erraticwisdom: Activation Synthesis

Post

One of the most interesting areas of psychology is dreams. While there are many theories about the purpose of dreams, one of the most fascinating (and strongest philosophical implications) is the activation synthesis theory.

The theory basically states that our dreams are products of random neural activity during REM sleep that is converted into plausible stories usually based on the day’s events.

Our brains are constantly reconstructing and synthesizing things from external stimuli to create the complete effect we are familiar with. For example, our brain fills in the blind spot that results from the rod and cone-free part of the retina where the optic nerve connects to the back of the eye.

What is interesting about the activation synthesis theory of dreams is that entire situations are synthesized with very little preliminary information. Other forms of reconstruction rely heavily on simultaneously-perceived stimuli to “fill in the gaps” whereas these dreams would be only loosely based on recent events with the remainder of the in-dream sensations being synthesized by the brain.

The prospect that complex and “realistic” sensations (such as in lucid dreams) could be fabrications of our brains is both amazing and alarming. If our dreams can be completely artificial, what else is simply our brain’s interpretation of random activity?

Post Meta

At: 07:59:00 AM
On: March 21
In: Science
By: Tom Fadial

Comments

See also the autokinetic effect.
See also linguistic cognition.
See also Elizabeth Loftus.
See also superstition.

I have to say, it’s fun watching someone discover psychology for the first time.
Jonathan Dobres

Mar 21, 12:57 PM #
I notice that my dreams are typically about things that were in the back of my mind when I fell asleep. That would tend to agree with the idea that they are based on the day’s events.

One thing that’s really neat is how when I’m half asleep (usually in the morning), my dreams incorporate things that happen in my surroundings, such as noises. It’s almost as if our minds TiVo and freeze time to incorporate the real time sound into the dream a bit later.
Atul

Mar 21, 03:59 PM #
They’ve also done experiments where squirting water on people’s faces causes them to dream about something to do with rain, or waterfalls, etc.

It’s fairly hard to say if the activation synthesis hypothesis is fully correct though, or if it’s really more orderly than it seems.

Case in point: how many people have recurrent dreams? Therefore how can it be truly random?
Eric. I

Mar 21, 04:12 PM #
Jon:
Some of those are very interesting, thanks.

Atul: I know what you mean…I’ve had some weird dreams resulting from the music that my cell phone plays as my alarm.

Eric:

“Case in point: how many people have recurrent dreams? Therefore how can it be truly random?”

How many people go through the same routine every day?
Thame

Mar 21, 08:04 PM #
But it’s not that simple. We can’t predict a person’s dreams from their daily events. Loosely maybe, on rare occasion, but there’s other stuff going on that we don’t fully understand – at all.

The theory also doesn’t answer why our sleep progresses in stages, which is very interesting when you think about it.

I do think that the theory is pointed in the right direction; it might just take a while to work out the details – we don’t even truly know how memory is stored yet.
Eric. I

Mar 21, 10:01 PM #
If the dreams are random, how come we have some dreams more than once? Are they stored in our brains?
Tarun

Mar 22, 05:02 AM #
Eric:
It’s true that we can’t “predict” dreams based on daily activities, but the theory states that sometimes, the events we experience in our dreams are tied to our daily experiences. If our daily experiences are generally the same, it is possible to have recurring dreams.

Also, I don’t think sleeps stages are within the scope of this theory. Although it seems that most people dream during REM sleep (or recall their dreams more clearly when awakened during REM sleep), people also dream in other stages of sleep. I don’t think any theory of dreams also aims to explain sleep stages.

“I do think that the theory is pointed in the right direction; it might just take a while to work out the details – we don’t even truly know how memory is stored yet.”

Yeah, even if we were to understand dreams, there is so much stuff that we have no clue about.

Tarun: We were kinda disussing that right now :D
Thame

Mar 22, 07:56 PM #
I would just like to lay out what I think I know and what I assume about how the brain works to see if I can get any further insights:

1) The reticular formation in the brainstem definitely controls arousal: in activation-synthesis theory the random firings emerge from the brainstem (if I recall correctly).

2) I assume that the frontal lobe interprets signals from the rest of the brain and here is where “I” experience things.

3) I assume that memory resides in every neuron, most likely at the synapses.

So far i’m pretty much decribing the activation-synthesis theory. The brainstem fires, others neurons in other areas fire and the frontal lobe interprets – everything is wonky because there’s no outside sensory input and yet the brainstem is still “switched on”.

Here’s some questions: why does REM sleep rebound after sleep deprivation or intense studying sessions? I can’t fit it into the theory.

Why do young children have proportionately more REM sleep in a night (even when total sleep is around 12h)?

If the brainstem is “switched on”, then why does it change its concerto throughout the night to certain distinct stages (I know I already mentioned this)?

Is there some active, intelligent information processing going on from the day before as evidence suggests?

This one’s disturbing and I apologize: why do males always have an erection during REM sleep? Possibly some relation to the reticular formation?

... I’m not really getting at anything. I just wanted to put some questions out there that just popped into my head. I do like the idea about active processing of information but maybe that’s just wishful thinking.
Eric. I

Mar 22, 10:22 PM #
“Case in point: how many people have recurrent dreams? Therefore how can it be truly random?”

Err… sorry. Missed that. :o
Tarun

Mar 23, 11:11 AM #
Eric:
“So far i’m pretty much decribing the activation-synthesis theory. The brainstem fires, others neurons in other areas fire and the frontal lobe interprets.”

Yes, I think the activity initiates at the pons and I can imagine it confuses the hell out of the frontal lobe (or whatever is processing things) because there is not actual sensory input.

REM sleep is definitely still a mystery and seems to be one of the most important stages of sleep. In addition to the research you mentioned, people consistently awakened during REM sleep report feeling less rested and more irritable than people awakened the same number of times in NREM sleep.

Also, the fact that males almost always have erections during REM sleep is interesting (in addition to it being a really weird idea to discuss in a blog comment :D) because the body is otherwise completely “paralyzed”.

“I’m not really getting at anything. I just wanted to put some questions out there that just popped into my head. I do like the idea about active processing of information but maybe that’s just wishful thinking.”

I like that idea. It’s easier to work with concepts once we have them clearly laid out in front of us.

Tarun:
“Err… sorry. Missed that. :o”

Get with the program man :D
Thame

Mar 23, 10:22 PM #
The links between psychology (study of the mind) and neurology (study of the brain) are fascinating, but they are two distinct subjects, and I don’t believe a purely neurological theory can ever give a full explanation of dreams. Dreams can often highlight the less scientifically palatable aspects of the mind, and I could give a number of examples from amongst my own friends and family of dreams that defy rationalisation. I’ll just give one.

Some years ago I had a lucid dream. The content of the dream was trivial: I was, in my dream, lying in my bed searching for a lost ticket in the folds of my sheets. However, the atmosphere of the dream was powerful and I woke in a strange state of mind. I had a very strong conviction that something was happening at that moment to someone close to me. I guessed that it was something to do with my girlfriend as she was prone to strange experiences herself. I felt helpless that I could do nothing about it, (she lived several miles away and this was before mobile phones!) and all I could do was get up, put the light on, and make a note of the time – 2:30am.

I awoke the next morning and went downstairs, my parents had left me note: “Your sister gave birth to a son at 2:30 this morning”. She lived on the other side of the country and I hadn’t been aware that she was due.

It’s easy to rationalise such stories, (‘He must have known she was due’, ‘Coincidences are statistically inevitable’, ‘He’s exaggerating because he likes to think of himself as psychic’, and so on), but I just want to say this: in trying to understand the nature or mechanics of dreaming I think we shouldn’t limit ourselves to textbooks and theories – often the most interesting and illuminating information comes from asking non-academic people about their own experiences.

But I repeat: the links between psychology and neurology are fascinating!
Tom

Mar 26, 09:02 AM #
“But I repeat: the links between psychology and neurology are fascinating!”

They are, and that’s an amazing story Tom and I never really know what to think when I hear things like this.

I definitely don’t doubt your story or its obvious connections, but what the hell does it mean? How do things like this fit into science?
Thame

Mar 26, 05:07 PM #
Tom,

I had a similar dream experience in which I found a parakeet, (used to have them as pets), and at some point in the dream somebody mentioned that it was a male. That morning, my brother called me to tell me that my sister’n’law had a baby (more than a week early), and sure enough it was a boy.

It still freaks me out, but in a good way,
Atul

P.S. I’m watching a CNN specials on dreams right now.
Atul

Mar 27, 12:45 AM #
Have any of you ever had one of those odd dreams where you actually realize that you’re dreaming while you’re still asleep? It’s the weirdest feeling. Sometimes you realize that you are dreaming right before you wake up, but in this case I continued to stay asleep after I became consciously aware of the fact. It was like I was free to experiment for awhile in some strange world that had no rules. In this particular dream, I was at school. I don’t remember what caused me to realize what I was dreaming, but I once I did, I proceeded to stand up and dance on my desk. Then I ran outside and threw myself against the wall of some building (knowing somehow that I’d be able to climb it), and jumped off the roof knowing before I did so that I wouldn’t fall, but fly. I’ve only had this kind of dream once in my life, but I’d love to have more like it—it was so much fun. This particular dream was rudely interrupted when my alarm went off, unfortunately.
Colleen

Mar 27, 05:22 PM #
Colleen: That sounds like alot of fun! I actually rarely remember my dreams so I don’t think I’ve ever experienced anything like that.
Thame

Mar 28, 08:11 AM #
What i’m really interested in is the role that sleep plays in information consolidation, as it appears to.

The following paper (brand new research) indicates that information processing occurs automatically in the brain even when awake. It’s a neat idea to think that sleep is linked to the same kind of function by strengthening our memories.

Offline Persistence of Memory-Related Cerebral Activity during Active Wakefulness

Could this mechanism temporarily store information while awake until we are asleep and can store it better?
Eric. I

Mar 29, 04:35 PM #
Thank you for this wonderful article that generates such great discussion. The personal study of dreams & lucid dreaming is a great passion of mine; however, I’ve yet to dwelve too far into many theories of dreaming so I appreciate this information on Activation Synthesis. I’m familiar with this idea (though not the name) but I’m skeptical of explaining away dreams in there entirety by this theory.

Lucid dreaming endlessly fascinates me. I was fortunate enough to actually have one this morning after waking up, recalling all my dreams, and then going back to sleep. (AKA WBTB: Wake Back to Bed Method.) The lucid dream was short and mostly trivial, but fascinating nevertheless!

It’s nice to see lucid dreaming mentioned in the context of such a high quality, professional blog. Keep it up. I really enjoy what you’re doing here.
Ben

Jun 12, 02:48 PM #