WHERE DO DIRTY THOUGHTS STIMULATE YOU THE MOST?

“Hemispheric asymmetries during processing of immoral stimuli”

Abstract: Evolutionary approaches to dissecting our psychological architecture underscore the importance of both function and structure. Here we focus on both the function and structure of our neural circuitry and report a functional bilateral asymmetry associated with the processing of immoral stimuli. Many processes in the human brain are associated with functional specialization unique to one hemisphere. With respect to emotions, most research points to right-hemispheric lateralization. Here we provide evidence that not all emotional stimuli share right-hemispheric lateralization. Across three studies employing different paradigms, the processing of negative morally laden stimuli was found to be highly left-lateralized. Regions of engagement common to the three studies include the left medial prefrontal cortex, left temporoparietal junction, and left posterior cingulate. These data support the hypothesis that processing of immoral stimuli preferentially engages left hemispheric processes and sheds light on our evolved neural architecture. Article

The Guardian serves it up like this.

Immoral thoughts: how does the brain react?

In one test, volunteers saw different kinds of printed statements. Some were about pathogens (“You eating your sister’s spoiled hamburger, You sipping your sister’s urine, You eating your sister’s scab”); some about incest (“You giving your sister an orgasm, You watching your sister masturbate, You fondling your sister’s nipples”), some about “nonsexual immoral acts” (“You burgling your sister’s home, You killing your sister’s child”); and others about “neutral acts” (“You reading to your sister, You holding your sister’s groceries”).

In other tests, volunteers saw other kinds of statements or pictures, each chosen for its evident moral content.

After all the immorality was seen, and the measurements made, the researchers calculated that the left side of the brain had been more involved than the right side. Thus, concludes the study: “There is a left-hemisphere bias for the processing of immoral stimuli across multiple domains.” Via