Here are some quotes and observations regarding the concept of attention, on of many cognitive functions often assessed by clinicians, in a wide variety of contexts. It seems like a simple thing to understand, but there's much more to attention than meets the eye. All of the quotes below are from the book Neuropsychological Assessment, by Muriel Lezak.
Attention has been placed in several different functional sub-categories, depending on how it is conceptualized. Features of attention that have been observed or discussed have included reflexive versus voluntary attention, stimulus-driven versus memory-driven, and the varying amounts of attention that can be focused on different stimuli.
As an example, an individual who is fatigued, weak from malnourishment, etc. will demonstrate less attentional capacity than they would under improved conditions.
This is akin to working memory - how much information an individual can hold at one time, in the moment (for example, when someone is attempting to remember a telephone number they just heard).
“(1) Focused or selective attention - is probably the most studied aspect and the one people usually have in mind when talking about attention. It is the capacity to highlight the one or two most important stimuli or ideas being dealt with while suppressing awareness of competing distractions. It is commonly referred to as concentration.”
“(3) Divided attention - involves the ability to respond to more than one task at a time or to multiple elements or operations within a task, as in a complex mental task. It is thus very sensitive to any condition that reduces attentional capacity.”
“Impaired attention and concentration are among the most common mental problems associated with brain damage. When attentional deficits occur, all the cognitive functions may be intact and the person may even be capable of some high level performances, yet overall cognitive productivity suffers from inattentiveness, faulty concentration, and consequent fatigue.”
The issue that generally comes to mind first when discussing attentional deficits is Attention Deficit Hyperactivity Disorder (ADHD). However, as noted above, an individual’s attentional capacity will suffer due to a wide variety of impairments, including head injuries, medical issues, and other trauma that impacts the brain. Attention is generally screened as part of any sort of mental status examination (an assessment of an individual’s current cognitive state). However, if an issue with attention is observed, more detailed assessment can be conducted. As these quotes demonstrate, attention is a much more complex concept than many realize, and it requires a thorough assessment if there is concern it is impacting an individual’s overall cognitive functioning.