Dreaming to forget: the real reason why

heads. It has also been shown that we can teach even autistic children some of the basics for empathy, despite their initial marked lack of emotional understanding.[26]

Dreams are for forgetting

So this is where the cutting edge of brain research is. However, there is another important aspect of dreaming that I have alluded to but that I want to look at properly now. None of the dream theories I have discussed can satisfactorily explain why we forget almost all of our dreams. The question that has to be answered is, what is the function of forgetting our dreams? We shall see that the expectation theory of dreaming provides a satisfying explanation for this widely observed phenomenon.

Brains evolved to help animals make more accurate predictions about what behaviours would help them survive. But the type of expectations we have as humans, or that other animals have, for that matter, are infinitely more complex than those of a bee. When mammals evolved, they developed warm-bloodedness, which meant that they were no longer dependent on the sun's heat for mobility. But maintaining a constant warm body temperature required a greatly increased energy intake (estimated at up to a 500 per cent increase in calories needed). So, to meet this need, mammals had to become much better at locating food supplies while also avoiding becoming food themselves for other warm-blooded predatory mammals — all of which required a much more sophisticated prediction system, to reduce the risks.

The cortex provided the answer. The evolution of the cortex, with its much increased processing capacity, enabled mammals not just to act purely on instinct — see a food source and go for it — but to weigh up the risks and benefits of an action — do I have time to make the kill and hide it or will I get eaten by another animal while I'm doing it? In more technical terms, it enabled the ancient dopamine prediction circuits of the limbic system to be subjected to a higher-order risk analysis, based on the additional computing power provided by the cortex.

However, that left another problem to be solved. The limbic system communicates with the cortex via behavioural impulses (emotions). If these are not acted upon (for instance, because the strategy is deemed too risky or because the cortex has set other priorities — such as deciding, in certain circumstances, that it is more important to protect young than to chase a possible food source) they don't go away. In the case of humans, this state of unfulfilled expectation can also occur when we think about something in the future or the past that causes emotional arousal in the present but which can't, by its very nature, be acted upon. These uncompleted emotional impulses — expectations — stay switched on, taking up processing capacity in the expectation system.

So far, two strategies have evolved for dealing with this. The first, as I mentioned in connection with the spiny anteater, is the development of
a much bigger cortex to store all these expectations whilst retaining sufficient spare computing power for making new, ongoing risk assessments. This may also be the strategy evolved by dolphins, which have an exceptionally large cortex. The muscle paralysis that accompanies REM sleep places dolphins at risk of drowning, so they can have hardly any REM sleep.

The second and much more efficient method is dreaming. In dreaming, we act out the unrealised expectations from waking by pattern match-
ing them to analogous sensory patterns — images and events stored in memory — as it is through pattern matching that the REM system works.
I am often asked why the pattern match has to be analogical or metaphorical. Apart from the evidence I have published explaining this point,[20] there is a sound physiological reason for why it must be so. An expectation is an imagined scenario, using images from memory.

In dreaming, we are asking memory to provide a scenario that matches a scenario that is already a part of memory — the event that aroused the expectation. So the matching scenario has to be the best fit that memory can provide. Think of it this way — if I hold up my left hand and ask my brain for a best-fit pattern match, it can't use my left hand because that is the one I want a match for — so it must use my right hand, as the best-fit pattern match for my left. (This does not happen in waking because we pattern match our expectations to whatever stimulates them in the environment, not to a memory. If we want an ice cream, the expectation is fulfilled when we are actually eating it.)

The dream, then, by fulfilling the expectation, completes the circuit and switches off the arousal. But that is not the end of the matter, for we have now converted an unrealised expectation into a factual memory of completing it. Ordinarily, the hippocampus, the conscious memory store, holds our memories of recent events and quickly deconstructs those memories and sends them to various parts of the cortex — the parts concerned with vision, hearing, touch, etc — for storage. It does that to facilitate efficient pattern matching. But, if the dream is allowed to be stored as a real memory, it will corrupt the memory store and greatly diminish our ability reliably to predict the outcome of similar experiences in the future. This is avoided by preventing the hippocampus from sending the dream information to the cortex for long-term storage.[27] As explained earlier, PET scans and other types of research have shown that, in dreaming, the prefrontal cortex is closed down.

So it is no accident that the prefrontal cortex is switched off during dreaming. It is no accident that the hippocampus doesn't de-construct information and send it all around the brain because what the hippocampus is doing in dreaming is getting rid of expectations that didn't pan out while we were awake. It is getting them out of the way, making them inaccessible, in effect, so as to allow us to build up a proper, intelligence prediction and expectation system, an accurate storage of knowledge. (This also explains the evidence for memory consolidation — if you take away all the false expectations, the memories that are consolidated are more accurate.)

The expectation fulfilment theory can therefore explain why dreams are about emotionally arousing events, particularly about emotionally arousing expectations. It explains why dreams are consistent over time. It explains the developmental aspects of dreaming. It can explain the other tests put down by Domhoff. But, more than that, it explains the cutting-edge evidence that the brain is ever malleable, by explaining how it can be so malleable.

The purpose of the brain is to predict, so that we can get our needs met. We need to have a system that can continually adapt itself, and the expectation fulfilment theory shows how the brain does that by cancelling out the expectations that didn't work. It enables us to have a bang-up-to-date register of what really does get needs met in our lives, so that we can more accurately predict what we need to do in the future. (But we can only work with the experiences we have had. If, as a child, a young woman experienced both abuse and love from her father, she may continually seek a relationship with abusive men, until eventually she can learn that love exists separately from abuse.)

(but what about remembered dreams?)

Knowledge contained in patterns

So, in the human givens theory, right from the beginning, we have argued that the evidence shows that templates programmed in during the REM state in the fetus aren't fixed. There is only ever a part of them that is specified; the rest comes from learning. The new discoveries about the brain showing, for example, that we can use for reading Braille the neurons in the cortex that were previously used for seeing, shows that the cortex is highly malleable, and that we can change the ways we complete patterns. What the human givens theory has postulated from the beginning, cutting-edge research is strongly supporting now — our brains are built for life-long learning.

Given this fact, and that dreaming is predominantly about bringing down emotional arousal and removing failed expectations and forgetting them, maybe it would make best sense to change the name of the expectation fulfilment theory. It is an accurate name — dreams do fulfil expectations — but it doesn't make plain that we need to do this specifically to forget them.

I am proposing "the elimination of emotional expectations theory". As this has three 'E's, it can be shortened to "the triple-E theory". Elimination of emotional expectation lowers emotional arousal. It frees up spare capacity in the cortex. And dreaming amnesia eliminates failed expectations and thus updates the expectation memory store — our internal guidance system. That is the function of dreaming in the REM state.

Take a look at the triple-E symbol. To me, it summarises all that I know about dreaming, and that I firmly believe to be accurate. The figure 3 stands for the three Es —elimination of emotional expectation. The 3 is a perfect reflection of the letter E, just as dreams are metaphorical pattern matches that eliminate failed expectations. If you focus on the space in between the 3 and the E, you can see it as a type of figurine, an oddly shaped vase, and then you can bring your mind back and see the triple-E again. That emphasises the fact that dreams are hallucinations.

Just that little symbol shows that a pattern can contain an incredible amount of knowledge. And that is what we have always said: knowledge is contained in patterns.

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References

What about remembered dreams?

You might then wonder if recalling our dreams, as sometimes happens, is undoing the dreamwork. The answer is no, because the arousal is switched off once the expectation is acted out. When we are awake, the cortex is switched on, enabling us to compare dream content to what is really happening around us and, thus, to distinguish between dream and reality.

Occasionally the cortex is alerted by some incongruity in the dream experience, such as flying, and we become aware that we are dreaming. (this is known as lucid dreaming) But this risks undoing the dream work of deactivating the experiences — because we now know we are experiencing a fantasy. (In more primitive mammals, if an altering of the cortex were to happen, it is less likely their brains could make the distinction between dream and reality; the fantasy would be treated as real and would therefore corrupt the memory stores.)

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© Joe Griffin and Ivan Tyrrell 2006

This article first appeared in Volume 12, No, 1 (2005) of the Human Givens journal.

JOE GRIFFIN is a psychologist and psychotherapist. he is co-founder with Ivan Tyrrell of the human givens approach.

> More information, including all references, can be found in the following book, by Joe Griffin and Ivan Tyrrell

Dreaming Reality: How dreaming keeps us sane or can drive us mad

> You can find out more about the importance of dreaming in this related article:

Sleep and dreaming

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> More information, including all references, can be found in the following book, by Joe Griffin and Ivan Tyrrell

Dreaming Reality: How dreaming keeps us sane or can drive us mad

> You can find out more about the importance of dreaming in this related article:

Sleep and dreaming

Return to top

Return to top