August 24, 2005

To Daydream or Not

Does too much daydreaming or, if you will, too much unfocused time contribute to Alzheimer's?

The researchers compared PET scans, MRI images, and other data from 764 participants with dementia, mild dementia, or no dementia. The images revealed that posterior cortical regions of the brain, including the posterior cingulated, retrosplenial, and lateral parietal cortex, were active in the "default state" of young adults without dementia. They were also the regions attacked by amyloid plaques in older adults with Alzheimer's.

The "default state" is the term Dr. Buckner and colleagues use to describe the brain's activity when it is not concentrating on a particular task but musing, daydreaming, or retrieving pleasant memories.

The study also found that metabolic abnormalities and atrophy emerged in these daydreaming areas of the brain during the early stages of Alzheimer's.

Even the brain's relatively inactive daydreaming mode requires considerable energy, and the researchers speculated that an accumulated lifetime of metabolic activity might lead to wear and tear that disposes default areas of the brain of the brain to amyloid deposition, metabolic disruption, and atrophy.

Let me, then, suggest an alternate hypothesis: amyloid plaque invasion represents an atrophy of the posterior cortical regions. In other words it is an underuse phenomena that has as its proximal cause radio, television, stereos, mp3 players, etc. Time folks once spent in the default state has been preempted by the always on sounds of these devices. It should be fairly easy to determine whether default state activity is turned off when listening/watching these devices.

Another unintended consequence of the always on society may be an overall reduction in creativity, even overall cultural intelligence. Test this yourself. If you always have something on, even just for background when you are cooking, doing the dishes, jogging, etc., turn it off for 30 minutes a day. Over the course of a week observe the difference in the quality of your mental activity during the off time. Some of you may not be able to handle the intensity of the change. But that's part of the point.

Update 8/26: Lindsay Beyerstein comments on this as do her commentors.

Posted by Steve on August 24, 2005

I'm not sure what the connection is, if any, but I've observed that children I see in my practice who have true ADHD, not just maturational issues, are actually helped by the hypnotic effects of hand held video games. I have one little 9 year old who can only take an active role in therapy (answer questions, etc.) if he is simultaneously focused on his GameBoy.

Another different, but maybe somehow related observation: all of the women in my book club- women of a certain age :-) - say that the television is louder, the phone rings more piercing and background noise so much more stimulating when they are experiencing hormone peaks and valleys.

Anyway- interesting post. Thanks! I actually stopped in to find the Ark- or have the Ark find me...

Posted by vicki at August 25, 2005 6:04 PM

I have found that the times I truly find myself engrossed and involved in a book are when I have "background" music on. However, I don't find myself listening actively to the music at all (instrumental music is best). After 10, 15, or 20 minutes of intense focus on the book material I'll return to reality and it's almost like coming up for air again. I don't have nearly the same experience when reading in a quiet room with ambient noise where I often find my mind wandering.

Posted by BP at August 25, 2005 7:08 PM

Vicki: interesting about the ADHD children. This suggests the possibility that these children may have over active default states leading to difficulty focusing in normal conditions. The Gameboy experience is intense enough to turn off the default state.

BP: Intriguing. I've had similar experiences. Music is most likely to produce it but also with background TV or radio. This seems to support the idea that music, radio, TV, etc., disable default state activity.

A research project might evaluate qualitative aspects of the reading experience in different environments, e.g., no background, music (even different types), radio (again different types), TV. Also, does it make a difference if the background sound is coming through earphones?

Posted by Steve at August 25, 2005 11:26 PM

I saw the Buckner, et al, research reported in _Science News_ recently and found it alarming since I spend a lot of time daydreaming. On the other hand I was surprised that the researchers would use such a fuzzy term as "daydreaming" to describe anything in a scientific journal.

For instance, me and another guy might both daydream about winning the lottery. He might think about lying on the deck of his yacht off Bora Bora being waited-on by a bevy of local beauties. I (an engineer) might imagine some house I would build and the photovoltaic electricity-generating system it would have and how I would manage problems like energy storage and load-balancing - a much more analytical and problem-solving type of thinking.

It's not clear that these two activities have the same neurophysiological consequences or deserve the same moniker "daydreaming" or even whether what constitutes "daydreaming" for me is any different from what I get paid to do as an engineer.

The need for constant stimulation is problematic for me. If I'm doing a task that does not require much analytical thought - cleaning, bill-paying, chopping or splitting wood - I feel a strong need to have something "interesting" going on in the background, e.g., books-on-audio or NPR programs like "Car Talk", "Fresh Air", "On Point" etc, or sports broadcasts like NE Patriots games. But if I'm doing something analytical like writing a computer program, I like instrumental music to block background noise and conversation - and preferably music that's not too "interesting" - right now I'm listening to Philip Glass.

. . . Still, one way or another it adds up to stimulation - I either feel like I have to be DOing something stimulating or EXPERIENCING something stimulating. I'm an intensely busy creative person (engineer, artist, poet, photographer, traveler, etc) so "downtime" seems like wasted time but based on this latest research maybe it's necessary to ward off Alzheimer's. . . . That's a scary thought; quick - I need something stimulating to distract me from thinking about it!

Posted by Peter Nelson at February 22, 2006 10:41 AM
follow me on Twitter