New research results out of Germany show how electroencephalography (EEG) neurofeedback can impact brain activity for criminal psychopaths.

A person with psychopathy has a lack of empathy and a tendency for heightened anger and aggressiveness. In addition, psychopaths may have little anticipatory fear or remorse for criminal acts.

Unlike other brain studies, EEG offers a visual representation of brain activity in real time that can be viewed by the person being monitored. Authors of a paper published in January 2021 in Plos One have found that they can utilize this feature as a form of biofeedback.

When doing this, patients can actually change their brain waves.

The authors saw this while studying psychopaths using a process they call slow cortical potential (SCP) neurofeedback. The 14 participants (all male) were recruited from high-security forensic-psychiatric clinics in Germany. All were serving long sentences for violent crimes.

The researchers analyzed the subjects’ resting-state EEGs and followed them as they completed 25 sessions of EEG neurofeedback training for five weeks. After that, they retested their resting-state EEGs.

The study shows EEG neurofeedback training can change resting brain activity. The subjects showed a reduction in slower frequencies (delta and theta) that ran parallel to an increase in faster brain waves (alpha). Previous research has linked overrepresentation of delta and theta frequencies with psychopathic behavior.

The authors noted this research was exploratory and may point to future applications of EEG neurofeedback training.

Participants were also assessed throughout the study using a standard psychological questionnaire called the Psychopathy-Checklist-Revised, and their skin responses were measured via electrodermal activity (EDA). Changes in both ran in parallel and confirmed what the authors saw on EEG.

Though these results were correlational and not causal, the authors concluded they suggest “an underlying biological mechanism relating the behavioral factors of psychopathy to resting-state EEG oscillations.”

In other words, their psychopathy could be “seen” on EEG. Moreover, using neurofeedback, some of the negative qualities associated with psychopathy could be changed.

The authors do urge caution when interpreting their results. Their sample size was small, for example, and they found significant challenges in studying this rare population under high-security conditions.

Their findings, however, do contribute significantly to science’s aim to find “biological signatures” of mental illness.