Posts Tagged ‘default-mode network’

How to Daydream Your Way to Better Concentration

May 20, 2017

The title of this post is identical to the title of an article by Caroline Williams in the Features Section of the 20 May 2017 Issue of the New Scientist.  Actually the magazine cover featured the title “CONCENTRATION!  How to take control of your wandering mind,” which referred to this article.

The article notes that “if losing concentration sometimes feels inevitable, that’s because it is—your brain is hardwired to give in to distractions and take you away with the fairies.  Unfortunately, science has long promoted the idea that a wandering mind is the enemy of productivity.  Failing to focus had been linked to a lack of success, unhappiness, stress, and poor relationships.  But remember that science should never be 100% confident.  There is always the chance that new research will change beliefs.  Beliefs always should be subject to change.

Psychologists have been wondering why we spend so much time in a state of revery if it’s truly harmful.  They’ve discovered that there are several kinds of mind-wandering, and they don’t all make us unhappy or unproductive.  If we know how to use it, a wandering mind could even be a key weapon in our cognitive arsenal.

Generally speaking, we have two attention systems that constantly keep track of what’s going on around us.  There is a constant tug of war between the executive control network, which is a set of brain areas responsible for goal-oriented thinking and controlling impulses, and the default mode network, which fires up when we think about nothing in particular.  The default mode network uses its time to do various bits of housekeeping—sorting through memories, forward planning and filing new information.  And it is also the brain region that is most active when we daydream.  “Our ability to stay on track largely depends on keeping the volume of chatter between them low.  Too much activity on the default mode network, or too little executive control, leads to a mind that is prone to losing focus.”

The brain seems to find mind-wandering easier than concentrating.  Recent research has shown that the default mode network is highly connected to itself and other brain regions, allowing it to flit between many different mental states with little energy input.  The executive control network is more sparsely connected, so it requires more input to shout over the noise, which is what is happening when we’re trying to concentrate.  Even on a normal day we spend as much as 50% of our time thinking about anything except what we should be doing.

There are advantages to this propensity to drift off.  For instance, we already know that daydreaming brings numerous benefits to do with creativity and forward planning.  After figuring out a flaw in previous research, we’re starting to see that those benefits extend even further.

Until recently, researchers assumed that volunteers asked to do a boring task in the lab would try their hardest to concentrate until mind-wandering unintentionally took over.  They failed to consider that sometimes we intentionally let our mind drift to more appealing topics, especially when doing something boring.

In an experiment, Paul Seli interrupted people during a task to ask if their minds were wandering.  If they were, he asked whether it had happened intentionally, or if their thoughts had just drifted unconsciously.  More than a third of the time, the mind-wandering was intentional.  Questionnaires asking people about their daydreaming habits put the number even higher suggesting that more than half the time it starts of as a choice.   Seli concluded “A considerable portion of our time seems to be spent off in la-la land.”

Seli used brain imaging to find out what’s going on during intentional and unintentional mind-wandering.  Seli and his team last year imaged the brains of people who tended towards one or the other and found that their brains are set up slightly differently.  Both groups did about the same amount of mind-wandering overall, but those who were prone to doing it intentionally had better connectivity between their brains’ executive control and default mode networks.  This result suggests that with intentional mind-wandering, rather than the executive control network losing its grip over the default mode network, it was actually in charge of the whole experience.  So although it feels like daydreaming, we are still in control of our mind.

The distinction between these different styles of mind-wandering is important.  Mind-wandering has been linked to some of the symptoms of ADHD and obsessive compulsive disorder, both conditions in which a lack of control over certain behaviors can interfere with getting things done.  But this recent research shows that this is true only of unintentional mind-wandering, not the more directed kind.

Deliberate mental meandering might also help us remember more when we revise.  The trick is to make our minds wander on topic, by nudging our thoughts to things we’re trying to learn.  According to Karl Szpunar, one way to make this happen is to build mini quizzes into the revision process.  In his experiments, students learned the contents of a 40-minute lecture either by stopping to recap what they had covered every 5 minutes, or by rereading the slides at the end.  Those who regularly self-tested retained more information.  Both groups seemed to mind-wander the same amount, but a second experiment showed that what was different between the groups was that the self-testers were mind-wandering about the lecture, as opposed to something unrelated.  Szpunar suggests “rather than waiting to self-test the night before an exam, make time to do this again and again at increasingly longer intervals.”  This advice applies to any kind of learning.

The psychologist Jonathan Smallwood has found that whether our mental meanderings are focused on the future or the past determines whether they derail us from our goals to  prepare us for challenges to come.  Thoughts about the past are much more likely  to lead to low mood and motivation than those about the future.  Future -related mind-wandering actually seems to boost mood and motivation, even if they are thoughts of flunking out.  As long as there is a future element, Small says that it can at least motivate you back to work.

Key here is the ability to control our thoughts.  Here mindfulness and meditation come to the rescue.  There are many healthy memory blog posts on these topics.

The easiest alternative, according to Christian Olivers is to remind ourselves not to focus too hard.

Smallwood’s latest finding is that although frequent mind-wanderers are worse than other people at focusing on the outside world, they were better than most at retrieving information from memory.  The article concludes, “So if the information is in there somewhere, let your mind wander free.  Your grades might thank you.”  And HM reminds you of the availability accessibility distinction in memory.  Although information might not be available at the moment, most information is eventually accessible.  (enter “availability accessibility distinction”  in the healthy memory blog search block.

© Douglas Griffith and healthymemory.wordpress.com, 2017. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Advertisements

The Hippocampus

May 18, 2017

The hippocampus receives considerable attention in “The Truth About Language” by Michael C. Corvallis.  As the hippocampus plays a critical role in memory, it is not surprising that it is central to language and time travel.  As we each have a hippocampus in each hemisphere of the brain, we have two hippocampi.

The importance of the hippocampus was first realized when an Englishman underwent surgery for epilepsy, and the surgery destroyed major parts of both hippocampi.  After this surgery he could no longer form new episodic memories.  Episodic memory involves memories having to do with the specific episodes of our lives.   Although his semantic memory, his general knowledge, remained intact.  Not only was he unable to recall the past, he was also incapable of imagining the future.

In the final years of my Mom’s life she suffered from dementia.  When I visited her, she was always glad to see me.  However, if an attendant took her to the restroom while I was visiting, when she returned she acted as if I had just arrived.  That is, she had stored no memory of my being there.

The hippocampus is the hub of the brain circuit involved in episodic memory and mental time travel.  Brain imaging shows it to be activated both when people remember past events and when they imagine possible future events.  It is also activated when people are asked to imagine purely fictitious  episodes.   Although other brain regions are involved, reflecting the fact that memory and imagination involve information stored in widely dispersed areas, the hippocampus appears to be the most critical component in that damage to it has the most debilitating effect on the ability to mentally escape the present.

The default-mode network, responsible for our mind wandering, is identifiable in primates and even in rats.  The hippocampus plays a critical role in both rat and human memory.  Recording from the hippocampus of the rat reveals that single neurons code where the animal is located in the spatial environment.  These neurons serve as place cells and together generate what has been termed a cognitive map of the environment that tells the rat where it is.  It plays the same role in humans.  Studies have shown that the hippocampus  is enlarged in licensed taxi drivers in London, who are required to memorize the map of London for their licenses.

Research using rats has indicated a similar competence.  In an experiment rats were trained to alternate left and right turns at a particular location in the maze.  Between trials they were introduced to a running wheel and, while they were running, activity in their hippocampi was recorded.  This activity coded which way the rats planned to turn in the maze on the next trial.  Apparently these rats were planning ahead for their next try at the maze.  The researchers also noted that autonomous activity in the hippocampus involved the computation of distances, and also supported the episodic recall of events and the planning of action sequences and goals.  One researcher wrote that “replay in the rat hippocampus can either lead or follow the behavior once the map of space is established.  This suggests that replay phenomena may support ‘mental time travel’ through the spatial map, both forward and backward in time.

Research on human patients about to undergo surgery had electrodes placed in cells in the medial temporal lobe, in an attempt to locate the source of epileptic seizures.  They were then asked to navigate a virtual town on a computer screen and to deliver items to one of the stores in the town.  Then were asked to recall only the items and not the location to which they were delivered.  However, the act of recall activated the place cells corresponding to that location, effectively mirroring the replay of place cells in the rat brain.

In another study, people were shown sequences of four videos of different events.  At one level. narratives were linked to each video, encouraging attention to individual details. At the next level, narratives linked a par of videos, and at the final level a narrative linked all four videos.  As the people processed these narratives, activation in the hippocampus progressed from the rearward end to the forward end as the scale of the narrative shifted from small and detailed to larger and more global.    Dr. Corvallis notes that this probably happens when we read novels.  Page by page, we focus on the details, but as the story progresses we build a more global understanding of what the story is about.  Dr. Corvallis writes, be thankful to your hippocampi that you can make sense of a novel at all.

Dr. Corvallis suggests that although  the generativity spatial mapping is nonlinguistic, it may well underlie the generativity of language itself.  “In the rat these elements may be restricted to simple aspects like sounds or smells, and we may perhaps allow ourselves the luxury of believing our own experiences to be incomparably richer.  Yet the generative component itself probably has a long evolutionary history.  As Darwin famously put it:  ‘The difference in mind between man the the higher animals, great as it is, certainly is one of degree, and not of kind.’”

© Douglas Griffith and healthymemory.wordpress.com, 2017. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.