Human knowledge is based upon directed connectivity between brain areas

Which brain processes enable humans to rapidly access their personal knowledge?

What happens if humans perceive either familiar or unfamiliar objects?

The answer to these questions may lie in the direction of information flow transmitted between specialized brain areas that together establish a dynamic cortical network. This finding is reported in the latest issue of the scientific journal PLoS ONE published on August 1st, 2007.

Fruit or vegetable, insect or bird, familiar or unfamiliar – humans are used to classify objects in the world around them and group them into categories that have been formed and shaped constantly through every day's experience. Categorization during visual perception is exceptionally fast. Within just a fraction of a second we effortlessly access object-based knowledge, in particular if sufficient sensory information is available and the respective category is distinctly characterized by object features...

...”Human knowledge is definitely not stored in one single brain area. Access to knowledge results from the cooperation of several brain areas that jointly build a dynamic brain network. In this study we were not only able to confirm that recognition of familiar and unfamiliar objects activates a set of distributed brain areas. Rather, importantly, for the first time we have measured in humans how brain areas communicate with each other by directed information transfer, depending whether object-specific knowledge was available or not,' tells co-author and initiator of the study, Thomas Gruber of the Department of Psychology of the University of Leipzig...

...The contribution of our study is that by using a new method of signal analysis we succeeded in measuring the directionality of neuronal interactions. Cooperating brain areas forming a dynamic network are not just connected, but rather each area can be engaged either in receiving or sending signals or both. Until now this has been difficult to investigate, but our analysis suggests that most areas are involved in both during access to object-related knowledge,” ...

This from Physorg.

Study May Help Develop ADD Treatments

Spot a bear in the woods, and a different part of your brain will yell "pay attention" than if you were studying bears at the zoo. New research shows it takes one part of the brain to start concentrating and another to be distracted. This discovery could help scientists develop better treatments for attention deficit disorder.

"This ability to willfully focus your attention is physically separate in the brain from distracting things grabbing your attention," said Earl Miller, a neuroscientist at the Massachusetts Institute of Technology. He led the study, published in Friday's edition of the journal Science.
"Now we know these two things are separate, it raises the possibility that we can fix them independently," Miller said.

There are two main ways the brain pays attention: "top down" or willful, goal-oriented attention, such as when you focus to read, and "bottom-up" or reflexive attention to sensory information - loud noises or bright colors or threatening animals.

Likewise, there are different degrees of attention disorders. Some people have a harder time focusing, while others have a harder time filtering out distractions.

Scientists knew that paying attention involved multiple brain regions but they did not know how, because studies until now have examined one region at a time.

This from My Way News.