Sigmund Freud (1905) said that dreams were “the royal road to the unconscious”. Through much of the second half of the 20th Century Freud’s ideas - especially to do with dreaming, fell more and more by the wayside. Various theories were put forward to explain dreaming - mostly biological in nature and usually tied to the paradox of REM sleep - when the sleeper’s brain is aroused even though they are sound asleep.

On an average night most people spend around 25% of our time in REM sleep. Between 70-95% of those woken from REM sleep report vivid dreams. In contrast between 5-30% of those woken from slow wave sleep have experienced dreaming of routine actions. (Sleepwalking, when it happens, takes place during slow wave sleep.) Because of the strong correlation between REM sleep and vivid dreaming, for a while REM sleep was portrayed as the physiological concomitant of dreaming. In 1977 Allan Hobson & Robert McCarley  had discovered that REM sleep is associated with random firings of cells in the brain stem which  appeared to give the experience of dreaming. (Hence the bizarre, random nature of dreams, it was thought.) If dreams are just the results of random firings of neurons, then dreams could not have the kinds of meaning Freud attributed to them.

This view could be supported by the work of Francine Roussy, Claude Camirand, David Foulkes, Joseph De Koninck, Maleah Loftis & Nancy H Kerr  (1996) who collected pre-sleep thoughts and issues of 8 participants before they went to sleep over 8 nights. The content of the participants’ dreams was also recorded. No association was found between dream content and pre-sleep thoughts and issues.

However, Mark Solms, a leading neuro-psychoanalyst, has put forward evidence (1999) that people with severe damage to (or even destruction of) the cortical-limbic circuit do not report dreaming - though they still experience REM sleep. Work with 9 such patients (7 had suffered cancers, one had an abscess and one had suffered a stab wounds) had faced him with this puzzle. Solms then researched the literature on pre-frontal labotomies - see Psychosurgery - in which the cortical-limbic circuit was cut in an attempt at treating mental disorders. He found that 70-90% of labotomy patients reported loss of dreams.

Since it is known that REM sleep was triggered from the pons, it was clear to Solms that REM sleep and dreaming, though they seem to coincide, are not one and the same. A fact further confirmed by studying patients with damage to the pons whose dreaming was unaffected.

Since the cortical-limbic circuit is strongly associated with motivation and goal-seeking behaviour, the implication is that dreaming is linked to the circuits in the brain which control our wishes and desires.

In 2000 Solms used PET scans on non-brain-damaged people to confirm that the cortical areas to do with rational conscious thought (primarily the pre-frontal cortex) - Ego and Superego? - are inactive during REM sleep while the limbic areas to do with memory and motivation are very active. Solms’ tentative conclusion was that what Freud called the Id is active in the limbic system. Solms’ work supports the work of Masao Ito (1998) who had first proposed the idea that the Id is based in the limbic system while the Ego and Superego were located primarily in the frontal lobes of the cerebral cortex.

Supporting evidence for the direction Solms is pursuing comes from Allen Braun who conducted his own PET scan studies the year before and found similar results. According to Braun, suppression of the pre-frontal cortex during REM sleep may help explain several of the cardinal features of dreaming, such as bizarre imagery, loss of critical insight and logic, diminished self-reflection, inability to shift attention, morphing of time, place and identity and forgetting of dreams. His team also found that the primary visual cortex--the point of entry for visual information from the external world--was deactivated during REM, but regions of the brain that conduct higher-level visual processing remained activated, perhaps explaining why people continue to ‘see’ while dreaming, even while the brain is cut off from the outside world. Deactivation of the prefrontal cortex may be consistent with Freud's ideas of encoding of wishes into dream imagery, emotional disinhibition and instinctual needs.

Solms’ summary: "I think that both my and Braun's findings suggest that dreaming is a higher mental function, generated by forebrain mechanisms. Dreams are evidently produced by motivational, emotional, memory and perceptual systems of the forebrain. It is, in short, the 'wishing system,' to allude back to Freud. Nothing that we know about in the brain comes closer to being the neurophysiological equivalent of what Freud described as the libidinal wish or libidinal drive."

However, Braun has been a little bit more cautious about linking the findings so unequivocally to Freud: "I think there are points of departure [from Freudian theory]. Rather than metaphor or symbol, dreams may constitute more direct, albeit distorted, access to unconscious processes. And meaning in dreams may be less disguised and more apparent than commonly believed."

An alternative map of the ;Freudian brain - as per the graphic - could see the location of the Ego as being in the posterior cortex while the self-conscious awareness present in the dorsal frontal cortex could be the Superego in action and the inhibitory processes observed in the ventral frontal cortex could be the act of repression.

Quite just how much of the ‘Freudian mind’ can be mapped to verifiable neuroanatomy is still an open question - with much research to be done. Nonetheless, the work of Solms and other neuro-psychoanalysts has most definitely put at least some of Freud’s ideas back at the forefront of Psychology.

Developed in part from an article by Sri Carpenter for the American Psychological Association