The belief in an afterlife rests firmly on the idea that humans have an immortal soul that is distinct unto itself in the same way the heart or liver is. Some people call it spirit, in ancient Egypt it was known as ka, and Hinduism refers to it as atman. Cultures describe it as their life force, their innermost self, the part of them that provides individuality and personality. I think, therefore I am. It must seem obvious to any thinking human being that the part that is doing the thinking is separate from the mind that contains the thoughts. It is then only a small leap to conclude that it, whatever “it” is, will continue to exist beyond the death of the body.
Most humanists do not believe this because supporting evidence is in very short supply. Over the centuries, attempts at offering proof of the continuing existence of the spirits of the dead fail to pass serious scrutiny. Now, scientists and researchers are expanding the boundaries of knowledge once again, making great headway in unraveling not only the evolutionary biology of the brain, but in understanding the part of us that thinks, by reducing that part down to its most elementary building blocks.
When I think back and conjure up an old memory, what exactly do I have? For instance, as a child, my mother literally farmed me out to members of our church. For weeks at a time, I would live on a farm and help tend it. One of my duties was feeding the animals. In a conscious attempt to build muscle, I would fill 5-gallon pails with grain and carry them, one in each hand, to the hog trough. The stress would burn my young shoulders and the narrow handles would cut into my soft palms. I did this many times and yet now, forty years latter, it seems as if it were something that happened to someone else. I have memories of the farmer and his family, the farm itself, and even the surrounding land, but they all seem so vague, as if from a dream, their details blurred by time and disuse. In fact, I do not have precise memories of anything, even recent events, let alone those that occurred so long ago. Instead, what I have are ghostly recollections and the steadfast belief that these things actually happened in the way I remember them, not caring where imagination starts or where truth begins. I remember, therefore I believe. From this simple self-examination, it seems evident that memories and belief are inseparable companions. One cannot exist without the other.
Sam Harris, along with co-authors Sameer Sheth and Mark Cohen, has published a remarkable report in the forthcoming issue of Annals of Neurology, Functional Neuroimaging of Belief, Disbelief, and Uncertainty. The objective of the study was to determine, at the most fundamental level of the brain, what the dynamic processes of belief, disbelief, and uncertainty look like and where they take place. To do this, they used functional magnetic resonance imaging (fMRI) to study the brains of 14 adults while they judged written statements to be “true” (belief), “false” (disbelief), or “undecidable” (uncertainty). What they observed was that each of these processes created differentiable activity within distinct regions of the brain. They concluded that the final acceptance or rejection of a statement appears to rely on primitive, hedonic processing within the prefrontal and parietal cortices, as well as the basal ganglia and anterior insula.
For those of us without a PhD in biology, this study not only points to where decision-making processes occur within our brains, it shows what they actually look like in dynamic 3D. Sam Harris and associates were able to show that humans process truth using a different part of their brains as they do when processing untruth. Uncertainty is different yet again. I do not believe, pun intended, it will take long for this technology to find its way into our courtrooms and boardrooms. How could anyone lie to a device that can literally separate true from false from uncertainty with such precision? Police and crime labs may soon have a tool to investigate criminal behavior that is far superior to any lie detector yet invented, not to mention that any dictator or crime boss could use it to further their interests.
Getting back to the science, in order to understand belief we must first understand memory. What is memory at the most basic level of our brains? To begin with, our brains are linked to our five senses, sight, sound, smell, touch, and taste. Sensory input creates multiple interconnected electrochemical patterns within our brains, each employing millions of neurons. Initially, each sense stimulates a specific region of our brain. This chemical energy quickly spreads, surging through our brain cells like a prairie rainstorm.
When looked at using an fMRI, a memory can be defined as the firing of neurons along three-dimensional paths that vary with time. The strength of the memory and the ease with which we recall it, improves with repetition. Students read and reread, take notes, and summarize the material they are studying in a process we call learning. The fact is, the more times we experience the same set of inputs, the more likely it is that we will recall it later. A smell can conjure up a face from years ago, or a sound bring to mind an event long since past. We can read and write, talk and walk, because these memories have become hardwired into our brains through endless iterations. Most of these patterns exist far below the level of our consciousness, which feeds the fallacy that we only use 10% of our brain’s capacity. The other 90% is busy doing something. I can only surmise that if it stopped, we would miss it terribly.
Watching a child grow from infancy to adulthood, one sees how repetition plays a crucial role in our ability to learn. We also measure a person’s IQ by their ability to recall obscure facts accurately and swiftly. We can drive a car, surf the internet, and cook a meal, because we have memories etched in our minds that give us a foundation with which to make appropriate decisions. Virtually every thought, every emotion, every instinct we have is the result of processing memories. Without memories, we are an empty vessel.
Chemicals called neurotransmitters control whether we are asleep or awake by acting on different groups of neurons within the brain. Ongoing research is finding that sleep plays a vital role in reinforcing the neurological pathways of a memory by replaying events in the form of dreams. A study using rats showed that certain nerve-signaling patterns, which the rats generated during the day, were repeated during deep sleep. This pattern repetition encodes memories and improves learning.
One way to see what sleep does for us is to take it away and note what happens. Sleep deprivation studies of adults over the last century missed finding the cumulative deficits observed when sleep was restricted to daily dosages below eight hours. These earlier studies failed to control a host of confounding variables, perpetuating the belief that humans do not need eight hours of sleep each day.
In August 2002, a study on sleep depravation was published in Neurology Reviews that exploded that myth. Conducted by Dr. David Dinges, a Professor at the University of Pennsylvania School of Medicine, the ongoing study adds hundreds of experiments each year where subjects agree to remain isolated from the outside world for as long as 20 days in an environment where all the normal ways we tell time have been removed. All outside light was eliminated, every clock, radio, computer, and television taken away, the subjects are not allowed visitors or even telephone conversations. These people were completely isolated and continuously monitored. What they discovered was that sleep loss is cumulative and adversely affects our memory’s recall speed and accuracy.
Every animal that ever existed on Earth did so because their memories gave them a survival advantage. They recognized (another term that describes memory recall) the rustle in the grass as danger and fled or they died. In this way, evolution selected for those with good memories and the ability to recall them quickly. This process has continued for hundreds of millions of years resulting in us.
However, our species has something that most others lack: imagination. To put it into the context of this article, imagination is our ability to create memories of objects or abstract ideas without actual input from our sensory organs. Imagination is one of the main things we, as human beings, do with memories.
Imagination is the ability to envision some future event that has not yet happened or may never happen. As a science fiction writer, imagination, or as some put it, the creative juices, intrigues me. How is it that I can envision a future that has never existed? Are there other species with this ability? A study by researchers at Washington University in St. Louis concluded that memory and future thought are highly interrelated. They go on to explain why future thought is impossible without memories. However, I suspect the extreme nature of human imagination is unique to our species.
In the coming decades, as Sam Harris and other scientists ferret out every nuance within our brains, I believe they will find that not only is memory at the heart of all we do, it is who we are. Our personality, what spiritual people call a soul, is simply the endless processing of memories. It starts while we are still in the womb and continues nonstop to our final breath. So make good memories, for they are the key to happiness.