Part I: A Selection of the Latest Research & Part II: Spiritual Experiences VS Awakening/Enlightenment

Because of  my new book coming out March 31, Spirituality Through a Highly Sensitive Lens: An Objective Look at Meditation Methods and Enlightenment), my blog posts now have two parts in each post—Part I will give brief reviews of a selection of recent research,  and Part II will be in keeping with the tone of my new book, something more “spiritual.” For that, scroll down in this post to Part II. 

Part I. A Selection of the Latest Research

As the subject of high sensitivity (aka differential susceptibility,environmental sensitivity,sensory processing sensitivity) attracts more researchers, the scientifically solid studies get more complicated and the not-as-solid, well, drop from my view. Here are three good, very complicated studies that I have tried to simplify for you, but in some cases you can easily read the original study if you want the detailed explanations. These three will be  added to the list of all the summaries of the best studies, found on the website here.

Your Differential Susceptibility Appears to be Genetic 

Torrecilla Gonzalez, P., Lavín Gutiérrez, V., Arias-Magnasco, A., Danae Lin, B., Menne-Lothmann, C., Decoster, J., van Winkel, R., Collip, D., Delespaul, P., De Hert, M., Derom, C., Thiery, E., Jacobs, N., Os, J. V., Rutten, B., Guloksuz, S., & Barrantes-Vidal, N. (Accepted/In press). Genetic Sensitivity to the Environment Moderates the Impact of Positive and Negative Childhood Experiences on Psychological Adjustment “For Good and for Bad”. European Psychiatry. Only the abstract is available here.

This study aimed at replicating previous differential susceptibility (DS; the finding that HSPs are more affected by both positive and negative environments) by looking at a set of genes typically found in HSPs along with asking about their positive and/or negative early life events to see how these factors, genes and environment, taken together, affected their scores on various measures of functioning and wellbeing.  The sample consisted of 638 adolescent twins. Those with high genetic sensitivity, if they also experience childhood adversity, were found to be more “eccentric” and less functional, but with a favorable childhood, those with genes for sensitivity were rated as less eccentric, better adjusted, and having better social coping skills. (For no reason suggested by the authors, there was no effect on measures of internalizing problems such as depression or anxiety) or wellbeing.

Bottom Line: Genetic measures of sensitivity operate in a “for better and for worse” manner depending on what you were exposed to as a child. Not exactly news, but good to see it replicated with genes rather than only self-report measures.

The HSP’s Brain is More Complex, Making it Better Able to Process Information 

Walter, N., Meinersen-Schmidt, N., Kulla, P., Loew, T., Kruse, J., & Hinterberger, T. (2023). Sensory-processing sensitivity Is associated with increased neural entropy. Entropy, 25(6), 890. View article here. 

This study sought to find out if differences in HSP Scale scores were associated with complexity or “criticality features” of the brain as measured using electroencephalogram (EEG) during a task-free resting state. In a second similar study, the authors compared the EEGs of those with very high and low scores on various measures of criticality.

What is criticality? Here is where it gets complicated. The brain-criticality hypothesis suggests that neural networks, and thus many aspects of brain activity, self-organize into a “critical state.” Critical states are unique configurations of physical systems that have been a central focus of statistical physics for more than a century. Criticality, another term for the topic, is the transition point or critical point between ordered and disordered states. In brief, the brain organizes itself so that it is often on the brink of being too disordered, but not quite.

Why should you be interested in criticality? Neural networks in the brain, by being at criticality–in that critical state–can process information, transmit it, and store it optimally. Criticality means there is a balance between the disordered aspect, which keeps allowing more new information, and the ordered aspect that keeps it all, well, organized. (You can imagine that when you are overstimulated you go through a phase transition from criticality to a completely disordered state!)

What does this have to do with neural entropy, the term in the title? Entropy refers to randomness or disorder in general, so in this case they were measuring the disorganized aspect of a brain’s critical state.  Without some entropy or disorder, that is some taking in of new information that we do not yet have organized, we would be brain dead (or under anesthesia). At the other extreme, high entropy can occur when taking psychedelic drugs, for example, when there is too much to comprehend.

Again, a living system, including a brain, must balance order and disorder, and the better it can do this, the better it can handle new information. Now I think you can see why these researchers were interested in HSPs. We are, at least in theory, genetically predisposed to take in more information than others and process it more deeply.  And this is indeed what they found. “The increased sample entropy [samples of the degree of entropy of neurons over time] in the highly sensitive group was most pronounced in the central, temporal, and parietal regions.” The HSPs were allowing more disorder and thus more new information than others in some of the most important parts of the brain.

Bottom Line:  For the first time, neurophysiological complexity was associated with SPS during a task-free resting state. As the authors stated, “The findings support the central theoretical assumption of enhanced information processing” in HSPs.

HSPs Notice Subtle Changes Without Even Trying

Yu, C. Y., Chiu, C. C., Huang, C. M., Lu, H., & Cheng, C. H. (2026). Neurophysiological correlates of sensory processing sensitivity: Altered alpha oscillations during auditory change detection. Personality and Individual Differences, 255, 113676. Read article here. 

An early brain study of HSPs (this was Jagiellowicz, J., Xu, X., Aron, A., Aron, E., Cao, G., Feng, T., & Weng, X.,2011, The trait of sensory processing sensitivity and neural responses to changes in visual scenes. Social cognitive and affective neuroscience, read article here) found that, when asked to notice differences between two photos, they used more “higher order” brain functions than those without the trait. This is an example of what is called top-down processing—we take some familiar information, like the words in a speech, and understand what the speech means. In the study I am referring to, study participants looked at a photo of some bales of hay along a fence and had to decide if it was the same or different from another, very similar photo. So, they examined the two photos (more carefully than those without the trait), starting at the top you might say, the overall photo, and then breaking each photo down into parts (number of bales of hay, number of fence posts, number of trees, etc.) to see if they were actually the same or slightly different photos. That is top-down processing at its best.

But are we better at bottom-up processing? That is the kind of processing where you are taking in differences that you have not thought of as important, at least not yet. You smell smoke, then begin thinking about the kind of smoke it might be or where it might be coming from. Or you hear a speech that’s in a foreign language and you need to guess the meaning of what is being said depending on the similarity of some of the words to words that you do know.

In this study, participants heard various tones and maybe noticed, without even being conscious of it, if the tones differed. How do you measure whether someone noticed something if they are not conscious of doing so?  You can look at what are called “evoked potentials,” or little bursts of energy that take place in the brain when something is perceived as a little bit different than what came before or after.

The participants were high and low scorers on the HSP Scale who also had the short serotonin allele (often but not always associated with being highly sensitive). Each participant was put in a quiet room and chose a video to watch, with subtitles, while the various tones were played in their ears, but they were told to ignore those sounds. As expected, HSPs differed from those without the trait in the way their brains handled the variations in sounds. Even though they were not paying any attention to the sounds, their brains showed that they were not ignoring these seemingly irrelevant stimuli. So they had engaged in the first step of bottom-up processing, noticing what could be processed if it was relevant, while the brains of the others were not bothering.

Sometimes I joke that HSPs at the horse races might notice the color of the jockeys’ outfits in each race, and if in two races in a row the winning jockey is wearing some red, only HSPs would notice and then might bet on whichever jockey is wearing red in the third race—losing money of course, as the color of the jockey’s clothing has nothing to do with the ability of the horse they are riding. But noticing details like this would be bottom-up processing as opposed to having been told that the color of the jockeys’ clothing can sometimes predict the winner, and using that top-down information, still probably useless, to choose a winner.  (Actually, when I was a little kid, my older brother would take me to the local race track and have me pick the horse he should bet on in each race.  I did not have a theory. That would be top down.  I just looked at subtle cues, going from the bottom, the broad base of possible indicators, to the top, the final pick.  Probably I was noticing how energetic and healthy each horse looked.  And the horse I picked often won.  I was famous for it!  Until the pressure of having to decide and risk losing the money he bet made me so nervous I stopped cooperating.  Ah, HSPs!)

Bottom Line: While there is already evidence that we process well when going from the “top down” (using what we know to figure something out), we also seem to process better than others do from the “bottom up,” taking in what seems like random information in case we need to find the meaning in it.

Part II.  Spiritual Experiences versus Awakening/Enlightenment

Spiritual experiences are precious to those who have them, whenever they occur and however you define them.  They make life meaningful; they provide the Big Picture. They can be planned, as when you go on a spiritual retreat or maybe take a psychedelic substance (not that I am recommending it), or they can come as a complete surprise.  Some are simply lovely; others are utterly life changing.

As a perfect example of a completely unplanned spiritual experience, a friend, when he was a teenager, learned that his mother was dying of cancer and was not expected to live much longer.  He prayed to God, begging that his mother be spared.  If she was, he promised he would dedicate his life to God.

Well, to everyone’s surprise, his mother went on to live a long life.  And my friend went on to become a university professor who teaches and writes about Jewish history (among a few other things) in a way that informs and inspires others.  He is also a really nice, kind person. That was a spiritual experience indeed.

Spiritual experiences can be a big, big deal. Some people find God through such an experience.  Or change how they spend the rest of their lives.  Maybe they see that they are one with all living things and dedicate their lives to preserving ecosystems or fighting climate change. After just one spiritual experience or a whole series of them, people may change professions, move to a different place, fall in love—anything can happen.

Spiritual Experiences are Events and Awakening/Enlightenment is Permanent

The point is, I am all in favor of such experiences. But I wrote about something else in my upcoming book, Spirituality Through a Highly Sensitive Lens: An Objective Look at Meditation Methods and Enlightenment. And I really do not want people to be disappointed that this book is not about spiritual experiences or how to have them. See, spiritual experiences are events. Epiphanies if you like. They are moments in time that begin and end.  They live on in your memory, perhaps entirely changing your attitudes and beliefs.  In that sense they are permanent.  But as you see from the subtitle, my book is partly about enlightenment/awakening (I use the terms interchangeably), which is a major, permanent change in how the brain operates all the time.  It begins at a certain point, yes, and then can keep changing, but you do not go back to how you were. (Occasionally there are flashes of it, making these flashes “mere” spiritual experiences, but usually an awakening returns and sticks.)

What do I mean by a permanent change? After this shift, your brain changes in such a major way that you will see yourself differently.  Your “Youness” becomes less important. One way it is described is that you go from seeing yourself as a this or a that to seeing yourself as pure, silent awareness or emptiness, watching or witnessing all of this and that.  I describe this state much more thoroughly in the book, along with research on it.  Spiritual events can certainly change our brains and our sense of ourselves, even permanently, but as a memory that then affects attitudes, decisions, and the like, and in that sense they stay in the brain. But they do not permanently change how your brain operates in a fundamental way.

What about Meditation?

The subtitle of my book also says it is about meditation methods.  Isn’t meditation a spiritual experience? You could say so, but the purpose of meditation, whether Buddhist meditation or from an Indian tradition or even within a Western tradition, is not to have a special experience in meditation.  Meditation experiences vary as you practice—some are deep, some are full of thoughts. It usually depends on how your life is going or what you were doing that day.  You do not hang on to meditation experiences or build your life around them. The purpose of meditation is to reach something like nirvana, enlightenment, or God realization.

True, meditation teachers may not mention awakening, especially those teaching Mindfulness or Transcendental Meditation.  Their upfront goal is to make you healthier, more effective, and all that, and the research shows that meditation is very effective in these ways.  But the traditions from which they came were all about enlightenment.  Again, from this perspective, experiences along the way are not important.  You want to focus with mindfulness, or transcend with TM, but if you do or do not in a particular meditation, it does not matter.  You can use experiences in meditation to understand where you are in your practice and improve it, always so that you can reach this permanent change.

What About Moments of Unity or Oneness with Everything?

Experiences of unity, even if brief, are often life changing.  They can be something of intellectual insight or an intuition.  They can occur during a genuine spiritual experience.  They are common with psychedelics.  Indeed, they are common occurrences for mystics in every religion.  See the Perennial Philosophy by Aldous Huxley, or Perennial Philosophy Reloaded by Dana Sawyer. It is perennial because it has occurred in every era and a wide variety of places on earth (although an argument can be made for their arising first among shamans in the Himalayas and north of there, in Tibet and Mongolia.)

The perennial philosophy has four tenets:

That there is a transcendent foundation behind all reality, or what Huxley termed the “Divine Ground of Being,” existing beyond the physical world of time and space.

Second, this Ground of Being is transcendent to the world of time and space but also is manifest as the world of time and space. Consequently, it is both transcendent and immanent, with no ultimate or impermeable separation between them.  They are ultimately one, a unity.

Third, it is possible for humans not only to understand theories about the above, but to experience it via “unitive knowledge,” which can come in a heightened state of consciousness.

Fourth, achieving this spiritual awakening of our oneness with this ultimate reality not only brings meaning to our lives, through a richer perspective on our circumstances in the world, but an awakening of our responsibilities toward others.

Perennial philosophers vary in their view of what changes as a result of a unitive experience. (“Perennial” is a category of philosophy, not a single perspective, so views differ.  Some perennial philosophers include, besides Aldous Huxley, Huston Smith, Ram Dass, Francis Vaughn, and Stanislav Grof, among others.)  Clearly they are talking about a unitive experience that is a true spiritual experience, able to permanently change your life.  Or perhaps they are talking about a “spiritual awakening” such that your brain and identity are changed forever.  I explain in my book the various higher states of consciousness, and one of the highest is called Unity.  You go on as a normal person, but simultaneously see everything, all the time, as a unity and you as just one part of it.  As described in Vedanta, in this state “I am That and thou art That and all of this is That.”  Either as an experience or as a constant state of consciousness, seeing our oneness with everything may be key to our survival as a species.

In sum, spiritual experiences are wonderful. So is awakening or enlightenment. They are just different kinds of wonderful. May you have all the wishes of any of them.