Barbershop Talk Edit page

fMRI
"The advent of the Default Mode Network created a major shift in scientific attention: mind-wandering research came into prominence within both mainstream psychology and cognitive neuroscience. However, this new research inherited a historical legacy from previous task-centric views: mind-wandering became predominantly defined as the opposite of task-related and/or stimulus-related thought." [See the Neuroscience Data Page and the MInd Wandering article at this Forum]. 

Impressive results have been obtained with fMRI equipment but what can it say about the mind itself (not the brain) if the agent under test is immobilized in the fMRI machine and does not wish to talk about or report what is on their mind?  Merlin Donald suggested that fMRI is fine for 15 second long episodes, but it is not capable of identifying intermediate term memory effects where people act as agents in 15 minute long episodes. [See Cognitive Psychology Page/"A Mind So Rare" at this Forum]. 

Here I make a case for a type of study that I call fPER that uses no special equipment and remembers the essential facts of conversations between the subject agent and the scientist agent during an episode or several events. fPER can be used independently of fMRI while complementing it. This method returns to William James original method of observing what is found in the stream of consciousness while the agent is paying close attention to what is going on in the world around them and to their own thoughts and deeds that are part of the episode. The acronym fPER means functional personal experience report. Let me illustrate with barbershop talk between a barber and his customer during a 30-40 minute hair cut. fPER is convenient for a barber who cannot cut hair for pay while immobilized in a fMRI machine. 

fPER 
Tom is an excellent young barber and proud of his skills. Joe is an older retired man who dabbles in the field of consciousness, appreciates the young man's skills and active mind as he discusses ideas without missing a beat while cutting a person's hair.  I always admired Tom's ability to cut hair as a foreground task while talking a lot with his customers as a background task. I have been exploring Gestalt ideas about background and foreground when a feature is focused on in the foreground, so here was a chance for field work with fPER. 

Tom said he always keeps his eyes on the sissors in his right hand, but told me his left hand holds the electric clippers and they automatically follow the lead of his right hand. He doesn't need to look at his clipper hand, or think about it. How does that happen he asked?  I said William James answered that question in his landmark book over 100 years ago. It's a habit. A memory is formed from the whole chain of actual sensory information for each task used to cut hair. All Tom needs to do is place his attention on the first step of the task and begin. The whole chain is rattled off under control of his attention. That explains why you don't need to pay close attention to your clippers hand. Your scissor hand is leading your clipper hand like a person leading their dog on a lease. 

Then we talked about mind wandering while driving a car. We both have experienced it and know that visual attention must be on the road ahead. Even 1-3 seconds of mind wandering can be dangerous when driving car at 60 mph with others passing you. Text messaging or dialing a number on your iPhone is taboo. It will get you in an accident fast. However, listening to the radio with your ears as a background task while driving a car with your eyes on the road as a foreground task is safe. But don't get lost in the background music or else eyes on the road are no longer in the foreground.

Our working memory is a serial bottleneck and only 5 to 9 individual elements of an event can be held together by attention in one coherent thread of consciousness. But various scenes are running in the background of this play, and unless they enter the serial stream of consciousness they will never become conscious to the agent walking down the street, or to an agent who is lying quietly in an fMRI machine. Bernard Baars points out that an individual element must have a duration of at least 160 milliseconds (1/6 of a second) to be recognized by a conscious agent as an individual thing and not merged with something else. The duration of a conscious episode in working memory is approximately 15 seconds. Take a look at Barrs architectural block diagram of the Global Workspace of Consciousness that is posted at this Forum from images available on the internet. 

Stanislas Dehaene points out from his fMRI studies that unless some elements has a duration above a 20 millisecond threshold, then it will never ignite a global wave of consciousness and never appear in the conscious mind to take its turn in the conscious serial stream of working memory. This 20 millisecond threshold was also discovered by fPER studies when light bulbs were powered by alternating current during the early days of the Ontario Hydro Electric Power system. As a young engineer during summer assignment at Niagara Falls, I was told that originally the motor generators ran at a 50 Hz rate (20 ms per cycle) but the noticeable flicker was distracting to customers. So the electric power frequency was increased slightly to 60 Hz (16 ms per cycle). This is quite a coincidence. It shows that fMRI testing can explain why consciousness or lack if consciousness works the way it does as Dehaene discovered. The fPER studies by electrical engineers offered a simple solution without knowing why it worked. Just increase the power line frequency until people don't complain about the annoying visual flicker of the light bulbs.