Psychopaths (sociopaths): White matter, unplugged

Thank you, scientists in De Crespigny Park , for mapping the white matter of psychopaths* and showing where the wiring is frayed.  H.a. l.l.e.l.u.j.a.h.

Add this to a report out of Haifa surmising the part of the brain damaged in psychopaths, and probably responsible for callous horrific behavior — you get the whole story: a direct line showing how psychopath brains are dysfunctional due to faulty neural wiring from the threat center to the compassion center.

When I first started blogging about this I thought psychopaths were “unplugged” — that they have a white matter disconnect. (Link to posts under “white matter” category). Well,  this is it.

* The term “psychopath” used here as synonymous with “sociopath”, to mean someone lacking a moral center, whether or not they have antisocial behavior.

The De Crespigny Park recent report uses imaging to demonstrate psychopaths have wobbly white matter running from the amygdala to the orbitofrontal cortex, the uncinate fasciculus (here).

The more highly rated on the psychopathy scale (PCL-R), the more frayed the wiring. The scientists back-tested this twice — first, by demonstrating that this was limbic-specific and not found in other white matter tracts, and second, by demonstrating that this was not just random, by comparing to the white matter of former druggies. Nope. The results are for real. (Abstract and cite below). (The illustration has two arrows pointing to the right and left sides of the uncinate fasciculus)(The right had one is hard to see because it’s white, sorry).

uncinate-fasciculus

Another report by the group in Haifa associates orbitofrontal cortex (OFC) dysfunction with that special kind of callousness that psychopaths show – a profound lack of capacity for altruism.

Psychopaths know other people think things — they just don’t care.  So you have people who know how to manipulate, but have no moral center (because it’s disconnected).  Everything else is more or less connected — it’s just the moral center that’s unplugged.

This explains a lot:

1. Some psychopaths are prone to smoking. Smoking tobacco ups your white matter integrity. Maybe smoking is a way to treat frayed white matter. Maybe all psychopaths should take up smoking.

2. Psychopaths have nervous energy/anxiety, and are prone to bursts of rage. Frayed white matter is implicated in anxiety disorders, and is also associated with low levels of serotonin transporter protein (the 5-HTTLPR). A report on “Intermittant Explosive Disorder” (and I don’t know what that is, but it sounds like a number of people in my orbit) demonstrates that people with unbridled impulsive  hostile aggression have an  “uncoupled” amygdala/orbitofrontal circuit.

3.  White matter integrity seems to be heritable.  Apologies to the parents out there. This makes an abundance of sense to me. I think there’s a trinucleotide repeat aspect in there somewhere, and a gene dosage effect (or something) inherited from the Y chromosome. But, white matter in the frontal lobes may be most affected by environment. The frontal lobes are late in developing. Perhaps parents can catch the psychopathic behavior and take steps to modulate white matter formation during development. I think that the brain can be induced to be more plastic at the cellular level, and tht white matter modulation could be done at any age. I wouldn’t try it at home with any adult psychopaths in my own orbit, though.

4.  You can have high functioning psychopaths.  Probably their gray matter — the modular components of the brain — are more or less intact (it seems).  Some psychopaths have reduced activity in the frontal lobes, and some thinning of the gray matter, and there may be some lesions. My guess is that high functioning sociopaths have less damage in the gray matter, but more severe damage in the white matter disconnect.

5. Psychopaths misinterpret social cues and have negative attributional bias.  The amygdala reactivity predicts automatic negative evaluations for facial emotions. Where there’s no feedback loop from the reasoning part of the brain, the amygdala is on its own.  Schzo-psycho  patients who don’t recognize fearful faces well seem have no strong amygdala activation. Or, even just due to anxiety (see point #2 above),  they may have negative attributional bias.

6. Psychopaths seem to have a 6th sense in picking targets. Perhaps psychopaths smell fear?  This makes sense if the white matter disconnect doesn’t register odor but can detect chemosensory information. I wonder if white matter disconnected from the olfactory doubles up on the chemosensory tracts.  A really great study was done, demonstrating that anxiety chemosensory information travels the empathy pathway in the recipient’s brain.  Sweat was taken from nervous people and separately from people doing sports.  Test subjects smelled each kind of sweat under a brain scanner. The “nervous” sweat lit up pathways involved in empathy. I don’t know how this can relate to the white matter impairments, but odor and chemosensory information can be decoupled and sent on separate pathways. I wonder if a perfume containing sweat of people doing sports would be a good psychopath repellent.

7.  Psychopaths seem to have a double dose of the wiring disconnects that people with autistic spectrum have.  People with autistic spectrum conditions — who may be slow to get that other people think things, but when it’s explained to them, they care very much – seem to have a different pattern of white matter wiring,  reported here, particularly in the left uncinate fasciculus.  Psychopath white matter is dysfunctional on both the right and the left sides.

8. Psychopaths seem to calm down as they get older, and that may be because people — not just psychopaths — have a Last in First Out (“LIFO”) white matter degeneration. The frontal lobe white matter is the last in during development, so it’s the first out.

1.  Craig MC, Catani M, Deeley Q, Latham R, Daly E, Kanaan R, Picchioni M, McGuire PK, Fahy T, Murphy DG. “Altered connections on the road to psychopathy,” Molecular Psychiatry advance online publication 9 June 2009; doi: 10.1038/mp.2009.40

Psychopathy is strongly associated with serious criminal behaviour (for example, rape and murder) and recidivism. However, the biological basis of psychopathy remains poorly understood. Earlier studies suggested that dysfunction of the amygdala and/or orbitofrontal cortex (OFC) may underpin psychopathy. Nobody, however, has ever studied the white matter connections (such as the uncinate fasciculus (UF)) linking these structures in psychopaths. Therefore, we used in vivo diffusion tensor magnetic resonance imaging (DT-MRI) tractography to analyse the microstructural integrity of the UF in psychopaths (defined by a Psychopathy Checklist Revised (PCL-R) score of greater than or equal to25) with convictions that included attempted murder, manslaughter, multiple rape with strangulation and false imprisonment. We report significantly reduced fractional anisotropy (FA) (P<0.003), an indirect measure of microstructural integrity, in the UF of psychopaths compared with age- and IQ-matched controls. We also found, within psychopaths, a correlation between measures of antisocial behaviour and anatomical differences in the UF. To confirm that these findings were specific to the limbic amygdala–OFC network, we also studied two ‘non-limbic’ control tracts connecting the posterior visual and auditory areas to the amygdala and the OFC, and found no significant between-group differences. Lastly, to determine that our findings in UF could not be totally explained by non-specific confounds, we carried out a post hoc comparison with a psychiatric control group with a past history of drug abuse and institutionalization. Our findings remained significant. Taken together, these results suggest that abnormalities in a specific amygdala–OFC limbic network underpin the neurobiological basis of psychopathy.

2.  Shamay-Tsoory SG, Harari H, Aharon-Peretz J, Levkovitz Y., “The role of the orbitofrontal cortex in affective theory of mind deficits in criminal offenders with psychopathic tendencies., ” Cortex. 2009 May 18. [Epub ahead of print]doi:10.1016/j.cortex.2009.04.008

Individuals with psychopathy show impaired emotional and social behavior, such as lack of emotional responsiveness to others and deficient empathy. However, there are controversies regarding these individuals theory of mind (ToM) abilities and the neuroanatomical basis of their aberrant social behavior. The present study tested the hypothesis that impairment in the emotional aspects of ToM (affective ToM) rather than general ToM abilities may account for the impaired social behavior observed in psychopathy and that this pattern of performance may be associated with orbitofrontal cortex (OFC) dysfunction.

To assess the emotional and cognitive aspects of ToM we used a task that examines affective versus cognitive ToM processing in separate conditions. ToM abilities of criminal offender diagnosed with antisocial personality disorder with high psychopathy features were compared to that of participants with localized lesions in the OFC or dorsolateral, participants with non-frontal lesions, and healthy control subjects. Individuals with psychopathy and those with OFC lesions were impaired on the ‘affective ToM’ conditions but not in cognitive ToM conditions, compared to the control groups. It was concluded that the pattern of mentalizing impairments in psychopathy resembles remarkably that seen in participants with lesions of the frontal lobe, particularly with OFC damage, providing support for the notion of amygdala–OFC dysfunction in psychopathy.