In some extreme cases people can become psychologically paralysed by their memories, for example in post-traumatic stress disorder (PTSD). Neuroscientist Dr Daniela Schiller, who researches memories which evoke fear, spoke about her work last week at a discussion entitled "The neuroimaging of emotion" at the The Royal Society – part of its Summer Science Exhibition. In the chair was neuropsychiatrist Professor Ray Dolan and on the panel were art historian Professor David Freeman, Dr Schiller, and the novelist Ian McEwan.

Emotions that drive artistic expression were on the agenda, but it was Schiller's research on the "reconsolidation of memories" that drew me to the event. Her work investigates the evolved, adaptive similarity between the brains of humans and rats, with a view to finding ways to eradicate overwhelming psychological pain without drugs.

The memories of both man and rat are influenced by a process known as the "reconsolidation period" which comes into play when memories of past experiences are recalled. During reconsolidation, memories are modified and updated with any new, relevant information that the individual becomes aware of.

Lab rats and humans have a minimum six-hour reconsolidation window after memory recall during which the memory is re-embedded with any new, useful information. Research has shown that rats that have learned, via painful experience, to be afraid of a particular stimulus, can be re-educated during the reconsolidation window and their fear extinguished. The old memory can be re-written and the emotion of fear turned into ambivalence or even into a feeling of safety. By contrast, rats that were given extinction training after the six-hour reconsolidation period retained a fear of the stimulus.

Schiller decided to see if the same could work in humans. She showed participants a yellow square with no stimulus attached and then a blue square accompanied by an electric shock to the wrist. On day one the volunteers learned to associate blue squares with shocks. On day two, to reactivate the memory and open up the reconsolidation window, they were shown the blue square once without the shock .

Participants who were subsequently given extinction training (repeatedly showing the blue square without an electric shock) in the 10 minutes immediately after the reactivation of the memory did not show any fear of the blue square (measured by how much they were sweating) the next day. Participants given extinction training outside the reconsolidation window, however, continued to sweat whenever they were shown the blue square.

Schiller tested the same participants a year later to see whether the effect persisted, with the same result. While this research does not prove that old memories from decades previously can undergo extinction and reconsolidation, patients suffering PTSD were tested and there did appear to be some positive effect upon old, painful memories.

Because we are long-lived animals our long-term memories are essential: they define us, shape us, inform us and guide us. The plasticity of the human psyche allows for modification, and hindsight can supply enlightenment and psychological growth.

But if memories can be modified and even inverted, and fear eliminated, what are the implications for the conduct of police interrogations or for the handling of witnesses in court cases? After repeated recall and cross-examination, our true, original memory may be harder to recall and we could become unreliable narrators of our own stories. Schiller told the audience she knew her research could be appropriated "by the CIA", but she pointed out that science is always open to abuse.

Psychiatrists have been using the window of reconsolidation for years. Cognitive behavioural therapy, for example, relies on the retrieval of painful memories and the analytic re-evaluation of them through discourse with a therapist. But Schiller's work proves there is a distinct window of opportunity in which to turn bad memories into good ones – and vice versa (perhaps this is the basis of false memory syndrome?)

I asked Schiller if the reconsolidation period in primates like humans differed from that in other animals – namely rats? "Maybe human memory works differently because there might be an interaction between different memory systems and also some effect of awareness to certain memories (when they become explicit)," she said. "But this is speculative and one of the challenges we face when we try to make a transition from animal to human research."

The universal importance of emotion to artistic expression was central to the debate at the Royal Society. The notion of the artist suffering for their art may be a cliché, but there is truth in it. Van Gogh was not the only tormented genius whose work was driven by pain. But would his paintings have the power they retain if Van Gogh had been treated in Schiller's lab?

Most creatives would argue that they cannot create if they dull their passions. I asked Ian McEwan if he would like to undergo Schiller's extinction training, and what effect did he think it would have on his writing if he did? McEwan replied that memories are what make us and drive us, and it is by learning to cope with random tragedy that we develop as humans. But if he were oppressed by fear he might feel differently, he added.

Knowing that I would be attending this lecture I recently asked another acclaimed British novelist, Sebastian Faulks (author of Human Traces, a story of psychiatry and memory), the same question. Faulks was emphatic: the loss of emotions attached to memories, even negative ones, was a bad idea.

I asked the same question of an unemployed, middle-aged woman with a borderline personality disorder who is currently receiving therapy for her long-term depression and addiction to antidepressants due to her experience of childhood abuse. She said that she would definitely want Schiller's treatment, but added she would also want an extinction process that made her stronger so she could protect herself in the future.

Clearly, while we debate the philosophical implications of research such as Schiller's – findings that threaten to undermine our perception of behavioural phenomena we hold sacred – those suffering the torment of extreme anxiety just want someone to make it stop.