psychopaths, but not in successful psychopaths. The higher-order executive functions of the frontal lobes of unsuccessful psychopaths seem to be impaired, compared to frontal-lobe function in successful psychopaths. In fact, preliminary research suggests that successful psychopaths may have better frontal-lobe function than both unsuccessful psychopaths and even many non-psychopaths.
Another difference between the two groups indicates a possible difference in the way their peripheral nervous systems work. Unsuccessful psychopaths have been shown to have reduced activity in the part of the nervous system that controls involuntary functions such as heart rate and sweating in response to events and stimuli with emotional meaning. Bothof these functions, heart rate and skin conductance, are reduced in unsuccessful, but not in successful, psychopaths. As with their frontal-lobe function, successful psychopaths may enjoy an advantage over others, criminal psychopaths and non-psychopaths, in their involuntary (or what scientists call autonomic) nervous systems too.
Remember the Hippocampus
Back in 2004, Adrian Raine and his group reported that a structure in the limbic system, the hippocampus (Figure 11), differed in unsuccessful psychopaths compared to successful psychopaths. 22 Previous studies had suggested that the hippocampus did not look or work the same in institutionalized violent individuals, including psychopaths, compared to non-offenders. Raine’s preliminary study was the first to make a side-by-side comparison of successful and unsuccessful psychopaths.
The researchers managed to locate 12 suitable, successful psychopaths working at temporary employment agencies who they defined as having PCL–R scores between 23 and 31. Their average was close to 28. These successful psychopaths had never been charged with crimes, although they reported breaking the law after being assured their interviews were protected by a legally binding confidentiality agreement between the researchers and subjects. This group was compared to 16 unsuccessful psychopaths who had been convicted of crimes. Their PCL–R scores averaged 31.5 and ranged from 23 to 40. The control group included 23 people with an average score of 11, ranging from 2 to 14.
The hippocampus was larger on the right side compared to the left in 94 percent of the unsuccessful psychopaths. Less than 50 percent of the successful psychopaths and non-psychopathic controls had this asymmetry.
The hippocampus is often described as the place in the brain where long-term memories are made. This association was tragically illustrated by a patient known as “HM” to several generations of neurologists and neuroscientists.
In 1953, Connecticut resident Henry Gustav Molaison involuntarily provided a famous example of just how specialized some brain tissue can appear to be. 23 Molaison was incapacitated by epileptic seizures, which hadstarted when he was ten years old. By the time he was sixteen, the severity and frequency of his seizures made it impossible for him to live even a semblance of a normal life.
Eighteen years later, in a last-ditch effort to provide some relief from his incapacitating symptoms, surgeon William Scoville cut out small sections of Molaison’s brain located beneath his temples to a depth of a little over 3 inches. Removing the medial temporal lobes including the hippocampi on both sides of Molaison’s brain partially relieved his epileptic symptoms, but at a terrible price.
He was still Henry Molaison—his personality had not changed—but the surgery cost him the ability to form new memories. He could no longer remember people he had just met if they left the room and came back in. He could not remember places or anything that happened for any significant length of time after his operation. He had lost his ability to form long-term memories, although he could remember what had happened before his surgery.
Known by his initials HM, Molaison
Another difference between the two groups indicates a possible difference in the way their peripheral nervous systems work. Unsuccessful psychopaths have been shown to have reduced activity in the part of the nervous system that controls involuntary functions such as heart rate and sweating in response to events and stimuli with emotional meaning. Bothof these functions, heart rate and skin conductance, are reduced in unsuccessful, but not in successful, psychopaths. As with their frontal-lobe function, successful psychopaths may enjoy an advantage over others, criminal psychopaths and non-psychopaths, in their involuntary (or what scientists call autonomic) nervous systems too.
Remember the Hippocampus
Back in 2004, Adrian Raine and his group reported that a structure in the limbic system, the hippocampus (Figure 11), differed in unsuccessful psychopaths compared to successful psychopaths. 22 Previous studies had suggested that the hippocampus did not look or work the same in institutionalized violent individuals, including psychopaths, compared to non-offenders. Raine’s preliminary study was the first to make a side-by-side comparison of successful and unsuccessful psychopaths.
The researchers managed to locate 12 suitable, successful psychopaths working at temporary employment agencies who they defined as having PCL–R scores between 23 and 31. Their average was close to 28. These successful psychopaths had never been charged with crimes, although they reported breaking the law after being assured their interviews were protected by a legally binding confidentiality agreement between the researchers and subjects. This group was compared to 16 unsuccessful psychopaths who had been convicted of crimes. Their PCL–R scores averaged 31.5 and ranged from 23 to 40. The control group included 23 people with an average score of 11, ranging from 2 to 14.
The hippocampus was larger on the right side compared to the left in 94 percent of the unsuccessful psychopaths. Less than 50 percent of the successful psychopaths and non-psychopathic controls had this asymmetry.
The hippocampus is often described as the place in the brain where long-term memories are made. This association was tragically illustrated by a patient known as “HM” to several generations of neurologists and neuroscientists.
In 1953, Connecticut resident Henry Gustav Molaison involuntarily provided a famous example of just how specialized some brain tissue can appear to be. 23 Molaison was incapacitated by epileptic seizures, which hadstarted when he was ten years old. By the time he was sixteen, the severity and frequency of his seizures made it impossible for him to live even a semblance of a normal life.
Eighteen years later, in a last-ditch effort to provide some relief from his incapacitating symptoms, surgeon William Scoville cut out small sections of Molaison’s brain located beneath his temples to a depth of a little over 3 inches. Removing the medial temporal lobes including the hippocampi on both sides of Molaison’s brain partially relieved his epileptic symptoms, but at a terrible price.
He was still Henry Molaison—his personality had not changed—but the surgery cost him the ability to form new memories. He could no longer remember people he had just met if they left the room and came back in. He could not remember places or anything that happened for any significant length of time after his operation. He had lost his ability to form long-term memories, although he could remember what had happened before his surgery.
Known by his initials HM, Molaison
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