalyses and
reinterpretation of brain wave abnormalities in psychopaths, and finally, a detailed review of what happens to people following brain damage to certain paralimbic regions. It turns out that if a person has a stroke or some other injury to a part of the paralimbic system of the brain, it may precipitate psychopathic symptoms.

Most people know that if you get knocked unconscious, you can develop some problems remembering things. Amnesia, or memory loss, is a common symptom following concussions. However, damage to the brain can lead to a vast array of other types of problems. Sometimes brain damage can even lead to changes in personality that mimic what we see in psychopaths.

The most relevant neurological case study in this regard is that of Vermont railroad worker Phineas Gage.
⁶
On September 13, 1848, Gage suffered a penetrating head trauma when a 1.2-inch-diameter iron rod was accidentally blasted up behind his left eye and out the top of his head.

Gage’s case is notable for several reasons. First, he miraculously survived. Indeed, it has been reported that he never even lost consciousness following the accident. Second, Gage had a doctor who wrote about his case so that we could all learn from it. And finally, Gage was transformed by this accident from a responsible railroad manager and husband to an impulsive, irresponsible, promiscuous, apathetic individual. Many of Gage’s symptoms are consistent with those classically associated with psychopathy. The rod that passed through Gage’s brain destroyed several parts of the paralimbic system.

Subsequent studies of patients with brain damage like Gage’s suggest that the paralimbic system mediates most of the behaviors related to psychopathy. Neurologists originally named the condition Gage suffered from
pseudopsychopathy
,
⁷
but it was subsequently called
acquired sociopathic personality
.
⁸
In other words, if you damage a part of the paralimbic system, you can
acquire
a psychopathic personality.

As a group, paralimbic brain damaged patients are characterized by problems with aggression, motivation, empathy, planning and organization, impulsivity, irresponsibility, poor insight, and lack of behavioral controls.
⁹
In some cases, paralimbic brain damaged patients may become prone to grandiosity and confabulation.
¹⁰
These are all symptoms that we see in psychopaths.

Damage to some areas of the paralimbic system are not that uncommon. For example, when the brain is slammed forward against the front part of the skull, it can rub against the bony ridge that exists right above the eyes. This rubbing can damage the
orbital frontal cortex
of the brain. This is the type of injury that can occur in football players who suffer repeated concussions. Whether due to a single event or to the cumulative impact of multiple head traumas, individuals who damage their orbital frontal cortex can end up developing problems just like Gage. It is this reality that is just beginning to be recognized by former National Football League players as a potential occupational risk to their sport.

As I put these pieces together, I realized that it might have been a blessing that my football career had been cut short in college by a knee injury. I’d already had four concussions in high school. Fortunately, my brain seems to have survived intact. I have to admit, though, every time I hop out of the MRI scanner after being in a research study, a part of me worries that my orbital frontal cortex might show up as damaged.

Gage did not have all the symptoms of psychopathy. My literature search clearly indicated that damage to just one or two parts of the paralimbic system does not lead to the full constellation of symptoms that we see in psychopaths. But damage to any part of the paralimbic system will often elicit one or more symptoms of psychopathy.

But even if multiple parts of the paralimbic system are damaged late in life, some symptoms of psychopathy don’t appear.
Callousness
, for example, is one of the traits that is found in psychopaths but rarely found in adult patients with paralimbic brain damage. The reason? It may take years of paralimbic abnormalities in an individual for a callous streak to develop; most paralimbic brain damaged patients don’t live long enough to develop this trait.

This reasoning is supported by a study of two individuals who, as infants, suffered brain trauma to the paralimbic system. The researchers indicated that as adults, these two patients had a higher incidence of callous behavior than is typically observed in patients who suffer similar lesions as adults.
¹¹

In other words, if psychopaths are set up from birth with paralimbic brain abnormalities, it might precipitate the development of callousness in them as adults.

Interestingly, paralimbic brain damaged patients sometimes also develop incontinence (i.e., bed-wetting). Earlier I pointed out that youth who experience chronic bed-wetting may be at higher risk for future violent behavior. It remains unanswered whether the paralimbic brain damaged patients who develop incontinence are more violent than other paralimbic brain damaged patients. This is clearly an avenue that needs to be examined.

In addition to the similarities between the symptoms of psychopathy and the behavioral changes exhibited by patients following brain damage to the paralimbic system, there are also similarities in neuropsychological profiles between these two groups.

Neuropsychology uses tasks, or games, to understand the problems a person might be experiencing following brain damage. During my literature review, I discovered that the kinds of games patients fail following paralimbic brain damage were strikingly similar to the games psychopathic inmates fail.

Paralimbic brain damaged patients, like criminal psychopaths, have problems recognizing the nuances of voice or facial expressions. They also have problems regulating their behavior, have poor decision-making skills, have trouble inhibiting their behavior, appear apathetic, have trouble avoiding harmful situations, are promiscuous, show rebelliousness, tend to disregard social convention, and lack respect for authorities.

Damage to other regions of the frontal cortex (i.e., superior frontal or dorsolateral prefrontal), to the parietal cortex, or to the occipital cortex does not lead to these kinds of behavioral symptoms or cognitive abnormalities; that is, damage outside of the areas that Brodmann labeled paralimbic does not lead to psychopathic symptoms.

In other words, it appears that it was the paralimbic system that was failing in psychopaths.

And so all the pieces came together. I had found an answer in my quest to unravel the mysteries of the psychopathic brain. Armed with my new theory of psychopathic brain abnormalities, I started to design new studies to test specific components of the paralimbic system in psychopaths.

My life at Yale University and the Institute of Living was richly rewarding, both personally and professionally. I had developed a close group of friends with whom I skied, mountain biked, and went on vacation, adding some balance to my life after my workaholic graduate school life.

I was winning grants from the National Institutes of Mental Health and the National Institute on Drug Abuse to study psychopaths and substance abuse. And I’d been asked to serve on the NIH study section—a special privilege, where you are asked to review grants submitted by other scientists. I was climbing up the academic ranks.

But life was not without its hiccups. One frustration was that finding and then recruiting psychopaths for research was proving to be much harder in the community than it was in prison. Psychopaths, as one might imagine, often disappear once they are released from prison. And even if you can find them, they hardly ever show up for research appointments on time, if at all.