The Neurobiology of ADHD

Components of Attention

To understand attention, one must first deconstruct its components. A process as complex as attention is not one process but many processes acting in concert. Attention must encompass at least these components:

• Arousal and alertness -- the prerequisites to attention
  
  

• External or receptive attention: sensory processing and interpretation -- as with reading
  
  

• Internal or reflective attention which includes thinking about ideas, concepts, and organization of projects or tasks
  
  

• Processing attention or selective attention. This includes:
  
  

  1. Focus -- tuning in to an object or topic
     
     

  2. Filtering -- signal:noise gradient -- enhancement or activation of relevant stimuli
     
     

  3. Inhibition of sensation (sensory inhibition) -- selective sensory input
     
     

• External or expressive attention -- encompasses what we choose to communicate or suppress, which also evokes components of focusing, filtering, and inhibition.
  
  

• Working memory -- accessing the retrieval and storage of working memory, ie, the flow of information, the content of active thought

Medscape Psychiatry. 2006;11(2) © 2006  Medscape

Cite this: The Neurobiology of ADHD - Medscape - Sep 25, 2006.