Does the human soul transcend the lifetime of the body it inhabits? Do humans even have souls? If we do, what happens to that soul after we die?

Big questions, such as these, require big answers. And despite what some people want you to believe, these ones are far from being answered. There’s good evidence on both sides of the line, depending on who you ask. Philosophers have been scrutinizing these questions for millennia, and though science has long tried to enter this particular discussion, until recently scientific thinking hasn’t had much to add.

That’s all changed though, with research projects like AWARE, wherein Dr. Sam Parnia has been seeking evidence of Near-Death-Experiences by studying what happens to people, physiologically, when they die. There’s also the neurophysical research of people like Roger Penrose and Stuart Hammeroff. Their Orch-OR (Orchestrated Objective Reduction) theory, which tries to provide a description and explanation of the soul through quantum mechanics, is impressive, and is gaining support in the scientific community.

But there are so many aspects to these questions that one could spend a lifetime reading about the various theories, hypotheses, and ideas, and still not have a solid grasp on an answer for the questions above.

Related to this is the idea of past-life regression. Many people confuse past-life regression, or PLR, with reincarnation, and while they seem related, they are quite separate ideas. PLR is, in fact, the phenomena of recalling details, events and people, from what seem like previous lives lived. This is where the confusion comes into it. PLR sort of requires that one believe in a form of reincarnation, in that there must have been a previous life to remember, in order for there to be recall of events from it. However, reincarnation doesn’t require PLR, and in fact, most schools of spirituality that employ a belief in reincarnation don’t hold any real position on PLR.

Past-life regression is most often facilitated through hypnotic therapy, often called hypnotherapy. In fact the term hypnotherapy is often used synonymously to mean PLR, though this is incorrect. It usually comes about through guided regression into childhood memories, sometimes as a part of serious psychotherapy, wherein the patient or participant enters a hypnagogic state and relays thoughts and memories to the therapist. Sometimes these memories don’t conform to the participant’s current life, whether because of location, age, or culture, and are thus thought to be memories of a life lived prior to their current one.

It can also come about spontaneously, and often those kinds of past-life memories are disconnected and alien, and are difficult for the participant to reconcile with their own life. There are many examples and stories of people who famously recalled places, experiences, people and things from their previous lives with shocking detail. Children who recognise people they’ve never met, and know them by name…even children who seem to already know languages that aren’t native to their current family or region.

Traditionally, the skeptical crowd has viewed PLR as nothing more than hypnotically-induced delusion or confabulation (a manufactured memory brought about through manipulation or leading by hypnotherapists), commonly known as cryptomnesia. It’s long been known that memories brought out through hypnotic regression are notoriously unreliable, as the participant is easily led through interviewer bias, but the more skill the hypnotist possesses as an interviewer/therapist, the more reliable the results tend to be. There’s also the issue of reincarnation being thought of as religious hokum not based in reality, but this sentiment may amount to nothing more than academic denialism.

Strange fact number 1

Scientists trained flat worms to curl up when exposed to light by electrocuting them every time the light was turned on. A pure Pavlovian, conditioned response. Even more unfortunate for the flat worms is their ability to regenerate themselves if cut in half . An amazing thing in itself; cut them in half and the head end grows a new tail and the tail end grows a new head. When the scientists did just that they found something bizarre; when exposed to light both versions of the worm responded according to the conditioning. How can this be? Common sense and contempory neuroscience both agree that memory is contained in the brain, so how can a newly grown brain come complete with memories?

Strange fact number 2

Take a calf born of stock that is used to cattle grids but has never seen one itself and introduce it to lines painted on a road to resemble a grid. It will not cross. How has this knowledge been communicated?

Strange fact number 3

A new-born chick is placed in a room with a hawk. It frantically tries to find cover. It meets a chicken for the very first time and is completely comfortable. People would call this instinct, and I’m sure it is –but how is instinct passed from one generation to the next? Wouldn’t it have to be stored in the DNA? And instinct is just a form of memory, so if that form of memory is stored in the DNA, then why not other forms of memory. It would explain facts 1–3 wouldn’t it?

The idea that our memories are stored in our genes is a very recent and controversial one. It has been accepted since the experiments of Wilder Penfield back in the fifties, that hidden away in each of us is a permanent record of our past. We are reminded of it regularly; how many times have you smelt a particular smell or heard a particular song, and been instantly transported back to an intense childhood memory. However, most neuroscientists believed and continue to believe that long-term memories are built into the brain by creating and strengthening connections between neighbouring neurons. These connections, known as synapses, are thought to join neurons up into complex networks that can recreate specific patterns of brain activity (memories), days, weeks, or even years, later.

There are problems with this model. These connections would need to be permanent and stable, and the brain is not. Nearly all the brain’s molecules, including those that form the neural connections thought to be involved in memory, are replaced every few weeks. How long-lasting memories can be stored by such an impermanent medium has confounded neuroscience for years. It is like writing a message on a piece of paper. Suppose we could replace the paper one molecule at a time. Eventually we would have a completely new piece of paper, with exactly the same appearance – except it would not still have the message written on it. Neurobiologist Sandra Pena de Ortiz suggests that somehow the brain must retain an archived blueprint of each neural network in order to create the replacement neuron as a structural and functional clone of its predecessor. Nature’s blueprint of choice is, of course, DNA, and it has the advantage of not undergoing the turnover that other molecules do. Not only is it quite stable over time, it even has a repair facility if anything goes wrong.

Pena believes that permanent memories are stored in altered genes. She and her colleagues believe that our DNA creates ‘memory molecules,’ new novel proteins, from a unique blueprint that could be formed by neurons rearranging their DNA in response to each new experience. The unique structure of these memory molecules would enable them to snap into a specific position at the synapses, helping make memories stable without disturbing other synaptic structures. “Changes in synaptic connections wouldn’t remain intact for long, but gene rearrangements could be kept throughout the neuron’s life.

Some scientists go even further and suggest that these memory molecules might store information themselves, that each individual neuron contains memory.

Either way this is a radical concept because the usual concept of our genetic code is of something fixed at the beginning of our lives, not something that gets re-written on a daily basis, and certainly not every brain cell being allowed to tamper with that code. But looking at it from an evolutionary point of view this arrangement does fulfil an abiding principle – that of Occam’s razor.

Occam’s razor states that nature always reduces things to the simplest solution. We know of only three ‘memory systems in nature. There is the evolutionary memory of how to build an organism; a cognitive memory of events we experience; and an immune memory of past infections. Two out of three of these are based on DNA, we would normally expect nature to be efficient enough to use the same tools for the third as well, not evolve something unique.

The impact of this theory, if true, is that our identity, our self, leaves a permanent mark on our genome. We may pass onto our descendents much more than eye colour. It has already been estimated that perhaps 40% of known personality traits are inherited, such as introversion/extraversion. This theory could explain how. It also poses other intriguing questions for our field.

Carl Jung popularised the idea of a collective unconscious that we are all plugged into, and suggested it as the repository of racial memories and universal archetypes. With genetic research now proving the inter-relatedness of all racial branches of the humanity – we are all related at some point in the past with Caesar, Sitting Bull, Nelson Mandela, Confucius and Uncle Tom Cobbly – the genetic transmission of memory would be a sensible transport mechanism for Jung’s theory. And of course we can get crazier:

If memories are stored in our DNA (and as 97% of it has no obvious function there is plenty of room), and we pass on our DNA to our children, who do the same thing with their children, could this be how the instincts of the chick and calf were passed on? If memory is stored in the genes is that how the flat worm’s tail can grow a new brain with an old memory? And finally, if they have access to instinctive memory (as we do – think of the grip response in a child when it thinks it’s being dropped), is it possible to access other ancestral memories located in our DNA? Could this be an explanation for past-life regression? When clients regress to memories from a previous life, is it actually them accessing something present in their genome blueprint, an ancestral experience?

It is the case that the mind uses past experiences as references to decide the meaning of what is occurring in the present. In the main we are used to thinking of such past experiences being limited to this lifetime. Perhaps this research opens the possibility that the unconscious has access to reference experiences stretching back generations. Certainly many people who experience such memories under hypnosis find an answer to a present problem. This would be consistent with the theory predicting that the effects of our experiences would be expressed in our genome. If this is inherited by our successors then it would also suggest that they would be subject to the consequences of those experiences. This doesn’t explain all past-life experiences – the memory of death, for example, couldn’t be explained by genetic transmission, but just because one class of experiences doesn’t fit, doesn’t render the possibility invalid.

According to recent research, however, PLR may not be as dependent on reincarnation as has long been thought.

Brian G. Dias PhD., and Kerry Ressler M.D., PhD. of Ressler Lab at the Yerkes National Primate Research Center in Atlanta, Georgia have discovered something quite interesting in their work with rodents. As reported in December 2013, in the scientific journal Nature, Dias and Ressler have found that memories can be inherited.

What they did was, using mice, demonstrate that an aversion to a particular smell, in this case rose blossoms, was passed from the parent onto offspring, genetically, and that this inheritance was passed on for multiple generations. More than that, they illustrated the genetic and neural changes that occurred in order to facilitate this inheritance. In their paper, titled Parental olfactory experience influences behaviour and neural structure in subsequent generations, they detail how they managed to create a deep aversion to the smell of rose blossoms in mice. They then examined the sperm of the mice and found that there had been changes to the genotype of the sperm, which, upon breeding, was expressed in the phenotype of the offspring as an inherited aversion to the same smell, even though the offspring had never encountered the smell before.

“The experiences of a parent, even before conceiving, markedly influence both structure and function in the nervous system of subsequent generations,”

This phenomena has long been theorised to be possible, but this is the first time it’s been demonstrated in a lab and shown to have a definitive genetic cause. The process is called transgenerational epigenetic inheritance, which refers to all types of influences that the parent’s life experiences can have on their offspring, from mutations caused by drug use, or exposure to certain environments, or even physical trauma.

This is also known as Lamarckian Inheritance, or Lamarckism, which is slightly different and speaks of an organism being able to pass on acquired characteristics to offspring – meaning characteristics that they weren’t born with and are therefore not part of their genetic code – and has typically been thought of in terms of superficial anatomical characteristics rather than environmental influences on the unborn. It would seem that Dias and Ressler have narrowed the gap between Lamarckian Inheritance and epigenetic inheritance.

Other experts have commented on their results, suggesting that this process may explain apparently inherited phobias and other psychoses, as well as instinctual behaviour, but it’s not known how far this may go.

“Prof Marcus Pembrey, from University College London, said the findings were “highly relevant to phobias, anxiety and post-traumatic stress disorders” and provided “compelling evidence” that a form of memory could be passed between generations. He commented: “It is high time public health researchers took human transgenerational responses seriously.””

Are our parents passing on more than just their base instinctual fears? Could they be giving us actual memories? Conceptual, contextual glimpses into their early life, and the early life of their parents, grandparents and so on? How far back might this genetic memory go? It seems, in light of this ground-breaking research, that we might be that much closer to an explanation for past-life memories. An explanation that doesn’t invoke reincarnation or the concept of the soul.

Not much is known about how memories are formed and maintained in the human brain, but everything that goes on in our bodies is the product of a set of genetic rules expressed against our living environment. And the argument between nature and nurture, which is essentially the argument between the genotype and the phenotype, has now gotten that much more complicated. We still don’t have any answers, but with this ongoing research at hand, we’re getting there.

References

Brian G. Dias & Kerry Ressler. Parental olfactory experience influences behaviour and neural structure in subsequent generations. Nature Neuroscience. 17, 89-96 (2014) | doi:10.1038/nn.3594 http://www.nature.com/neuro/journal/v17/n1/abs/nn.3594.html

James Gallagher. ‘Memories’ pass between generations. BBC News – December 2013: http://www.bbc.co.uk/news/health-25156510