Attention Deficit

Scientific American, Ocotober 2004 reports that learning retunes the brain, so that more cells respond best to behaviorally important sounds. The researchers also maintain that training responses also depend on the experiences and training of the listener. Even a little training can quickly alter the brain’s reactions. This contradicts previous brain theory that held until about 10 years ago that tuning was "fixed" for each cell in the auditory cortex. The scientists’ studies on contour, however, made them suspect that cell tuning might be altered during learning so that certain cells become extra sensitive to sounds that attract attention and are stored in memory. The retuning was remarkably durable: it became stronger over time without additional training and lasted for months. These findings initiated a growing body of research indicating that one way the brain stores the learned importance of a stimulus is by devoting more brain cells to the processing of that stimulus.

While this research confirms current knowledge about brain reorganization (neuroplasticity) during learning, their research also found that "the pattern of a melody matters: processing in the auditory system is not like the simple relaying of sound in a telephone or stereo system." For many years scientists have held that certain sites are responsible for reading, listening, etc. But researchers have found that listening, especially to music, "But in recent years we have begun to gain a firmer understanding of where and how music is processed in the brain, which should lay a foundation for answering evolutionary questions. Collectively, studies of patients with brain injuries and imaging of healthy individuals have unexpectedly uncovered no specialized brain "center" for music. Rather music engages many areas distributed throughout the brain, including those that are normally involved in other kinds of cognition. The active areas vary with the person’s individual experiences and musical training. The ear has the fewest sensory cells of any sensory organ–3,500 inner hair cells occupy the ear versus 100 million photoreceptors in the eye. Yet our mental response to music is remarkably adaptable; even a little study can "retune" the way the brain handles musical inputs."

Localization is the foundation for fMRI and other imaging techniques in that many fMri proponents claim to be able to locate 6 - 8 different types of ADHD via analysis of these scans. If non-localization is true, i.e., the brain processes using a variety of modalities, subcortical as well as cortical tissue, then the superficial images exposed via fMRI may be a dead end as they can only reveal tiny pieces of a very large puzzle.

The bottom line is: The brain can be retrained to overcome learning disabilities, cognitive impairments, ADHD, etc. What we now know is that this is done over a vast network in the brain that encompasses many other minor and major networks. You could think of retraining as the confluence of several telephone companies coming together to in order to overcome a limitation. Each has its own network and substructure but can become bigger and stronger (overcoming their respective limitations) by merging with the other network (think AT&T and Cingular). In the brain, this is done over a wide area of networks – not locally in distinct surface areas as superficial brain imaging might indicate.