Tasers Cause Serious Short-Term Cognitive Impairments

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Justine Alford

Guest Author

1156 Tasers Cause Serious Short-Term Cognitive Impairments
The study has implications for suspect questioning. Kbiros/Shutterstock

They might be less lethal than guns, but delivering 50,000 volts of electricity to a person is, unsurprisingly, not without harm, both to the body and the brain. So it may not come as a shock that new research has indicated that Tasers can cause significant reductions in some aspects of cognitive function, although the effects were short-term.

While the study isn’t suggesting that being Tased will give people lasting brain damage, the fact that it can result in temporary cognitive impairment has serious implications for crime scenes, as it could mean that suspects don’t understand the rights uttered to them while being arrested. Furthermore, the effects may cause a person to respond or act irrationally at the point of arrest, such as waiving their Miranda Rights, a decision that could ultimately affect their outcome at a court of law.


Published in Criminology & Public Policy, the Drexel and Arizona State University investigation involved 142 participants, all of whom were extensively screened using various psychological and physiological tests in order to reduce the likelihood of harm. Participants were then randomly assigned one of four conditions: nothing (controls), hitting a punch bag to simulate the heightened arousal that would be anticipated during arrest, a five-second Taser shock, and the punch bag followed by the shock.

Due to the inherent risks of Tasing someone, the experiment was conducted in a hospital. During the screening, immediately before, and straight after the treatment, participants had various aspects of cognitive function measured, including learning and memory using the Hopkins Verbal Learning Test (HVLT). This involves learning a series of words and then recalling them after varying periods of time, and can give indications of deficits ranging from learning difficulties to dementia.

The researchers found that exposure to a Taser resulted in temporary but significant reductions in short-term recall and the ability to integrate new auditory information. For instance, while all of the groups scored slightly above average on the HVLT prior to the conditions, those who were Tased dropped down to a typical score attained by 79-year-old adults, a figure that could be used to indicate mild cognitive impairment. However, the effects didn’t last longer than an hour for any individual, and almost everyone returned to their pre-Taser scores within this timeframe.

In a statement, the authors also address another important aspect of this study. All of the participants were young, healthy, in a highly-controlled and calm setting, and in the absence of any alcohol or illicit substances. This hardly reflects the situation at the majority of arrests, so it may well be that the effects would be more dramatic during real-life arrests, although that is purely speculation at this stage.


Tasers are inarguably safer than guns, so the take-home message is not to discontinue their use. Rather, the authors conclude that their findings suggest that questioning or interrogation should be delayed by an hour so that the suspect is in a better cognitive state to be making decisions and responding. 


  • tag
  • memory,

  • dementia,

  • learning,

  • crime,

  • cognitive function,

  • taser