Excerpts from the book “The Psychopath Whisperer”

Facts:

• One in four maximum-security inmates is a psychopath.
• There are over 29,000,000 psychopaths worldwide.*
• Psychopaths kill more people in North America every year than the number killed in the terrorist attacks on September 11, 2001.
• Seventy-seven percent of psychopaths in the United States are incarcerated.
• Psychopaths are six times more likely than other criminals to commit new crimes following release from prison.
• A psychopath is born every 47 seconds.*
• There are approximately 500,000 adult male psychopaths in the United States.
• Some forms of group therapy may make psychopaths more likely to commit new crimes following release from prison than no treatment at all.

In [the oddball task], participants are presented with a series of different tones. Most of the tones are the same pitch, but occasionally a tone is presented at a higher pitch (the oddball or target tone). Participants have to press a button as quickly as possible when they hear that higher-pitched tone, but not press it for any other tone. Sometimes we also play a few funny, random tones, just to mix things up a bit. The latter tones examine the brain’s response to novelty.

………..

Figure 2. Event-related brain response (ERP) from a frontal brain site for forty psychopaths (gray line) compared to forty nonpsychopaths (black line) for the auditory oddball stimuli. Note the prominent difference between the psychopaths and nonpsychopaths starting at about 400 milliseconds and extending out to 800 milliseconds. This is the abnormal brain wave response of psychopaths. Units on the x-axis are in microvolts with negative amplitude plotted up; units on the y-axis are in milliseconds following the onset of the oddball stimuli. Data from Kiehl, K.A., et al. (2006). Brain potentials implicate temporal lobe abnormalities in criminal psychopaths. Journal of Abnormal Psychology, 115, 443–453.

I [the author] printed out the eighty-one inmates’ brain responses to the Oddball Task. I assigned a random number to each case and removed any details about whether the plot was a psychopath or not. I asked a research assistant to sort the brain wave plots based on the presence or absence of the weird P3. The assistant correctly sorted forty out of forty-one psychopaths. None of the nonpsychopaths were put in the wrong group. In other words, the weird P3 was literally diagnostic of psychopathy. Ninety-seven percent of the psychopaths showed this weird brain wave response, and none of the nonpsychopaths showed any evidence of it.

Source: The Psychopath Whisperer: The Science of Those Without Conscience (2014) by Kent A. Kiehl, Ph. D. 

*😮😦