The Neuropsychology of Dreams

Mark Solms and Neuropsychoanalysis

At a first glance, neuroscience and psychoanalysis seem to be an odd pair — just not if you ask Mark Solms, who is a neuroscientist and psychoanalyst. He might argue that the combination of the two, which called Neuropsychoanalysis, can help answer age old questions, such as What is the meaning of dreams? or Why does consciousness exist? which Solms lays out in his book “The Hidden Spring: A Journey to the Source of Consciousness” (Amazon affiliate link).

In fact, the combination of neuroscience and psychoanalysis is as old as psychoanalysis itself. Sigmund Freud was himself a neurologist. Solms refers back to an old forgotten paper of Freud from 1895 his “Project for a scientific psychology” in which Freud tried “to place his early insights about the mind on a neuroscientific footing.” (p. 30).

But the scientific methods of his time were just not sufficient, which, as Solms writes, led Freud to develop the method of psychoanalysis to gain insight into the mind through the psychological rather than the neuroscientific route.

I read psychodynamic literature every day and I started compiling everything I ever read into a Notion book list that includes my rating, the notes I took, and much more. If you are curious about what I’m reading right now, or your looking for your next favourite book, join my email list and I’ll send you the link to my personal psychodynamic library:

Freud took the psychological route through studying dreams. He called dreams “The royal road to the unconscious” (Der Königsweg zum Unbewussten). His work “The Interpretation of Dreams” put psychoanalysis on the map and argued that dreams are neither prophecies, nor meaningless — but that dreams are wish-fulfilments.

If we come back to neuroscience, you might say that Solms takes over where Freud had to stop – and this is precisely what Solms does in his magnificent and complex book “The Hidden Spring” (Amazon affiliate link). He is a highly interesting thinker and researcher. In his book he not just makes a case for the spring of consciousness not being in the frontal cortex but rather in the brain stem — and the purpose of consciousness being feeling feelings (which is damn interesting from a psychodynamic perspective, where we put so much emphasis on feelings) — he also summarizes his revolutionary findings on the neuropsychology of dreams.

Let’s start with some context.

Solms became a neuroscientist because he really wanted to understand the meaning and origin of consciousness but soon found that neuropsychology excluded an important thing: the psyche. He quotes the famous neurologist Oliver Sacks who said: “Neuropsychology is admirable, but it excludes the psyche – it excludes the experiencing, active, living ‘I’.” Oliver Sacks, A Leg to Stand On (1984), p. 164

If you wanted to study aspects of consciousness, the only area that neuroscience thought proper to study was the distinction between wakefulness and sleep. This is where Solms started.

He found a big gap in the literature on how damage to different parts of the brain affected dreaming. But of course whenever you want to study dreams, you are confronted with their subjectivity: You cannot record the contents of someone’s dream, not through a fMRI, EEG, or PET scan. You need to rely on subjective reports you can only get after the dream occurred.

This “problem” had long been neutralized in neuroscience by the discovery of the connection between REM sleep and dreaming. If you study someone who is asleep with an EEG, you’d see that about 90 minutes after they fall asleep, brain activity increases almost to wakefulness levels but despite that the body is paralysed. This was first called “paradoxical sleep” because of being almost awake and asleep at the same time. Due to the rapid-eye movement during this phase it was then called REM sleep.

From then on dreaming was equated with REM-sleep, they were basically considered to be the same thing, and now dreaming could simply be studied physiologically. Once the neurological mechanism of REM-sleep would be uncovered, we would understand why we dream. The neurological basis of REM-sleep was eventually found in the cholinergic brainstem (more on that later), and not in the frontal cortex, and the conclusion was that dreams were physiologically rather than psychologically motivated. Dreams don’t represent wish-fulfillments as Freud argued. They are motivationally neutral, meaningless. And with that, wheeew, one could finally get rid of the whole Freudian nonsense.

As if he hadn’t heard all about those big new discoveries, Solms was still interested in studying the subjectivity and the contents of dreams. In 1985, starting his doctoral thesis on how damage to different parts of the brain affected dreaming, he studied the dreams of over 350 of his neurological patients.

And what he found was a big surprise and flew in the face of the entire dreaming equals REM-sleep hypothesis.

Solms discovered that “patients with damage to the part of the brain that generates REM sleep still experienced dreams. Moreover, patients in whom dreaming was abolished had damage to a completely different part of the brain. Dreaming and REM sleep […] were correlated with each other (i.e. they usually happened at the same time) but they were not the same thing.” (p. 23)

He found that patients lost the ability to dream while still getting REM sleep if they had damage either in a certain part of the cortex important for short-term memory (which makes sense) or if they had damage in certain connecting bits between the frontal cortex and various subcortical structures. This second one was interesting because it was exactly the area of the brain that was targeted way back in the day in a procedure called “frontal lobotomy” used in what today feels like the stone-age of treatment for various psychiatry and neurological disorders. Doctors had already found that those lobotomies had “side effects”, namely reduced hallucinations and delusions (which was often why this procedure was performed), but also reduced motivation, AND losing the ability to dream.

Today, a similar effect is achieved with so called “antipsychotics”, which luckily made lobotomies obsolete. What these medications do is they block the dopamine at the terminals of a brain circuit known as the mesocortical-mesolimbic dopamine system. And Solms found that it was indeed this mesocortical-mesolimbic dopamine circuit which is the major driver of dreaming.

Remember that before it was said not just that dreams and REM sleep are the same thing but also that dreams are meaningless and “motivationally-neutral”. But now that Solms found the mesocortical-mesolimbic dopamine circuit responsible for dreaming, that statement just falls apart.

A quick Wikipedia search clarifies that: mesocorticolimbic system is the opposite of “meaningless” and “motivationally-neutral”. This system is all about reward, wanting, pleasure, positive reinforcement.

Solms concluded that “neuroscience owed Freud an apology. If there is one part of the brain that might be considered responsible for ‘wishes’, it is the mesocortical-mesolimbic dopamine circuit.” (p. 27)

Also we need to take another look at a different pathway that is connected to dreaming. It’s the one in the cholinergic brainstem, that was found to be responsible for REM-sleep (and back in the day was falsely thought to be the on-switch for dreaming as well). The important neurotransmitter of this pathway is Acetylcholine. If the cholinergic pathway is damaged or blocked with anticholinergic medication, people dream more rather then less! The effect is the opposite.

Solms consequently translated these neuroscientific findings into Freudian theory:
First, he links up the mesocortical-mesolimbic dopamine circuit which is the major driver of dreaming with Freud’s concepts of wish-fulfilment and drives. And, second, he connects the function of specific cholinergic pathways with Freud’s idea of reality-testing:

“This enabled me […] to tentatively link the unconstrained dopaminergic ‘reward’ or ‘wanting’ or ‘SEEKING’ mechanism with Freud’s notion of ‘wish-fulfilment’ – a meta-psychological concept that was closely linked with his concept of ‘drive’. Conversely, the functions of the cholinergic forebrain nuclei can be linked in some respects with the inhibitory influences of ‘reality-testing’.” (pp. 43-44)

And when reality-testing is diminished, we dream (or hallucinate) more.

On a personal note, I found Solms’s ideas absolutely fascinating – and his research on the neuropsychology of dreams is just the beginning. In the rest of the book he dives into complex questions around consciousness and why we have it. Solms makes it as readable as he possibly can but it is a difficult read, so be prepared – but I found it well worth it.

And another sidenote: Of course the entire field of psychoanalysis is full different theories on what dreams mean and stand for — and many psychoanalysts disagree with Freud that every dream is a wish fulfilment. Jung argued that different parts of us and inner conflicts can show up in dreams and we could use our dreams for creative problem solving. Fairbairn sees dreams as “dramatizations or “shorts” of situations existing in inner reality” that dreams contain information about the self and objects. There is much more to dreams and their interpretation, I’m not a specialist yet – but I wanted to comment that in the field of psychodynamics there is a vast and detailed tradition on dreams that go way beyond Freud’s wish fulfilment.