Suppose we could erase memories we no longer wish to keep. In such a world, the victim of a terrifying assault could wipe away memories of the incident and be free of the nightmares that such memories often cause. Some memories, however, even quite unpleasant ones, are extremely valuable to society and ought not be eliminated without due consideration. An assault victim who hastily erases memory of a crime may thereby impede the investigation and prosecution of the perpetrator. In a world with memory erasure, our individual interest in controlling our memories may conflict with society's interest in maintaining access to those memories. We tend to think of our memories as our own in some fundamental way. No one else should have the right to control such an important aspect of our minds. But what if we really could manipulate our memories? Is it so clear that our memories are entirely our own?
Neuroscientists are working to develop drugs that dampen the emotional intensity of traumatic memories. Some research suggests that propranolol, a drug already approved by the FDA for treating hypertension, can dull the emotional pain associated with the memory of an event when taken within six hours after the event occurs. Researchers are now conducting larger studies with propranolol to test these preliminary results and to explore whether propranolol can safely be used to ease traumatic memories from the more distant past. While we already have lots of other drugs that affect the formation of memories once you start taking the drug (common in certain forms of anesthesia, for example), there isn't much we can do to affect memories that have already formed. And that's what we'd need to treat past trauma. So it's possible that propranolol could fill an important niche.
If propranolol does affect the emotional valence of memory, the effects are probably modest. And it is unclear whether propranolol also dampens factual associations with memories (the PDR lists short-term memory loss as a side effect of the drug). But even if propranolol falls flat, some more potent drug is likely to step into its place. In 2004, U.S. veterans received benefits payments for PTSD totaling $4.3 billion. Clearly, there's lots of interest in finding comparatively inexpensive pharmaceutical methods of easing or preventing the emotional distress associated with bad memories.
How, if at all, ought the law to change in a world where we can dampen factual or emotional aspects of memory? Memories serve two distinct roles in the legal system. First, they play an indispensable role in fact-finding. We gather memories in depositions, trial testimony, police investigations, lineups, and more to help establish the underlying facts that set the entitlements of disputing parties. We value these memories principally for the information they can provide. Second, memories and their associated affective states can themselves form part of a claim for damages. If you injure me and cause me to have upsetting memories, I can sometimes seek redress for the intentional or negligent infliction of the emotional distress associated with those memories.
So, memory-dampening drugs that affect factual recall could raise interesting legal questions relating to obstruction of justice, spoliation of evidence, hearsay evidence, the value of eyewitness testimony, and more. Drugs that affect the emotional valence of memories raise questions about informed consent, mitigation of emotional distress, the valuation of the harm of erasing memories that should have been kept and the harm of keeping memories that should have been erased, and more. There are also plenty of interesting questions of constitutional law, many of which straddle both factual and emotional aspects of memory.
Admittedly, the technology will have to improve before we have to confront these issues on any regular basis. Nevertheless, drugs like propranolol have already been tested on human subjects who show up in the emergency room with trauma from assaults and car accidents. Suppose, as seems quite plausible, that there is civil or criminal litigation associated with some of those assaults and car accidents. Even if propranolol has no significant effects on memory, courts will at least need to explore and address the scientific validity of claims made about propranolol. After all, a good attorney will certainly ask a witness who participated in one of these studies, "So, is it true that you participated in an experiment by a researcher at Harvard Medical School into drugs that alter the intensity of memories?" We are thus confronted with legal and ethical issues related to memory dampening even before we have effective memory-dampening technologies.
Moreover, in my next post, I'll discuss a true story that raises several interesting legal and ethical questions related not to some weak form of memory dampening but to what we can fairly call memory erasure. Not only is the story not science fiction, it's over ten years old! Stay tuned . . . (In the meantime, you can find my much fuller account of the above discussion with citations here. My article challenges some of the ethical claims of the President's Council on Bioethics, which is highly skeptical of the merits of memory dampening.)