Some research hints at a very low level link between psychopathy and (non-sexual) sadism… only nobody writing about it seems to acknowledge this, so I’m not sure if I’m reading too much into it. Anyone with more expertise, feel free to let me know.
To sum up:
Researchers showed some jailed psychopaths images of other people being hurt, while scanning their brains using fMRI.
Not surprisingly, it seems they’re not capable of being concerned for others.
But the article tucks in one other interesting tidbid — that didn’t even make it into the official abstract. As well as slightly puzzling activation of the little-known insula (“involved in emotion and somatic resonance”), another brain area that lit up when the psychopaths saw others being hurt was the striatum.
The article doesn’t say what the stratum is, so I’ll cite wiseGEEK… it’s part of the reward pathway. (http://www.wisegeek.com/what-is-the-striatum.htm)
Might it therefore be that these criminal psychopaths weren’t just incapable of sympathizing with others, but actually enjoyed seeing them get hurt?
It turns out that clenching your right fist helps you memorize things (if you do it while you’re trying to memorize something). Clenching your left fist while trying to recall helps you remember. (http://www.sciencedaily.com/releases/2013/04/130424185159.htm)
This gives a whole new meaning to a lot of political gestures! (https://en.wikipedia.org/wiki/Raised_fist)
It seems you can also selectively activate the left and right hemispheres of the brain.
To shift things a little, press your left nostril shut for a little while to activate the left brain, and vice versa. (if you’re already breathing through the opposite nostril, you’re already there)
To shift to full-blown left or right brain dominance, lie on your left side (for left brain dominance) for a few minutes. Pressing your fist under your armpit for a few minutes will also activate the opposite side.
(from Ostrander & Schroeder, “Supermemory,” p. 71)
“They were then studied with functional MRI technology, to determine their responses to a series of scenarios depicting people being intentionally hurt. They were also tested on their responses to seeing short videos of facial expressions showing pain.
The participants in the high psychopathy group exhibited significantly less activation in the ventromedial prefrontal cortex, lateral orbitofrontal cortex, amygdala and periaqueductal gray parts of the brain, but more activity in the striatum and the insula when compared to control participants, the study found.
The high response in the insula in psychopaths was an unexpected finding, as this region is critically involved in emotion and somatic resonance.”